[PATCH 3/6] drm/gem: use new ww_mutex_(un)lock_for_each macros

From: Christian KÃnig
Date: Fri Jun 14 2019 - 08:46:32 EST


Use the provided macros instead of implementing deadlock handling on our own.

Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/drm_gem.c | 49 ++++++++++-----------------------------
1 file changed, 12 insertions(+), 37 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 50de138c89e0..6e4623d3bee2 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -1307,51 +1307,26 @@ int
drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
struct ww_acquire_ctx *acquire_ctx)
{
- int contended = -1;
+ struct ww_mutex *contended;
int i, ret;

ww_acquire_init(acquire_ctx, &reservation_ww_class);

-retry:
- if (contended != -1) {
- struct drm_gem_object *obj = objs[contended];
-
- ret = ww_mutex_lock_slow_interruptible(&obj->resv->lock,
- acquire_ctx);
- if (ret) {
- ww_acquire_done(acquire_ctx);
- return ret;
- }
- }
-
- for (i = 0; i < count; i++) {
- if (i == contended)
- continue;
-
- ret = ww_mutex_lock_interruptible(&objs[i]->resv->lock,
- acquire_ctx);
- if (ret) {
- int j;
-
- for (j = 0; j < i; j++)
- ww_mutex_unlock(&objs[j]->resv->lock);
-
- if (contended != -1 && contended >= i)
- ww_mutex_unlock(&objs[contended]->resv->lock);
-
- if (ret == -EDEADLK) {
- contended = i;
- goto retry;
- }
-
- ww_acquire_done(acquire_ctx);
- return ret;
- }
- }
+ ww_mutex_lock_for_each(for (i = 0; i < count; i++),
+ &objs[i]->resv->lock, contended, ret, true,
+ acquire_ctx)
+ if (ret)
+ goto error;

ww_acquire_done(acquire_ctx);

return 0;
+
+error:
+ ww_mutex_unlock_for_each(for (i = 0; i < count; i++),
+ &objs[i]->resv->lock, contended);
+ ww_acquire_done(acquire_ctx);
+ return ret;
}
EXPORT_SYMBOL(drm_gem_lock_reservations);

--
2.17.1