diff mbox series

[v13,01/10] drm/shmem-helper: Switch to reservation lock

Message ID 20230314022659.1816246-2-dmitry.osipenko@collabora.com
State New
Headers
Series Add generic memory shrinker to VirtIO-GPU and Panfrost DRM drivers |

Commit Message

Dmitry Osipenko March 14, 2023, 2:26 a.m. UTC 
  Replace all drm-shmem locks with a GEM reservation lock. This makes locks
consistent with dma-buf locking convention where importers are responsible
for holding reservation lock for all operations performed over dma-bufs,
preventing deadlock between dma-buf importers and exporters.

Suggested-by: Daniel Vetter <daniel@ffwll.ch>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
---
 drivers/gpu/drm/drm_gem_shmem_helper.c        | 217 ++++++++----------
 drivers/gpu/drm/lima/lima_gem.c               |   8 +-
 drivers/gpu/drm/panfrost/panfrost_drv.c       |   7 +-
 .../gpu/drm/panfrost/panfrost_gem_shrinker.c  |   6 +-
 drivers/gpu/drm/panfrost/panfrost_mmu.c       |  19 +-
 include/drm/drm_gem_shmem_helper.h            |  14 +-
 6 files changed, 120 insertions(+), 151 deletions(-)

Comments

Dmitry Osipenko March 15, 2023, 1:46 p.m. UTC | #1 
On 3/14/23 05:26, Dmitry Osipenko wrote:
> @@ -633,7 +605,10 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
>  		return ret;
>  	}
>  
> +	dma_resv_lock(shmem->base.resv, NULL);
>  	ret = drm_gem_shmem_get_pages(shmem);
> +	dma_resv_unlock(shmem->base.resv);

Intel CI reported locking problem [1] here. It actually was also
reported for v12, but I missed that report because of the other noisy
reports.

[1]
https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_114671v2/shard-snb5/igt@prime_vgem@sync@rcs0.html

The test does the following:

1. creates vgem
2. export it do dmabuf
3. mmaps dmabuf

There is an obvious deadlock there. The DRM code assumes that mmap() is
unlocked, while for dma-buf it's locked. I'll see how to fix it for v14.
Dmitry Osipenko March 25, 2023, 2:58 p.m. UTC | #2 
On 3/15/23 16:46, Dmitry Osipenko wrote:
> On 3/14/23 05:26, Dmitry Osipenko wrote:
>> @@ -633,7 +605,10 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
>>  		return ret;
>>  	}
>>  
>> +	dma_resv_lock(shmem->base.resv, NULL);
>>  	ret = drm_gem_shmem_get_pages(shmem);
>> +	dma_resv_unlock(shmem->base.resv);
> 
> Intel CI reported locking problem [1] here. It actually was also
> reported for v12, but I missed that report because of the other noisy
> reports.
> 
> [1]
> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_114671v2/shard-snb5/igt@prime_vgem@sync@rcs0.html
> 
> The test does the following:
> 
> 1. creates vgem
> 2. export it do dmabuf
> 3. mmaps dmabuf
> 
> There is an obvious deadlock there. The DRM code assumes that mmap() is
> unlocked, while for dma-buf it's locked. I'll see how to fix it for v14.
> 

Christian, there is a deadlock problem in drm_gem_shmem_mmap() once we
move drm-shmem to use resv lock. The current dma-buf locking policy
claims that importer holds the lock for mmap(), but DRM code assumes
that obj->mmap() handles the locking itself and then the same
obj->mmap() code path is used by both dma-buf DRM and a usual DRM object
paths. Hence importer -> dma_buf_mmap_internal()[takes the lock] ->
exporter -> drm_gem_shmem_mmap()[takes the lock] deadlocks.

I was looking at how to fix it and to me the best option is to change
the dma-buf locking policy, making exporter responsible for handling the
resv lock. Changing DRM code mmap lockings might be possible too [moving
locking to drm_gem_mmap_obj()], but will be very messy and doesn't feel
intuitive.

Want to get yours thoughts on this before sending out the dma-buf mmap()
policy-change patch. Does the new mmap() locking policy sound good to
you? Thanks!
Christian König March 26, 2023, 9:19 a.m. UTC | #3 
Am 25.03.23 um 15:58 schrieb Dmitry Osipenko:
> On 3/15/23 16:46, Dmitry Osipenko wrote:
>> On 3/14/23 05:26, Dmitry Osipenko wrote:
>>> @@ -633,7 +605,10 @@ int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
>>>   		return ret;
>>>   	}
>>>   
>>> +	dma_resv_lock(shmem->base.resv, NULL);
>>>   	ret = drm_gem_shmem_get_pages(shmem);
>>> +	dma_resv_unlock(shmem->base.resv);
>> Intel CI reported locking problem [1] here. It actually was also
>> reported for v12, but I missed that report because of the other noisy
>> reports.
>>
>> [1]
>> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_114671v2/shard-snb5/igt@prime_vgem@sync@rcs0.html
>>
>> The test does the following:
>>
>> 1. creates vgem
>> 2. export it do dmabuf
>> 3. mmaps dmabuf
>>
>> There is an obvious deadlock there. The DRM code assumes that mmap() is
>> unlocked, while for dma-buf it's locked. I'll see how to fix it for v14.
>>
> Christian, there is a deadlock problem in drm_gem_shmem_mmap() once we
> move drm-shmem to use resv lock. The current dma-buf locking policy
> claims that importer holds the lock for mmap(), but DRM code assumes
> that obj->mmap() handles the locking itself and then the same
> obj->mmap() code path is used by both dma-buf DRM and a usual DRM object
> paths. Hence importer -> dma_buf_mmap_internal()[takes the lock] ->
> exporter -> drm_gem_shmem_mmap()[takes the lock] deadlocks.
>
> I was looking at how to fix it and to me the best option is to change
> the dma-buf locking policy, making exporter responsible for handling the
> resv lock. Changing DRM code mmap lockings might be possible too [moving
> locking to drm_gem_mmap_obj()], but will be very messy and doesn't feel
> intuitive.
>
> Want to get yours thoughts on this before sending out the dma-buf mmap()
> policy-change patch. Does the new mmap() locking policy sound good to
> you? Thanks!


IIRC we tried that before and ran into problems.

dma_buf_mmap() needs to swap the backing file of the VMA and for this 
calls fput() on the old file.

This fput() in turn could (in theory) grab the resv lock as well and 
there isn't anything we could do about that.

Just information from the back of my memory, probably best if you double 
check that.

Regards,
Christian.
Dmitry Osipenko April 2, 2023, 2:54 p.m. UTC | #4 
On 3/26/23 12:19, Christian König wrote:
> Am 25.03.23 um 15:58 schrieb Dmitry Osipenko:
>> On 3/15/23 16:46, Dmitry Osipenko wrote:
>>> On 3/14/23 05:26, Dmitry Osipenko wrote:
>>>> @@ -633,7 +605,10 @@ int drm_gem_shmem_mmap(struct
>>>> drm_gem_shmem_object *shmem, struct vm_area_struct
>>>>           return ret;
>>>>       }
>>>>   +    dma_resv_lock(shmem->base.resv, NULL);
>>>>       ret = drm_gem_shmem_get_pages(shmem);
>>>> +    dma_resv_unlock(shmem->base.resv);
>>> Intel CI reported locking problem [1] here. It actually was also
>>> reported for v12, but I missed that report because of the other noisy
>>> reports.
>>>
>>> [1]
>>> https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_114671v2/shard-snb5/igt@prime_vgem@sync@rcs0.html
>>>
>>> The test does the following:
>>>
>>> 1. creates vgem
>>> 2. export it do dmabuf
>>> 3. mmaps dmabuf
>>>
>>> There is an obvious deadlock there. The DRM code assumes that mmap() is
>>> unlocked, while for dma-buf it's locked. I'll see how to fix it for v14.
>>>
>> Christian, there is a deadlock problem in drm_gem_shmem_mmap() once we
>> move drm-shmem to use resv lock. The current dma-buf locking policy
>> claims that importer holds the lock for mmap(), but DRM code assumes
>> that obj->mmap() handles the locking itself and then the same
>> obj->mmap() code path is used by both dma-buf DRM and a usual DRM object
>> paths. Hence importer -> dma_buf_mmap_internal()[takes the lock] ->
>> exporter -> drm_gem_shmem_mmap()[takes the lock] deadlocks.
>>
>> I was looking at how to fix it and to me the best option is to change
>> the dma-buf locking policy, making exporter responsible for handling the
>> resv lock. Changing DRM code mmap lockings might be possible too [moving
>> locking to drm_gem_mmap_obj()], but will be very messy and doesn't feel
>> intuitive.
>>
>> Want to get yours thoughts on this before sending out the dma-buf mmap()
>> policy-change patch. Does the new mmap() locking policy sound good to
>> you? Thanks!
> 
> 
> IIRC we tried that before and ran into problems.
> 
> dma_buf_mmap() needs to swap the backing file of the VMA and for this
> calls fput() on the old file.
> 
> This fput() in turn could (in theory) grab the resv lock as well and
> there isn't anything we could do about that.
> 
> Just information from the back of my memory, probably best if you double
> check that.

Thanks, Christian! The fput() code path will be unlocked with updated
locking policy, like it was before. The new locking policy looks goods
on my side, don't see anything that needs locking protection from the
importer side for mmap().

I'll send the patches, letting intel-ci test them. Will be also easier
to discuss it there with the code.
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4ea6507a77e5..8fc2a3277486 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -88,8 +88,6 @@  __drm_gem_shmem_create(struct drm_device *dev, size_t size, bool private)
 	if (ret)
 		goto err_release;
 
-	mutex_init(&shmem->pages_lock);
-	mutex_init(&shmem->vmap_lock);
 	INIT_LIST_HEAD(&shmem->madv_list);
 
 	if (!private) {
@@ -141,11 +139,13 @@  void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
-	drm_WARN_ON(obj->dev, shmem->vmap_use_count);
-
 	if (obj->import_attach) {
 		drm_prime_gem_destroy(obj, shmem->sgt);
 	} else {
+		dma_resv_lock(shmem->base.resv, NULL);
+
+		drm_WARN_ON(obj->dev, shmem->vmap_use_count);
+
 		if (shmem->sgt) {
 			dma_unmap_sgtable(obj->dev->dev, shmem->sgt,
 					  DMA_BIDIRECTIONAL, 0);
@@ -154,18 +154,18 @@  void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem)
 		}
 		if (shmem->pages)
 			drm_gem_shmem_put_pages(shmem);
-	}
 
-	drm_WARN_ON(obj->dev, shmem->pages_use_count);
+		drm_WARN_ON(obj->dev, shmem->pages_use_count);
+
+		dma_resv_unlock(shmem->base.resv);
+	}
 
 	drm_gem_object_release(obj);
-	mutex_destroy(&shmem->pages_lock);
-	mutex_destroy(&shmem->vmap_lock);
 	kfree(shmem);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_free);
 
-static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
+static int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	struct page **pages;
@@ -197,35 +197,16 @@  static int drm_gem_shmem_get_pages_locked(struct drm_gem_shmem_object *shmem)
 }
 
 /*
- * drm_gem_shmem_get_pages - Allocate backing pages for a shmem GEM object
+ * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object
  * @shmem: shmem GEM object
  *
- * This function makes sure that backing pages exists for the shmem GEM object
- * and increases the use count.
- *
- * Returns:
- * 0 on success or a negative error code on failure.
+ * This function decreases the use count and puts the backing pages when use drops to zero.
  */
-int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem)
+void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
-	int ret;
 
-	drm_WARN_ON(obj->dev, obj->import_attach);
-
-	ret = mutex_lock_interruptible(&shmem->pages_lock);
-	if (ret)
-		return ret;
-	ret = drm_gem_shmem_get_pages_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(drm_gem_shmem_get_pages);
-
-static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
-{
-	struct drm_gem_object *obj = &shmem->base;
+	dma_resv_assert_held(shmem->base.resv);
 
 	if (drm_WARN_ON_ONCE(obj->dev, !shmem->pages_use_count))
 		return;
@@ -243,20 +224,32 @@  static void drm_gem_shmem_put_pages_locked(struct drm_gem_shmem_object *shmem)
 			  shmem->pages_mark_accessed_on_put);
 	shmem->pages = NULL;
 }
+EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 
-/*
- * drm_gem_shmem_put_pages - Decrease use count on the backing pages for a shmem GEM object
- * @shmem: shmem GEM object
- *
- * This function decreases the use count and puts the backing pages when use drops to zero.
- */
-void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem)
+static int drm_gem_shmem_pin_locked(struct drm_gem_shmem_object *shmem)
 {
-	mutex_lock(&shmem->pages_lock);
-	drm_gem_shmem_put_pages_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	struct drm_gem_object *obj = &shmem->base;
+	int ret;
+
+	dma_resv_assert_held(shmem->base.resv);
+
+	drm_WARN_ON(obj->dev, obj->import_attach);
+
+	ret = drm_gem_shmem_get_pages(shmem);
+
+	return ret;
+}
+
+static void drm_gem_shmem_unpin_locked(struct drm_gem_shmem_object *shmem)
+{
+	struct drm_gem_object *obj = &shmem->base;
+
+	dma_resv_assert_held(shmem->base.resv);
+
+	drm_WARN_ON(obj->dev, obj->import_attach);
+
+	drm_gem_shmem_put_pages(shmem);
 }
-EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 
 /**
  * drm_gem_shmem_pin - Pin backing pages for a shmem GEM object
@@ -271,10 +264,15 @@  EXPORT_SYMBOL(drm_gem_shmem_put_pages);
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
+	int ret;
 
-	drm_WARN_ON(obj->dev, obj->import_attach);
+	ret = dma_resv_lock_interruptible(obj->resv, NULL);
+	if (ret)
+		return ret;
+	ret = drm_gem_shmem_pin_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
 
-	return drm_gem_shmem_get_pages(shmem);
+	return ret;
 }
 EXPORT_SYMBOL(drm_gem_shmem_pin);
 
@@ -289,14 +287,29 @@  void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
-	drm_WARN_ON(obj->dev, obj->import_attach);
-
-	drm_gem_shmem_put_pages(shmem);
+	dma_resv_lock(obj->resv, NULL);
+	drm_gem_shmem_unpin_locked(shmem);
+	dma_resv_unlock(shmem->base.resv);
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
 
-static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
-				     struct iosys_map *map)
+/*
+ * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
+ * @shmem: shmem GEM object
+ * @map: Returns the kernel virtual address of the SHMEM GEM object's backing
+ *       store.
+ *
+ * This function makes sure that a contiguous kernel virtual address mapping
+ * exists for the buffer backing the shmem GEM object. It hides the differences
+ * between dma-buf imported and natively allocated objects.
+ *
+ * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap().
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
+		       struct iosys_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	int ret = 0;
@@ -312,6 +325,8 @@  static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
+		dma_resv_assert_held(shmem->base.resv);
+
 		if (shmem->vmap_use_count++ > 0) {
 			iosys_map_set_vaddr(map, shmem->vaddr);
 			return 0;
@@ -346,45 +361,30 @@  static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem,
 
 	return ret;
 }
+EXPORT_SYMBOL(drm_gem_shmem_vmap);
 
 /*
- * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
+ * drm_gem_shmem_vunmap - Unmap a virtual mapping for a shmem GEM object
  * @shmem: shmem GEM object
- * @map: Returns the kernel virtual address of the SHMEM GEM object's backing
- *       store.
- *
- * This function makes sure that a contiguous kernel virtual address mapping
- * exists for the buffer backing the shmem GEM object. It hides the differences
- * between dma-buf imported and natively allocated objects.
+ * @map: Kernel virtual address where the SHMEM GEM object was mapped
  *
- * Acquired mappings should be cleaned up by calling drm_gem_shmem_vunmap().
+ * This function cleans up a kernel virtual address mapping acquired by
+ * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to
+ * zero.
  *
- * Returns:
- * 0 on success or a negative error code on failure.
+ * This function hides the differences between dma-buf imported and natively
+ * allocated objects.
  */
-int drm_gem_shmem_vmap(struct drm_gem_shmem_object *shmem,
-		       struct iosys_map *map)
-{
-	int ret;
-
-	ret = mutex_lock_interruptible(&shmem->vmap_lock);
-	if (ret)
-		return ret;
-	ret = drm_gem_shmem_vmap_locked(shmem, map);
-	mutex_unlock(&shmem->vmap_lock);
-
-	return ret;
-}
-EXPORT_SYMBOL(drm_gem_shmem_vmap);
-
-static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
-					struct iosys_map *map)
+void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
+			  struct iosys_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
 
 	if (obj->import_attach) {
 		dma_buf_vunmap(obj->import_attach->dmabuf, map);
 	} else {
+		dma_resv_assert_held(shmem->base.resv);
+
 		if (drm_WARN_ON_ONCE(obj->dev, !shmem->vmap_use_count))
 			return;
 
@@ -397,26 +397,6 @@  static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
 
 	shmem->vaddr = NULL;
 }
-
-/*
- * drm_gem_shmem_vunmap - Unmap a virtual mapping for a shmem GEM object
- * @shmem: shmem GEM object
- * @map: Kernel virtual address where the SHMEM GEM object was mapped
- *
- * This function cleans up a kernel virtual address mapping acquired by
- * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to
- * zero.
- *
- * This function hides the differences between dma-buf imported and natively
- * allocated objects.
- */
-void drm_gem_shmem_vunmap(struct drm_gem_shmem_object *shmem,
-			  struct iosys_map *map)
-{
-	mutex_lock(&shmem->vmap_lock);
-	drm_gem_shmem_vunmap_locked(shmem, map);
-	mutex_unlock(&shmem->vmap_lock);
-}
 EXPORT_SYMBOL(drm_gem_shmem_vunmap);
 
 static int
@@ -447,24 +427,24 @@  drm_gem_shmem_create_with_handle(struct drm_file *file_priv,
  */
 int drm_gem_shmem_madvise(struct drm_gem_shmem_object *shmem, int madv)
 {
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_assert_held(shmem->base.resv);
 
 	if (shmem->madv >= 0)
 		shmem->madv = madv;
 
 	madv = shmem->madv;
 
-	mutex_unlock(&shmem->pages_lock);
-
 	return (madv >= 0);
 }
 EXPORT_SYMBOL(drm_gem_shmem_madvise);
 
-void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
+void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
 	struct drm_device *dev = obj->dev;
 
+	dma_resv_assert_held(shmem->base.resv);
+
 	drm_WARN_ON(obj->dev, !drm_gem_shmem_is_purgeable(shmem));
 
 	dma_unmap_sgtable(dev->dev, shmem->sgt, DMA_BIDIRECTIONAL, 0);
@@ -472,7 +452,7 @@  void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
 	kfree(shmem->sgt);
 	shmem->sgt = NULL;
 
-	drm_gem_shmem_put_pages_locked(shmem);
+	drm_gem_shmem_put_pages(shmem);
 
 	shmem->madv = -1;
 
@@ -488,17 +468,6 @@  void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem)
 
 	invalidate_mapping_pages(file_inode(obj->filp)->i_mapping, 0, (loff_t)-1);
 }
-EXPORT_SYMBOL(drm_gem_shmem_purge_locked);
-
-bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem)
-{
-	if (!mutex_trylock(&shmem->pages_lock))
-		return false;
-	drm_gem_shmem_purge_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
-
-	return true;
-}
 EXPORT_SYMBOL(drm_gem_shmem_purge);
 
 /**
@@ -551,7 +520,7 @@  static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 	/* We don't use vmf->pgoff since that has the fake offset */
 	page_offset = (vmf->address - vma->vm_start) >> PAGE_SHIFT;
 
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_lock(shmem->base.resv, NULL);
 
 	if (page_offset >= num_pages ||
 	    drm_WARN_ON_ONCE(obj->dev, !shmem->pages) ||
@@ -563,7 +532,7 @@  static vm_fault_t drm_gem_shmem_fault(struct vm_fault *vmf)
 		ret = vmf_insert_pfn(vma, vmf->address, page_to_pfn(page));
 	}
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return ret;
 }
@@ -575,7 +544,7 @@  static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
 
 	drm_WARN_ON(obj->dev, obj->import_attach);
 
-	mutex_lock(&shmem->pages_lock);
+	dma_resv_lock(shmem->base.resv, NULL);
 
 	/*
 	 * We should have already pinned the pages when the buffer was first
@@ -585,7 +554,7 @@  static void drm_gem_shmem_vm_open(struct vm_area_struct *vma)
 	if (!drm_WARN_ON_ONCE(obj->dev, !shmem->pages_use_count))
 		shmem->pages_use_count++;
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	drm_gem_vm_open(vma);
 }
@@ -595,7 +564,10 @@  static void drm_gem_shmem_vm_close(struct vm_area_struct *vma)
 	struct drm_gem_object *obj = vma->vm_private_data;
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
+	dma_resv_lock(shmem->base.resv, NULL);
 	drm_gem_shmem_put_pages(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
 	drm_gem_vm_close(vma);
 }
 
@@ -633,7 +605,10 @@  int drm_gem_shmem_mmap(struct drm_gem_shmem_object *shmem, struct vm_area_struct
 		return ret;
 	}
 
+	dma_resv_lock(shmem->base.resv, NULL);
 	ret = drm_gem_shmem_get_pages(shmem);
+	dma_resv_unlock(shmem->base.resv);
+
 	if (ret)
 		return ret;
 
@@ -699,7 +674,7 @@  static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_
 
 	drm_WARN_ON(obj->dev, obj->import_attach);
 
-	ret = drm_gem_shmem_get_pages_locked(shmem);
+	ret = drm_gem_shmem_get_pages(shmem);
 	if (ret)
 		return ERR_PTR(ret);
 
@@ -721,7 +696,7 @@  static struct sg_table *drm_gem_shmem_get_pages_sgt_locked(struct drm_gem_shmem_
 	sg_free_table(sgt);
 	kfree(sgt);
 err_put_pages:
-	drm_gem_shmem_put_pages_locked(shmem);
+	drm_gem_shmem_put_pages(shmem);
 	return ERR_PTR(ret);
 }
 
@@ -746,11 +721,11 @@  struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem)
 	int ret;
 	struct sg_table *sgt;
 
-	ret = mutex_lock_interruptible(&shmem->pages_lock);
+	ret = dma_resv_lock_interruptible(shmem->base.resv, NULL);
 	if (ret)
 		return ERR_PTR(ret);
 	sgt = drm_gem_shmem_get_pages_sgt_locked(shmem);
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 	return sgt;
 }
diff --git a/drivers/gpu/drm/lima/lima_gem.c b/drivers/gpu/drm/lima/lima_gem.c
index 0f1ca0b0db49..5008f0c2428f 100644
--- a/drivers/gpu/drm/lima/lima_gem.c
+++ b/drivers/gpu/drm/lima/lima_gem.c
@@ -34,7 +34,7 @@  int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 
 	new_size = min(new_size, bo->base.base.size);
 
-	mutex_lock(&bo->base.pages_lock);
+	dma_resv_lock(bo->base.base.resv, NULL);
 
 	if (bo->base.pages) {
 		pages = bo->base.pages;
@@ -42,7 +42,7 @@  int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 		pages = kvmalloc_array(bo->base.base.size >> PAGE_SHIFT,
 				       sizeof(*pages), GFP_KERNEL | __GFP_ZERO);
 		if (!pages) {
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(bo->base.base.resv);
 			return -ENOMEM;
 		}
 
@@ -56,13 +56,13 @@  int lima_heap_alloc(struct lima_bo *bo, struct lima_vm *vm)
 		struct page *page = shmem_read_mapping_page(mapping, i);
 
 		if (IS_ERR(page)) {
-			mutex_unlock(&bo->base.pages_lock);
+			dma_resv_unlock(bo->base.base.resv);
 			return PTR_ERR(page);
 		}
 		pages[i] = page;
 	}
 
-	mutex_unlock(&bo->base.pages_lock);
+	dma_resv_unlock(bo->base.base.resv);
 
 	ret = sg_alloc_table_from_pages(&sgt, pages, i, 0,
 					new_size, GFP_KERNEL);
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index f49096f53141..aa292e4a86eb 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -407,6 +407,10 @@  static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 
 	bo = to_panfrost_bo(gem_obj);
 
+	ret = dma_resv_lock_interruptible(bo->base.base.resv, NULL);
+	if (ret)
+		goto out_put_object;
+
 	mutex_lock(&pfdev->shrinker_lock);
 	mutex_lock(&bo->mappings.lock);
 	if (args->madv == PANFROST_MADV_DONTNEED) {
@@ -444,7 +448,8 @@  static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 out_unlock_mappings:
 	mutex_unlock(&bo->mappings.lock);
 	mutex_unlock(&pfdev->shrinker_lock);
-
+	dma_resv_unlock(bo->base.base.resv);
+out_put_object:
 	drm_gem_object_put(gem_obj);
 	return ret;
 }
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
index bf0170782f25..6a71a2555f85 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -48,14 +48,14 @@  static bool panfrost_gem_purge(struct drm_gem_object *obj)
 	if (!mutex_trylock(&bo->mappings.lock))
 		return false;
 
-	if (!mutex_trylock(&shmem->pages_lock))
+	if (!dma_resv_trylock(shmem->base.resv))
 		goto unlock_mappings;
 
 	panfrost_gem_teardown_mappings_locked(bo);
-	drm_gem_shmem_purge_locked(&bo->base);
+	drm_gem_shmem_purge(&bo->base);
 	ret = true;
 
-	mutex_unlock(&shmem->pages_lock);
+	dma_resv_unlock(shmem->base.resv);
 
 unlock_mappings:
 	mutex_unlock(&bo->mappings.lock);
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 666a5e53fe19..0679df57f394 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -443,6 +443,7 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	struct panfrost_gem_mapping *bomapping;
 	struct panfrost_gem_object *bo;
 	struct address_space *mapping;
+	struct drm_gem_object *obj;
 	pgoff_t page_offset;
 	struct sg_table *sgt;
 	struct page **pages;
@@ -465,15 +466,16 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	page_offset = addr >> PAGE_SHIFT;
 	page_offset -= bomapping->mmnode.start;
 
-	mutex_lock(&bo->base.pages_lock);
+	obj = &bo->base.base;
+
+	dma_resv_lock(obj->resv, NULL);
 
 	if (!bo->base.pages) {
 		bo->sgts = kvmalloc_array(bo->base.base.size / SZ_2M,
 				     sizeof(struct sg_table), GFP_KERNEL | __GFP_ZERO);
 		if (!bo->sgts) {
-			mutex_unlock(&bo->base.pages_lock);
 			ret = -ENOMEM;
-			goto err_bo;
+			goto err_unlock;
 		}
 
 		pages = kvmalloc_array(bo->base.base.size >> PAGE_SHIFT,
@@ -481,9 +483,8 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		if (!pages) {
 			kvfree(bo->sgts);
 			bo->sgts = NULL;
-			mutex_unlock(&bo->base.pages_lock);
 			ret = -ENOMEM;
-			goto err_bo;
+			goto err_unlock;
 		}
 		bo->base.pages = pages;
 		bo->base.pages_use_count = 1;
@@ -491,7 +492,6 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		pages = bo->base.pages;
 		if (pages[page_offset]) {
 			/* Pages are already mapped, bail out. */
-			mutex_unlock(&bo->base.pages_lock);
 			goto out;
 		}
 	}
@@ -502,14 +502,11 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	for (i = page_offset; i < page_offset + NUM_FAULT_PAGES; i++) {
 		pages[i] = shmem_read_mapping_page(mapping, i);
 		if (IS_ERR(pages[i])) {
-			mutex_unlock(&bo->base.pages_lock);
 			ret = PTR_ERR(pages[i]);
 			goto err_pages;
 		}
 	}
 
-	mutex_unlock(&bo->base.pages_lock);
-
 	sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)];
 	ret = sg_alloc_table_from_pages(sgt, pages + page_offset,
 					NUM_FAULT_PAGES, 0, SZ_2M, GFP_KERNEL);
@@ -528,6 +525,8 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	dev_dbg(pfdev->dev, "mapped page fault @ AS%d %llx", as, addr);
 
 out:
+	dma_resv_unlock(obj->resv);
+
 	panfrost_gem_mapping_put(bomapping);
 
 	return 0;
@@ -536,6 +535,8 @@  static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 	sg_free_table(sgt);
 err_pages:
 	drm_gem_shmem_put_pages(&bo->base);
+err_unlock:
+	dma_resv_unlock(obj->resv);
 err_bo:
 	panfrost_gem_mapping_put(bomapping);
 	return ret;
diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h
index 5994fed5e327..20ddcd799df9 100644
--- a/include/drm/drm_gem_shmem_helper.h
+++ b/include/drm/drm_gem_shmem_helper.h
@@ -26,11 +26,6 @@  struct drm_gem_shmem_object {
 	 */
 	struct drm_gem_object base;
 
-	/**
-	 * @pages_lock: Protects the page table and use count
-	 */
-	struct mutex pages_lock;
-
 	/**
 	 * @pages: Page table
 	 */
@@ -65,11 +60,6 @@  struct drm_gem_shmem_object {
 	 */
 	struct sg_table *sgt;
 
-	/**
-	 * @vmap_lock: Protects the vmap address and use count
-	 */
-	struct mutex vmap_lock;
-
 	/**
 	 * @vaddr: Kernel virtual address of the backing memory
 	 */
@@ -109,7 +99,6 @@  struct drm_gem_shmem_object {
 struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev, size_t size);
 void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem);
 
-int drm_gem_shmem_get_pages(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_put_pages(struct drm_gem_shmem_object *shmem);
 int drm_gem_shmem_pin(struct drm_gem_shmem_object *shmem);
 void drm_gem_shmem_unpin(struct drm_gem_shmem_object *shmem);
@@ -128,8 +117,7 @@  static inline bool drm_gem_shmem_is_purgeable(struct drm_gem_shmem_object *shmem
 		!shmem->base.dma_buf && !shmem->base.import_attach;
 }
 
-void drm_gem_shmem_purge_locked(struct drm_gem_shmem_object *shmem);
-bool drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
+void drm_gem_shmem_purge(struct drm_gem_shmem_object *shmem);
 
 struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_shmem_object *shmem);
 struct sg_table *drm_gem_shmem_get_pages_sgt(struct drm_gem_shmem_object *shmem);