[PATCH 6/6] drm/vc4: use new ww_mutex_(un)lock_for_each macros

From: Christian KÃnig
Date: Fri Jun 14 2019 - 08:46:25 EST


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

Signed-off-by: Christian KÃnig <christian.koenig@xxxxxxx>
---
drivers/gpu/drm/vc4/vc4_gem.c | 56 ++++++++---------------------------
1 file changed, 13 insertions(+), 43 deletions(-)

diff --git a/drivers/gpu/drm/vc4/vc4_gem.c b/drivers/gpu/drm/vc4/vc4_gem.c
index d9311be32a4f..628b3a8bcf6a 100644
--- a/drivers/gpu/drm/vc4/vc4_gem.c
+++ b/drivers/gpu/drm/vc4/vc4_gem.c
@@ -584,53 +584,17 @@ vc4_lock_bo_reservations(struct drm_device *dev,
struct vc4_exec_info *exec,
struct ww_acquire_ctx *acquire_ctx)
{
- int contended_lock = -1;
- int i, ret;
+ struct ww_mutex *contended;
struct drm_gem_object *bo;
+ int i, ret;

ww_acquire_init(acquire_ctx, &reservation_ww_class);

-retry:
- if (contended_lock != -1) {
- bo = &exec->bo[contended_lock]->base;
- ret = ww_mutex_lock_slow_interruptible(&bo->resv->lock,
- acquire_ctx);
- if (ret) {
- ww_acquire_done(acquire_ctx);
- return ret;
- }
- }
-
- for (i = 0; i < exec->bo_count; i++) {
- if (i == contended_lock)
- continue;
-
- bo = &exec->bo[i]->base;
-
- ret = ww_mutex_lock_interruptible(&bo->resv->lock, acquire_ctx);
- if (ret) {
- int j;
-
- for (j = 0; j < i; j++) {
- bo = &exec->bo[j]->base;
- ww_mutex_unlock(&bo->resv->lock);
- }
-
- if (contended_lock != -1 && contended_lock >= i) {
- bo = &exec->bo[contended_lock]->base;
-
- ww_mutex_unlock(&bo->resv->lock);
- }
-
- if (ret == -EDEADLK) {
- contended_lock = i;
- goto retry;
- }
-
- ww_acquire_done(acquire_ctx);
- return ret;
- }
- }
+ ww_mutex_lock_for_each(for (i = 0; i < exec->bo_count; i++),
+ &exec->bo[i]->base.resv->lock, contended, ret,
+ true, acquire_ctx)
+ if (ret)
+ goto error;

ww_acquire_done(acquire_ctx);

@@ -648,6 +612,12 @@ vc4_lock_bo_reservations(struct drm_device *dev,
}

return 0;
+
+error:
+ ww_mutex_unlock_for_each(for (i = 0; i < exec->bo_count; i++),
+ &exec->bo[i]->base.resv->lock, contended);
+ ww_acquire_done(acquire_ctx);
+ return ret;
}

/* Queues a struct vc4_exec_info for execution. If no job is
--
2.17.1