[PATCH v3 2/3] drm/amdgpu: Reset the clear flag in buddy during resume
Arunpravin Paneer Selvam
arunpravin.paneerselvam at amd.com
Thu Jul 10 14:54:18 UTC 2025
On 7/10/2025 7:50 PM, Matthew Auld wrote:
> 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!
>
>>
>> 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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