5.10-stable review patch. If anyone has any objections, please let me know.
------------------
From: Rob Clark <robdclark@xxxxxxxxxxxx>
[ Upstream commit d984457b31c4c53d2af374d5e78b3eb64debd483 ]
Rather than relying on the big dev->struct_mutex hammer, introduce a
more specific lock for protecting the bo lists.
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Reviewed-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx>
Reviewed-by: Kristian H. Kristensen <hoegsberg@xxxxxxxxxx>
Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Stable-dep-of: a30f9f65b5ac ("drm/msm/a5xx: workaround early ring-buffer emptiness check")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/gpu/drm/msm/msm_debugfs.c | 7 +++++++
drivers/gpu/drm/msm/msm_drv.c | 7 +++++++
drivers/gpu/drm/msm/msm_drv.h | 13 +++++++++++-
drivers/gpu/drm/msm/msm_gem.c | 28 +++++++++++++++-----------
drivers/gpu/drm/msm/msm_gem_shrinker.c | 12 +++++++++++
drivers/gpu/drm/msm/msm_gpu.h | 5 ++++-
6 files changed, 58 insertions(+), 14 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_debugfs.c b/drivers/gpu/drm/msm/msm_debugfs.c
index 7a7ccad65c922..97cbb850ad6d4 100644
--- a/drivers/gpu/drm/msm/msm_debugfs.c
+++ b/drivers/gpu/drm/msm/msm_debugfs.c
@@ -113,6 +113,11 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
{
struct msm_drm_private *priv = dev->dev_private;
struct msm_gpu *gpu = priv->gpu;
+ int ret;
+
+ ret = mutex_lock_interruptible(&priv->mm_lock);
+ if (ret)
+ return ret;
if (gpu) {
seq_printf(m, "Active Objects (%s):\n", gpu->name);
@@ -122,6 +127,8 @@ static int msm_gem_show(struct drm_device *dev, struct seq_file *m)
seq_printf(m, "Inactive Objects:\n");
msm_gem_describe_objects(&priv->inactive_list, m);
+ mutex_unlock(&priv->mm_lock);
+
return 0;
}
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index 087efcb1f34cf..130c721fcd4e6 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -7,6 +7,7 @@
#include <linux/dma-mapping.h>
#include <linux/kthread.h>
+#include <linux/sched/mm.h>
#include <linux/uaccess.h>
#include <uapi/linux/sched/types.h>
@@ -442,6 +443,12 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
init_llist_head(&priv->free_list);
INIT_LIST_HEAD(&priv->inactive_list);
+ mutex_init(&priv->mm_lock);
+
+ /* Teach lockdep about lock ordering wrt. shrinker: */
+ fs_reclaim_acquire(GFP_KERNEL);
+ might_lock(&priv->mm_lock);
+ fs_reclaim_release(GFP_KERNEL);
drm_mode_config_init(ddev);
diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
index 1fe809add8f62..3a49e8eb338c0 100644
--- a/drivers/gpu/drm/msm/msm_drv.h
+++ b/drivers/gpu/drm/msm/msm_drv.h
@@ -175,8 +175,19 @@ struct msm_drm_private {
struct msm_rd_state *hangrd; /* debugfs to dump hanging submits */
struct msm_perf_state *perf;
- /* list of GEM objects: */
+ /*
+ * List of inactive GEM objects. Every bo is either in the inactive_list
+ * or gpu->active_list (for the gpu it is active on[1])
+ *
+ * These lists are protected by mm_lock. If struct_mutex is involved, it
+ * should be aquired prior to mm_lock. One should *not* hold mm_lock in
+ * get_pages()/vmap()/etc paths, as they can trigger the shrinker.
+ *
+ * [1] if someone ever added support for the old 2d cores, there could be
+ * more than one gpu object
+ */
struct list_head inactive_list;
+ struct mutex mm_lock;
/* worker for delayed free of objects: */
struct work_struct free_work;
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 9c05bf6c45510..d0201909ee7ae 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -745,13 +745,17 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
void msm_gem_active_get(struct drm_gem_object *obj, struct msm_gpu *gpu)
{
struct msm_gem_object *msm_obj = to_msm_bo(obj);
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ struct msm_drm_private *priv = obj->dev->dev_private;
+
+ might_sleep();
WARN_ON(msm_obj->madv != MSM_MADV_WILLNEED);
if (!atomic_fetch_inc(&msm_obj->active_count)) {
+ mutex_lock(&priv->mm_lock);
msm_obj->gpu = gpu;
list_del_init(&msm_obj->mm_list);
list_add_tail(&msm_obj->mm_list, &gpu->active_list);
+ mutex_unlock(&priv->mm_lock);
}
}
@@ -760,12 +764,14 @@ void msm_gem_active_put(struct drm_gem_object *obj)
struct msm_gem_object *msm_obj = to_msm_bo(obj);
struct msm_drm_private *priv = obj->dev->dev_private;
- WARN_ON(!mutex_is_locked(&obj->dev->struct_mutex));
+ might_sleep();
if (!atomic_dec_return(&msm_obj->active_count)) {
+ mutex_lock(&priv->mm_lock);
msm_obj->gpu = NULL;
list_del_init(&msm_obj->mm_list);
list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+ mutex_unlock(&priv->mm_lock);
}
}
@@ -921,13 +927,16 @@ static void free_object(struct msm_gem_object *msm_obj)
{
struct drm_gem_object *obj = &msm_obj->base;
struct drm_device *dev = obj->dev;
+ struct msm_drm_private *priv = dev->dev_private;
WARN_ON(!mutex_is_locked(&dev->struct_mutex));
/* object should not be on active list: */
WARN_ON(is_active(msm_obj));
+ mutex_lock(&priv->mm_lock);
list_del(&msm_obj->mm_list);
+ mutex_unlock(&priv->mm_lock);
mutex_lock(&msm_obj->lock);
@@ -1103,14 +1112,9 @@ static struct drm_gem_object *_msm_gem_new(struct drm_device *dev,
mapping_set_gfp_mask(obj->filp->f_mapping, GFP_HIGHUSER);
}
- if (struct_mutex_locked) {
- WARN_ON(!mutex_is_locked(&dev->struct_mutex));
- list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
- } else {
- mutex_lock(&dev->struct_mutex);
- list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
- mutex_unlock(&dev->struct_mutex);
- }
+ mutex_lock(&priv->mm_lock);
+ list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
+ mutex_unlock(&priv->mm_lock);
return obj;
@@ -1174,9 +1178,9 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
mutex_unlock(&msm_obj->lock);
- mutex_lock(&dev->struct_mutex);
+ mutex_lock(&priv->mm_lock);
list_add_tail(&msm_obj->mm_list, &priv->inactive_list);
- mutex_unlock(&dev->struct_mutex);
+ mutex_unlock(&priv->mm_lock);
return obj;
diff --git a/drivers/gpu/drm/msm/msm_gem_shrinker.c b/drivers/gpu/drm/msm/msm_gem_shrinker.c
index 482576d7a39a5..c41b84a3a4842 100644
--- a/drivers/gpu/drm/msm/msm_gem_shrinker.c
+++ b/drivers/gpu/drm/msm/msm_gem_shrinker.c
@@ -51,11 +51,15 @@ msm_gem_shrinker_count(struct shrinker *shrinker, struct shrink_control *sc)
if (!msm_gem_shrinker_lock(dev, &unlock))
return 0;
+ mutex_lock(&priv->mm_lock);
+
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (is_purgeable(msm_obj))
count += msm_obj->base.size >> PAGE_SHIFT;
}
+ mutex_unlock(&priv->mm_lock);
+
if (unlock)
mutex_unlock(&dev->struct_mutex);
@@ -75,6 +79,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
if (!msm_gem_shrinker_lock(dev, &unlock))
return SHRINK_STOP;
+ mutex_lock(&priv->mm_lock);
+
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (freed >= sc->nr_to_scan)
break;
@@ -84,6 +90,8 @@ msm_gem_shrinker_scan(struct shrinker *shrinker, struct shrink_control *sc)
}
}
+ mutex_unlock(&priv->mm_lock);
+
if (unlock)
mutex_unlock(&dev->struct_mutex);
@@ -106,6 +114,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
if (!msm_gem_shrinker_lock(dev, &unlock))
return NOTIFY_DONE;
+ mutex_lock(&priv->mm_lock);
+
list_for_each_entry(msm_obj, &priv->inactive_list, mm_list) {
if (is_vunmapable(msm_obj)) {
msm_gem_vunmap(&msm_obj->base, OBJ_LOCK_SHRINKER);
@@ -118,6 +128,8 @@ msm_gem_shrinker_vmap(struct notifier_block *nb, unsigned long event, void *ptr)
}
}
+ mutex_unlock(&priv->mm_lock);
+
if (unlock)
mutex_unlock(&dev->struct_mutex);
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index 6c9e1fdc1a762..1806e87600c0e 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -94,7 +94,10 @@ struct msm_gpu {
struct msm_ringbuffer *rb[MSM_GPU_MAX_RINGS];
int nr_rings;
- /* list of GEM active objects: */
+ /*
+ * List of GEM active objects on this gpu. Protected by
+ * msm_drm_private::mm_lock
+ */
struct list_head active_list;
/* does gpu need hw_init? */
--
2.43.0
