/**************************************************************************
*
* Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
#include <drm/ttm/ttm_execbuf_util.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
#include <linux/wait.h>
#include <linux/sched.h>
#include <linux/module.h>
static void ttm_eu_backoff_reservation_locked(struct list_head *list)
{
struct ttm_validate_buffer *entry;
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
if (!entry->reserved)
continue;
if (entry->removed) {
ttm_bo_add_to_lru(bo);
entry->removed = false;
}
entry->reserved = false;
atomic_set(&bo->reserved, 0);
wake_up_all(&bo->event_queue);
}
}
static void ttm_eu_del_from_lru_locked(struct list_head *list)
{
struct ttm_validate_buffer *entry;
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
if (!entry->reserved)
continue;
if (!entry->removed) {
entry->put_count = ttm_bo_del_from_lru(bo);
entry->removed = true;
}
}
}
static void ttm_eu_list_ref_sub(struct list_head *list)
{
struct ttm_validate_buffer *entry;
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
if (entry->put_count) {
ttm_bo_list_ref_sub(bo, entry->put_count, true);
entry->put_count = 0;
}
}
}
void ttm_eu_backoff_reservation(struct list_head *list)
{
struct ttm_validate_buffer *entry;
struct ttm_bo_global *glob;
if (list_empty(list))
return;
entry = list_first_entry(list, struct ttm_validate_buffer, head);
glob = entry->bo->glob;
spin_lock(&glob->lru_lock);
ttm_eu_backoff_reservation_locked(list);
spin_unlock(&glob->lru_lock);
}
EXPORT_SYMBOL(ttm_eu_backoff_reservation);
/*
* Reserve buffers for validation.
*
* If a buffer in the list is marked for CPU access, we back off and
* wait for that buffer to become free for GPU access.
*
* If a buffer is reserved for another validation, the validator with
* the highest validation sequence backs off and waits for that buffer
* to become unreserved. This prevents deadlocks when validating multiple
* buffers in different orders.
*/
int ttm_eu_reserve_buffers(struct list_head *list)
{
struct ttm_bo_global *glob;
struct ttm_validate_buffer *entry;
int ret;
uint32_t val_seq;
if (list_empty(list))
return 0;
list_for_each_entry(entry, list, head) {
entry->reserved = false;
entry->put_count = 0;
entry->removed = false;
}
entry = list_first_entry(list, struct ttm_validate_buffer, head);
glob = entry->bo->glob;
spin_lock(&glob->lru_lock);
val_seq = entry->bo->bdev->val_seq++;
retry:
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
/* already slowpath reserved? */
if (entry->reserved)
continue;
ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
switch (ret) {
case 0:
break;
case -EBUSY:
ttm_eu_del_from_lru_locked(list);
spin_unlock(&glob->lru_lock);
ret = ttm_bo_reserve_nolru(bo, true, false,
true, val_seq);
spin_lock(&glob->lru_lock);
if (!ret)
break;
if (unlikely(ret != -EAGAIN))
goto err;
/* fallthrough */
case -EAGAIN:
ttm_eu_backoff_reservation_locked(list);
/*
* temporarily increase sequence number every retry,
* to prevent us from seeing our old reservation
* sequence when someone else reserved the buffer,
* but hasn't updated the seq_valid/seqno members yet.
*/
val_seq = entry->bo->bdev->val_seq++;
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
ret = ttm_bo_reserve_slowpath_nolru(bo, true, val_seq);
if (unlikely(ret != 0))
return ret;
spin_lock(&glob->lru_lock);
entry->reserved = true;
if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
ret = -EBUSY;
goto err;
}
goto retry;
default:
goto err;
}
entry->reserved = true;
if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
ret = -EBUSY;
goto err;
}
}
ttm_eu_del_from_lru_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
return 0;
err:
ttm_eu_backoff_reservation_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
return ret;
}
EXPORT_SYMBOL(ttm_eu_reserve_buffers);
void ttm_eu_fence_buffer_objects(struct list_head *list, void *sync_obj)
{
struct ttm_validate_buffer *entry;
struct ttm_buffer_object *bo;
struct ttm_bo_global *glob;
struct ttm_bo_device *bdev;
struct ttm_bo_driver *driver;
if (list_empty(list))
return;
bo = list_first_entry(list, struct ttm_validate_buffer, head)->bo;
bdev = bo->bdev;
driver = bdev->driver;
glob = bo->glob;
spin_lock(&glob->lru_lock);
spin_lock(&bdev->fence_lock);
list_for_each_entry(entry, list, head) {
bo = entry->bo;
entry->old_sync_obj = bo->sync_obj;
bo->sync_obj = driver->sync_obj_ref(sync_obj);
ttm_bo_unreserve_locked(bo);
entry->reserved = false;
}
spin_unlock(&bdev->fence_lock);
spin_unlock(&glob->lru_lock);
list_for_each_entry(entry, list, head) {
if (entry->old_sync_obj)
driver->sync_obj_unref(&entry->old_sync_obj);
}
}
EXPORT_SYMBOL(ttm_eu_fence_buffer_objects);