[PATCH v4 13/13] drm/msm/gem: Mark active before pinning

Rob Clark
2021-07-28T01:03:26Z

From: Rob Clark <robdclark@chromium.org>

Mark all the bos in the submit as active, before pinning, to prevent
evicting a buffer in the same submit to make room for a buffer earlier
in the table.

Signed-off-by: Rob Clark <robdclark@chromium.org>
---
drivers/gpu/drm/msm/msm_gem.c | 2 --
drivers/gpu/drm/msm/msm_gem_submit.c | 28 ++++++++++++++++++++--------
2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index af199ef53d2f..15b1804fa64e 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -131,7 +131,6 @@ static struct page **get_pages(struct drm_gem_object *obj)
if (msm_obj->flags & (MSM_BO_WC|MSM_BO_UNCACHED))
sync_for_device(msm_obj);

- GEM_WARN_ON(msm_obj->active_count);
update_inactive(msm_obj);
}

@@ -815,7 +814,6 @@ void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
GEM_WARN_ON(!msm_gem_is_locked(obj));
GEM_WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
GEM_WARN_ON(msm_obj->dontneed);
- GEM_WARN_ON(!msm_obj->sgt);

if (msm_obj->active_count++ == 0) {
mutex_lock(&priv->mm_lock);
diff --git a/drivers/gpu/drm/msm/msm_gem_submit.c b/drivers/gpu/drm/msm/msm_gem_submit.c
index c2ecec5b11c4..fc25a85eb1ca 100644
--- a/drivers/gpu/drm/msm/msm_gem_submit.c
+++ b/drivers/gpu/drm/msm/msm_gem_submit.c
@@ -24,7 +24,8 @@
/* make sure these don't conflict w/ MSM_SUBMIT_BO_x */
#define BO_VALID 0x8000 /* is current addr in cmdstream correct/valid? */
#define BO_LOCKED 0x4000 /* obj lock is held */
-#define BO_PINNED 0x2000 /* obj is pinned and on active list */
+#define BO_ACTIVE 0x2000 /* active refcnt is held */
+#define BO_PINNED 0x1000 /* obj is pinned and on active list */

static struct msm_gem_submit *submit_create(struct drm_device *dev,
struct msm_gpu *gpu,
@@ -239,10 +240,11 @@ static void submit_cleanup_bo(struct msm_gem_submit *submit, int i,
struct drm_gem_object *obj = &submit->bos[i].obj->base;
unsigned flags = submit->bos[i].flags & cleanup_flags;

- if (flags & BO_PINNED) {
+ if (flags & BO_PINNED)
msm_gem_unpin_iova_locked(obj, submit->aspace);
+
+ if (flags & BO_ACTIVE)
msm_gem_active_put(obj);
- }

if (flags & BO_LOCKED)
dma_resv_unlock(obj->resv);
@@ -252,7 +254,7 @@ static void submit_cleanup_bo(struct msm_gem_submit *submit, int i,

static void submit_unlock_unpin_bo(struct msm_gem_submit *submit, int i)
{
- submit_cleanup_bo(submit, i, BO_PINNED | BO_LOCKED);
+ submit_cleanup_bo(submit, i, BO_PINNED | BO_ACTIVE | BO_LOCKED);

if (!(submit->bos[i].flags & BO_VALID))
submit->bos[i].iova = 0;
@@ -356,6 +358,18 @@ static int submit_pin_objects(struct msm_gem_submit *submit)

submit->valid = true;

+ /*
+ * Increment active_count first, so if under memory pressure, we
+ * don't inadvertently evict a bo needed by the submit in order
+ * to pin an earlier bo in the same submit.
+ */
+ for (i = 0; i < submit->nr_bos; i++) {
+ struct drm_gem_object *obj = &submit->bos[i].obj->base;
+
+ msm_gem_active_get(obj, submit->gpu);
+ submit->bos[i].flags |= BO_ACTIVE;
+ }
+
for (i = 0; i < submit->nr_bos; i++) {
struct drm_gem_object *obj = &submit->bos[i].obj->base;
uint64_t iova;
@@ -367,8 +381,6 @@ static int submit_pin_objects(struct msm_gem_submit *submit)
if (ret)
break;

- msm_gem_active_get(obj, submit->gpu);
-
submit->bos[i].flags |= BO_PINNED;

if (iova == submit->bos[i].iova) {
@@ -502,7 +514,7 @@ static void submit_cleanup(struct msm_gem_submit *submit, bool error)
unsigned i;

if (error)
- cleanup_flags |= BO_PINNED;
+ cleanup_flags |= BO_PINNED | BO_ACTIVE;

for (i = 0; i < submit->nr_bos; i++) {
struct msm_gem_object *msm_obj = submit->bos[i].obj;
@@ -520,7 +532,7 @@ void msm_submit_retire(struct msm_gem_submit *submit)
struct drm_gem_object *obj = &submit->bos[i].obj->base;

msm_gem_lock(obj);
- submit_cleanup_bo(submit, i, BO_PINNED);
+ submit_cleanup_bo(submit, i, BO_PINNED | BO_ACTIVE);
msm_gem_unlock(obj);
drm_gem_object_put(obj);
}
--
2.31.1