drivers/target/tcm_fc/tfc_io.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (c) 2010 Cisco Systems, Inc.
   4  *
   5  * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
   6  *
   7  * Copyright (c) 2007 Intel Corporation. All rights reserved.
   8  * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
   9  * Copyright (c) 2008 Mike Christie
  10  * Copyright (c) 2009 Rising Tide, Inc.
  11  * Copyright (c) 2009 Linux-iSCSI.org
  12  * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
  13  */
  14
  15 /* XXX TBD some includes may be extraneous */
  16
  17 #include <linux/module.h>
  18 #include <linux/moduleparam.h>
  19 #include <linux/utsname.h>
  20 #include <linux/init.h>
  21 #include <linux/slab.h>
  22 #include <linux/kthread.h>
  23 #include <linux/types.h>
  24 #include <linux/string.h>
  25 #include <linux/configfs.h>
  26 #include <linux/ctype.h>
  27 #include <linux/hash.h>
  28 #include <linux/ratelimit.h>
  29 #include <linux/unaligned.h>
  30 #include <scsi/libfc.h>
  31
  32 #include <target/target_core_base.h>
  33 #include <target/target_core_fabric.h>
  34
  35 #include "tcm_fc.h"
  36
  37 /*
  38  * Deliver read data back to initiator.
  39  * XXX TBD handle resource problems later.
  40  */
  41 int ft_queue_data_in(struct se_cmd *se_cmd)
  42 {
  43         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  44         struct fc_frame *fp = NULL;
  45         struct fc_exch *ep;
  46         struct fc_lport *lport;
  47         struct scatterlist *sg = NULL;
  48         size_t remaining;
  49         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  50         u32 mem_off = 0;
  51         u32 fh_off = 0;
  52         u32 frame_off = 0;
  53         size_t frame_len = 0;
  54         size_t mem_len = 0;
  55         size_t tlen;
  56         size_t off_in_page;
  57         struct page *page = NULL;
  58         int use_sg;
  59         int error;
  60         void *page_addr;
  61         void *from;
  62         void *to = NULL;
  63
  64         if (cmd->aborted)
  65                 return 0;
  66
  67         if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
  68                 goto queue_status;
  69
  70         ep = fc_seq_exch(cmd->seq);
  71         lport = ep->lp;
  72         cmd->seq = fc_seq_start_next(cmd->seq);
  73
  74         remaining = se_cmd->data_length;
  75
  76         /*
  77          * Setup to use first mem list entry, unless no data.
  78          */
  79         BUG_ON(remaining && !se_cmd->t_data_sg);
  80         if (remaining) {
  81                 sg = se_cmd->t_data_sg;
  82                 mem_len = sg->length;
  83                 mem_off = sg->offset;
  84                 page = sg_page(sg);
  85         }
  86
  87         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
  88         use_sg = !(remaining % 4);
  89
  90         while (remaining) {
  91                 struct fc_seq *seq = cmd->seq;
  92
  93                 if (!seq) {
  94                         pr_debug("%s: Command aborted, xid 0x%x\n",
  95                                  __func__, ep->xid);
  96                         break;
  97                 }
  98                 if (!mem_len) {
  99                         sg = sg_next(sg);
 100                         mem_len = min((size_t)sg->length, remaining);
 101                         mem_off = sg->offset;
 102                         page = sg_page(sg);
 103                 }
 104                 if (!frame_len) {
 105                         /*
 106                          * If lport's has capability of Large Send Offload LSO)
 107                          * , then allow 'frame_len' to be as big as 'lso_max'
 108                          * if indicated transfer length is >= lport->lso_max
 109                          */
 110                         frame_len = (lport->seq_offload) ? lport->lso_max :
 111                                                           cmd->sess->max_frame;
 112                         frame_len = min(frame_len, remaining);
 113                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 114                         if (!fp)
 115                                 return -ENOMEM;
 116                         to = fc_frame_payload_get(fp, 0);
 117                         fh_off = frame_off;
 118                         frame_off += frame_len;
 119                         /*
 120                          * Setup the frame's max payload which is used by base
 121                          * driver to indicate HW about max frame size, so that
 122                          * HW can do fragmentation appropriately based on
 123                          * "gso_max_size" of underline netdev.
 124                          */
 125                         fr_max_payload(fp) = cmd->sess->max_frame;
 126                 }
 127                 tlen = min(mem_len, frame_len);
 128
 129                 if (use_sg) {
 130                         off_in_page = mem_off;
 131                         BUG_ON(!page);
 132                         get_page(page);
 133                         skb_fill_page_desc(fp_skb(fp),
 134                                            skb_shinfo(fp_skb(fp))->nr_frags,
 135                                            page, off_in_page, tlen);
 136                         fr_len(fp) += tlen;
 137                         fp_skb(fp)->data_len += tlen;
 138                         fp_skb(fp)->truesize += page_size(page);
 139                 } else {
 140                         BUG_ON(!page);
 141                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 142                         page_addr = from;
 143                         from += offset_in_page(mem_off);
 144                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 145                                                 offset_in_page(mem_off)));
 146                         memcpy(to, from, tlen);
 147                         kunmap_atomic(page_addr);
 148                         to += tlen;
 149                 }
 150
 151                 mem_off += tlen;
 152                 mem_len -= tlen;
 153                 frame_len -= tlen;
 154                 remaining -= tlen;
 155
 156                 if (frame_len &&
 157                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 158                         continue;
 159                 if (!remaining)
 160                         f_ctl |= FC_FC_END_SEQ;
 161                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 162                                FC_TYPE_FCP, f_ctl, fh_off);
 163                 error = fc_seq_send(lport, seq, fp);
 164                 if (error) {
 165                         pr_info_ratelimited("%s: Failed to send frame %p, "
 166                                                 "xid <0x%x>, remaining %zu, "
 167                                                 "lso_max <0x%x>\n",
 168                                                 __func__, fp, ep->xid,
 169                                                 remaining, lport->lso_max);
 170                         /*
 171                          * Go ahead and set TASK_SET_FULL status ignoring the
 172                          * rest of the DataIN, and immediately attempt to
 173                          * send the response via ft_queue_status() in order
 174                          * to notify the initiator that it should reduce it's
 175                          * per LUN queue_depth.
 176                          */
 177                         se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
 178                         break;
 179                 }
 180         }
 181 queue_status:
 182         return ft_queue_status(se_cmd);
 183 }
 184
 185 static void ft_execute_work(struct work_struct *work)
 186 {
 187         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
 188
 189         target_execute_cmd(&cmd->se_cmd);
 190 }
 191
 192 /*
 193  * Receive write data frame.
 194  */
 195 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 196 {
 197         struct se_cmd *se_cmd = &cmd->se_cmd;
 198         struct fc_seq *seq = cmd->seq;
 199         struct fc_exch *ep;
 200         struct fc_lport *lport;
 201         struct fc_frame_header *fh;
 202         struct scatterlist *sg = NULL;
 203         u32 mem_off = 0;
 204         u32 rel_off;
 205         size_t frame_len;
 206         size_t mem_len = 0;
 207         size_t tlen;
 208         struct page *page = NULL;
 209         void *page_addr;
 210         void *from;
 211         void *to;
 212         u32 f_ctl;
 213         void *buf;
 214
 215         fh = fc_frame_header_get(fp);
 216         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 217                 goto drop;
 218
 219         f_ctl = ntoh24(fh->fh_f_ctl);
 220         ep = fc_seq_exch(seq);
 221         lport = ep->lp;
 222         if (cmd->was_ddp_setup) {
 223                 BUG_ON(!lport);
 224                 /*
 225                  * Since DDP (Large Rx offload) was setup for this request,
 226                  * payload is expected to be copied directly to user buffers.
 227                  */
 228                 buf = fc_frame_payload_get(fp, 1);
 229                 if (buf)
 230                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 231                                 "cmd->sg_cnt 0x%x. DDP was setup"
 232                                 " hence not expected to receive frame with "
 233                                 "payload, Frame will be dropped if"
 234                                 "'Sequence Initiative' bit in f_ctl is"
 235                                 "not set\n", __func__, ep->xid, f_ctl,
 236                                 se_cmd->t_data_sg, se_cmd->t_data_nents);
 237                 /*
 238                  * Invalidate HW DDP context if it was setup for respective
 239                  * command. Invalidation of HW DDP context is requited in both
 240                  * situation (success and error).
 241                  */
 242                 ft_invl_hw_context(cmd);
 243
 244                 /*
 245                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 246                  * write data frame is received successfully where payload is
 247                  * posted directly to user buffer and only the last frame's
 248                  * header is posted in receive queue.
 249                  *
 250                  * If "Sequence Initiative (TSI)" bit is not set, means error
 251                  * condition w.r.t. DDP, hence drop the packet and let explict
 252                  * ABORTS from other end of exchange timer trigger the recovery.
 253                  */
 254                 if (f_ctl & FC_FC_SEQ_INIT)
 255                         goto last_frame;
 256                 else
 257                         goto drop;
 258         }
 259
 260         rel_off = ntohl(fh->fh_parm_offset);
 261         frame_len = fr_len(fp);
 262         if (frame_len <= sizeof(*fh))
 263                 goto drop;
 264         frame_len -= sizeof(*fh);
 265         from = fc_frame_payload_get(fp, 0);
 266         if (rel_off >= se_cmd->data_length)
 267                 goto drop;
 268         if (frame_len + rel_off > se_cmd->data_length)
 269                 frame_len = se_cmd->data_length - rel_off;
 270
 271         /*
 272          * Setup to use first mem list entry, unless no data.
 273          */
 274         BUG_ON(frame_len && !se_cmd->t_data_sg);
 275         if (frame_len) {
 276                 sg = se_cmd->t_data_sg;
 277                 mem_len = sg->length;
 278                 mem_off = sg->offset;
 279                 page = sg_page(sg);
 280         }
 281
 282         while (frame_len) {
 283                 if (!mem_len) {
 284                         sg = sg_next(sg);
 285                         mem_len = sg->length;
 286                         mem_off = sg->offset;
 287                         page = sg_page(sg);
 288                 }
 289                 if (rel_off >= mem_len) {
 290                         rel_off -= mem_len;
 291                         mem_len = 0;
 292                         continue;
 293                 }
 294                 mem_off += rel_off;
 295                 mem_len -= rel_off;
 296                 rel_off = 0;
 297
 298                 tlen = min(mem_len, frame_len);
 299
 300                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
 301                 page_addr = to;
 302                 to += offset_in_page(mem_off);
 303                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 304                                           offset_in_page(mem_off)));
 305                 memcpy(to, from, tlen);
 306                 kunmap_atomic(page_addr);
 307
 308                 from += tlen;
 309                 frame_len -= tlen;
 310                 mem_off += tlen;
 311                 mem_len -= tlen;
 312                 cmd->write_data_len += tlen;
 313         }
 314 last_frame:
 315         if (cmd->write_data_len == se_cmd->data_length) {
 316                 INIT_WORK(&cmd->work, ft_execute_work);
 317                 queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work);
 318         }
 319 drop:
 320         fc_frame_free(fp);
 321 }
 322
 323 /*
 324  * Handle and cleanup any HW specific resources if
 325  * received ABORTS, errors, timeouts.
 326  */
 327 void ft_invl_hw_context(struct ft_cmd *cmd)
 328 {
 329         struct fc_seq *seq;
 330         struct fc_exch *ep = NULL;
 331         struct fc_lport *lport = NULL;
 332
 333         BUG_ON(!cmd);
 334         seq = cmd->seq;
 335
 336         /* Cleanup the DDP context in HW if DDP was setup */
 337         if (cmd->was_ddp_setup && seq) {
 338                 ep = fc_seq_exch(seq);
 339                 if (ep) {
 340                         lport = ep->lp;
 341                         if (lport && (ep->xid <= lport->lro_xid)) {
 342                                 /*
 343                                  * "ddp_done" trigger invalidation of HW
 344                                  * specific DDP context
 345                                  */
 346                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 347                                                                       ep->xid);
 348
 349                                 /*
 350                                  * Resetting same variable to indicate HW's
 351                                  * DDP context has been invalidated to avoid
 352                                  * re_invalidation of same context (context is
 353                                  * identified using ep->xid)
 354                                  */
 355                                 cmd->was_ddp_setup = 0;
 356                         }
 357                 }
 358         }
 359 }