[RFC PATCH v1 13/16] drm/nouveau: use rcu in nouveau_gem_ioctl_cpu_prep

Maarten Lankhorst
2014-05-14T14:58:40Z

With the conversion to the reservation api this should be safe.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
---
drivers/gpu/drm/nouveau/nouveau_gem.c | 28 ++++++++++++----------------
1 file changed, 12 insertions(+), 16 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 4beaa897adad..c2ca894f6507 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -863,33 +863,29 @@ nouveau_gem_ioctl_cpu_prep(struct drm_device *dev, void *data,
struct drm_gem_object *gem;
struct nouveau_bo *nvbo;
bool no_wait = !!(req->flags & NOUVEAU_GEM_CPU_PREP_NOWAIT);
+ bool write = !!(req->flags & NOUVEAU_GEM_CPU_PREP_WRITE);
int ret;
- struct nouveau_fence *fence = NULL;

gem = drm_gem_object_lookup(dev, file_priv, req->handle);
if (!gem)
return -ENOENT;
nvbo = nouveau_gem_object(gem);

- ret = ttm_bo_reserve(&nvbo->bo, true, false, false, 0);
- if (!ret) {
- ret = ttm_bo_wait(&nvbo->bo, true, true, true);
- if (!no_wait && ret) {
- struct fence *excl;
-
- excl = reservation_object_get_excl(nvbo->bo.resv);
- fence = nouveau_fence_ref((struct nouveau_fence *)excl);
- }
+ if (no_wait)
+ ret = reservation_object_test_signaled_rcu(nvbo->bo.resv, write) ? 0 : -EBUSY;
+ else {
+ long lret;

- ttm_bo_unreserve(&nvbo->bo);
+ lret = reservation_object_wait_timeout_rcu(nvbo->bo.resv, write, true, 30 * HZ);
+ if (!lret)
+ ret = -EBUSY;
+ else if (lret > 0)
+ ret = 0;
+ else
+ ret = lret;
}
drm_gem_object_unreference_unlocked(gem);

- if (fence) {
- ret = nouveau_fence_wait(fence, true, no_wait);
- nouveau_fence_unref(&fence);
- }
-
return ret;
}