drivers/usb/host/xhci-mtk-sch.c

   1 /*
   2  * Copyright (c) 2015 MediaTek Inc.
   3  * Author:
   4  *  Zhigang.Wei <zhigang.wei@mediatek.com>
   5  *  Chunfeng.Yun <chunfeng.yun@mediatek.com>
   6  *
   7  * This software is licensed under the terms of the GNU General Public
   8  * License version 2, as published by the Free Software Foundation, and
   9  * may be copied, distributed, and modified under those terms.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/slab.h>
  21
  22 #include "xhci.h"
  23 #include "xhci-mtk.h"
  24
  25 #define SS_BW_BOUNDARY  51000
  26 /* table 5-5. High-speed Isoc Transaction Limits in usb_20 spec */
  27 #define HS_BW_BOUNDARY  6144
  28 /* usb2 spec section11.18.1: at most 188 FS bytes per microframe */
  29 #define FS_PAYLOAD_MAX 188
  30
  31 /* mtk scheduler bitmasks */
  32 #define EP_BPKTS(p)     ((p) & 0x3f)
  33 #define EP_BCSCOUNT(p)  (((p) & 0x7) << 8)
  34 #define EP_BBM(p)       ((p) << 11)
  35 #define EP_BOFFSET(p)   ((p) & 0x3fff)
  36 #define EP_BREPEAT(p)   (((p) & 0x7fff) << 16)
  37
  38 static int is_fs_or_ls(enum usb_device_speed speed)
  39 {
  40         return speed == USB_SPEED_FULL || speed == USB_SPEED_LOW;
  41 }
  42
  43 /*
  44 * get the index of bandwidth domains array which @ep belongs to.
  45 *
  46 * the bandwidth domain array is saved to @sch_array of struct xhci_hcd_mtk,
  47 * each HS root port is treated as a single bandwidth domain,
  48 * but each SS root port is treated as two bandwidth domains, one for IN eps,
  49 * one for OUT eps.
  50 * @real_port value is defined as follow according to xHCI spec:
  51 * 1 for SSport0, ..., N+1 for SSportN, N+2 for HSport0, N+3 for HSport1, etc
  52 * so the bandwidth domain array is organized as follow for simplification:
  53 * SSport0-OUT, SSport0-IN, ..., SSportX-OUT, SSportX-IN, HSport0, ..., HSportY
  54 */
  55 static int get_bw_index(struct xhci_hcd *xhci, struct usb_device *udev,
  56         struct usb_host_endpoint *ep)
  57 {
  58         struct xhci_virt_device *virt_dev;
  59         int bw_index;
  60
  61         virt_dev = xhci->devs[udev->slot_id];
  62
  63         if (udev->speed == USB_SPEED_SUPER) {
  64                 if (usb_endpoint_dir_out(&ep->desc))
  65                         bw_index = (virt_dev->real_port - 1) * 2;
  66                 else
  67                         bw_index = (virt_dev->real_port - 1) * 2 + 1;
  68         } else {
  69                 /* add one more for each SS port */
  70                 bw_index = virt_dev->real_port + xhci->num_usb3_ports - 1;
  71         }
  72
  73         return bw_index;
  74 }
  75
  76 static void setup_sch_info(struct usb_device *udev,
  77                 struct xhci_ep_ctx *ep_ctx, struct mu3h_sch_ep_info *sch_ep)
  78 {
  79         u32 ep_type;
  80         u32 ep_interval;
  81         u32 max_packet_size;
  82         u32 max_burst;
  83         u32 mult;
  84         u32 esit_pkts;
  85
  86         ep_type = CTX_TO_EP_TYPE(le32_to_cpu(ep_ctx->ep_info2));
  87         ep_interval = CTX_TO_EP_INTERVAL(le32_to_cpu(ep_ctx->ep_info));
  88         max_packet_size = MAX_PACKET_DECODED(le32_to_cpu(ep_ctx->ep_info2));
  89         max_burst = CTX_TO_MAX_BURST(le32_to_cpu(ep_ctx->ep_info2));
  90         mult = CTX_TO_EP_MULT(le32_to_cpu(ep_ctx->ep_info));
  91
  92         sch_ep->esit = 1 << ep_interval;
  93         sch_ep->offset = 0;
  94         sch_ep->burst_mode = 0;
  95
  96         if (udev->speed == USB_SPEED_HIGH) {
  97                 sch_ep->cs_count = 0;
  98
  99                 /*
 100                  * usb_20 spec section5.9
 101                  * a single microframe is enough for HS synchromous endpoints
 102                  * in a interval
 103                  */
 104                 sch_ep->num_budget_microframes = 1;
 105                 sch_ep->repeat = 0;
 106
 107                 /*
 108                  * xHCI spec section6.2.3.4
 109                  * @max_burst is the number of additional transactions
 110                  * opportunities per microframe
 111                  */
 112                 sch_ep->pkts = max_burst + 1;
 113                 sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
 114         } else if (udev->speed == USB_SPEED_SUPER) {
 115                 /* usb3_r1 spec section4.4.7 & 4.4.8 */
 116                 sch_ep->cs_count = 0;
 117                 esit_pkts = (mult + 1) * (max_burst + 1);
 118                 if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
 119                         sch_ep->pkts = esit_pkts;
 120                         sch_ep->num_budget_microframes = 1;
 121                         sch_ep->repeat = 0;
 122                 }
 123
 124                 if (ep_type == ISOC_IN_EP || ep_type == ISOC_OUT_EP) {
 125                         if (esit_pkts <= sch_ep->esit)
 126                                 sch_ep->pkts = 1;
 127                         else
 128                                 sch_ep->pkts = roundup_pow_of_two(esit_pkts)
 129                                         / sch_ep->esit;
 130
 131                         sch_ep->num_budget_microframes =
 132                                 DIV_ROUND_UP(esit_pkts, sch_ep->pkts);
 133
 134                         if (sch_ep->num_budget_microframes > 1)
 135                                 sch_ep->repeat = 1;
 136                         else
 137                                 sch_ep->repeat = 0;
 138                 }
 139                 sch_ep->bw_cost_per_microframe = max_packet_size * sch_ep->pkts;
 140         } else if (is_fs_or_ls(udev->speed)) {
 141
 142                 /*
 143                  * usb_20 spec section11.18.4
 144                  * assume worst cases
 145                  */
 146                 sch_ep->repeat = 0;
 147                 sch_ep->pkts = 1; /* at most one packet for each microframe */
 148                 if (ep_type == INT_IN_EP || ep_type == INT_OUT_EP) {
 149                         sch_ep->cs_count = 3; /* at most need 3 CS*/
 150                         /* one for SS and one for budgeted transaction */
 151                         sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
 152                         sch_ep->bw_cost_per_microframe = max_packet_size;
 153                 }
 154                 if (ep_type == ISOC_OUT_EP) {
 155
 156                         /*
 157                          * the best case FS budget assumes that 188 FS bytes
 158                          * occur in each microframe
 159                          */
 160                         sch_ep->num_budget_microframes = DIV_ROUND_UP(
 161                                 max_packet_size, FS_PAYLOAD_MAX);
 162                         sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
 163                         sch_ep->cs_count = sch_ep->num_budget_microframes;
 164                 }
 165                 if (ep_type == ISOC_IN_EP) {
 166                         /* at most need additional two CS. */
 167                         sch_ep->cs_count = DIV_ROUND_UP(
 168                                 max_packet_size, FS_PAYLOAD_MAX) + 2;
 169                         sch_ep->num_budget_microframes = sch_ep->cs_count + 2;
 170                         sch_ep->bw_cost_per_microframe = FS_PAYLOAD_MAX;
 171                 }
 172         }
 173 }
 174
 175 /* Get maximum bandwidth when we schedule at offset slot. */
 176 static u32 get_max_bw(struct mu3h_sch_bw_info *sch_bw,
 177         struct mu3h_sch_ep_info *sch_ep, u32 offset)
 178 {
 179         u32 num_esit;
 180         u32 max_bw = 0;
 181         int i;
 182         int j;
 183
 184         num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
 185         for (i = 0; i < num_esit; i++) {
 186                 u32 base = offset + i * sch_ep->esit;
 187
 188                 for (j = 0; j < sch_ep->num_budget_microframes; j++) {
 189                         if (sch_bw->bus_bw[base + j] > max_bw)
 190                                 max_bw = sch_bw->bus_bw[base + j];
 191                 }
 192         }
 193         return max_bw;
 194 }
 195
 196 static void update_bus_bw(struct mu3h_sch_bw_info *sch_bw,
 197         struct mu3h_sch_ep_info *sch_ep, int bw_cost)
 198 {
 199         u32 num_esit;
 200         u32 base;
 201         int i;
 202         int j;
 203
 204         num_esit = XHCI_MTK_MAX_ESIT / sch_ep->esit;
 205         for (i = 0; i < num_esit; i++) {
 206                 base = sch_ep->offset + i * sch_ep->esit;
 207                 for (j = 0; j < sch_ep->num_budget_microframes; j++)
 208                         sch_bw->bus_bw[base + j] += bw_cost;
 209         }
 210 }
 211
 212 static int check_sch_bw(struct usb_device *udev,
 213         struct mu3h_sch_bw_info *sch_bw, struct mu3h_sch_ep_info *sch_ep)
 214 {
 215         u32 offset;
 216         u32 esit;
 217         u32 num_budget_microframes;
 218         u32 min_bw;
 219         u32 min_index;
 220         u32 worst_bw;
 221         u32 bw_boundary;
 222
 223         if (sch_ep->esit > XHCI_MTK_MAX_ESIT)
 224                 sch_ep->esit = XHCI_MTK_MAX_ESIT;
 225
 226         esit = sch_ep->esit;
 227         num_budget_microframes = sch_ep->num_budget_microframes;
 228
 229         /*
 230          * Search through all possible schedule microframes.
 231          * and find a microframe where its worst bandwidth is minimum.
 232          */
 233         min_bw = ~0;
 234         min_index = 0;
 235         for (offset = 0; offset < esit; offset++) {
 236                 if ((offset + num_budget_microframes) > sch_ep->esit)
 237                         break;
 238
 239                 /*
 240                  * usb_20 spec section11.18:
 241                  * must never schedule Start-Split in Y6
 242                  */
 243                 if (is_fs_or_ls(udev->speed) && (offset % 8 == 6))
 244                         continue;
 245
 246                 worst_bw = get_max_bw(sch_bw, sch_ep, offset);
 247                 if (min_bw > worst_bw) {
 248                         min_bw = worst_bw;
 249                         min_index = offset;
 250                 }
 251                 if (min_bw == 0)
 252                         break;
 253         }
 254         sch_ep->offset = min_index;
 255
 256         bw_boundary = (udev->speed == USB_SPEED_SUPER)
 257                                 ? SS_BW_BOUNDARY : HS_BW_BOUNDARY;
 258
 259         /* check bandwidth */
 260         if (min_bw + sch_ep->bw_cost_per_microframe > bw_boundary)
 261                 return -ERANGE;
 262
 263         /* update bus bandwidth info */
 264         update_bus_bw(sch_bw, sch_ep, sch_ep->bw_cost_per_microframe);
 265
 266         return 0;
 267 }
 268
 269 static bool need_bw_sch(struct usb_host_endpoint *ep,
 270         enum usb_device_speed speed, int has_tt)
 271 {
 272         /* only for periodic endpoints */
 273         if (usb_endpoint_xfer_control(&ep->desc)
 274                 || usb_endpoint_xfer_bulk(&ep->desc))
 275                 return false;
 276
 277         /*
 278          * for LS & FS periodic endpoints which its device is not behind
 279          * a TT are also ignored, root-hub will schedule them directly,
 280          * but need set @bpkts field of endpoint context to 1.
 281          */
 282         if (is_fs_or_ls(speed) && !has_tt)
 283                 return false;
 284
 285         return true;
 286 }
 287
 288 int xhci_mtk_sch_init(struct xhci_hcd_mtk *mtk)
 289 {
 290         struct mu3h_sch_bw_info *sch_array;
 291         int num_usb_bus;
 292         int i;
 293
 294         /* ss IN and OUT are separated */
 295         num_usb_bus = mtk->num_u3_ports * 2 + mtk->num_u2_ports;
 296
 297         sch_array = kcalloc(num_usb_bus, sizeof(*sch_array), GFP_KERNEL);
 298         if (sch_array == NULL)
 299                 return -ENOMEM;
 300
 301         for (i = 0; i < num_usb_bus; i++)
 302                 INIT_LIST_HEAD(&sch_array[i].bw_ep_list);
 303
 304         mtk->sch_array = sch_array;
 305
 306         return 0;
 307 }
 308 EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);
 309
 310 void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
 311 {
 312         kfree(mtk->sch_array);
 313 }
 314 EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);
 315
 316 int xhci_mtk_add_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
 317                 struct usb_host_endpoint *ep)
 318 {
 319         struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
 320         struct xhci_hcd *xhci;
 321         struct xhci_ep_ctx *ep_ctx;
 322         struct xhci_slot_ctx *slot_ctx;
 323         struct xhci_virt_device *virt_dev;
 324         struct mu3h_sch_bw_info *sch_bw;
 325         struct mu3h_sch_ep_info *sch_ep;
 326         struct mu3h_sch_bw_info *sch_array;
 327         unsigned int ep_index;
 328         int bw_index;
 329         int ret = 0;
 330
 331         xhci = hcd_to_xhci(hcd);
 332         virt_dev = xhci->devs[udev->slot_id];
 333         ep_index = xhci_get_endpoint_index(&ep->desc);
 334         slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
 335         ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
 336         sch_array = mtk->sch_array;
 337
 338         xhci_dbg(xhci, "%s() type:%d, speed:%d, mpkt:%d, dir:%d, ep:%p\n",
 339                 __func__, usb_endpoint_type(&ep->desc), udev->speed,
 340                 usb_endpoint_maxp(&ep->desc),
 341                 usb_endpoint_dir_in(&ep->desc), ep);
 342
 343         if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT)) {
 344                 /*
 345                  * set @bpkts to 1 if it is LS or FS periodic endpoint, and its
 346                  * device does not connected through an external HS hub
 347                  */
 348                 if (usb_endpoint_xfer_int(&ep->desc)
 349                         || usb_endpoint_xfer_isoc(&ep->desc))
 350                         ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(1));
 351
 352                 return 0;
 353         }
 354
 355         bw_index = get_bw_index(xhci, udev, ep);
 356         sch_bw = &sch_array[bw_index];
 357
 358         sch_ep = kzalloc(sizeof(struct mu3h_sch_ep_info), GFP_NOIO);
 359         if (!sch_ep)
 360                 return -ENOMEM;
 361
 362         setup_sch_info(udev, ep_ctx, sch_ep);
 363
 364         ret = check_sch_bw(udev, sch_bw, sch_ep);
 365         if (ret) {
 366                 xhci_err(xhci, "Not enough bandwidth!\n");
 367                 kfree(sch_ep);
 368                 return -ENOSPC;
 369         }
 370
 371         list_add_tail(&sch_ep->endpoint, &sch_bw->bw_ep_list);
 372         sch_ep->ep = ep;
 373
 374         ep_ctx->reserved[0] |= cpu_to_le32(EP_BPKTS(sch_ep->pkts)
 375                 | EP_BCSCOUNT(sch_ep->cs_count) | EP_BBM(sch_ep->burst_mode));
 376         ep_ctx->reserved[1] |= cpu_to_le32(EP_BOFFSET(sch_ep->offset)
 377                 | EP_BREPEAT(sch_ep->repeat));
 378
 379         xhci_dbg(xhci, " PKTS:%x, CSCOUNT:%x, BM:%x, OFFSET:%x, REPEAT:%x\n",
 380                         sch_ep->pkts, sch_ep->cs_count, sch_ep->burst_mode,
 381                         sch_ep->offset, sch_ep->repeat);
 382
 383         return 0;
 384 }
 385 EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);
 386
 387 void xhci_mtk_drop_ep_quirk(struct usb_hcd *hcd, struct usb_device *udev,
 388                 struct usb_host_endpoint *ep)
 389 {
 390         struct xhci_hcd_mtk *mtk = hcd_to_mtk(hcd);
 391         struct xhci_hcd *xhci;
 392         struct xhci_slot_ctx *slot_ctx;
 393         struct xhci_virt_device *virt_dev;
 394         struct mu3h_sch_bw_info *sch_array;
 395         struct mu3h_sch_bw_info *sch_bw;
 396         struct mu3h_sch_ep_info *sch_ep;
 397         int bw_index;
 398
 399         xhci = hcd_to_xhci(hcd);
 400         virt_dev = xhci->devs[udev->slot_id];
 401         slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
 402         sch_array = mtk->sch_array;
 403
 404         xhci_dbg(xhci, "%s() type:%d, speed:%d, mpks:%d, dir:%d, ep:%p\n",
 405                 __func__, usb_endpoint_type(&ep->desc), udev->speed,
 406                 usb_endpoint_maxp(&ep->desc),
 407                 usb_endpoint_dir_in(&ep->desc), ep);
 408
 409         if (!need_bw_sch(ep, udev->speed, slot_ctx->tt_info & TT_SLOT))
 410                 return;
 411
 412         bw_index = get_bw_index(xhci, udev, ep);
 413         sch_bw = &sch_array[bw_index];
 414
 415         list_for_each_entry(sch_ep, &sch_bw->bw_ep_list, endpoint) {
 416                 if (sch_ep->ep == ep) {
 417                         update_bus_bw(sch_bw, sch_ep,
 418                                 -sch_ep->bw_cost_per_microframe);
 419                         list_del(&sch_ep->endpoint);
 420                         kfree(sch_ep);
 421                         break;
 422                 }
 423         }
 424 }
 425 EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);