drm/ttm: cleanup ttm_eu_reserve_buffers handling

With the lru lock no longer required for protecting reservations we
can just do a ttm_bo_reserve_nolru on -EBUSY, and handle all errors
in a single path.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
This commit is contained in:
Maarten Lankhorst 2013-01-15 14:56:48 +01:00
parent 63d0a41955
commit 7a1863084c
1 changed files with 21 additions and 32 deletions

View File

@ -82,22 +82,6 @@ static void ttm_eu_list_ref_sub(struct list_head *list)
}
}
static int ttm_eu_wait_unreserved_locked(struct list_head *list,
struct ttm_buffer_object *bo)
{
struct ttm_bo_global *glob = bo->glob;
int ret;
ttm_eu_del_from_lru_locked(list);
spin_unlock(&glob->lru_lock);
ret = ttm_bo_wait_unreserved(bo, true);
spin_lock(&glob->lru_lock);
if (unlikely(ret != 0))
ttm_eu_backoff_reservation_locked(list);
return ret;
}
void ttm_eu_backoff_reservation(struct list_head *list)
{
struct ttm_validate_buffer *entry;
@ -152,19 +136,23 @@ retry:
list_for_each_entry(entry, list, head) {
struct ttm_buffer_object *bo = entry->bo;
retry_this_bo:
ret = ttm_bo_reserve_nolru(bo, true, true, true, val_seq);
switch (ret) {
case 0:
break;
case -EBUSY:
ret = ttm_eu_wait_unreserved_locked(list, bo);
if (unlikely(ret != 0)) {
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
return ret;
}
goto retry_this_bo;
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);
spin_unlock(&glob->lru_lock);
@ -174,18 +162,13 @@ retry_this_bo:
return ret;
goto retry;
default:
ttm_eu_backoff_reservation_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
return ret;
goto err;
}
entry->reserved = true;
if (unlikely(atomic_read(&bo->cpu_writers) > 0)) {
ttm_eu_backoff_reservation_locked(list);
spin_unlock(&glob->lru_lock);
ttm_eu_list_ref_sub(list);
return -EBUSY;
ret = -EBUSY;
goto err;
}
}
@ -194,6 +177,12 @@ retry_this_bo:
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);