Marek
On Tue, Jul 23, 2024, 11:04 Matthew Auld <matthew.auld@xxxxxxxxx
<mailto:matthew.auld@xxxxxxxxx>> wrote:
On 23/07/2024 14:43, Paneer Selvam, Arunpravin wrote:
> Hi Matthew,
>
> Can we push this version for now as we need to mainline the DCC
changes
> ASAP,
> while we continue our discussion and proceed to implement the
permanent
> solution
> for address alignment?
Yeah, we can always merge now and circle back around later, if
this for
sure helps your usecase and is needed asap. I just didn't fully
get the
idea for needing this interface, but likely I am missing something.
>
> Thanks,
> Arun.
>
> On 7/23/2024 6:55 PM, Arunpravin Paneer Selvam 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@xxxxxxx
<mailto:Arunpravin.PaneerSelvam@xxxxxxx>>
>> Acked-by: Alex Deucher <alexander.deucher@xxxxxxx
<mailto:alexander.deucher@xxxxxxx>>
>> Acked-by: Christian König <christian.koenig@xxxxxxx
<mailto:christian.koenig@xxxxxxx>>
>> ---
>> 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 6a8e45e9d0ec..103c185bb1c8 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 2a74fa9d0ce5..9689a7c5dd36 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);
>>
>> base-commit: b27d70e1042bf6a31ba7e5acf58b61c9cd28f95b
>
