LXR linux/drivers/gpu/drm/ttm/ttm_execbuf

   1/**************************************************************************
   2 *
   3 * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
   4 * All Rights Reserved.
   5 *
   6 * Permission is hereby granted, free of charge, to any person obtaining a
   7 * copy of this software and associated documentation files (the
   8 * "Software"), to deal in the Software without restriction, including
   9 * without limitation the rights to use, copy, modify, merge, publish,
  10 * distribute, sub license, and/or sell copies of the Software, and to
  11 * permit persons to whom the Software is furnished to do so, subject to
  12 * the following conditions:
  13 *
  14 * The above copyright notice and this permission notice (including the
  15 * next paragraph) shall be included in all copies or substantial portions
  16 * of the Software.
  17 *
  18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
  21 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
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  24 * USE OR OTHER DEALINGS IN THE SOFTWARE.
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  26 **************************************************************************/
  27
  28#include <drm/ttm/ttm_execbuf_util.h>
  29#include <drm/ttm/ttm_bo_driver.h>
  30#include <drm/ttm/ttm_placement.h>
  31#include <linux/wait.h>
  32#include <linux/sched.h>
  33#include <linux/module.h>
  34
  35static void ttm_eu_backoff_reservation_reverse(struct list_head *list,
  36                                              struct ttm_validate_buffer *entry)
  37{
  38        list_for_each_entry_continue_reverse(entry, list, head) {
  39                struct ttm_buffer_object *bo = entry->bo;
  40
  41                __ttm_bo_unreserve(bo);
  42        }
  43}
  44
  45static void ttm_eu_del_from_lru_locked(struct list_head *list)
  46{
  47        struct ttm_validate_buffer *entry;
  48
  49        list_for_each_entry(entry, list, head) {
  50                struct ttm_buffer_object *bo = entry->bo;
  51                unsigned put_count = ttm_bo_del_from_lru(bo);
  52
  53                ttm_bo_list_ref_sub(bo, put_count, true);
  54        }
  55}
  56
  57void ttm_eu_backoff_reservation(struct ww_acquire_ctx *ticket,
  58                                struct list_head *list)
  59{
  60        struct ttm_validate_buffer *entry;
  61        struct ttm_bo_global *glob;
  62
  63        if (list_empty(list))
  64                return;
  65
  66        entry = list_first_entry(list, struct ttm_validate_buffer, head);
  67        glob = entry->bo->glob;
  68
  69        spin_lock(&glob->lru_lock);
  70        list_for_each_entry(entry, list, head) {
  71                struct ttm_buffer_object *bo = entry->bo;
  72
  73                ttm_bo_add_to_lru(bo);
  74                __ttm_bo_unreserve(bo);
  75        }
  76        spin_unlock(&glob->lru_lock);
  77
  78        if (ticket)
  79                ww_acquire_fini(ticket);
  80}
  81EXPORT_SYMBOL(ttm_eu_backoff_reservation);
  82
  83/*
  84 * Reserve buffers for validation.
  85 *
  86 * If a buffer in the list is marked for CPU access, we back off and
  87 * wait for that buffer to become free for GPU access.
  88 *
  89 * If a buffer is reserved for another validation, the validator with
  90 * the highest validation sequence backs off and waits for that buffer
  91 * to become unreserved. This prevents deadlocks when validating multiple
  92 * buffers in different orders.
  93 */
  94
  95int ttm_eu_reserve_buffers(struct ww_acquire_ctx *ticket,
  96                           struct list_head *list, bool intr,
  97                           struct list_head *dups)
  98{
  99        struct ttm_bo_global *glob;
 100        struct ttm_validate_buffer *entry;
 101        int ret;
 102
 103        if (list_empty(list))
 104                return 0;
 105
 106        entry = list_first_entry(list, struct ttm_validate_buffer, head);
 107        glob = entry->bo->glob;
 108
 109        if (ticket)
 110                ww_acquire_init(ticket, &reservation_ww_class);
 111
 112        list_for_each_entry(entry, list, head) {
 113                struct ttm_buffer_object *bo = entry->bo;
 114
 115                ret = __ttm_bo_reserve(bo, intr, (ticket == NULL), ticket);
 116                if (!ret && unlikely(atomic_read(&bo->cpu_writers) > 0)) {
 117                        __ttm_bo_unreserve(bo);
 118
 119                        ret = -EBUSY;
 120
 121                } else if (ret == -EALREADY && dups) {
 122                        struct ttm_validate_buffer *safe = entry;
 123                        entry = list_prev_entry(entry, head);
 124                        list_del(&safe->head);
 125                        list_add(&safe->head, dups);
 126                        continue;
 127                }
 128
 129                if (!ret) {
 130                        if (!entry->shared)
 131                                continue;
 132
 133                        ret = reservation_object_reserve_shared(bo->resv);
 134                        if (!ret)
 135                                continue;
 136                }
 137
 138                /* uh oh, we lost out, drop every reservation and try
 139                 * to only reserve this buffer, then start over if
 140                 * this succeeds.
 141                 */
 142                ttm_eu_backoff_reservation_reverse(list, entry);
 143
 144                if (ret == -EDEADLK && intr) {
 145                        ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
 146                                                               ticket);
 147                } else if (ret == -EDEADLK) {
 148                        ww_mutex_lock_slow(&bo->resv->lock, ticket);
 149                        ret = 0;
 150                }
 151
 152                if (!ret && entry->shared)
 153                        ret = reservation_object_reserve_shared(bo->resv);
 154
 155                if (unlikely(ret != 0)) {
 156                        if (ret == -EINTR)
 157                                ret = -ERESTARTSYS;
 158                        if (ticket) {
 159                                ww_acquire_done(ticket);
 160                                ww_acquire_fini(ticket);
 161                        }
 162                        return ret;
 163                }
 164
 165                /* move this item to the front of the list,
 166                 * forces correct iteration of the loop without keeping track
 167                 */
 168                list_del(&entry->head);
 169                list_add(&entry->head, list);
 170        }
 171
 172        if (ticket)
 173                ww_acquire_done(ticket);
 174        spin_lock(&glob->lru_lock);
 175        ttm_eu_del_from_lru_locked(list);
 176        spin_unlock(&glob->lru_lock);
 177        return 0;
 178}
 179EXPORT_SYMBOL(ttm_eu_reserve_buffers);
 180
 181void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
 182                                 struct list_head *list, struct fence *fence)
 183{
 184        struct ttm_validate_buffer *entry;
 185        struct ttm_buffer_object *bo;
 186        struct ttm_bo_global *glob;
 187        struct ttm_bo_device *bdev;
 188        struct ttm_bo_driver *driver;
 189
 190        if (list_empty(list))
 191                return;
 192
 193        bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
 194        bdev = bo->bdev;
 195        driver = bdev->driver;
 196        glob = bo->glob;
 197
 198        spin_lock(&glob->lru_lock);
 199
 200        list_for_each_entry(entry, list, head) {
 201                bo = entry->bo;
 202                if (entry->shared)
 203                        reservation_object_add_shared_fence(bo->resv, fence);
 204                else
 205                        reservation_object_add_excl_fence(bo->resv, fence);
 206                ttm_bo_add_to_lru(bo);
 207                __ttm_bo_unreserve(bo);
 208        }
 209        spin_unlock(&glob->lru_lock);
 210        if (ticket)
 211                ww_acquire_fini(ticket);
 212}
 213EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);
 214