[PATCH v5 1/3] drm/amdgpu: Add WARN_ON to the resource clear function

[PATCH v5 1/3] drm/amdgpu: Add WARN_ON to the resource clear function

[Arunpravin Paneer Selvam]

Set the dirty bit when the memory resource is not cleared
during BO release.

v2(Christian):
  - Drop the cleared flag set to false.
  - Improve the amdgpu_vram_mgr_set_clear_state() function.

v3:
  - Add back the resource clear flag set function call after
    being wiped during eviction (Christian).
  - Modified the patch subject name.

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
index b256cbc2bc27..2c88d5fd87da 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.h
@@ -66,7 +66,10 @@ to_amdgpu_vram_mgr_resource(struct ttm_resource *res)
 
 static inline void amdgpu_vram_mgr_set_cleared(struct ttm_resource *res)
 {
-	to_amdgpu_vram_mgr_resource(res)->flags |= DRM_BUDDY_CLEARED;
+	struct amdgpu_vram_mgr_resource *ares = to_amdgpu_vram_mgr_resource(res);
+
+	WARN_ON(ares->flags & DRM_BUDDY_CLEARED);
+	ares->flags |= DRM_BUDDY_CLEARED;
 }
 
 #endif
-- 
2.43.0

[PATCH v5 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

[Arunpravin Paneer Selvam]

- Added a handler in DRM buddy manager to reset the cleared
  flag for the blocks in the freelist.

- This is necessary because, upon resuming, the VRAM becomes
  cluttered with BIOS data, yet the VRAM backend manager
  believes that everything has been cleared.

v2:
  - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
  - Force merge the two dirty blocks.(Matthew Auld)
  - Add a new unit test case for this issue.(Matthew Auld)
  - Having this function being able to flip the state either way would be
    good. (Matthew Brost)

v3(Matthew Auld):
  - Do merge step first to avoid the use of extra reset flag.

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Cc: stable@vger.kernel.org
Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   |  2 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  1 +
 drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++
 drivers/gpu/drm/drm_buddy.c                  | 43 ++++++++++++++++++++
 include/drm/drm_buddy.h                      |  2 +
 5 files changed, 65 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 723ab95d8c48..ac92220f9fc3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
 		dev->dev->power.disable_depth--;
 #endif
 	}
+
+	amdgpu_vram_mgr_clear_reset_blocks(adev);
 	adev->in_suspend = false;
 
 	if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index 215c198e4aff..2309df3f68a9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
 				  uint64_t start, uint64_t size);
 int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
 				      uint64_t start);
+void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev);
 
 bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
 			    struct ttm_resource *res);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
index abdc52b0895a..07c936e90d8e 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr)
 	return atomic64_read(&mgr->vis_usage);
 }
 
+/**
+ * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks
+ *
+ * @adev: amdgpu device pointer
+ *
+ * Reset the cleared drm buddy blocks.
+ */
+void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev)
+{
+	struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
+	struct drm_buddy *mm = &mgr->mm;
+
+	mutex_lock(&mgr->lock);
+	drm_buddy_reset_clear(mm, false);
+	mutex_unlock(&mgr->lock);
+}
+
 /**
  * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection
  *
diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
index a1e652b7631d..a94061f373de 100644
--- a/drivers/gpu/drm/drm_buddy.c
+++ b/drivers/gpu/drm/drm_buddy.c
@@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block)
 }
 EXPORT_SYMBOL(drm_get_buddy);
 
+/**
+ * drm_buddy_reset_clear - reset blocks clear state
+ *
+ * @mm: DRM buddy manager
+ * @is_clear: blocks clear state
+ *
+ * Reset the clear state based on @is_clear value for each block
+ * in the freelist.
+ */
+void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear)
+{
+	u64 root_size, size, start;
+	unsigned int order;
+	int i;
+
+	size = mm->size;
+	for (i = 0; i < mm->n_roots; ++i) {
+		order = ilog2(size) - ilog2(mm->chunk_size);
+		start = drm_buddy_block_offset(mm->roots[i]);
+		__force_merge(mm, start, start + size, order);
+
+		root_size = mm->chunk_size << order;
+		size -= root_size;
+	}
+
+	for (i = 0; i <= mm->max_order; ++i) {
+		struct drm_buddy_block *block;
+
+		list_for_each_entry_reverse(block, &mm->free_list[i], link) {
+			if (is_clear != drm_buddy_block_is_clear(block)) {
+				if (is_clear) {
+					mark_cleared(block);
+					mm->clear_avail += drm_buddy_block_size(mm, block);
+				} else {
+					clear_reset(block);
+					mm->clear_avail -= drm_buddy_block_size(mm, block);
+				}
+			}
+		}
+	}
+}
+EXPORT_SYMBOL(drm_buddy_reset_clear);
+
 /**
  * drm_buddy_free_block - free a block
  *
diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
index 9689a7c5dd36..513837632b7d 100644
--- a/include/drm/drm_buddy.h
+++ b/include/drm/drm_buddy.h
@@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
 			 u64 new_size,
 			 struct list_head *blocks);
 
+void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear);
+
 void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block);
 
 void drm_buddy_free_list(struct drm_buddy *mm,
-- 
2.43.0

[PATCH v5 3/3] drm/buddy: Add a new unit test case for buffer clearance issue

[Arunpravin Paneer Selvam]

Add a new unit test case for buffer clearance issue during
resume.

Using a non-power-of-two mm size, allocate alternating blocks of
4KiB in an even sequence and free them as cleared. All alternate
blocks should be marked as dirty and the split blocks should be
merged back to their original size when the blocks clear reset
function is called.

Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
---
 drivers/gpu/drm/tests/drm_buddy_test.c | 41 ++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

diff --git a/drivers/gpu/drm/tests/drm_buddy_test.c b/drivers/gpu/drm/tests/drm_buddy_test.c
index 7a0e523651f0..26f8be8ceecd 100644
--- a/drivers/gpu/drm/tests/drm_buddy_test.c
+++ b/drivers/gpu/drm/tests/drm_buddy_test.c
@@ -408,6 +408,47 @@ static void drm_test_buddy_alloc_clear(struct kunit *test)
 				"buddy_alloc hit an error size=%lu\n", ps);
 	drm_buddy_free_list(&mm, &allocated, DRM_BUDDY_CLEARED);
 	drm_buddy_fini(&mm);
+
+	/*
+	 * Using a non-power-of-two mm size, allocate alternating blocks of 4KiB in an
+	 * even sequence and free them as cleared. All blocks should be marked as
+	 * dirty and the split blocks should be merged back to their original
+	 * size when the blocks clear reset function is called.
+	 */
+	KUNIT_EXPECT_FALSE(test, drm_buddy_init(&mm, mm_size, ps));
+	KUNIT_EXPECT_EQ(test, mm.max_order, max_order);
+
+	i = 0;
+	n_pages = mm_size / ps;
+	do {
+		if (i % 2 == 0)
+			KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+									    ps, ps, &allocated, 0),
+						"buddy_alloc hit an error size=%lu\n", ps);
+	} while (++i < n_pages);
+
+	drm_buddy_free_list(&mm, &allocated, DRM_BUDDY_CLEARED);
+	drm_buddy_reset_clear(&mm, false);
+	KUNIT_EXPECT_EQ(test, mm.clear_avail, 0);
+
+	/*
+	 * Using a non-power-of-two mm size, allocate alternating blocks of 4KiB in an
+	 * odd sequence and free them as cleared. All blocks should be marked as
+	 * cleared and the split blocks should be merged back to their original
+	 * size when the blocks clear reset function is called.
+	 */
+	i = 0;
+	do {
+		if (i % 2 != 0)
+			KUNIT_ASSERT_FALSE_MSG(test, drm_buddy_alloc_blocks(&mm, 0, mm_size,
+									    ps, ps, &allocated, 0),
+						"buddy_alloc hit an error size=%lu\n", ps);
+	} while (++i < n_pages);
+
+	drm_buddy_free_list(&mm, &allocated, DRM_BUDDY_CLEARED);
+	drm_buddy_reset_clear(&mm, true);
+	KUNIT_EXPECT_EQ(test, mm.clear_avail, mm_size);
+	drm_buddy_fini(&mm);
 }
 
 static void drm_test_buddy_alloc_contiguous(struct kunit *test)
-- 
2.43.0

Re: [PATCH v5 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

[Arunpravin Paneer Selvam]

Hi Dave,

I am trying to push this series into drm-misc-fixes, but I get the below 
error when dim push-branch drm-misc-fixes.

dim:ERROR:e24c180b4300("drm/amdgpu:Reset the clear flag in buddy during 
resume"): Mandatory Maintainer Acked-by missing., aborting

Looks like maintainers Acked-by is required to push the patches into 
drm-misc-fixes ?

Regards,

Arun.

On 7/16/2025 1:21 PM, Arunpravin Paneer Selvam wrote:
> - Added a handler in DRM buddy manager to reset the cleared
>    flag for the blocks in the freelist.
>
> - This is necessary because, upon resuming, the VRAM becomes
>    cluttered with BIOS data, yet the VRAM backend manager
>    believes that everything has been cleared.
>
> v2:
>    - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
>    - Force merge the two dirty blocks.(Matthew Auld)
>    - Add a new unit test case for this issue.(Matthew Auld)
>    - Having this function being able to flip the state either way would be
>      good. (Matthew Brost)
>
> v3(Matthew Auld):
>    - Do merge step first to avoid the use of extra reset flag.
>
> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
> Suggested-by: Christian König <christian.koenig@amd.com>
> Acked-by: Christian König <christian.koenig@amd.com>
> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
> Cc: stable@vger.kernel.org
> Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   |  2 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  1 +
>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++
>   drivers/gpu/drm/drm_buddy.c                  | 43 ++++++++++++++++++++
>   include/drm/drm_buddy.h                      |  2 +
>   5 files changed, 65 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 723ab95d8c48..ac92220f9fc3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
>   		dev->dev->power.disable_depth--;
>   #endif
>   	}
> +
> +	amdgpu_vram_mgr_clear_reset_blocks(adev);
>   	adev->in_suspend = false;
>   
>   	if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> index 215c198e4aff..2309df3f68a9 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
> @@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>   				  uint64_t start, uint64_t size);
>   int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>   				      uint64_t start);
> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev);
>   
>   bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
>   			    struct ttm_resource *res);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index abdc52b0895a..07c936e90d8e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr)
>   	return atomic64_read(&mgr->vis_usage);
>   }
>   
> +/**
> + * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks
> + *
> + * @adev: amdgpu device pointer
> + *
> + * Reset the cleared drm buddy blocks.
> + */
> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev)
> +{
> +	struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
> +	struct drm_buddy *mm = &mgr->mm;
> +
> +	mutex_lock(&mgr->lock);
> +	drm_buddy_reset_clear(mm, false);
> +	mutex_unlock(&mgr->lock);
> +}
> +
>   /**
>    * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection
>    *
> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
> index a1e652b7631d..a94061f373de 100644
> --- a/drivers/gpu/drm/drm_buddy.c
> +++ b/drivers/gpu/drm/drm_buddy.c
> @@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block)
>   }
>   EXPORT_SYMBOL(drm_get_buddy);
>   
> +/**
> + * drm_buddy_reset_clear - reset blocks clear state
> + *
> + * @mm: DRM buddy manager
> + * @is_clear: blocks clear state
> + *
> + * Reset the clear state based on @is_clear value for each block
> + * in the freelist.
> + */
> +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear)
> +{
> +	u64 root_size, size, start;
> +	unsigned int order;
> +	int i;
> +
> +	size = mm->size;
> +	for (i = 0; i < mm->n_roots; ++i) {
> +		order = ilog2(size) - ilog2(mm->chunk_size);
> +		start = drm_buddy_block_offset(mm->roots[i]);
> +		__force_merge(mm, start, start + size, order);
> +
> +		root_size = mm->chunk_size << order;
> +		size -= root_size;
> +	}
> +
> +	for (i = 0; i <= mm->max_order; ++i) {
> +		struct drm_buddy_block *block;
> +
> +		list_for_each_entry_reverse(block, &mm->free_list[i], link) {
> +			if (is_clear != drm_buddy_block_is_clear(block)) {
> +				if (is_clear) {
> +					mark_cleared(block);
> +					mm->clear_avail += drm_buddy_block_size(mm, block);
> +				} else {
> +					clear_reset(block);
> +					mm->clear_avail -= drm_buddy_block_size(mm, block);
> +				}
> +			}
> +		}
> +	}
> +}
> +EXPORT_SYMBOL(drm_buddy_reset_clear);
> +
>   /**
>    * drm_buddy_free_block - free a block
>    *
> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
> index 9689a7c5dd36..513837632b7d 100644
> --- a/include/drm/drm_buddy.h
> +++ b/include/drm/drm_buddy.h
> @@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>   			 u64 new_size,
>   			 struct list_head *blocks);
>   
> +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear);
> +
>   void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block);
>   
>   void drm_buddy_free_list(struct drm_buddy *mm,

Re: [PATCH v5 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

[Christian König]

On 16.07.25 12:28, Arunpravin Paneer Selvam wrote:
> Hi Dave,
> 
> I am trying to push this series into drm-misc-fixes, but I get the below error when dim push-branch drm-misc-fixes.
> 
> dim:ERROR:e24c180b4300("drm/amdgpu:Reset the clear flag in buddy during resume"): Mandatory Maintainer Acked-by missing., aborting
> 
> Looks like maintainers Acked-by is required to push the patches into drm-misc-fixes ?

Strange, it should work with my Acked-by. Let me give it a try.

Regards,
Christian.

> 
> Regards,
> 
> Arun.
> 
> On 7/16/2025 1:21 PM, Arunpravin Paneer Selvam wrote:
>> - Added a handler in DRM buddy manager to reset the cleared
>>    flag for the blocks in the freelist.
>>
>> - This is necessary because, upon resuming, the VRAM becomes
>>    cluttered with BIOS data, yet the VRAM backend manager
>>    believes that everything has been cleared.
>>
>> v2:
>>    - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
>>    - Force merge the two dirty blocks.(Matthew Auld)
>>    - Add a new unit test case for this issue.(Matthew Auld)
>>    - Having this function being able to flip the state either way would be
>>      good. (Matthew Brost)
>>
>> v3(Matthew Auld):
>>    - Do merge step first to avoid the use of extra reset flag.
>>
>> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
>> Suggested-by: Christian König <christian.koenig@amd.com>
>> Acked-by: Christian König <christian.koenig@amd.com>
>> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
>> Cc: stable@vger.kernel.org
>> Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   |  2 +
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  1 +
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++
>>   drivers/gpu/drm/drm_buddy.c                  | 43 ++++++++++++++++++++
>>   include/drm/drm_buddy.h                      |  2 +
>>   5 files changed, 65 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> index 723ab95d8c48..ac92220f9fc3 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>> @@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
>>           dev->dev->power.disable_depth--;
>>   #endif
>>       }
>> +
>> +    amdgpu_vram_mgr_clear_reset_blocks(adev);
>>       adev->in_suspend = false;
>>         if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> index 215c198e4aff..2309df3f68a9 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> @@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>>                     uint64_t start, uint64_t size);
>>   int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>>                         uint64_t start);
>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev);
>>     bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
>>                   struct ttm_resource *res);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> index abdc52b0895a..07c936e90d8e 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>> @@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr)
>>       return atomic64_read(&mgr->vis_usage);
>>   }
>>   +/**
>> + * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks
>> + *
>> + * @adev: amdgpu device pointer
>> + *
>> + * Reset the cleared drm buddy blocks.
>> + */
>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev)
>> +{
>> +    struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
>> +    struct drm_buddy *mm = &mgr->mm;
>> +
>> +    mutex_lock(&mgr->lock);
>> +    drm_buddy_reset_clear(mm, false);
>> +    mutex_unlock(&mgr->lock);
>> +}
>> +
>>   /**
>>    * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection
>>    *
>> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
>> index a1e652b7631d..a94061f373de 100644
>> --- a/drivers/gpu/drm/drm_buddy.c
>> +++ b/drivers/gpu/drm/drm_buddy.c
>> @@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block)
>>   }
>>   EXPORT_SYMBOL(drm_get_buddy);
>>   +/**
>> + * drm_buddy_reset_clear - reset blocks clear state
>> + *
>> + * @mm: DRM buddy manager
>> + * @is_clear: blocks clear state
>> + *
>> + * Reset the clear state based on @is_clear value for each block
>> + * in the freelist.
>> + */
>> +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear)
>> +{
>> +    u64 root_size, size, start;
>> +    unsigned int order;
>> +    int i;
>> +
>> +    size = mm->size;
>> +    for (i = 0; i < mm->n_roots; ++i) {
>> +        order = ilog2(size) - ilog2(mm->chunk_size);
>> +        start = drm_buddy_block_offset(mm->roots[i]);
>> +        __force_merge(mm, start, start + size, order);
>> +
>> +        root_size = mm->chunk_size << order;
>> +        size -= root_size;
>> +    }
>> +
>> +    for (i = 0; i <= mm->max_order; ++i) {
>> +        struct drm_buddy_block *block;
>> +
>> +        list_for_each_entry_reverse(block, &mm->free_list[i], link) {
>> +            if (is_clear != drm_buddy_block_is_clear(block)) {
>> +                if (is_clear) {
>> +                    mark_cleared(block);
>> +                    mm->clear_avail += drm_buddy_block_size(mm, block);
>> +                } else {
>> +                    clear_reset(block);
>> +                    mm->clear_avail -= drm_buddy_block_size(mm, block);
>> +                }
>> +            }
>> +        }
>> +    }
>> +}
>> +EXPORT_SYMBOL(drm_buddy_reset_clear);
>> +
>>   /**
>>    * drm_buddy_free_block - free a block
>>    *
>> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
>> index 9689a7c5dd36..513837632b7d 100644
>> --- a/include/drm/drm_buddy.h
>> +++ b/include/drm/drm_buddy.h
>> @@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>                u64 new_size,
>>                struct list_head *blocks);
>>   +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear);
>> +
>>   void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block);
>>     void drm_buddy_free_list(struct drm_buddy *mm,

Re: [PATCH v5 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

[Arunpravin Paneer Selvam]

Hi Christian,

On 7/16/2025 4:17 PM, Christian König wrote:
> On 16.07.25 12:28, Arunpravin Paneer Selvam wrote:
>> Hi Dave,
>>
>> I am trying to push this series into drm-misc-fixes, but I get the below error when dim push-branch drm-misc-fixes.
>>
>> dim:ERROR:e24c180b4300("drm/amdgpu:Reset the clear flag in buddy during resume"): Mandatory Maintainer Acked-by missing., aborting
>>
>> Looks like maintainers Acked-by is required to push the patches into drm-misc-fixes ?
> Strange, it should work with my Acked-by. Let me give it a try.

Sure, thanks!

Regards,

Arun.

>
> Regards,
> Christian.
>
>> Regards,
>>
>> Arun.
>>
>> On 7/16/2025 1:21 PM, Arunpravin Paneer Selvam wrote:
>>> - Added a handler in DRM buddy manager to reset the cleared
>>>     flag for the blocks in the freelist.
>>>
>>> - This is necessary because, upon resuming, the VRAM becomes
>>>     cluttered with BIOS data, yet the VRAM backend manager
>>>     believes that everything has been cleared.
>>>
>>> v2:
>>>     - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
>>>     - Force merge the two dirty blocks.(Matthew Auld)
>>>     - Add a new unit test case for this issue.(Matthew Auld)
>>>     - Having this function being able to flip the state either way would be
>>>       good. (Matthew Brost)
>>>
>>> v3(Matthew Auld):
>>>     - Do merge step first to avoid the use of extra reset flag.
>>>
>>> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
>>> Suggested-by: Christian König <christian.koenig@amd.com>
>>> Acked-by: Christian König <christian.koenig@amd.com>
>>> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
>>> Cc: stable@vger.kernel.org
>>> Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
>>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
>>> ---
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   |  2 +
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  1 +
>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++
>>>    drivers/gpu/drm/drm_buddy.c                  | 43 ++++++++++++++++++++
>>>    include/drm/drm_buddy.h                      |  2 +
>>>    5 files changed, 65 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> index 723ab95d8c48..ac92220f9fc3 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
>>>            dev->dev->power.disable_depth--;
>>>    #endif
>>>        }
>>> +
>>> +    amdgpu_vram_mgr_clear_reset_blocks(adev);
>>>        adev->in_suspend = false;
>>>          if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> index 215c198e4aff..2309df3f68a9 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> @@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>>>                      uint64_t start, uint64_t size);
>>>    int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>>>                          uint64_t start);
>>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev);
>>>      bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
>>>                    struct ttm_resource *res);
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> index abdc52b0895a..07c936e90d8e 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> @@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr)
>>>        return atomic64_read(&mgr->vis_usage);
>>>    }
>>>    +/**
>>> + * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks
>>> + *
>>> + * @adev: amdgpu device pointer
>>> + *
>>> + * Reset the cleared drm buddy blocks.
>>> + */
>>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev)
>>> +{
>>> +    struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
>>> +    struct drm_buddy *mm = &mgr->mm;
>>> +
>>> +    mutex_lock(&mgr->lock);
>>> +    drm_buddy_reset_clear(mm, false);
>>> +    mutex_unlock(&mgr->lock);
>>> +}
>>> +
>>>    /**
>>>     * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection
>>>     *
>>> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
>>> index a1e652b7631d..a94061f373de 100644
>>> --- a/drivers/gpu/drm/drm_buddy.c
>>> +++ b/drivers/gpu/drm/drm_buddy.c
>>> @@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block)
>>>    }
>>>    EXPORT_SYMBOL(drm_get_buddy);
>>>    +/**
>>> + * drm_buddy_reset_clear - reset blocks clear state
>>> + *
>>> + * @mm: DRM buddy manager
>>> + * @is_clear: blocks clear state
>>> + *
>>> + * Reset the clear state based on @is_clear value for each block
>>> + * in the freelist.
>>> + */
>>> +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear)
>>> +{
>>> +    u64 root_size, size, start;
>>> +    unsigned int order;
>>> +    int i;
>>> +
>>> +    size = mm->size;
>>> +    for (i = 0; i < mm->n_roots; ++i) {
>>> +        order = ilog2(size) - ilog2(mm->chunk_size);
>>> +        start = drm_buddy_block_offset(mm->roots[i]);
>>> +        __force_merge(mm, start, start + size, order);
>>> +
>>> +        root_size = mm->chunk_size << order;
>>> +        size -= root_size;
>>> +    }
>>> +
>>> +    for (i = 0; i <= mm->max_order; ++i) {
>>> +        struct drm_buddy_block *block;
>>> +
>>> +        list_for_each_entry_reverse(block, &mm->free_list[i], link) {
>>> +            if (is_clear != drm_buddy_block_is_clear(block)) {
>>> +                if (is_clear) {
>>> +                    mark_cleared(block);
>>> +                    mm->clear_avail += drm_buddy_block_size(mm, block);
>>> +                } else {
>>> +                    clear_reset(block);
>>> +                    mm->clear_avail -= drm_buddy_block_size(mm, block);
>>> +                }
>>> +            }
>>> +        }
>>> +    }
>>> +}
>>> +EXPORT_SYMBOL(drm_buddy_reset_clear);
>>> +
>>>    /**
>>>     * drm_buddy_free_block - free a block
>>>     *
>>> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
>>> index 9689a7c5dd36..513837632b7d 100644
>>> --- a/include/drm/drm_buddy.h
>>> +++ b/include/drm/drm_buddy.h
>>> @@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>>                 u64 new_size,
>>>                 struct list_head *blocks);
>>>    +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear);
>>> +
>>>    void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block);
>>>      void drm_buddy_free_list(struct drm_buddy *mm,

Re: [PATCH v5 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

[Christian König]

On 16.07.25 12:47, Christian König wrote:
> On 16.07.25 12:28, Arunpravin Paneer Selvam wrote:
>> Hi Dave,
>>
>> I am trying to push this series into drm-misc-fixes, but I get the below error when dim push-branch drm-misc-fixes.
>>
>> dim:ERROR:e24c180b4300("drm/amdgpu:Reset the clear flag in buddy during resume"): Mandatory Maintainer Acked-by missing., aborting
>>
>> Looks like maintainers Acked-by is required to push the patches into drm-misc-fixes ?
> 
> Strange, it should work with my Acked-by. Let me give it a try.

I successfully pushed the patch to drm-misc-fixes.

No idea why that didn't worked for you. Maybe update your dim script Arun.

Regards,
Christian.

> 
> Regards,
> Christian.
> 
>>
>> Regards,
>>
>> Arun.
>>
>> On 7/16/2025 1:21 PM, Arunpravin Paneer Selvam wrote:
>>> - Added a handler in DRM buddy manager to reset the cleared
>>>    flag for the blocks in the freelist.
>>>
>>> - This is necessary because, upon resuming, the VRAM becomes
>>>    cluttered with BIOS data, yet the VRAM backend manager
>>>    believes that everything has been cleared.
>>>
>>> v2:
>>>    - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
>>>    - Force merge the two dirty blocks.(Matthew Auld)
>>>    - Add a new unit test case for this issue.(Matthew Auld)
>>>    - Having this function being able to flip the state either way would be
>>>      good. (Matthew Brost)
>>>
>>> v3(Matthew Auld):
>>>    - Do merge step first to avoid the use of extra reset flag.
>>>
>>> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
>>> Suggested-by: Christian König <christian.koenig@amd.com>
>>> Acked-by: Christian König <christian.koenig@amd.com>
>>> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
>>> Cc: stable@vger.kernel.org
>>> Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
>>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
>>> ---
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   |  2 +
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  1 +
>>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++
>>>   drivers/gpu/drm/drm_buddy.c                  | 43 ++++++++++++++++++++
>>>   include/drm/drm_buddy.h                      |  2 +
>>>   5 files changed, 65 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> index 723ab95d8c48..ac92220f9fc3 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
>>>           dev->dev->power.disable_depth--;
>>>   #endif
>>>       }
>>> +
>>> +    amdgpu_vram_mgr_clear_reset_blocks(adev);
>>>       adev->in_suspend = false;
>>>         if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> index 215c198e4aff..2309df3f68a9 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> @@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>>>                     uint64_t start, uint64_t size);
>>>   int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>>>                         uint64_t start);
>>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev);
>>>     bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
>>>                   struct ttm_resource *res);
>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> index abdc52b0895a..07c936e90d8e 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>> @@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr)
>>>       return atomic64_read(&mgr->vis_usage);
>>>   }
>>>   +/**
>>> + * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks
>>> + *
>>> + * @adev: amdgpu device pointer
>>> + *
>>> + * Reset the cleared drm buddy blocks.
>>> + */
>>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev)
>>> +{
>>> +    struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
>>> +    struct drm_buddy *mm = &mgr->mm;
>>> +
>>> +    mutex_lock(&mgr->lock);
>>> +    drm_buddy_reset_clear(mm, false);
>>> +    mutex_unlock(&mgr->lock);
>>> +}
>>> +
>>>   /**
>>>    * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection
>>>    *
>>> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
>>> index a1e652b7631d..a94061f373de 100644
>>> --- a/drivers/gpu/drm/drm_buddy.c
>>> +++ b/drivers/gpu/drm/drm_buddy.c
>>> @@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block)
>>>   }
>>>   EXPORT_SYMBOL(drm_get_buddy);
>>>   +/**
>>> + * drm_buddy_reset_clear - reset blocks clear state
>>> + *
>>> + * @mm: DRM buddy manager
>>> + * @is_clear: blocks clear state
>>> + *
>>> + * Reset the clear state based on @is_clear value for each block
>>> + * in the freelist.
>>> + */
>>> +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear)
>>> +{
>>> +    u64 root_size, size, start;
>>> +    unsigned int order;
>>> +    int i;
>>> +
>>> +    size = mm->size;
>>> +    for (i = 0; i < mm->n_roots; ++i) {
>>> +        order = ilog2(size) - ilog2(mm->chunk_size);
>>> +        start = drm_buddy_block_offset(mm->roots[i]);
>>> +        __force_merge(mm, start, start + size, order);
>>> +
>>> +        root_size = mm->chunk_size << order;
>>> +        size -= root_size;
>>> +    }
>>> +
>>> +    for (i = 0; i <= mm->max_order; ++i) {
>>> +        struct drm_buddy_block *block;
>>> +
>>> +        list_for_each_entry_reverse(block, &mm->free_list[i], link) {
>>> +            if (is_clear != drm_buddy_block_is_clear(block)) {
>>> +                if (is_clear) {
>>> +                    mark_cleared(block);
>>> +                    mm->clear_avail += drm_buddy_block_size(mm, block);
>>> +                } else {
>>> +                    clear_reset(block);
>>> +                    mm->clear_avail -= drm_buddy_block_size(mm, block);
>>> +                }
>>> +            }
>>> +        }
>>> +    }
>>> +}
>>> +EXPORT_SYMBOL(drm_buddy_reset_clear);
>>> +
>>>   /**
>>>    * drm_buddy_free_block - free a block
>>>    *
>>> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
>>> index 9689a7c5dd36..513837632b7d 100644
>>> --- a/include/drm/drm_buddy.h
>>> +++ b/include/drm/drm_buddy.h
>>> @@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>>                u64 new_size,
>>>                struct list_head *blocks);
>>>   +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear);
>>> +
>>>   void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block);
>>>     void drm_buddy_free_list(struct drm_buddy *mm,
> 

Re: [PATCH v5 2/3] drm/amdgpu: Reset the clear flag in buddy during resume

[Arunpravin Paneer Selvam]

On 7/16/2025 4:31 PM, Christian König wrote:
> On 16.07.25 12:47, Christian König wrote:
>> On 16.07.25 12:28, Arunpravin Paneer Selvam wrote:
>>> Hi Dave,
>>>
>>> I am trying to push this series into drm-misc-fixes, but I get the below error when dim push-branch drm-misc-fixes.
>>>
>>> dim:ERROR:e24c180b4300("drm/amdgpu:Reset the clear flag in buddy during resume"): Mandatory Maintainer Acked-by missing., aborting
>>>
>>> Looks like maintainers Acked-by is required to push the patches into drm-misc-fixes ?
>> Strange, it should work with my Acked-by. Let me give it a try.
> I successfully pushed the patch to drm-misc-fixes.
>
> No idea why that didn't worked for you. Maybe update your dim script Arun.

Thanks Christian, I will check the dim script.

Regards,

Arun.

>
> Regards,
> Christian.
>
>> Regards,
>> Christian.
>>
>>> Regards,
>>>
>>> Arun.
>>>
>>> On 7/16/2025 1:21 PM, Arunpravin Paneer Selvam wrote:
>>>> - Added a handler in DRM buddy manager to reset the cleared
>>>>     flag for the blocks in the freelist.
>>>>
>>>> - This is necessary because, upon resuming, the VRAM becomes
>>>>     cluttered with BIOS data, yet the VRAM backend manager
>>>>     believes that everything has been cleared.
>>>>
>>>> v2:
>>>>     - Add lock before accessing drm_buddy_clear_reset_blocks()(Matthew Auld)
>>>>     - Force merge the two dirty blocks.(Matthew Auld)
>>>>     - Add a new unit test case for this issue.(Matthew Auld)
>>>>     - Having this function being able to flip the state either way would be
>>>>       good. (Matthew Brost)
>>>>
>>>> v3(Matthew Auld):
>>>>     - Do merge step first to avoid the use of extra reset flag.
>>>>
>>>> Signed-off-by: Arunpravin Paneer Selvam <Arunpravin.PaneerSelvam@amd.com>
>>>> Suggested-by: Christian König <christian.koenig@amd.com>
>>>> Acked-by: Christian König <christian.koenig@amd.com>
>>>> Reviewed-by: Matthew Auld <matthew.auld@intel.com>
>>>> Cc: stable@vger.kernel.org
>>>> Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
>>>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
>>>> ---
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_device.c   |  2 +
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h      |  1 +
>>>>    drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 17 ++++++++
>>>>    drivers/gpu/drm/drm_buddy.c                  | 43 ++++++++++++++++++++
>>>>    include/drm/drm_buddy.h                      |  2 +
>>>>    5 files changed, 65 insertions(+)
>>>>
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> index 723ab95d8c48..ac92220f9fc3 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>>> @@ -5327,6 +5327,8 @@ int amdgpu_device_resume(struct drm_device *dev, bool notify_clients)
>>>>            dev->dev->power.disable_depth--;
>>>>    #endif
>>>>        }
>>>> +
>>>> +    amdgpu_vram_mgr_clear_reset_blocks(adev);
>>>>        adev->in_suspend = false;
>>>>          if (amdgpu_acpi_smart_shift_update(dev, AMDGPU_SS_DEV_D0))
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> index 215c198e4aff..2309df3f68a9 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>>> @@ -155,6 +155,7 @@ int amdgpu_vram_mgr_reserve_range(struct amdgpu_vram_mgr *mgr,
>>>>                      uint64_t start, uint64_t size);
>>>>    int amdgpu_vram_mgr_query_page_status(struct amdgpu_vram_mgr *mgr,
>>>>                          uint64_t start);
>>>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev);
>>>>      bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
>>>>                    struct ttm_resource *res);
>>>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>>> index abdc52b0895a..07c936e90d8e 100644
>>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
>>>> @@ -782,6 +782,23 @@ uint64_t amdgpu_vram_mgr_vis_usage(struct amdgpu_vram_mgr *mgr)
>>>>        return atomic64_read(&mgr->vis_usage);
>>>>    }
>>>>    +/**
>>>> + * amdgpu_vram_mgr_clear_reset_blocks - reset clear blocks
>>>> + *
>>>> + * @adev: amdgpu device pointer
>>>> + *
>>>> + * Reset the cleared drm buddy blocks.
>>>> + */
>>>> +void amdgpu_vram_mgr_clear_reset_blocks(struct amdgpu_device *adev)
>>>> +{
>>>> +    struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
>>>> +    struct drm_buddy *mm = &mgr->mm;
>>>> +
>>>> +    mutex_lock(&mgr->lock);
>>>> +    drm_buddy_reset_clear(mm, false);
>>>> +    mutex_unlock(&mgr->lock);
>>>> +}
>>>> +
>>>>    /**
>>>>     * amdgpu_vram_mgr_intersects - test each drm buddy block for intersection
>>>>     *
>>>> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
>>>> index a1e652b7631d..a94061f373de 100644
>>>> --- a/drivers/gpu/drm/drm_buddy.c
>>>> +++ b/drivers/gpu/drm/drm_buddy.c
>>>> @@ -405,6 +405,49 @@ drm_get_buddy(struct drm_buddy_block *block)
>>>>    }
>>>>    EXPORT_SYMBOL(drm_get_buddy);
>>>>    +/**
>>>> + * drm_buddy_reset_clear - reset blocks clear state
>>>> + *
>>>> + * @mm: DRM buddy manager
>>>> + * @is_clear: blocks clear state
>>>> + *
>>>> + * Reset the clear state based on @is_clear value for each block
>>>> + * in the freelist.
>>>> + */
>>>> +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear)
>>>> +{
>>>> +    u64 root_size, size, start;
>>>> +    unsigned int order;
>>>> +    int i;
>>>> +
>>>> +    size = mm->size;
>>>> +    for (i = 0; i < mm->n_roots; ++i) {
>>>> +        order = ilog2(size) - ilog2(mm->chunk_size);
>>>> +        start = drm_buddy_block_offset(mm->roots[i]);
>>>> +        __force_merge(mm, start, start + size, order);
>>>> +
>>>> +        root_size = mm->chunk_size << order;
>>>> +        size -= root_size;
>>>> +    }
>>>> +
>>>> +    for (i = 0; i <= mm->max_order; ++i) {
>>>> +        struct drm_buddy_block *block;
>>>> +
>>>> +        list_for_each_entry_reverse(block, &mm->free_list[i], link) {
>>>> +            if (is_clear != drm_buddy_block_is_clear(block)) {
>>>> +                if (is_clear) {
>>>> +                    mark_cleared(block);
>>>> +                    mm->clear_avail += drm_buddy_block_size(mm, block);
>>>> +                } else {
>>>> +                    clear_reset(block);
>>>> +                    mm->clear_avail -= drm_buddy_block_size(mm, block);
>>>> +                }
>>>> +            }
>>>> +        }
>>>> +    }
>>>> +}
>>>> +EXPORT_SYMBOL(drm_buddy_reset_clear);
>>>> +
>>>>    /**
>>>>     * drm_buddy_free_block - free a block
>>>>     *
>>>> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
>>>> index 9689a7c5dd36..513837632b7d 100644
>>>> --- a/include/drm/drm_buddy.h
>>>> +++ b/include/drm/drm_buddy.h
>>>> @@ -160,6 +160,8 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>>>                 u64 new_size,
>>>>                 struct list_head *blocks);
>>>>    +void drm_buddy_reset_clear(struct drm_buddy *mm, bool is_clear);
>>>> +
>>>>    void drm_buddy_free_block(struct drm_buddy *mm, struct drm_buddy_block *block);
>>>>      void drm_buddy_free_list(struct drm_buddy *mm,