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From:   Rob Clark <robdclark@gmail.com>
To:     dri-devel@lists.freedesktop.org
Cc:     freedreno@lists.freedesktop.org,
        Rob Clark <robdclark@chromium.org>,
        Rob Clark <robdclark@gmail.com>, Sean Paul <sean@poorly.run>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        linux-arm-msm@vger.kernel.org (open list:DRM DRIVER FOR MSM ADRENO GPU),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v4 13/13] drm/msm/gem: Mark active before pinning
Date:   Tue, 27 Jul 2021 18:06:18 -0700
Message-Id: <20210728010632.2633470-14-robdclark@gmail.com>
In-Reply-To: <20210728010632.2633470-1-robdclark@gmail.com>
References: <20210728010632.2633470-1-robdclark@gmail.com>
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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