LXR linux/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
  38static 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*/
  55static 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
  76static 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. */
 176static 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
 196static 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
 212static 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
 269static 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
 288int 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}
 308EXPORT_SYMBOL_GPL(xhci_mtk_sch_init);
 309
 310void xhci_mtk_sch_exit(struct xhci_hcd_mtk *mtk)
 311{
 312        kfree(mtk->sch_array);
 313}
 314EXPORT_SYMBOL_GPL(xhci_mtk_sch_exit);
 315
 316int 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}
 385EXPORT_SYMBOL_GPL(xhci_mtk_add_ep_quirk);
 386
 387void 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}
 425EXPORT_SYMBOL_GPL(xhci_mtk_drop_ep_quirk);
 426