[PATCH] drm/buddy: Add start address support to trim function
Matthew Auld
matthew.auld at intel.com
Tue Jul 16 10:04:03 UTC 2024
On 16/07/2024 10:50, Paneer Selvam, Arunpravin wrote:
> Hi Matthew,
>
> On 7/10/2024 6:20 PM, Matthew Auld wrote:
>> On 10/07/2024 07:03, Paneer Selvam, Arunpravin wrote:
>>> Thanks Alex.
>>>
>>> Hi Matthew,
>>> Any comments?
>>
>> Do we not pass the required address alignment when allocating the
>> pages in the first place?
> If address alignment is really useful, we can add that in the
> drm_buddy_alloc_blocks() function.
I mean don't we already pass the min page size, which should give us
matching physical address alignment?
>
> Thanks,
> Arun.
>>
>>>
>>> Thanks,
>>> Arun.
>>>
>>> On 7/9/2024 1:42 AM, Alex Deucher wrote:
>>>> On Thu, Jul 4, 2024 at 4:40 AM Arunpravin Paneer Selvam
>>>> <Arunpravin.PaneerSelvam at amd.com> wrote:
>>>>> - Add a new start parameter in trim function to specify exact
>>>>> address from where to start the trimming. This would help us
>>>>> in situations like if drivers would like to do address alignment
>>>>> for specific requirements.
>>>>>
>>>>> - Add a new flag DRM_BUDDY_TRIM_DISABLE. Drivers can use this
>>>>> flag to disable the allocator trimming part. This patch enables
>>>>> the drivers control trimming and they can do it themselves
>>>>> based on the application requirements.
>>>>>
>>>>> v1:(Matthew)
>>>>> - check new_start alignment with min chunk_size
>>>>> - use range_overflows()
>>>>>
>>>>> Signed-off-by: Arunpravin Paneer Selvam
>>>>> <Arunpravin.PaneerSelvam at amd.com>
>>>> Series is:
>>>> Acked-by: Alex Deucher <alexander.deucher at amd.com>
>>>>
>>>> I'd like to take this series through the amdgpu tree if there are no
>>>> objections as it's required for display buffers on some chips and I'd
>>>> like to make sure it lands in 6.11.
>>>>
>>>> Thanks,
>>>>
>>>> Alex
>>>>
>>>>> ---
>>>>> drivers/gpu/drm/drm_buddy.c | 25 +++++++++++++++++++++++--
>>>>> drivers/gpu/drm/xe/xe_ttm_vram_mgr.c | 2 +-
>>>>> include/drm/drm_buddy.h | 2 ++
>>>>> 3 files changed, 26 insertions(+), 3 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/drm_buddy.c b/drivers/gpu/drm/drm_buddy.c
>>>>> index 94f8c34fc293..8cebe1fa4e9d 100644
>>>>> --- a/drivers/gpu/drm/drm_buddy.c
>>>>> +++ b/drivers/gpu/drm/drm_buddy.c
>>>>> @@ -851,6 +851,7 @@ static int __alloc_contig_try_harder(struct
>>>>> drm_buddy *mm,
>>>>> * drm_buddy_block_trim - free unused pages
>>>>> *
>>>>> * @mm: DRM buddy manager
>>>>> + * @start: start address to begin the trimming.
>>>>> * @new_size: original size requested
>>>>> * @blocks: Input and output list of allocated blocks.
>>>>> * MUST contain single block as input to be trimmed.
>>>>> @@ -866,11 +867,13 @@ static int __alloc_contig_try_harder(struct
>>>>> drm_buddy *mm,
>>>>> * 0 on success, error code on failure.
>>>>> */
>>>>> int drm_buddy_block_trim(struct drm_buddy *mm,
>>>>> + u64 *start,
>>>>> u64 new_size,
>>>>> struct list_head *blocks)
>>>>> {
>>>>> struct drm_buddy_block *parent;
>>>>> struct drm_buddy_block *block;
>>>>> + u64 block_start, block_end;
>>>>> LIST_HEAD(dfs);
>>>>> u64 new_start;
>>>>> int err;
>>>>> @@ -882,6 +885,9 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>>>> struct drm_buddy_block,
>>>>> link);
>>>>>
>>>>> + block_start = drm_buddy_block_offset(block);
>>>>> + block_end = block_start + drm_buddy_block_size(mm, block);
>>>>> +
>>>>> if (WARN_ON(!drm_buddy_block_is_allocated(block)))
>>>>> return -EINVAL;
>>>>>
>>>>> @@ -894,6 +900,20 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>>>> if (new_size == drm_buddy_block_size(mm, block))
>>>>> return 0;
>>>>>
>>>>> + new_start = block_start;
>>>>> + if (start) {
>>>>> + new_start = *start;
>>>>> +
>>>>> + if (new_start < block_start)
>>>>> + return -EINVAL;
>>>>> +
>>>>> + if (!IS_ALIGNED(new_start, mm->chunk_size))
>>>>> + return -EINVAL;
>>>>> +
>>>>> + if (range_overflows(new_start, new_size, block_end))
>>>>> + return -EINVAL;
>>>>> + }
>>>>> +
>>>>> list_del(&block->link);
>>>>> mark_free(mm, block);
>>>>> mm->avail += drm_buddy_block_size(mm, block);
>>>>> @@ -904,7 +924,6 @@ int drm_buddy_block_trim(struct drm_buddy *mm,
>>>>> parent = block->parent;
>>>>> block->parent = NULL;
>>>>>
>>>>> - new_start = drm_buddy_block_offset(block);
>>>>> list_add(&block->tmp_link, &dfs);
>>>>> err = __alloc_range(mm, &dfs, new_start, new_size,
>>>>> blocks, NULL);
>>>>> if (err) {
>>>>> @@ -1066,7 +1085,8 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
>>>>> } while (1);
>>>>>
>>>>> /* Trim the allocated block to the required size */
>>>>> - if (original_size != size) {
>>>>> + if (!(flags & DRM_BUDDY_TRIM_DISABLE) &&
>>>>> + original_size != size) {
>>>>> struct list_head *trim_list;
>>>>> LIST_HEAD(temp);
>>>>> u64 trim_size;
>>>>> @@ -1083,6 +1103,7 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
>>>>> }
>>>>>
>>>>> drm_buddy_block_trim(mm,
>>>>> + NULL,
>>>>> trim_size,
>>>>> trim_list);
>>>>>
>>>>> diff --git a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>>> b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>>> index fe3779fdba2c..423b261ea743 100644
>>>>> --- a/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>>> +++ b/drivers/gpu/drm/xe/xe_ttm_vram_mgr.c
>>>>> @@ -150,7 +150,7 @@ static int xe_ttm_vram_mgr_new(struct
>>>>> ttm_resource_manager *man,
>>>>> } while (remaining_size);
>>>>>
>>>>> if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
>>>>> - if (!drm_buddy_block_trim(mm, vres->base.size,
>>>>> &vres->blocks))
>>>>> + if (!drm_buddy_block_trim(mm, NULL,
>>>>> vres->base.size, &vres->blocks))
>>>>> size = vres->base.size;
>>>>> }
>>>>>
>>>>> diff --git a/include/drm/drm_buddy.h b/include/drm/drm_buddy.h
>>>>> index 82570f77e817..0c2f735f0265 100644
>>>>> --- a/include/drm/drm_buddy.h
>>>>> +++ b/include/drm/drm_buddy.h
>>>>> @@ -27,6 +27,7 @@
>>>>> #define DRM_BUDDY_CONTIGUOUS_ALLOCATION BIT(2)
>>>>> #define DRM_BUDDY_CLEAR_ALLOCATION BIT(3)
>>>>> #define DRM_BUDDY_CLEARED BIT(4)
>>>>> +#define DRM_BUDDY_TRIM_DISABLE BIT(5)
>>>>>
>>>>> struct drm_buddy_block {
>>>>> #define DRM_BUDDY_HEADER_OFFSET GENMASK_ULL(63, 12)
>>>>> @@ -155,6 +156,7 @@ int drm_buddy_alloc_blocks(struct drm_buddy *mm,
>>>>> unsigned long flags);
>>>>>
>>>>> int drm_buddy_block_trim(struct drm_buddy *mm,
>>>>> + u64 *start,
>>>>> u64 new_size,
>>>>> struct list_head *blocks);
>>>>>
>>>>> --
>>>>> 2.25.1
>>>>>
>>>
>
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