[PATCH v3 2/3] drm/amdgpu: Reset the clear flag in buddy during resume
Matthew Auld
matthew.auld at intel.com
Thu Jul 10 14:20:10 UTC 2025
On 10/07/2025 08:14, Arunpravin Paneer Selvam wrote:
>
> On 7/8/2025 2:30 PM, Matthew Auld wrote:
>> On 08/07/2025 07:54, 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 at amd.com>
>>> Suggested-by: Christian König <christian.koenig at amd.com>
>>> Cc: stable at vger.kernel.org
>>> Fixes: a68c7eaa7a8f ("drm/amdgpu: Enable clear page functionality")
>>> Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3812
>>
>> Reviewed-by: Matthew Auld <matthew.auld at intel.com>
>
> Is this RB also for the unit test case (patch 3).
Feel free to apply my r-b there also.
>
> Thanks,
>
> Arun.
>
>>
>>> ---
>>> 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 a59f194e3360..b89e46f29b51 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
>>> @@ -5193,6 +5193,8 @@ 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 208b7d1d8a27..450e4bf093b7 100644
>>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>>> @@ -154,6 +154,7 @@ 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,
>>
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