drivers/gpu/drm/drm_dp_mst_topology.c

   1 /*
   2  * Copyright © 2014 Red Hat
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and its
   5  * documentation for any purpose is hereby granted without fee, provided that
   6  * the above copyright notice appear in all copies and that both that copyright
   7  * notice and this permission notice appear in supporting documentation, and
   8  * that the name of the copyright holders not be used in advertising or
   9  * publicity pertaining to distribution of the software without specific,
  10  * written prior permission.  The copyright holders make no representations
  11  * about the suitability of this software for any purpose.  It is provided "as
  12  * is" without express or implied warranty.
  13  *
  14  * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15  * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16  * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17  * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18  * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19  * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20  * OF THIS SOFTWARE.
  21  */
  22
  23 #include <linux/kernel.h>
  24 #include <linux/delay.h>
  25 #include <linux/init.h>
  26 #include <linux/errno.h>
  27 #include <linux/sched.h>
  28 #include <linux/seq_file.h>
  29 #include <linux/i2c.h>
  30 #include <drm/drm_dp_mst_helper.h>
  31 #include <drm/drmP.h>
  32
  33 #include <drm/drm_fixed.h>
  34
  35 /**
  36  * DOC: dp mst helper
  37  *
  38  * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
  39  * protocol. The helpers contain a topology manager and bandwidth manager.
  40  * The helpers encapsulate the sending and received of sideband msgs.
  41  */
  42 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
  43                                   char *buf);
  44 static int test_calc_pbn_mode(void);
  45
  46 static void drm_dp_put_port(struct drm_dp_mst_port *port);
  47
  48 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
  49                                      int id,
  50                                      struct drm_dp_payload *payload);
  51
  52 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
  53                                   struct drm_dp_mst_port *port,
  54                                   int offset, int size, u8 *bytes);
  55
  56 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
  57                                      struct drm_dp_mst_branch *mstb);
  58 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
  59                                            struct drm_dp_mst_branch *mstb,
  60                                            struct drm_dp_mst_port *port);
  61 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
  62                                  u8 *guid);
  63
  64 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
  65 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
  66 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
  67 /* sideband msg handling */
  68 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
  69 {
  70         u8 bitmask = 0x80;
  71         u8 bitshift = 7;
  72         u8 array_index = 0;
  73         int number_of_bits = num_nibbles * 4;
  74         u8 remainder = 0;
  75
  76         while (number_of_bits != 0) {
  77                 number_of_bits--;
  78                 remainder <<= 1;
  79                 remainder |= (data[array_index] & bitmask) >> bitshift;
  80                 bitmask >>= 1;
  81                 bitshift--;
  82                 if (bitmask == 0) {
  83                         bitmask = 0x80;
  84                         bitshift = 7;
  85                         array_index++;
  86                 }
  87                 if ((remainder & 0x10) == 0x10)
  88                         remainder ^= 0x13;
  89         }
  90
  91         number_of_bits = 4;
  92         while (number_of_bits != 0) {
  93                 number_of_bits--;
  94                 remainder <<= 1;
  95                 if ((remainder & 0x10) != 0)
  96                         remainder ^= 0x13;
  97         }
  98
  99         return remainder;
 100 }
 101
 102 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
 103 {
 104         u8 bitmask = 0x80;
 105         u8 bitshift = 7;
 106         u8 array_index = 0;
 107         int number_of_bits = number_of_bytes * 8;
 108         u16 remainder = 0;
 109
 110         while (number_of_bits != 0) {
 111                 number_of_bits--;
 112                 remainder <<= 1;
 113                 remainder |= (data[array_index] & bitmask) >> bitshift;
 114                 bitmask >>= 1;
 115                 bitshift--;
 116                 if (bitmask == 0) {
 117                         bitmask = 0x80;
 118                         bitshift = 7;
 119                         array_index++;
 120                 }
 121                 if ((remainder & 0x100) == 0x100)
 122                         remainder ^= 0xd5;
 123         }
 124
 125         number_of_bits = 8;
 126         while (number_of_bits != 0) {
 127                 number_of_bits--;
 128                 remainder <<= 1;
 129                 if ((remainder & 0x100) != 0)
 130                         remainder ^= 0xd5;
 131         }
 132
 133         return remainder & 0xff;
 134 }
 135 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
 136 {
 137         u8 size = 3;
 138         size += (hdr->lct / 2);
 139         return size;
 140 }
 141
 142 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 143                                            u8 *buf, int *len)
 144 {
 145         int idx = 0;
 146         int i;
 147         u8 crc4;
 148         buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
 149         for (i = 0; i < (hdr->lct / 2); i++)
 150                 buf[idx++] = hdr->rad[i];
 151         buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
 152                 (hdr->msg_len & 0x3f);
 153         buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
 154
 155         crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
 156         buf[idx - 1] |= (crc4 & 0xf);
 157
 158         *len = idx;
 159 }
 160
 161 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 162                                            u8 *buf, int buflen, u8 *hdrlen)
 163 {
 164         u8 crc4;
 165         u8 len;
 166         int i;
 167         u8 idx;
 168         if (buf[0] == 0)
 169                 return false;
 170         len = 3;
 171         len += ((buf[0] & 0xf0) >> 4) / 2;
 172         if (len > buflen)
 173                 return false;
 174         crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
 175
 176         if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
 177                 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
 178                 return false;
 179         }
 180
 181         hdr->lct = (buf[0] & 0xf0) >> 4;
 182         hdr->lcr = (buf[0] & 0xf);
 183         idx = 1;
 184         for (i = 0; i < (hdr->lct / 2); i++)
 185                 hdr->rad[i] = buf[idx++];
 186         hdr->broadcast = (buf[idx] >> 7) & 0x1;
 187         hdr->path_msg = (buf[idx] >> 6) & 0x1;
 188         hdr->msg_len = buf[idx] & 0x3f;
 189         idx++;
 190         hdr->somt = (buf[idx] >> 7) & 0x1;
 191         hdr->eomt = (buf[idx] >> 6) & 0x1;
 192         hdr->seqno = (buf[idx] >> 4) & 0x1;
 193         idx++;
 194         *hdrlen = idx;
 195         return true;
 196 }
 197
 198 static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
 199                                        struct drm_dp_sideband_msg_tx *raw)
 200 {
 201         int idx = 0;
 202         int i;
 203         u8 *buf = raw->msg;
 204         buf[idx++] = req->req_type & 0x7f;
 205
 206         switch (req->req_type) {
 207         case DP_ENUM_PATH_RESOURCES:
 208                 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
 209                 idx++;
 210                 break;
 211         case DP_ALLOCATE_PAYLOAD:
 212                 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
 213                         (req->u.allocate_payload.number_sdp_streams & 0xf);
 214                 idx++;
 215                 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
 216                 idx++;
 217                 buf[idx] = (req->u.allocate_payload.pbn >> 8);
 218                 idx++;
 219                 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
 220                 idx++;
 221                 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
 222                         buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
 223                                 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
 224                         idx++;
 225                 }
 226                 if (req->u.allocate_payload.number_sdp_streams & 1) {
 227                         i = req->u.allocate_payload.number_sdp_streams - 1;
 228                         buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
 229                         idx++;
 230                 }
 231                 break;
 232         case DP_QUERY_PAYLOAD:
 233                 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
 234                 idx++;
 235                 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
 236                 idx++;
 237                 break;
 238         case DP_REMOTE_DPCD_READ:
 239                 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
 240                 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
 241                 idx++;
 242                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
 243                 idx++;
 244                 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
 245                 idx++;
 246                 buf[idx] = (req->u.dpcd_read.num_bytes);
 247                 idx++;
 248                 break;
 249
 250         case DP_REMOTE_DPCD_WRITE:
 251                 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
 252                 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
 253                 idx++;
 254                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
 255                 idx++;
 256                 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
 257                 idx++;
 258                 buf[idx] = (req->u.dpcd_write.num_bytes);
 259                 idx++;
 260                 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
 261                 idx += req->u.dpcd_write.num_bytes;
 262                 break;
 263         case DP_REMOTE_I2C_READ:
 264                 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
 265                 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
 266                 idx++;
 267                 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
 268                         buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
 269                         idx++;
 270                         buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
 271                         idx++;
 272                         memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
 273                         idx += req->u.i2c_read.transactions[i].num_bytes;
 274
 275                         buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
 276                         buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
 277                         idx++;
 278                 }
 279                 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
 280                 idx++;
 281                 buf[idx] = (req->u.i2c_read.num_bytes_read);
 282                 idx++;
 283                 break;
 284
 285         case DP_REMOTE_I2C_WRITE:
 286                 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
 287                 idx++;
 288                 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
 289                 idx++;
 290                 buf[idx] = (req->u.i2c_write.num_bytes);
 291                 idx++;
 292                 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
 293                 idx += req->u.i2c_write.num_bytes;
 294                 break;
 295         }
 296         raw->cur_len = idx;
 297 }
 298
 299 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
 300 {
 301         u8 crc4;
 302         crc4 = drm_dp_msg_data_crc4(msg, len);
 303         msg[len] = crc4;
 304 }
 305
 306 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
 307                                          struct drm_dp_sideband_msg_tx *raw)
 308 {
 309         int idx = 0;
 310         u8 *buf = raw->msg;
 311
 312         buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
 313
 314         raw->cur_len = idx;
 315 }
 316
 317 /* this adds a chunk of msg to the builder to get the final msg */
 318 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
 319                                       u8 *replybuf, u8 replybuflen, bool hdr)
 320 {
 321         int ret;
 322         u8 crc4;
 323
 324         if (hdr) {
 325                 u8 hdrlen;
 326                 struct drm_dp_sideband_msg_hdr recv_hdr;
 327                 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
 328                 if (ret == false) {
 329                         print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
 330                         return false;
 331                 }
 332
 333                 /*
 334                  * ignore out-of-order messages or messages that are part of a
 335                  * failed transaction
 336                  */
 337                 if (!recv_hdr.somt && !msg->have_somt)
 338                         return false;
 339
 340                 /* get length contained in this portion */
 341                 msg->curchunk_len = recv_hdr.msg_len;
 342                 msg->curchunk_hdrlen = hdrlen;
 343
 344                 /* we have already gotten an somt - don't bother parsing */
 345                 if (recv_hdr.somt && msg->have_somt)
 346                         return false;
 347
 348                 if (recv_hdr.somt) {
 349                         memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
 350                         msg->have_somt = true;
 351                 }
 352                 if (recv_hdr.eomt)
 353                         msg->have_eomt = true;
 354
 355                 /* copy the bytes for the remainder of this header chunk */
 356                 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
 357                 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
 358         } else {
 359                 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
 360                 msg->curchunk_idx += replybuflen;
 361         }
 362
 363         if (msg->curchunk_idx >= msg->curchunk_len) {
 364                 /* do CRC */
 365                 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
 366                 /* copy chunk into bigger msg */
 367                 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 368                 msg->curlen += msg->curchunk_len - 1;
 369         }
 370         return true;
 371 }
 372
 373 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
 374                                                struct drm_dp_sideband_msg_reply_body *repmsg)
 375 {
 376         int idx = 1;
 377         int i;
 378         memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
 379         idx += 16;
 380         repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
 381         idx++;
 382         if (idx > raw->curlen)
 383                 goto fail_len;
 384         for (i = 0; i < repmsg->u.link_addr.nports; i++) {
 385                 if (raw->msg[idx] & 0x80)
 386                         repmsg->u.link_addr.ports[i].input_port = 1;
 387
 388                 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
 389                 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
 390
 391                 idx++;
 392                 if (idx > raw->curlen)
 393                         goto fail_len;
 394                 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
 395                 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
 396                 if (repmsg->u.link_addr.ports[i].input_port == 0)
 397                         repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 398                 idx++;
 399                 if (idx > raw->curlen)
 400                         goto fail_len;
 401                 if (repmsg->u.link_addr.ports[i].input_port == 0) {
 402                         repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
 403                         idx++;
 404                         if (idx > raw->curlen)
 405                                 goto fail_len;
 406                         memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
 407                         idx += 16;
 408                         if (idx > raw->curlen)
 409                                 goto fail_len;
 410                         repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
 411                         repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
 412                         idx++;
 413
 414                 }
 415                 if (idx > raw->curlen)
 416                         goto fail_len;
 417         }
 418
 419         return true;
 420 fail_len:
 421         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 422         return false;
 423 }
 424
 425 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
 426                                                    struct drm_dp_sideband_msg_reply_body *repmsg)
 427 {
 428         int idx = 1;
 429         repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
 430         idx++;
 431         if (idx > raw->curlen)
 432                 goto fail_len;
 433         repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
 434         if (idx > raw->curlen)
 435                 goto fail_len;
 436
 437         memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
 438         return true;
 439 fail_len:
 440         DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 441         return false;
 442 }
 443
 444 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
 445                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 446 {
 447         int idx = 1;
 448         repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
 449         idx++;
 450         if (idx > raw->curlen)
 451                 goto fail_len;
 452         return true;
 453 fail_len:
 454         DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
 455         return false;
 456 }
 457
 458 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
 459                                                       struct drm_dp_sideband_msg_reply_body *repmsg)
 460 {
 461         int idx = 1;
 462
 463         repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
 464         idx++;
 465         if (idx > raw->curlen)
 466                 goto fail_len;
 467         repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
 468         idx++;
 469         /* TODO check */
 470         memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
 471         return true;
 472 fail_len:
 473         DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
 474         return false;
 475 }
 476
 477 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
 478                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 479 {
 480         int idx = 1;
 481         repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
 482         idx++;
 483         if (idx > raw->curlen)
 484                 goto fail_len;
 485         repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 486         idx += 2;
 487         if (idx > raw->curlen)
 488                 goto fail_len;
 489         repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 490         idx += 2;
 491         if (idx > raw->curlen)
 492                 goto fail_len;
 493         return true;
 494 fail_len:
 495         DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
 496         return false;
 497 }
 498
 499 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 500                                                           struct drm_dp_sideband_msg_reply_body *repmsg)
 501 {
 502         int idx = 1;
 503         repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 504         idx++;
 505         if (idx > raw->curlen)
 506                 goto fail_len;
 507         repmsg->u.allocate_payload.vcpi = raw->msg[idx];
 508         idx++;
 509         if (idx > raw->curlen)
 510                 goto fail_len;
 511         repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 512         idx += 2;
 513         if (idx > raw->curlen)
 514                 goto fail_len;
 515         return true;
 516 fail_len:
 517         DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
 518         return false;
 519 }
 520
 521 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 522                                                     struct drm_dp_sideband_msg_reply_body *repmsg)
 523 {
 524         int idx = 1;
 525         repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 526         idx++;
 527         if (idx > raw->curlen)
 528                 goto fail_len;
 529         repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 530         idx += 2;
 531         if (idx > raw->curlen)
 532                 goto fail_len;
 533         return true;
 534 fail_len:
 535         DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
 536         return false;
 537 }
 538
 539 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
 540                                         struct drm_dp_sideband_msg_reply_body *msg)
 541 {
 542         memset(msg, 0, sizeof(*msg));
 543         msg->reply_type = (raw->msg[0] & 0x80) >> 7;
 544         msg->req_type = (raw->msg[0] & 0x7f);
 545
 546         if (msg->reply_type) {
 547                 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
 548                 msg->u.nak.reason = raw->msg[17];
 549                 msg->u.nak.nak_data = raw->msg[18];
 550                 return false;
 551         }
 552
 553         switch (msg->req_type) {
 554         case DP_LINK_ADDRESS:
 555                 return drm_dp_sideband_parse_link_address(raw, msg);
 556         case DP_QUERY_PAYLOAD:
 557                 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
 558         case DP_REMOTE_DPCD_READ:
 559                 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
 560         case DP_REMOTE_DPCD_WRITE:
 561                 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
 562         case DP_REMOTE_I2C_READ:
 563                 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
 564         case DP_ENUM_PATH_RESOURCES:
 565                 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
 566         case DP_ALLOCATE_PAYLOAD:
 567                 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
 568         default:
 569                 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
 570                 return false;
 571         }
 572 }
 573
 574 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
 575                                                            struct drm_dp_sideband_msg_req_body *msg)
 576 {
 577         int idx = 1;
 578
 579         msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 580         idx++;
 581         if (idx > raw->curlen)
 582                 goto fail_len;
 583
 584         memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
 585         idx += 16;
 586         if (idx > raw->curlen)
 587                 goto fail_len;
 588
 589         msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
 590         msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 591         msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
 592         msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
 593         msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
 594         idx++;
 595         return true;
 596 fail_len:
 597         DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
 598         return false;
 599 }
 600
 601 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
 602                                                            struct drm_dp_sideband_msg_req_body *msg)
 603 {
 604         int idx = 1;
 605
 606         msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 607         idx++;
 608         if (idx > raw->curlen)
 609                 goto fail_len;
 610
 611         memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
 612         idx += 16;
 613         if (idx > raw->curlen)
 614                 goto fail_len;
 615
 616         msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 617         idx++;
 618         return true;
 619 fail_len:
 620         DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
 621         return false;
 622 }
 623
 624 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
 625                                       struct drm_dp_sideband_msg_req_body *msg)
 626 {
 627         memset(msg, 0, sizeof(*msg));
 628         msg->req_type = (raw->msg[0] & 0x7f);
 629
 630         switch (msg->req_type) {
 631         case DP_CONNECTION_STATUS_NOTIFY:
 632                 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
 633         case DP_RESOURCE_STATUS_NOTIFY:
 634                 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
 635         default:
 636                 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
 637                 return false;
 638         }
 639 }
 640
 641 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
 642 {
 643         struct drm_dp_sideband_msg_req_body req;
 644
 645         req.req_type = DP_REMOTE_DPCD_WRITE;
 646         req.u.dpcd_write.port_number = port_num;
 647         req.u.dpcd_write.dpcd_address = offset;
 648         req.u.dpcd_write.num_bytes = num_bytes;
 649         req.u.dpcd_write.bytes = bytes;
 650         drm_dp_encode_sideband_req(&req, msg);
 651
 652         return 0;
 653 }
 654
 655 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
 656 {
 657         struct drm_dp_sideband_msg_req_body req;
 658
 659         req.req_type = DP_LINK_ADDRESS;
 660         drm_dp_encode_sideband_req(&req, msg);
 661         return 0;
 662 }
 663
 664 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
 665 {
 666         struct drm_dp_sideband_msg_req_body req;
 667
 668         req.req_type = DP_ENUM_PATH_RESOURCES;
 669         req.u.port_num.port_number = port_num;
 670         drm_dp_encode_sideband_req(&req, msg);
 671         msg->path_msg = true;
 672         return 0;
 673 }
 674
 675 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
 676                                   u8 vcpi, uint16_t pbn,
 677                                   u8 number_sdp_streams,
 678                                   u8 *sdp_stream_sink)
 679 {
 680         struct drm_dp_sideband_msg_req_body req;
 681         memset(&req, 0, sizeof(req));
 682         req.req_type = DP_ALLOCATE_PAYLOAD;
 683         req.u.allocate_payload.port_number = port_num;
 684         req.u.allocate_payload.vcpi = vcpi;
 685         req.u.allocate_payload.pbn = pbn;
 686         req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
 687         memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
 688                    number_sdp_streams);
 689         drm_dp_encode_sideband_req(&req, msg);
 690         msg->path_msg = true;
 691         return 0;
 692 }
 693
 694 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 695                                         struct drm_dp_vcpi *vcpi)
 696 {
 697         int ret, vcpi_ret;
 698
 699         mutex_lock(&mgr->payload_lock);
 700         ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
 701         if (ret > mgr->max_payloads) {
 702                 ret = -EINVAL;
 703                 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
 704                 goto out_unlock;
 705         }
 706
 707         vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
 708         if (vcpi_ret > mgr->max_payloads) {
 709                 ret = -EINVAL;
 710                 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
 711                 goto out_unlock;
 712         }
 713
 714         set_bit(ret, &mgr->payload_mask);
 715         set_bit(vcpi_ret, &mgr->vcpi_mask);
 716         vcpi->vcpi = vcpi_ret + 1;
 717         mgr->proposed_vcpis[ret - 1] = vcpi;
 718 out_unlock:
 719         mutex_unlock(&mgr->payload_lock);
 720         return ret;
 721 }
 722
 723 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 724                                       int vcpi)
 725 {
 726         int i;
 727         if (vcpi == 0)
 728                 return;
 729
 730         mutex_lock(&mgr->payload_lock);
 731         DRM_DEBUG_KMS("putting payload %d\n", vcpi);
 732         clear_bit(vcpi - 1, &mgr->vcpi_mask);
 733
 734         for (i = 0; i < mgr->max_payloads; i++) {
 735                 if (mgr->proposed_vcpis[i])
 736                         if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
 737                                 mgr->proposed_vcpis[i] = NULL;
 738                                 clear_bit(i + 1, &mgr->payload_mask);
 739                         }
 740         }
 741         mutex_unlock(&mgr->payload_lock);
 742 }
 743
 744 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 745                               struct drm_dp_sideband_msg_tx *txmsg)
 746 {
 747         bool ret;
 748
 749         /*
 750          * All updates to txmsg->state are protected by mgr->qlock, and the two
 751          * cases we check here are terminal states. For those the barriers
 752          * provided by the wake_up/wait_event pair are enough.
 753          */
 754         ret = (txmsg->state == DRM_DP_SIDEBAND_TX_RX ||
 755                txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 756         return ret;
 757 }
 758
 759 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 760                                     struct drm_dp_sideband_msg_tx *txmsg)
 761 {
 762         struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 763         int ret;
 764
 765         ret = wait_event_timeout(mgr->tx_waitq,
 766                                  check_txmsg_state(mgr, txmsg),
 767                                  (4 * HZ));
 768         mutex_lock(&mstb->mgr->qlock);
 769         if (ret > 0) {
 770                 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 771                         ret = -EIO;
 772                         goto out;
 773                 }
 774         } else {
 775                 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 776
 777                 /* dump some state */
 778                 ret = -EIO;
 779
 780                 /* remove from q */
 781                 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 782                     txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 783                         list_del(&txmsg->next);
 784                 }
 785
 786                 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 787                     txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 788                         mstb->tx_slots[txmsg->seqno] = NULL;
 789                 }
 790         }
 791 out:
 792         mutex_unlock(&mgr->qlock);
 793
 794         return ret;
 795 }
 796
 797 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 798 {
 799         struct drm_dp_mst_branch *mstb;
 800
 801         mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 802         if (!mstb)
 803                 return NULL;
 804
 805         mstb->lct = lct;
 806         if (lct > 1)
 807                 memcpy(mstb->rad, rad, lct / 2);
 808         INIT_LIST_HEAD(&mstb->ports);
 809         kref_init(&mstb->kref);
 810         return mstb;
 811 }
 812
 813 static void drm_dp_free_mst_port(struct kref *kref);
 814
 815 static void drm_dp_free_mst_branch_device(struct kref *kref)
 816 {
 817         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 818         if (mstb->port_parent) {
 819                 if (list_empty(&mstb->port_parent->next))
 820                         kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
 821         }
 822         kfree(mstb);
 823 }
 824
 825 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 826 {
 827         struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 828         struct drm_dp_mst_port *port, *tmp;
 829         bool wake_tx = false;
 830
 831         /*
 832          * init kref again to be used by ports to remove mst branch when it is
 833          * not needed anymore
 834          */
 835         kref_init(kref);
 836
 837         if (mstb->port_parent && list_empty(&mstb->port_parent->next))
 838                 kref_get(&mstb->port_parent->kref);
 839
 840         /*
 841          * destroy all ports - don't need lock
 842          * as there are no more references to the mst branch
 843          * device at this point.
 844          */
 845         list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 846                 list_del(&port->next);
 847                 drm_dp_put_port(port);
 848         }
 849
 850         /* drop any tx slots msg */
 851         mutex_lock(&mstb->mgr->qlock);
 852         if (mstb->tx_slots[0]) {
 853                 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 854                 mstb->tx_slots[0] = NULL;
 855                 wake_tx = true;
 856         }
 857         if (mstb->tx_slots[1]) {
 858                 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 859                 mstb->tx_slots[1] = NULL;
 860                 wake_tx = true;
 861         }
 862         mutex_unlock(&mstb->mgr->qlock);
 863
 864         if (wake_tx)
 865                 wake_up(&mstb->mgr->tx_waitq);
 866
 867         kref_put(kref, drm_dp_free_mst_branch_device);
 868 }
 869
 870 static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 871 {
 872         kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 873 }
 874
 875
 876 static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 877 {
 878         struct drm_dp_mst_branch *mstb;
 879
 880         switch (old_pdt) {
 881         case DP_PEER_DEVICE_DP_LEGACY_CONV:
 882         case DP_PEER_DEVICE_SST_SINK:
 883                 /* remove i2c over sideband */
 884                 drm_dp_mst_unregister_i2c_bus(&port->aux);
 885                 break;
 886         case DP_PEER_DEVICE_MST_BRANCHING:
 887                 mstb = port->mstb;
 888                 port->mstb = NULL;
 889                 drm_dp_put_mst_branch_device(mstb);
 890                 break;
 891         }
 892 }
 893
 894 static void drm_dp_destroy_port(struct kref *kref)
 895 {
 896         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 897         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 898
 899         if (!port->input) {
 900                 port->vcpi.num_slots = 0;
 901
 902                 kfree(port->cached_edid);
 903
 904                 /*
 905                  * The only time we don't have a connector
 906                  * on an output port is if the connector init
 907                  * fails.
 908                  */
 909                 if (port->connector) {
 910                         /* we can't destroy the connector here, as
 911                          * we might be holding the mode_config.mutex
 912                          * from an EDID retrieval */
 913
 914                         mutex_lock(&mgr->destroy_connector_lock);
 915                         kref_get(&port->parent->kref);
 916                         list_add(&port->next, &mgr->destroy_connector_list);
 917                         mutex_unlock(&mgr->destroy_connector_lock);
 918                         schedule_work(&mgr->destroy_connector_work);
 919                         return;
 920                 }
 921                 /* no need to clean up vcpi
 922                  * as if we have no connector we never setup a vcpi */
 923                 drm_dp_port_teardown_pdt(port, port->pdt);
 924                 port->pdt = DP_PEER_DEVICE_NONE;
 925         }
 926         kfree(port);
 927 }
 928
 929 static void drm_dp_put_port(struct drm_dp_mst_port *port)
 930 {
 931         kref_put(&port->kref, drm_dp_destroy_port);
 932 }
 933
 934 static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
 935 {
 936         struct drm_dp_mst_port *port;
 937         struct drm_dp_mst_branch *rmstb;
 938         if (to_find == mstb) {
 939                 kref_get(&mstb->kref);
 940                 return mstb;
 941         }
 942         list_for_each_entry(port, &mstb->ports, next) {
 943                 if (port->mstb) {
 944                         rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 945                         if (rmstb)
 946                                 return rmstb;
 947                 }
 948         }
 949         return NULL;
 950 }
 951
 952 static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
 953 {
 954         struct drm_dp_mst_branch *rmstb = NULL;
 955         mutex_lock(&mgr->lock);
 956         if (mgr->mst_primary)
 957                 rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
 958         mutex_unlock(&mgr->lock);
 959         return rmstb;
 960 }
 961
 962 static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
 963 {
 964         struct drm_dp_mst_port *port, *mport;
 965
 966         list_for_each_entry(port, &mstb->ports, next) {
 967                 if (port == to_find) {
 968                         kref_get(&port->kref);
 969                         return port;
 970                 }
 971                 if (port->mstb) {
 972                         mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
 973                         if (mport)
 974                                 return mport;
 975                 }
 976         }
 977         return NULL;
 978 }
 979
 980 static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
 981 {
 982         struct drm_dp_mst_port *rport = NULL;
 983         mutex_lock(&mgr->lock);
 984         if (mgr->mst_primary)
 985                 rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
 986         mutex_unlock(&mgr->lock);
 987         return rport;
 988 }
 989
 990 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
 991 {
 992         struct drm_dp_mst_port *port;
 993
 994         list_for_each_entry(port, &mstb->ports, next) {
 995                 if (port->port_num == port_num) {
 996                         kref_get(&port->kref);
 997                         return port;
 998                 }
 999         }
1000
1001         return NULL;
1002 }
1003
1004 /*
1005  * calculate a new RAD for this MST branch device
1006  * if parent has an LCT of 2 then it has 1 nibble of RAD,
1007  * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1008  */
1009 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1010                                  u8 *rad)
1011 {
1012         int parent_lct = port->parent->lct;
1013         int shift = 4;
1014         int idx = (parent_lct - 1) / 2;
1015         if (parent_lct > 1) {
1016                 memcpy(rad, port->parent->rad, idx + 1);
1017                 shift = (parent_lct % 2) ? 4 : 0;
1018         } else
1019                 rad[0] = 0;
1020
1021         rad[idx] |= port->port_num << shift;
1022         return parent_lct + 1;
1023 }
1024
1025 /*
1026  * return sends link address for new mstb
1027  */
1028 static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1029 {
1030         int ret;
1031         u8 rad[6], lct;
1032         bool send_link = false;
1033         switch (port->pdt) {
1034         case DP_PEER_DEVICE_DP_LEGACY_CONV:
1035         case DP_PEER_DEVICE_SST_SINK:
1036                 /* add i2c over sideband */
1037                 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1038                 break;
1039         case DP_PEER_DEVICE_MST_BRANCHING:
1040                 lct = drm_dp_calculate_rad(port, rad);
1041
1042                 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1043                 port->mstb->mgr = port->mgr;
1044                 port->mstb->port_parent = port;
1045
1046                 send_link = true;
1047                 break;
1048         }
1049         return send_link;
1050 }
1051
1052 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1053 {
1054         int ret;
1055
1056         memcpy(mstb->guid, guid, 16);
1057
1058         if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1059                 if (mstb->port_parent) {
1060                         ret = drm_dp_send_dpcd_write(
1061                                         mstb->mgr,
1062                                         mstb->port_parent,
1063                                         DP_GUID,
1064                                         16,
1065                                         mstb->guid);
1066                 } else {
1067
1068                         ret = drm_dp_dpcd_write(
1069                                         mstb->mgr->aux,
1070                                         DP_GUID,
1071                                         mstb->guid,
1072                                         16);
1073                 }
1074         }
1075 }
1076
1077 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1078                                 int pnum,
1079                                 char *proppath,
1080                                 size_t proppath_size)
1081 {
1082         int i;
1083         char temp[8];
1084         snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1085         for (i = 0; i < (mstb->lct - 1); i++) {
1086                 int shift = (i % 2) ? 0 : 4;
1087                 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1088                 snprintf(temp, sizeof(temp), "-%d", port_num);
1089                 strlcat(proppath, temp, proppath_size);
1090         }
1091         snprintf(temp, sizeof(temp), "-%d", pnum);
1092         strlcat(proppath, temp, proppath_size);
1093 }
1094
1095 static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1096                             struct device *dev,
1097                             struct drm_dp_link_addr_reply_port *port_msg)
1098 {
1099         struct drm_dp_mst_port *port;
1100         bool ret;
1101         bool created = false;
1102         int old_pdt = 0;
1103         int old_ddps = 0;
1104         port = drm_dp_get_port(mstb, port_msg->port_number);
1105         if (!port) {
1106                 port = kzalloc(sizeof(*port), GFP_KERNEL);
1107                 if (!port)
1108                         return;
1109                 kref_init(&port->kref);
1110                 port->parent = mstb;
1111                 port->port_num = port_msg->port_number;
1112                 port->mgr = mstb->mgr;
1113                 port->aux.name = "DPMST";
1114                 port->aux.dev = dev;
1115                 created = true;
1116         } else {
1117                 old_pdt = port->pdt;
1118                 old_ddps = port->ddps;
1119         }
1120
1121         port->pdt = port_msg->peer_device_type;
1122         port->input = port_msg->input_port;
1123         port->mcs = port_msg->mcs;
1124         port->ddps = port_msg->ddps;
1125         port->ldps = port_msg->legacy_device_plug_status;
1126         port->dpcd_rev = port_msg->dpcd_revision;
1127         port->num_sdp_streams = port_msg->num_sdp_streams;
1128         port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1129
1130         /* manage mstb port lists with mgr lock - take a reference
1131            for this list */
1132         if (created) {
1133                 mutex_lock(&mstb->mgr->lock);
1134                 kref_get(&port->kref);
1135                 list_add(&port->next, &mstb->ports);
1136                 mutex_unlock(&mstb->mgr->lock);
1137         }
1138
1139         if (old_ddps != port->ddps) {
1140                 if (port->ddps) {
1141                         if (!port->input)
1142                                 drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1143                 } else {
1144                         port->available_pbn = 0;
1145                         }
1146         }
1147
1148         if (old_pdt != port->pdt && !port->input) {
1149                 drm_dp_port_teardown_pdt(port, old_pdt);
1150
1151                 ret = drm_dp_port_setup_pdt(port);
1152                 if (ret == true)
1153                         drm_dp_send_link_address(mstb->mgr, port->mstb);
1154         }
1155
1156         if (created && !port->input) {
1157                 char proppath[255];
1158
1159                 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1160                 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1161                 if (!port->connector) {
1162                         /* remove it from the port list */
1163                         mutex_lock(&mstb->mgr->lock);
1164                         list_del(&port->next);
1165                         mutex_unlock(&mstb->mgr->lock);
1166                         /* drop port list reference */
1167                         drm_dp_put_port(port);
1168                         goto out;
1169                 }
1170                 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1171                      port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1172                     port->port_num >= DP_MST_LOGICAL_PORT_0) {
1173                         port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1174                         drm_mode_connector_set_tile_property(port->connector);
1175                 }
1176                 (*mstb->mgr->cbs->register_connector)(port->connector);
1177         }
1178
1179 out:
1180         /* put reference to this port */
1181         drm_dp_put_port(port);
1182 }
1183
1184 static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1185                                struct drm_dp_connection_status_notify *conn_stat)
1186 {
1187         struct drm_dp_mst_port *port;
1188         int old_pdt;
1189         int old_ddps;
1190         bool dowork = false;
1191         port = drm_dp_get_port(mstb, conn_stat->port_number);
1192         if (!port)
1193                 return;
1194
1195         old_ddps = port->ddps;
1196         old_pdt = port->pdt;
1197         port->pdt = conn_stat->peer_device_type;
1198         port->mcs = conn_stat->message_capability_status;
1199         port->ldps = conn_stat->legacy_device_plug_status;
1200         port->ddps = conn_stat->displayport_device_plug_status;
1201
1202         if (old_ddps != port->ddps) {
1203                 if (port->ddps) {
1204                         dowork = true;
1205                 } else {
1206                         port->available_pbn = 0;
1207                 }
1208         }
1209         if (old_pdt != port->pdt && !port->input) {
1210                 drm_dp_port_teardown_pdt(port, old_pdt);
1211
1212                 if (drm_dp_port_setup_pdt(port))
1213                         dowork = true;
1214         }
1215
1216         drm_dp_put_port(port);
1217         if (dowork)
1218                 queue_work(system_long_wq, &mstb->mgr->work);
1219
1220 }
1221
1222 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1223                                                                u8 lct, u8 *rad)
1224 {
1225         struct drm_dp_mst_branch *mstb;
1226         struct drm_dp_mst_port *port;
1227         int i;
1228         /* find the port by iterating down */
1229
1230         mutex_lock(&mgr->lock);
1231         mstb = mgr->mst_primary;
1232
1233         if (!mstb)
1234                 goto out;
1235
1236         for (i = 0; i < lct - 1; i++) {
1237                 int shift = (i % 2) ? 0 : 4;
1238                 int port_num = (rad[i / 2] >> shift) & 0xf;
1239
1240                 list_for_each_entry(port, &mstb->ports, next) {
1241                         if (port->port_num == port_num) {
1242                                 mstb = port->mstb;
1243                                 if (!mstb) {
1244                                         DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1245                                         goto out;
1246                                 }
1247
1248                                 break;
1249                         }
1250                 }
1251         }
1252         kref_get(&mstb->kref);
1253 out:
1254         mutex_unlock(&mgr->lock);
1255         return mstb;
1256 }
1257
1258 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1259         struct drm_dp_mst_branch *mstb,
1260         uint8_t *guid)
1261 {
1262         struct drm_dp_mst_branch *found_mstb;
1263         struct drm_dp_mst_port *port;
1264
1265         if (memcmp(mstb->guid, guid, 16) == 0)
1266                 return mstb;
1267
1268
1269         list_for_each_entry(port, &mstb->ports, next) {
1270                 if (!port->mstb)
1271                         continue;
1272
1273                 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1274
1275                 if (found_mstb)
1276                         return found_mstb;
1277         }
1278
1279         return NULL;
1280 }
1281
1282 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1283         struct drm_dp_mst_topology_mgr *mgr,
1284         uint8_t *guid)
1285 {
1286         struct drm_dp_mst_branch *mstb;
1287
1288         /* find the port by iterating down */
1289         mutex_lock(&mgr->lock);
1290
1291         mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1292
1293         if (mstb)
1294                 kref_get(&mstb->kref);
1295
1296         mutex_unlock(&mgr->lock);
1297         return mstb;
1298 }
1299
1300 static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1301                                                struct drm_dp_mst_branch *mstb)
1302 {
1303         struct drm_dp_mst_port *port;
1304         struct drm_dp_mst_branch *mstb_child;
1305         if (!mstb->link_address_sent)
1306                 drm_dp_send_link_address(mgr, mstb);
1307
1308         list_for_each_entry(port, &mstb->ports, next) {
1309                 if (port->input)
1310                         continue;
1311
1312                 if (!port->ddps)
1313                         continue;
1314
1315                 if (!port->available_pbn)
1316                         drm_dp_send_enum_path_resources(mgr, mstb, port);
1317
1318                 if (port->mstb) {
1319                         mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1320                         if (mstb_child) {
1321                                 drm_dp_check_and_send_link_address(mgr, mstb_child);
1322                                 drm_dp_put_mst_branch_device(mstb_child);
1323                         }
1324                 }
1325         }
1326 }
1327
1328 static void drm_dp_mst_link_probe_work(struct work_struct *work)
1329 {
1330         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1331         struct drm_dp_mst_branch *mstb;
1332
1333         mutex_lock(&mgr->lock);
1334         mstb = mgr->mst_primary;
1335         if (mstb) {
1336                 kref_get(&mstb->kref);
1337         }
1338         mutex_unlock(&mgr->lock);
1339         if (mstb) {
1340                 drm_dp_check_and_send_link_address(mgr, mstb);
1341                 drm_dp_put_mst_branch_device(mstb);
1342         }
1343 }
1344
1345 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1346                                  u8 *guid)
1347 {
1348         static u8 zero_guid[16];
1349
1350         if (!memcmp(guid, zero_guid, 16)) {
1351                 u64 salt = get_jiffies_64();
1352                 memcpy(&guid[0], &salt, sizeof(u64));
1353                 memcpy(&guid[8], &salt, sizeof(u64));
1354                 return false;
1355         }
1356         return true;
1357 }
1358
1359 #if 0
1360 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1361 {
1362         struct drm_dp_sideband_msg_req_body req;
1363
1364         req.req_type = DP_REMOTE_DPCD_READ;
1365         req.u.dpcd_read.port_number = port_num;
1366         req.u.dpcd_read.dpcd_address = offset;
1367         req.u.dpcd_read.num_bytes = num_bytes;
1368         drm_dp_encode_sideband_req(&req, msg);
1369
1370         return 0;
1371 }
1372 #endif
1373
1374 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1375                                     bool up, u8 *msg, int len)
1376 {
1377         int ret;
1378         int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1379         int tosend, total, offset;
1380         int retries = 0;
1381
1382 retry:
1383         total = len;
1384         offset = 0;
1385         do {
1386                 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1387
1388                 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1389                                         &msg[offset],
1390                                         tosend);
1391                 if (ret != tosend) {
1392                         if (ret == -EIO && retries < 5) {
1393                                 retries++;
1394                                 goto retry;
1395                         }
1396                         DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1397
1398                         return -EIO;
1399                 }
1400                 offset += tosend;
1401                 total -= tosend;
1402         } while (total > 0);
1403         return 0;
1404 }
1405
1406 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1407                                   struct drm_dp_sideband_msg_tx *txmsg)
1408 {
1409         struct drm_dp_mst_branch *mstb = txmsg->dst;
1410         u8 req_type;
1411
1412         /* both msg slots are full */
1413         if (txmsg->seqno == -1) {
1414                 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1415                         DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1416                         return -EAGAIN;
1417                 }
1418                 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1419                         txmsg->seqno = mstb->last_seqno;
1420                         mstb->last_seqno ^= 1;
1421                 } else if (mstb->tx_slots[0] == NULL)
1422                         txmsg->seqno = 0;
1423                 else
1424                         txmsg->seqno = 1;
1425                 mstb->tx_slots[txmsg->seqno] = txmsg;
1426         }
1427
1428         req_type = txmsg->msg[0] & 0x7f;
1429         if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1430                 req_type == DP_RESOURCE_STATUS_NOTIFY)
1431                 hdr->broadcast = 1;
1432         else
1433                 hdr->broadcast = 0;
1434         hdr->path_msg = txmsg->path_msg;
1435         hdr->lct = mstb->lct;
1436         hdr->lcr = mstb->lct - 1;
1437         if (mstb->lct > 1)
1438                 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1439         hdr->seqno = txmsg->seqno;
1440         return 0;
1441 }
1442 /*
1443  * process a single block of the next message in the sideband queue
1444  */
1445 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1446                                    struct drm_dp_sideband_msg_tx *txmsg,
1447                                    bool up)
1448 {
1449         u8 chunk[48];
1450         struct drm_dp_sideband_msg_hdr hdr;
1451         int len, space, idx, tosend;
1452         int ret;
1453
1454         memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1455
1456         if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1457                 txmsg->seqno = -1;
1458                 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1459         }
1460
1461         /* make hdr from dst mst - for replies use seqno
1462            otherwise assign one */
1463         ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1464         if (ret < 0)
1465                 return ret;
1466
1467         /* amount left to send in this message */
1468         len = txmsg->cur_len - txmsg->cur_offset;
1469
1470         /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1471         space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1472
1473         tosend = min(len, space);
1474         if (len == txmsg->cur_len)
1475                 hdr.somt = 1;
1476         if (space >= len)
1477                 hdr.eomt = 1;
1478
1479
1480         hdr.msg_len = tosend + 1;
1481         drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1482         memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1483         /* add crc at end */
1484         drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1485         idx += tosend + 1;
1486
1487         ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1488         if (ret) {
1489                 DRM_DEBUG_KMS("sideband msg failed to send\n");
1490                 return ret;
1491         }
1492
1493         txmsg->cur_offset += tosend;
1494         if (txmsg->cur_offset == txmsg->cur_len) {
1495                 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1496                 return 1;
1497         }
1498         return 0;
1499 }
1500
1501 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1502 {
1503         struct drm_dp_sideband_msg_tx *txmsg;
1504         int ret;
1505
1506         WARN_ON(!mutex_is_locked(&mgr->qlock));
1507
1508         /* construct a chunk from the first msg in the tx_msg queue */
1509         if (list_empty(&mgr->tx_msg_downq))
1510                 return;
1511
1512         txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1513         ret = process_single_tx_qlock(mgr, txmsg, false);
1514         if (ret == 1) {
1515                 /* txmsg is sent it should be in the slots now */
1516                 list_del(&txmsg->next);
1517         } else if (ret) {
1518                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1519                 list_del(&txmsg->next);
1520                 if (txmsg->seqno != -1)
1521                         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1522                 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1523                 wake_up(&mgr->tx_waitq);
1524         }
1525 }
1526
1527 /* called holding qlock */
1528 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1529                                        struct drm_dp_sideband_msg_tx *txmsg)
1530 {
1531         int ret;
1532
1533         /* construct a chunk from the first msg in the tx_msg queue */
1534         ret = process_single_tx_qlock(mgr, txmsg, true);
1535
1536         if (ret != 1)
1537                 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1538
1539         txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1540 }
1541
1542 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1543                                  struct drm_dp_sideband_msg_tx *txmsg)
1544 {
1545         mutex_lock(&mgr->qlock);
1546         list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1547         if (list_is_singular(&mgr->tx_msg_downq))
1548                 process_single_down_tx_qlock(mgr);
1549         mutex_unlock(&mgr->qlock);
1550 }
1551
1552 static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1553                                      struct drm_dp_mst_branch *mstb)
1554 {
1555         int len;
1556         struct drm_dp_sideband_msg_tx *txmsg;
1557         int ret;
1558
1559         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1560         if (!txmsg)
1561                 return;
1562
1563         txmsg->dst = mstb;
1564         len = build_link_address(txmsg);
1565
1566         mstb->link_address_sent = true;
1567         drm_dp_queue_down_tx(mgr, txmsg);
1568
1569         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1570         if (ret > 0) {
1571                 int i;
1572
1573                 if (txmsg->reply.reply_type == 1)
1574                         DRM_DEBUG_KMS("link address nak received\n");
1575                 else {
1576                         DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1577                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1578                                 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
1579                                        txmsg->reply.u.link_addr.ports[i].input_port,
1580                                        txmsg->reply.u.link_addr.ports[i].peer_device_type,
1581                                        txmsg->reply.u.link_addr.ports[i].port_number,
1582                                        txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1583                                        txmsg->reply.u.link_addr.ports[i].mcs,
1584                                        txmsg->reply.u.link_addr.ports[i].ddps,
1585                                        txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1586                                        txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1587                                        txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1588                         }
1589
1590                         drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1591
1592                         for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1593                                 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1594                         }
1595                         (*mgr->cbs->hotplug)(mgr);
1596                 }
1597         } else {
1598                 mstb->link_address_sent = false;
1599                 DRM_DEBUG_KMS("link address failed %d\n", ret);
1600         }
1601
1602         kfree(txmsg);
1603 }
1604
1605 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1606                                            struct drm_dp_mst_branch *mstb,
1607                                            struct drm_dp_mst_port *port)
1608 {
1609         int len;
1610         struct drm_dp_sideband_msg_tx *txmsg;
1611         int ret;
1612
1613         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1614         if (!txmsg)
1615                 return -ENOMEM;
1616
1617         txmsg->dst = mstb;
1618         len = build_enum_path_resources(txmsg, port->port_num);
1619
1620         drm_dp_queue_down_tx(mgr, txmsg);
1621
1622         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1623         if (ret > 0) {
1624                 if (txmsg->reply.reply_type == 1)
1625                         DRM_DEBUG_KMS("enum path resources nak received\n");
1626                 else {
1627                         if (port->port_num != txmsg->reply.u.path_resources.port_number)
1628                                 DRM_ERROR("got incorrect port in response\n");
1629                         DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
1630                                txmsg->reply.u.path_resources.avail_payload_bw_number);
1631                         port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1632                 }
1633         }
1634
1635         kfree(txmsg);
1636         return 0;
1637 }
1638
1639 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1640 {
1641         if (!mstb->port_parent)
1642                 return NULL;
1643
1644         if (mstb->port_parent->mstb != mstb)
1645                 return mstb->port_parent;
1646
1647         return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1648 }
1649
1650 static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1651                                                                          struct drm_dp_mst_branch *mstb,
1652                                                                          int *port_num)
1653 {
1654         struct drm_dp_mst_branch *rmstb = NULL;
1655         struct drm_dp_mst_port *found_port;
1656         mutex_lock(&mgr->lock);
1657         if (mgr->mst_primary) {
1658                 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1659
1660                 if (found_port) {
1661                         rmstb = found_port->parent;
1662                         kref_get(&rmstb->kref);
1663                         *port_num = found_port->port_num;
1664                 }
1665         }
1666         mutex_unlock(&mgr->lock);
1667         return rmstb;
1668 }
1669
1670 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1671                                    struct drm_dp_mst_port *port,
1672                                    int id,
1673                                    int pbn)
1674 {
1675         struct drm_dp_sideband_msg_tx *txmsg;
1676         struct drm_dp_mst_branch *mstb;
1677         int len, ret, port_num;
1678         u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1679         int i;
1680
1681         port = drm_dp_get_validated_port_ref(mgr, port);
1682         if (!port)
1683                 return -EINVAL;
1684
1685         port_num = port->port_num;
1686         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1687         if (!mstb) {
1688                 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1689
1690                 if (!mstb) {
1691                         drm_dp_put_port(port);
1692                         return -EINVAL;
1693                 }
1694         }
1695
1696         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1697         if (!txmsg) {
1698                 ret = -ENOMEM;
1699                 goto fail_put;
1700         }
1701
1702         for (i = 0; i < port->num_sdp_streams; i++)
1703                 sinks[i] = i;
1704
1705         txmsg->dst = mstb;
1706         len = build_allocate_payload(txmsg, port_num,
1707                                      id,
1708                                      pbn, port->num_sdp_streams, sinks);
1709
1710         drm_dp_queue_down_tx(mgr, txmsg);
1711
1712         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1713         if (ret > 0) {
1714                 if (txmsg->reply.reply_type == 1) {
1715                         ret = -EINVAL;
1716                 } else
1717                         ret = 0;
1718         }
1719         kfree(txmsg);
1720 fail_put:
1721         drm_dp_put_mst_branch_device(mstb);
1722         drm_dp_put_port(port);
1723         return ret;
1724 }
1725
1726 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1727                                        int id,
1728                                        struct drm_dp_payload *payload)
1729 {
1730         int ret;
1731
1732         ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1733         if (ret < 0) {
1734                 payload->payload_state = 0;
1735                 return ret;
1736         }
1737         payload->payload_state = DP_PAYLOAD_LOCAL;
1738         return 0;
1739 }
1740
1741 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1742                                        struct drm_dp_mst_port *port,
1743                                        int id,
1744                                        struct drm_dp_payload *payload)
1745 {
1746         int ret;
1747         ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1748         if (ret < 0)
1749                 return ret;
1750         payload->payload_state = DP_PAYLOAD_REMOTE;
1751         return ret;
1752 }
1753
1754 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1755                                         struct drm_dp_mst_port *port,
1756                                         int id,
1757                                         struct drm_dp_payload *payload)
1758 {
1759         DRM_DEBUG_KMS("\n");
1760         /* its okay for these to fail */
1761         if (port) {
1762                 drm_dp_payload_send_msg(mgr, port, id, 0);
1763         }
1764
1765         drm_dp_dpcd_write_payload(mgr, id, payload);
1766         payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1767         return 0;
1768 }
1769
1770 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1771                                         int id,
1772                                         struct drm_dp_payload *payload)
1773 {
1774         payload->payload_state = 0;
1775         return 0;
1776 }
1777
1778 /**
1779  * drm_dp_update_payload_part1() - Execute payload update part 1
1780  * @mgr: manager to use.
1781  *
1782  * This iterates over all proposed virtual channels, and tries to
1783  * allocate space in the link for them. For 0->slots transitions,
1784  * this step just writes the VCPI to the MST device. For slots->0
1785  * transitions, this writes the updated VCPIs and removes the
1786  * remote VC payloads.
1787  *
1788  * after calling this the driver should generate ACT and payload
1789  * packets.
1790  */
1791 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1792 {
1793         int i, j;
1794         int cur_slots = 1;
1795         struct drm_dp_payload req_payload;
1796         struct drm_dp_mst_port *port;
1797
1798         mutex_lock(&mgr->payload_lock);
1799         for (i = 0; i < mgr->max_payloads; i++) {
1800                 /* solve the current payloads - compare to the hw ones
1801                    - update the hw view */
1802                 req_payload.start_slot = cur_slots;
1803                 if (mgr->proposed_vcpis[i]) {
1804                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1805                         port = drm_dp_get_validated_port_ref(mgr, port);
1806                         if (!port) {
1807                                 mutex_unlock(&mgr->payload_lock);
1808                                 return -EINVAL;
1809                         }
1810                         req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1811                         req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1812                 } else {
1813                         port = NULL;
1814                         req_payload.num_slots = 0;
1815                 }
1816
1817                 if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1818                         mgr->payloads[i].start_slot = req_payload.start_slot;
1819                 }
1820                 /* work out what is required to happen with this payload */
1821                 if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1822
1823                         /* need to push an update for this payload */
1824                         if (req_payload.num_slots) {
1825                                 drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1826                                 mgr->payloads[i].num_slots = req_payload.num_slots;
1827                                 mgr->payloads[i].vcpi = req_payload.vcpi;
1828                         } else if (mgr->payloads[i].num_slots) {
1829                                 mgr->payloads[i].num_slots = 0;
1830                                 drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
1831                                 req_payload.payload_state = mgr->payloads[i].payload_state;
1832                                 mgr->payloads[i].start_slot = 0;
1833                         }
1834                         mgr->payloads[i].payload_state = req_payload.payload_state;
1835                 }
1836                 cur_slots += req_payload.num_slots;
1837
1838                 if (port)
1839                         drm_dp_put_port(port);
1840         }
1841
1842         for (i = 0; i < mgr->max_payloads; i++) {
1843                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1844                         DRM_DEBUG_KMS("removing payload %d\n", i);
1845                         for (j = i; j < mgr->max_payloads - 1; j++) {
1846                                 memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1847                                 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1848                                 if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1849                                         set_bit(j + 1, &mgr->payload_mask);
1850                                 } else {
1851                                         clear_bit(j + 1, &mgr->payload_mask);
1852                                 }
1853                         }
1854                         memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1855                         mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1856                         clear_bit(mgr->max_payloads, &mgr->payload_mask);
1857
1858                 }
1859         }
1860         mutex_unlock(&mgr->payload_lock);
1861
1862         return 0;
1863 }
1864 EXPORT_SYMBOL(drm_dp_update_payload_part1);
1865
1866 /**
1867  * drm_dp_update_payload_part2() - Execute payload update part 2
1868  * @mgr: manager to use.
1869  *
1870  * This iterates over all proposed virtual channels, and tries to
1871  * allocate space in the link for them. For 0->slots transitions,
1872  * this step writes the remote VC payload commands. For slots->0
1873  * this just resets some internal state.
1874  */
1875 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1876 {
1877         struct drm_dp_mst_port *port;
1878         int i;
1879         int ret = 0;
1880         mutex_lock(&mgr->payload_lock);
1881         for (i = 0; i < mgr->max_payloads; i++) {
1882
1883                 if (!mgr->proposed_vcpis[i])
1884                         continue;
1885
1886                 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1887
1888                 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1889                 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1890                         ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1891                 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1892                         ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1893                 }
1894                 if (ret) {
1895                         mutex_unlock(&mgr->payload_lock);
1896                         return ret;
1897                 }
1898         }
1899         mutex_unlock(&mgr->payload_lock);
1900         return 0;
1901 }
1902 EXPORT_SYMBOL(drm_dp_update_payload_part2);
1903
1904 #if 0 /* unused as of yet */
1905 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1906                                  struct drm_dp_mst_port *port,
1907                                  int offset, int size)
1908 {
1909         int len;
1910         struct drm_dp_sideband_msg_tx *txmsg;
1911
1912         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1913         if (!txmsg)
1914                 return -ENOMEM;
1915
1916         len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1917         txmsg->dst = port->parent;
1918
1919         drm_dp_queue_down_tx(mgr, txmsg);
1920
1921         return 0;
1922 }
1923 #endif
1924
1925 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
1926                                   struct drm_dp_mst_port *port,
1927                                   int offset, int size, u8 *bytes)
1928 {
1929         int len;
1930         int ret;
1931         struct drm_dp_sideband_msg_tx *txmsg;
1932         struct drm_dp_mst_branch *mstb;
1933
1934         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1935         if (!mstb)
1936                 return -EINVAL;
1937
1938         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1939         if (!txmsg) {
1940                 ret = -ENOMEM;
1941                 goto fail_put;
1942         }
1943
1944         len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
1945         txmsg->dst = mstb;
1946
1947         drm_dp_queue_down_tx(mgr, txmsg);
1948
1949         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1950         if (ret > 0) {
1951                 if (txmsg->reply.reply_type == 1) {
1952                         ret = -EINVAL;
1953                 } else
1954                         ret = 0;
1955         }
1956         kfree(txmsg);
1957 fail_put:
1958         drm_dp_put_mst_branch_device(mstb);
1959         return ret;
1960 }
1961
1962 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
1963 {
1964         struct drm_dp_sideband_msg_reply_body reply;
1965
1966         reply.reply_type = 0;
1967         reply.req_type = req_type;
1968         drm_dp_encode_sideband_reply(&reply, msg);
1969         return 0;
1970 }
1971
1972 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
1973                                     struct drm_dp_mst_branch *mstb,
1974                                     int req_type, int seqno, bool broadcast)
1975 {
1976         struct drm_dp_sideband_msg_tx *txmsg;
1977
1978         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1979         if (!txmsg)
1980                 return -ENOMEM;
1981
1982         txmsg->dst = mstb;
1983         txmsg->seqno = seqno;
1984         drm_dp_encode_up_ack_reply(txmsg, req_type);
1985
1986         mutex_lock(&mgr->qlock);
1987
1988         process_single_up_tx_qlock(mgr, txmsg);
1989
1990         mutex_unlock(&mgr->qlock);
1991
1992         kfree(txmsg);
1993         return 0;
1994 }
1995
1996 static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
1997                                      int dp_link_count,
1998                                      int *out)
1999 {
2000         switch (dp_link_bw) {
2001         default:
2002                 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2003                               dp_link_bw, dp_link_count);
2004                 return false;
2005
2006         case DP_LINK_BW_1_62:
2007                 *out = 3 * dp_link_count;
2008                 break;
2009         case DP_LINK_BW_2_7:
2010                 *out = 5 * dp_link_count;
2011                 break;
2012         case DP_LINK_BW_5_4:
2013                 *out = 10 * dp_link_count;
2014                 break;
2015         }
2016         return true;
2017 }
2018
2019 /**
2020  * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2021  * @mgr: manager to set state for
2022  * @mst_state: true to enable MST on this connector - false to disable.
2023  *
2024  * This is called by the driver when it detects an MST capable device plugged
2025  * into a DP MST capable port, or when a DP MST capable device is unplugged.
2026  */
2027 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2028 {
2029         int ret = 0;
2030         struct drm_dp_mst_branch *mstb = NULL;
2031
2032         mutex_lock(&mgr->lock);
2033         if (mst_state == mgr->mst_state)
2034                 goto out_unlock;
2035
2036         mgr->mst_state = mst_state;
2037         /* set the device into MST mode */
2038         if (mst_state) {
2039                 WARN_ON(mgr->mst_primary);
2040
2041                 /* get dpcd info */
2042                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2043                 if (ret != DP_RECEIVER_CAP_SIZE) {
2044                         DRM_DEBUG_KMS("failed to read DPCD\n");
2045                         goto out_unlock;
2046                 }
2047
2048                 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2049                                               mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2050                                               &mgr->pbn_div)) {
2051                         ret = -EINVAL;
2052                         goto out_unlock;
2053                 }
2054
2055                 mgr->total_pbn = 2560;
2056                 mgr->total_slots = DIV_ROUND_UP(mgr->total_pbn, mgr->pbn_div);
2057                 mgr->avail_slots = mgr->total_slots;
2058
2059                 /* add initial branch device at LCT 1 */
2060                 mstb = drm_dp_add_mst_branch_device(1, NULL);
2061                 if (mstb == NULL) {
2062                         ret = -ENOMEM;
2063                         goto out_unlock;
2064                 }
2065                 mstb->mgr = mgr;
2066
2067                 /* give this the main reference */
2068                 mgr->mst_primary = mstb;
2069                 kref_get(&mgr->mst_primary->kref);
2070
2071                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2072                                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2073                 if (ret < 0) {
2074                         goto out_unlock;
2075                 }
2076
2077                 {
2078                         struct drm_dp_payload reset_pay;
2079                         reset_pay.start_slot = 0;
2080                         reset_pay.num_slots = 0x3f;
2081                         drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2082                 }
2083
2084                 queue_work(system_long_wq, &mgr->work);
2085
2086                 ret = 0;
2087         } else {
2088                 /* disable MST on the device */
2089                 mstb = mgr->mst_primary;
2090                 mgr->mst_primary = NULL;
2091                 /* this can fail if the device is gone */
2092                 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2093                 ret = 0;
2094                 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2095                 mgr->payload_mask = 0;
2096                 set_bit(0, &mgr->payload_mask);
2097                 mgr->vcpi_mask = 0;
2098         }
2099
2100 out_unlock:
2101         mutex_unlock(&mgr->lock);
2102         if (mstb)
2103                 drm_dp_put_mst_branch_device(mstb);
2104         return ret;
2105
2106 }
2107 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2108
2109 /**
2110  * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2111  * @mgr: manager to suspend
2112  *
2113  * This function tells the MST device that we can't handle UP messages
2114  * anymore. This should stop it from sending any since we are suspended.
2115  */
2116 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2117 {
2118         mutex_lock(&mgr->lock);
2119         drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2120                            DP_MST_EN | DP_UPSTREAM_IS_SRC);
2121         mutex_unlock(&mgr->lock);
2122         flush_work(&mgr->work);
2123         flush_work(&mgr->destroy_connector_work);
2124 }
2125 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2126
2127 /**
2128  * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2129  * @mgr: manager to resume
2130  *
2131  * This will fetch DPCD and see if the device is still there,
2132  * if it is, it will rewrite the MSTM control bits, and return.
2133  *
2134  * if the device fails this returns -1, and the driver should do
2135  * a full MST reprobe, in case we were undocked.
2136  */
2137 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2138 {
2139         int ret = 0;
2140
2141         mutex_lock(&mgr->lock);
2142
2143         if (mgr->mst_primary) {
2144                 int sret;
2145                 u8 guid[16];
2146
2147                 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2148                 if (sret != DP_RECEIVER_CAP_SIZE) {
2149                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2150                         ret = -1;
2151                         goto out_unlock;
2152                 }
2153
2154                 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2155                                          DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2156                 if (ret < 0) {
2157                         DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2158                         ret = -1;
2159                         goto out_unlock;
2160                 }
2161
2162                 /* Some hubs forget their guids after they resume */
2163                 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2164                 if (sret != 16) {
2165                         DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2166                         ret = -1;
2167                         goto out_unlock;
2168                 }
2169                 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2170
2171                 ret = 0;
2172         } else
2173                 ret = -1;
2174
2175 out_unlock:
2176         mutex_unlock(&mgr->lock);
2177         return ret;
2178 }
2179 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2180
2181 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2182 {
2183         int len;
2184         u8 replyblock[32];
2185         int replylen, origlen, curreply;
2186         int ret;
2187         struct drm_dp_sideband_msg_rx *msg;
2188         int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2189         msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2190
2191         len = min(mgr->max_dpcd_transaction_bytes, 16);
2192         ret = drm_dp_dpcd_read(mgr->aux, basereg,
2193                                replyblock, len);
2194         if (ret != len) {
2195                 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2196                 return false;
2197         }
2198         ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2199         if (!ret) {
2200                 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2201                 return false;
2202         }
2203         replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2204
2205         origlen = replylen;
2206         replylen -= len;
2207         curreply = len;
2208         while (replylen > 0) {
2209                 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2210                 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2211                                     replyblock, len);
2212                 if (ret != len) {
2213                         DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2214                                       len, ret);
2215                         return false;
2216                 }
2217
2218                 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2219                 if (!ret) {
2220                         DRM_DEBUG_KMS("failed to build sideband msg\n");
2221                         return false;
2222                 }
2223
2224                 curreply += len;
2225                 replylen -= len;
2226         }
2227         return true;
2228 }
2229
2230 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2231 {
2232         int ret = 0;
2233
2234         if (!drm_dp_get_one_sb_msg(mgr, false)) {
2235                 memset(&mgr->down_rep_recv, 0,
2236                        sizeof(struct drm_dp_sideband_msg_rx));
2237                 return 0;
2238         }
2239
2240         if (mgr->down_rep_recv.have_eomt) {
2241                 struct drm_dp_sideband_msg_tx *txmsg;
2242                 struct drm_dp_mst_branch *mstb;
2243                 int slot = -1;
2244                 mstb = drm_dp_get_mst_branch_device(mgr,
2245                                                     mgr->down_rep_recv.initial_hdr.lct,
2246                                                     mgr->down_rep_recv.initial_hdr.rad);
2247
2248                 if (!mstb) {
2249                         DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2250                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2251                         return 0;
2252                 }
2253
2254                 /* find the message */
2255                 slot = mgr->down_rep_recv.initial_hdr.seqno;
2256                 mutex_lock(&mgr->qlock);
2257                 txmsg = mstb->tx_slots[slot];
2258                 /* remove from slots */
2259                 mutex_unlock(&mgr->qlock);
2260
2261                 if (!txmsg) {
2262                         DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2263                                mstb,
2264                                mgr->down_rep_recv.initial_hdr.seqno,
2265                                mgr->down_rep_recv.initial_hdr.lct,
2266                                       mgr->down_rep_recv.initial_hdr.rad[0],
2267                                       mgr->down_rep_recv.msg[0]);
2268                         drm_dp_put_mst_branch_device(mstb);
2269                         memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2270                         return 0;
2271                 }
2272
2273                 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2274                 if (txmsg->reply.reply_type == 1) {
2275                         DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
2276                 }
2277
2278                 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2279                 drm_dp_put_mst_branch_device(mstb);
2280
2281                 mutex_lock(&mgr->qlock);
2282                 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2283                 mstb->tx_slots[slot] = NULL;
2284                 mutex_unlock(&mgr->qlock);
2285
2286                 wake_up(&mgr->tx_waitq);
2287         }
2288         return ret;
2289 }
2290
2291 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2292 {
2293         int ret = 0;
2294
2295         if (!drm_dp_get_one_sb_msg(mgr, true)) {
2296                 memset(&mgr->up_req_recv, 0,
2297                        sizeof(struct drm_dp_sideband_msg_rx));
2298                 return 0;
2299         }
2300
2301         if (mgr->up_req_recv.have_eomt) {
2302                 struct drm_dp_sideband_msg_req_body msg;
2303                 struct drm_dp_mst_branch *mstb = NULL;
2304                 bool seqno;
2305
2306                 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2307                         mstb = drm_dp_get_mst_branch_device(mgr,
2308                                                             mgr->up_req_recv.initial_hdr.lct,
2309                                                             mgr->up_req_recv.initial_hdr.rad);
2310                         if (!mstb) {
2311                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2312                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2313                                 return 0;
2314                         }
2315                 }
2316
2317                 seqno = mgr->up_req_recv.initial_hdr.seqno;
2318                 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2319
2320                 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2321                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2322
2323                         if (!mstb)
2324                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2325
2326                         if (!mstb) {
2327                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2328                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2329                                 return 0;
2330                         }
2331
2332                         drm_dp_update_port(mstb, &msg.u.conn_stat);
2333
2334                         DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
2335                         (*mgr->cbs->hotplug)(mgr);
2336
2337                 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2338                         drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2339                         if (!mstb)
2340                                 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2341
2342                         if (!mstb) {
2343                                 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2344                                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2345                                 return 0;
2346                         }
2347
2348                         DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2349                 }
2350
2351                 if (mstb)
2352                         drm_dp_put_mst_branch_device(mstb);
2353
2354                 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2355         }
2356         return ret;
2357 }
2358
2359 /**
2360  * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2361  * @mgr: manager to notify irq for.
2362  * @esi: 4 bytes from SINK_COUNT_ESI
2363  * @handled: whether the hpd interrupt was consumed or not
2364  *
2365  * This should be called from the driver when it detects a short IRQ,
2366  * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2367  * topology manager will process the sideband messages received as a result
2368  * of this.
2369  */
2370 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2371 {
2372         int ret = 0;
2373         int sc;
2374         *handled = false;
2375         sc = esi[0] & 0x3f;
2376
2377         if (sc != mgr->sink_count) {
2378                 mgr->sink_count = sc;
2379                 *handled = true;
2380         }
2381
2382         if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2383                 ret = drm_dp_mst_handle_down_rep(mgr);
2384                 *handled = true;
2385         }
2386
2387         if (esi[1] & DP_UP_REQ_MSG_RDY) {
2388                 ret |= drm_dp_mst_handle_up_req(mgr);
2389                 *handled = true;
2390         }
2391
2392         drm_dp_mst_kick_tx(mgr);
2393         return ret;
2394 }
2395 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2396
2397 /**
2398  * drm_dp_mst_detect_port() - get connection status for an MST port
2399  * @connector: DRM connector for this port
2400  * @mgr: manager for this port
2401  * @port: unverified pointer to a port
2402  *
2403  * This returns the current connection state for a port. It validates the
2404  * port pointer still exists so the caller doesn't require a reference
2405  */
2406 enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2407                                                  struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2408 {
2409         enum drm_connector_status status = connector_status_disconnected;
2410
2411         /* we need to search for the port in the mgr in case its gone */
2412         port = drm_dp_get_validated_port_ref(mgr, port);
2413         if (!port)
2414                 return connector_status_disconnected;
2415
2416         if (!port->ddps)
2417                 goto out;
2418
2419         switch (port->pdt) {
2420         case DP_PEER_DEVICE_NONE:
2421         case DP_PEER_DEVICE_MST_BRANCHING:
2422                 break;
2423
2424         case DP_PEER_DEVICE_SST_SINK:
2425                 status = connector_status_connected;
2426                 /* for logical ports - cache the EDID */
2427                 if (port->port_num >= 8 && !port->cached_edid) {
2428                         port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2429                 }
2430                 break;
2431         case DP_PEER_DEVICE_DP_LEGACY_CONV:
2432                 if (port->ldps)
2433                         status = connector_status_connected;
2434                 break;
2435         }
2436 out:
2437         drm_dp_put_port(port);
2438         return status;
2439 }
2440 EXPORT_SYMBOL(drm_dp_mst_detect_port);
2441
2442 /**
2443  * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2444  * @mgr: manager for this port
2445  * @port: unverified pointer to a port.
2446  *
2447  * This returns whether the port supports audio or not.
2448  */
2449 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2450                                         struct drm_dp_mst_port *port)
2451 {
2452         bool ret = false;
2453
2454         port = drm_dp_get_validated_port_ref(mgr, port);
2455         if (!port)
2456                 return ret;
2457         ret = port->has_audio;
2458         drm_dp_put_port(port);
2459         return ret;
2460 }
2461 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2462
2463 /**
2464  * drm_dp_mst_get_edid() - get EDID for an MST port
2465  * @connector: toplevel connector to get EDID for
2466  * @mgr: manager for this port
2467  * @port: unverified pointer to a port.
2468  *
2469  * This returns an EDID for the port connected to a connector,
2470  * It validates the pointer still exists so the caller doesn't require a
2471  * reference.
2472  */
2473 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2474 {
2475         struct edid *edid = NULL;
2476
2477         /* we need to search for the port in the mgr in case its gone */
2478         port = drm_dp_get_validated_port_ref(mgr, port);
2479         if (!port)
2480                 return NULL;
2481
2482         if (port->cached_edid)
2483                 edid = drm_edid_duplicate(port->cached_edid);
2484         else {
2485                 edid = drm_get_edid(connector, &port->aux.ddc);
2486                 drm_mode_connector_set_tile_property(connector);
2487         }
2488         port->has_audio = drm_detect_monitor_audio(edid);
2489         drm_dp_put_port(port);
2490         return edid;
2491 }
2492 EXPORT_SYMBOL(drm_dp_mst_get_edid);
2493
2494 /**
2495  * drm_dp_find_vcpi_slots() - find slots for this PBN value
2496  * @mgr: manager to use
2497  * @pbn: payload bandwidth to convert into slots.
2498  */
2499 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2500                            int pbn)
2501 {
2502         int num_slots;
2503
2504         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2505
2506         if (num_slots > mgr->avail_slots)
2507                 return -ENOSPC;
2508         return num_slots;
2509 }
2510 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2511
2512 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2513                             struct drm_dp_vcpi *vcpi, int pbn)
2514 {
2515         int num_slots;
2516         int ret;
2517
2518         num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2519
2520         if (num_slots > mgr->avail_slots)
2521                 return -ENOSPC;
2522
2523         vcpi->pbn = pbn;
2524         vcpi->aligned_pbn = num_slots * mgr->pbn_div;
2525         vcpi->num_slots = num_slots;
2526
2527         ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2528         if (ret < 0)
2529                 return ret;
2530         return 0;
2531 }
2532
2533 /**
2534  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2535  * @mgr: manager for this port
2536  * @port: port to allocate a virtual channel for.
2537  * @pbn: payload bandwidth number to request
2538  * @slots: returned number of slots for this PBN.
2539  */
2540 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port, int pbn, int *slots)
2541 {
2542         int ret;
2543
2544         port = drm_dp_get_validated_port_ref(mgr, port);
2545         if (!port)
2546                 return false;
2547
2548         if (port->vcpi.vcpi > 0) {
2549                 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2550                 if (pbn == port->vcpi.pbn) {
2551                         *slots = port->vcpi.num_slots;
2552                         drm_dp_put_port(port);
2553                         return true;
2554                 }
2555         }
2556
2557         ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn);
2558         if (ret) {
2559                 DRM_DEBUG_KMS("failed to init vcpi %d %d %d\n", DIV_ROUND_UP(pbn, mgr->pbn_div), mgr->avail_slots, ret);
2560                 goto out;
2561         }
2562         DRM_DEBUG_KMS("initing vcpi for %d %d\n", pbn, port->vcpi.num_slots);
2563         *slots = port->vcpi.num_slots;
2564
2565         drm_dp_put_port(port);
2566         return true;
2567 out:
2568         return false;
2569 }
2570 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2571
2572 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2573 {
2574         int slots = 0;
2575         port = drm_dp_get_validated_port_ref(mgr, port);
2576         if (!port)
2577                 return slots;
2578
2579         slots = port->vcpi.num_slots;
2580         drm_dp_put_port(port);
2581         return slots;
2582 }
2583 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2584
2585 /**
2586  * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2587  * @mgr: manager for this port
2588  * @port: unverified pointer to a port.
2589  *
2590  * This just resets the number of slots for the ports VCPI for later programming.
2591  */
2592 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2593 {
2594         port = drm_dp_get_validated_port_ref(mgr, port);
2595         if (!port)
2596                 return;
2597         port->vcpi.num_slots = 0;
2598         drm_dp_put_port(port);
2599 }
2600 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2601
2602 /**
2603  * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2604  * @mgr: manager for this port
2605  * @port: unverified port to deallocate vcpi for
2606  */
2607 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2608 {
2609         port = drm_dp_get_validated_port_ref(mgr, port);
2610         if (!port)
2611                 return;
2612
2613         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2614         port->vcpi.num_slots = 0;
2615         port->vcpi.pbn = 0;
2616         port->vcpi.aligned_pbn = 0;
2617         port->vcpi.vcpi = 0;
2618         drm_dp_put_port(port);
2619 }
2620 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2621
2622 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2623                                      int id, struct drm_dp_payload *payload)
2624 {
2625         u8 payload_alloc[3], status;
2626         int ret;
2627         int retries = 0;
2628
2629         drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2630                            DP_PAYLOAD_TABLE_UPDATED);
2631
2632         payload_alloc[0] = id;
2633         payload_alloc[1] = payload->start_slot;
2634         payload_alloc[2] = payload->num_slots;
2635
2636         ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2637         if (ret != 3) {
2638                 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2639                 goto fail;
2640         }
2641
2642 retry:
2643         ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2644         if (ret < 0) {
2645                 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2646                 goto fail;
2647         }
2648
2649         if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2650                 retries++;
2651                 if (retries < 20) {
2652                         usleep_range(10000, 20000);
2653                         goto retry;
2654                 }
2655                 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2656                 ret = -EINVAL;
2657                 goto fail;
2658         }
2659         ret = 0;
2660 fail:
2661         return ret;
2662 }
2663
2664
2665 /**
2666  * drm_dp_check_act_status() - Check ACT handled status.
2667  * @mgr: manager to use
2668  *
2669  * Check the payload status bits in the DPCD for ACT handled completion.
2670  */
2671 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2672 {
2673         u8 status;
2674         int ret;
2675         int count = 0;
2676
2677         do {
2678                 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2679
2680                 if (ret < 0) {
2681                         DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2682                         goto fail;
2683                 }
2684
2685                 if (status & DP_PAYLOAD_ACT_HANDLED)
2686                         break;
2687                 count++;
2688                 udelay(100);
2689
2690         } while (count < 30);
2691
2692         if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2693                 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2694                 ret = -EINVAL;
2695                 goto fail;
2696         }
2697         return 0;
2698 fail:
2699         return ret;
2700 }
2701 EXPORT_SYMBOL(drm_dp_check_act_status);
2702
2703 /**
2704  * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2705  * @clock: dot clock for the mode
2706  * @bpp: bpp for the mode.
2707  *
2708  * This uses the formula in the spec to calculate the PBN value for a mode.
2709  */
2710 int drm_dp_calc_pbn_mode(int clock, int bpp)
2711 {
2712         u64 kbps;
2713         s64 peak_kbps;
2714         u32 numerator;
2715         u32 denominator;
2716
2717         kbps = clock * bpp;
2718
2719         /*
2720          * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2721          * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2722          * common multiplier to render an integer PBN for all link rate/lane
2723          * counts combinations
2724          * calculate
2725          * peak_kbps *= (1006/1000)
2726          * peak_kbps *= (64/54)
2727          * peak_kbps *= 8    convert to bytes
2728          */
2729
2730         numerator = 64 * 1006;
2731         denominator = 54 * 8 * 1000 * 1000;
2732
2733         kbps *= numerator;
2734         peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2735
2736         return drm_fixp2int_ceil(peak_kbps);
2737 }
2738 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2739
2740 static int test_calc_pbn_mode(void)
2741 {
2742         int ret;
2743         ret = drm_dp_calc_pbn_mode(154000, 30);
2744         if (ret != 689) {
2745                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2746                                 154000, 30, 689, ret);
2747                 return -EINVAL;
2748         }
2749         ret = drm_dp_calc_pbn_mode(234000, 30);
2750         if (ret != 1047) {
2751                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2752                                 234000, 30, 1047, ret);
2753                 return -EINVAL;
2754         }
2755         ret = drm_dp_calc_pbn_mode(297000, 24);
2756         if (ret != 1063) {
2757                 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2758                                 297000, 24, 1063, ret);
2759                 return -EINVAL;
2760         }
2761         return 0;
2762 }
2763
2764 /* we want to kick the TX after we've ack the up/down IRQs. */
2765 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2766 {
2767         queue_work(system_long_wq, &mgr->tx_work);
2768 }
2769
2770 static void drm_dp_mst_dump_mstb(struct seq_file *m,
2771                                  struct drm_dp_mst_branch *mstb)
2772 {
2773         struct drm_dp_mst_port *port;
2774         int tabs = mstb->lct;
2775         char prefix[10];
2776         int i;
2777
2778         for (i = 0; i < tabs; i++)
2779                 prefix[i] = '\t';
2780         prefix[i] = '\0';
2781
2782         seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2783         list_for_each_entry(port, &mstb->ports, next) {
2784                 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
2785                 if (port->mstb)
2786                         drm_dp_mst_dump_mstb(m, port->mstb);
2787         }
2788 }
2789
2790 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2791                                   char *buf)
2792 {
2793         int ret;
2794         int i;
2795         for (i = 0; i < 4; i++) {
2796                 ret = drm_dp_dpcd_read(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS + (i * 16), &buf[i * 16], 16);
2797                 if (ret != 16)
2798                         break;
2799         }
2800         if (i == 4)
2801                 return true;
2802         return false;
2803 }
2804
2805 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
2806                                struct drm_dp_mst_port *port, char *name,
2807                                int namelen)
2808 {
2809         struct edid *mst_edid;
2810
2811         mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
2812         drm_edid_get_monitor_name(mst_edid, name, namelen);
2813 }
2814
2815 /**
2816  * drm_dp_mst_dump_topology(): dump topology to seq file.
2817  * @m: seq_file to dump output to
2818  * @mgr: manager to dump current topology for.
2819  *
2820  * helper to dump MST topology to a seq file for debugfs.
2821  */
2822 void drm_dp_mst_dump_topology(struct seq_file *m,
2823                               struct drm_dp_mst_topology_mgr *mgr)
2824 {
2825         int i;
2826         struct drm_dp_mst_port *port;
2827
2828         mutex_lock(&mgr->lock);
2829         if (mgr->mst_primary)
2830                 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2831
2832         /* dump VCPIs */
2833         mutex_unlock(&mgr->lock);
2834
2835         mutex_lock(&mgr->payload_lock);
2836         seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
2837                 mgr->max_payloads);
2838
2839         for (i = 0; i < mgr->max_payloads; i++) {
2840                 if (mgr->proposed_vcpis[i]) {
2841                         char name[14];
2842
2843                         port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2844                         fetch_monitor_name(mgr, port, name, sizeof(name));
2845                         seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
2846                                    port->port_num, port->vcpi.vcpi,
2847                                    port->vcpi.num_slots,
2848                                    (*name != 0) ? name :  "Unknown");
2849                 } else
2850                         seq_printf(m, "vcpi %d:unused\n", i);
2851         }
2852         for (i = 0; i < mgr->max_payloads; i++) {
2853                 seq_printf(m, "payload %d: %d, %d, %d\n",
2854                            i,
2855                            mgr->payloads[i].payload_state,
2856                            mgr->payloads[i].start_slot,
2857                            mgr->payloads[i].num_slots);
2858
2859
2860         }
2861         mutex_unlock(&mgr->payload_lock);
2862
2863         mutex_lock(&mgr->lock);
2864         if (mgr->mst_primary) {
2865                 u8 buf[64];
2866                 bool bret;
2867                 int ret;
2868                 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
2869                 seq_printf(m, "dpcd: ");
2870                 for (i = 0; i < DP_RECEIVER_CAP_SIZE; i++)
2871                         seq_printf(m, "%02x ", buf[i]);
2872                 seq_printf(m, "\n");
2873                 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
2874                 seq_printf(m, "faux/mst: ");
2875                 for (i = 0; i < 2; i++)
2876                         seq_printf(m, "%02x ", buf[i]);
2877                 seq_printf(m, "\n");
2878                 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
2879                 seq_printf(m, "mst ctrl: ");
2880                 for (i = 0; i < 1; i++)
2881                         seq_printf(m, "%02x ", buf[i]);
2882                 seq_printf(m, "\n");
2883
2884                 /* dump the standard OUI branch header */
2885                 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
2886                 seq_printf(m, "branch oui: ");
2887                 for (i = 0; i < 0x3; i++)
2888                         seq_printf(m, "%02x", buf[i]);
2889                 seq_printf(m, " devid: ");
2890                 for (i = 0x3; i < 0x8 && buf[i]; i++)
2891                         seq_printf(m, "%c", buf[i]);
2892
2893                 seq_printf(m, " revision: hw: %x.%x sw: %x.%x", buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
2894                 seq_printf(m, "\n");
2895                 bret = dump_dp_payload_table(mgr, buf);
2896                 if (bret == true) {
2897                         seq_printf(m, "payload table: ");
2898                         for (i = 0; i < 63; i++)
2899                                 seq_printf(m, "%02x ", buf[i]);
2900                         seq_printf(m, "\n");
2901                 }
2902
2903         }
2904
2905         mutex_unlock(&mgr->lock);
2906
2907 }
2908 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
2909
2910 static void drm_dp_tx_work(struct work_struct *work)
2911 {
2912         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
2913
2914         mutex_lock(&mgr->qlock);
2915         if (!list_empty(&mgr->tx_msg_downq))
2916                 process_single_down_tx_qlock(mgr);
2917         mutex_unlock(&mgr->qlock);
2918 }
2919
2920 static void drm_dp_free_mst_port(struct kref *kref)
2921 {
2922         struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
2923         kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
2924         kfree(port);
2925 }
2926
2927 static void drm_dp_destroy_connector_work(struct work_struct *work)
2928 {
2929         struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
2930         struct drm_dp_mst_port *port;
2931         bool send_hotplug = false;
2932         /*
2933          * Not a regular list traverse as we have to drop the destroy
2934          * connector lock before destroying the connector, to avoid AB->BA
2935          * ordering between this lock and the config mutex.
2936          */
2937         for (;;) {
2938                 mutex_lock(&mgr->destroy_connector_lock);
2939                 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
2940                 if (!port) {
2941                         mutex_unlock(&mgr->destroy_connector_lock);
2942                         break;
2943                 }
2944                 list_del(&port->next);
2945                 mutex_unlock(&mgr->destroy_connector_lock);
2946
2947                 kref_init(&port->kref);
2948                 INIT_LIST_HEAD(&port->next);
2949
2950                 mgr->cbs->destroy_connector(mgr, port->connector);
2951
2952                 drm_dp_port_teardown_pdt(port, port->pdt);
2953                 port->pdt = DP_PEER_DEVICE_NONE;
2954
2955                 if (!port->input && port->vcpi.vcpi > 0) {
2956                         drm_dp_mst_reset_vcpi_slots(mgr, port);
2957                         drm_dp_update_payload_part1(mgr);
2958                         drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2959                 }
2960
2961                 kref_put(&port->kref, drm_dp_free_mst_port);
2962                 send_hotplug = true;
2963         }
2964         if (send_hotplug)
2965                 (*mgr->cbs->hotplug)(mgr);
2966 }
2967
2968 /**
2969  * drm_dp_mst_topology_mgr_init - initialise a topology manager
2970  * @mgr: manager struct to initialise
2971  * @dev: device providing this structure - for i2c addition.
2972  * @aux: DP helper aux channel to talk to this device
2973  * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
2974  * @max_payloads: maximum number of payloads this GPU can source
2975  * @conn_base_id: the connector object ID the MST device is connected to.
2976  *
2977  * Return 0 for success, or negative error code on failure
2978  */
2979 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
2980                                  struct device *dev, struct drm_dp_aux *aux,
2981                                  int max_dpcd_transaction_bytes,
2982                                  int max_payloads, int conn_base_id)
2983 {
2984         mutex_init(&mgr->lock);
2985         mutex_init(&mgr->qlock);
2986         mutex_init(&mgr->payload_lock);
2987         mutex_init(&mgr->destroy_connector_lock);
2988         INIT_LIST_HEAD(&mgr->tx_msg_downq);
2989         INIT_LIST_HEAD(&mgr->destroy_connector_list);
2990         INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
2991         INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
2992         INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
2993         init_waitqueue_head(&mgr->tx_waitq);
2994         mgr->dev = dev;
2995         mgr->aux = aux;
2996         mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
2997         mgr->max_payloads = max_payloads;
2998         mgr->conn_base_id = conn_base_id;
2999         if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3000             max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3001                 return -EINVAL;
3002         mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3003         if (!mgr->payloads)
3004                 return -ENOMEM;
3005         mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3006         if (!mgr->proposed_vcpis)
3007                 return -ENOMEM;
3008         set_bit(0, &mgr->payload_mask);
3009         if (test_calc_pbn_mode() < 0)
3010                 DRM_ERROR("MST PBN self-test failed\n");
3011
3012         return 0;
3013 }
3014 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3015
3016 /**
3017  * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3018  * @mgr: manager to destroy
3019  */
3020 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3021 {
3022         flush_work(&mgr->work);
3023         flush_work(&mgr->destroy_connector_work);
3024         mutex_lock(&mgr->payload_lock);
3025         kfree(mgr->payloads);
3026         mgr->payloads = NULL;
3027         kfree(mgr->proposed_vcpis);
3028         mgr->proposed_vcpis = NULL;
3029         mutex_unlock(&mgr->payload_lock);
3030         mgr->dev = NULL;
3031         mgr->aux = NULL;
3032 }
3033 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3034
3035 /* I2C device */
3036 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3037                                int num)
3038 {
3039         struct drm_dp_aux *aux = adapter->algo_data;
3040         struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3041         struct drm_dp_mst_branch *mstb;
3042         struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3043         unsigned int i;
3044         bool reading = false;
3045         struct drm_dp_sideband_msg_req_body msg;
3046         struct drm_dp_sideband_msg_tx *txmsg = NULL;
3047         int ret;
3048
3049         mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3050         if (!mstb)
3051                 return -EREMOTEIO;
3052
3053         /* construct i2c msg */
3054         /* see if last msg is a read */
3055         if (msgs[num - 1].flags & I2C_M_RD)
3056                 reading = true;
3057
3058         if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3059                 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3060                 ret = -EIO;
3061                 goto out;
3062         }
3063
3064         memset(&msg, 0, sizeof(msg));
3065         msg.req_type = DP_REMOTE_I2C_READ;
3066         msg.u.i2c_read.num_transactions = num - 1;
3067         msg.u.i2c_read.port_number = port->port_num;
3068         for (i = 0; i < num - 1; i++) {
3069                 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3070                 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3071                 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3072         }
3073         msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3074         msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3075
3076         txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3077         if (!txmsg) {
3078                 ret = -ENOMEM;
3079                 goto out;
3080         }
3081
3082         txmsg->dst = mstb;
3083         drm_dp_encode_sideband_req(&msg, txmsg);
3084
3085         drm_dp_queue_down_tx(mgr, txmsg);
3086
3087         ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3088         if (ret > 0) {
3089
3090                 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3091                         ret = -EREMOTEIO;
3092                         goto out;
3093                 }
3094                 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3095                         ret = -EIO;
3096                         goto out;
3097                 }
3098                 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3099                 ret = num;
3100         }
3101 out:
3102         kfree(txmsg);
3103         drm_dp_put_mst_branch_device(mstb);
3104         return ret;
3105 }
3106
3107 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3108 {
3109         return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3110                I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3111                I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3112                I2C_FUNC_10BIT_ADDR;
3113 }
3114
3115 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3116         .functionality = drm_dp_mst_i2c_functionality,
3117         .master_xfer = drm_dp_mst_i2c_xfer,
3118 };
3119
3120 /**
3121  * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3122  * @aux: DisplayPort AUX channel
3123  *
3124  * Returns 0 on success or a negative error code on failure.
3125  */
3126 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3127 {
3128         aux->ddc.algo = &drm_dp_mst_i2c_algo;
3129         aux->ddc.algo_data = aux;
3130         aux->ddc.retries = 3;
3131
3132         aux->ddc.class = I2C_CLASS_DDC;
3133         aux->ddc.owner = THIS_MODULE;
3134         aux->ddc.dev.parent = aux->dev;
3135         aux->ddc.dev.of_node = aux->dev->of_node;
3136
3137         strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3138                 sizeof(aux->ddc.name));
3139
3140         return i2c_add_adapter(&aux->ddc);
3141 }
3142
3143 /**
3144  * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3145  * @aux: DisplayPort AUX channel
3146  */
3147 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3148 {
3149         i2c_del_adapter(&aux->ddc);
3150 }