/**************************************************************************
*
* 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>
DEFINE_WW_CLASS(reservation_ww_class);
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;
entry->reserved = false;
if (entry->removed) {
ttm_bo_add_to_lru(bo);
entry->removed = false;
}
__ttm_bo_unreserve(bo);
}
}
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 ww_acquire_ctx *ticket,
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);
if (ticket)
ww_acquire_fini(ticket);
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 ww_acquire_ctx *ticket,
struct list_head *list)
{
struct ttm_bo_global *glob;
struct ttm_validate_buffer *entry;
int ret;
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;
if (ticket)
ww_acquire_init(ticket, &reservation_ww_class);
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(bo, true, (ticket == NULL), true,
ticket);
if (ret == -EDEADLK) {
/* uh oh, we lost out, drop every reservation and try
* to only reserve this buffer, then start over if
* this succeeds.
*/
BUG_ON(ticket == NULL);
spin_lock(&glob->lru_lock);
ttm_eu_backoff_reservation_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
ticket);
if (unlikely(ret != 0)) {
if (ret == -EINTR)
ret = -ERESTARTSYS;
goto err_fini;
}
entry->reserved = true;
if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
ret = -EBUSY;
goto err;
}
goto retry;
} else if (ret)
goto err;
entry->reserved = true;
if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
ret = -EBUSY;
goto err;
}
}
if (ticket)
ww_acquire_done(ticket);
spin_lock(&glob->lru_lock);
ttm_eu_del_from_lru_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
return 0;
err:
spin_lock(&glob->lru_lock);
ttm_eu_backoff_reservation_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
err_fini:
if (ticket) {
ww_acquire_done(ticket);
ww_acquire_fini(ticket);
}
return ret;
}
EXPORT_SYMBOL(ttm_eu_reserve_buffers);
void ttm_eu_fence_buffer_objects(struct ww_acquire_ctx *ticket,
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_add_to_lru(bo);
__ttm_bo_unreserve(bo);
entry->reserved = false;
}
spin_unlock(&bdev->fence_lock);
spin_unlock(&glob->lru_lock);
if (ticket)
ww_acquire_fini(ticket);
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);