AMDGPU_GEM_CREATE_GFX12_DCC is set on 90% of all memory allocations, and
almost all of them are not displayable. Shouldn't we use a different way to
indicate that we need a non-power-of-two alignment, such as looking at the
alignment field directly?
Marek
On Tue, Jul 16, 2024, 11:45 Arunpravin Paneer Selvam <
arunpravin.paneersel...@amd.com> wrote:
> Add address alignment support to the DCC VRAM buffers.
>
> v2:
> - adjust size based on the max_texture_channel_caches values
> only for GFX12 DCC buffers.
> - used AMDGPU_GEM_CREATE_GFX12_DCC flag to apply change only
> for DCC buffers.
> - roundup non power of two DCC buffer adjusted size to nearest
> power of two number as the buddy allocator does not support non
> power of two alignments. This applies only to the contiguous
> DCC buffers.
>
> v3:(Alex)
> - rewrite the max texture channel caches comparison code in an
> algorithmic way to determine the alignment size.
>
> v4:(Alex)
> - Move the logic from amdgpu_vram_mgr_dcc_alignment() to gmc_v12_0.c
> and add a new gmc func callback for dcc alignment. If the callback
> is non-NULL, call it to get the alignment, otherwise, use the default.
>
> v5:(Alex)
> - Set the Alignment to a default value if the callback doesn't exist.
> - Add the callback to amdgpu_gmc_funcs.
>
> v6:
> - Fix checkpatch error reported by Intel CI.
>
> Signed-off-by: Arunpravin Paneer Selvam <arunpravin.paneersel...@amd.com>
> Acked-by: Alex Deucher <alexander.deuc...@amd.com>
> Acked-by: Christian König <christian.koe...@amd.com>
> Reviewed-by: Frank Min <frank....@amd.com>
> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h | 6 ++++
> drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 36 ++++++++++++++++++--
> drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c | 15 ++++++++
> 3 files changed, 55 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> index febca3130497..654d0548a3f8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gmc.h
> @@ -156,6 +156,8 @@ struct amdgpu_gmc_funcs {
> uint64_t addr, uint64_t *flags);
> /* get the amount of memory used by the vbios for pre-OS console */
> unsigned int (*get_vbios_fb_size)(struct amdgpu_device *adev);
> + /* get the DCC buffer alignment */
> + u64 (*get_dcc_alignment)(struct amdgpu_device *adev);
>
> enum amdgpu_memory_partition (*query_mem_partition_mode)(
> struct amdgpu_device *adev);
> @@ -363,6 +365,10 @@ struct amdgpu_gmc {
> (adev)->gmc.gmc_funcs->override_vm_pte_flags \
> ((adev), (vm), (addr), (pte_flags))
> #define amdgpu_gmc_get_vbios_fb_size(adev)
> (adev)->gmc.gmc_funcs->get_vbios_fb_size((adev))
> +#define amdgpu_gmc_get_dcc_alignment(_adev) ({ \
> + typeof(_adev) (adev) = (_adev); \
> + ((adev)->gmc.gmc_funcs->get_dcc_alignment((adev))); \
> +})
>
> /**
> * amdgpu_gmc_vram_full_visible - Check if full VRAM is visible through
> the BAR
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> index f91cc149d06c..aa9dca12371c 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
> @@ -512,6 +512,16 @@ static int amdgpu_vram_mgr_new(struct
> ttm_resource_manager *man,
> vres->flags |= DRM_BUDDY_RANGE_ALLOCATION;
>
> remaining_size = (u64)vres->base.size;
> + if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS &&
> + bo->flags & AMDGPU_GEM_CREATE_GFX12_DCC) {
> + u64 adjust_size;
> +
> + if (adev->gmc.gmc_funcs->get_dcc_alignment) {
> + adjust_size = amdgpu_gmc_get_dcc_alignment(adev);
> + remaining_size = roundup_pow_of_two(remaining_size
> + adjust_size);
> + vres->flags |= DRM_BUDDY_TRIM_DISABLE;
> + }
> + }
>
> mutex_lock(&mgr->lock);
> while (remaining_size) {
> @@ -521,8 +531,12 @@ static int amdgpu_vram_mgr_new(struct
> ttm_resource_manager *man,
> min_block_size = mgr->default_page_size;
>
> size = remaining_size;
> - if ((size >= (u64)pages_per_block << PAGE_SHIFT) &&
> - !(size & (((u64)pages_per_block << PAGE_SHIFT) - 1)))
> +
> + if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS &&
> + bo->flags & AMDGPU_GEM_CREATE_GFX12_DCC)
> + min_block_size = size;
> + else if ((size >= (u64)pages_per_block << PAGE_SHIFT) &&
> + !(size & (((u64)pages_per_block << PAGE_SHIFT) -
> 1)))
> min_block_size = (u64)pages_per_block <<
> PAGE_SHIFT;
>
> BUG_ON(min_block_size < mm->chunk_size);
> @@ -553,6 +567,24 @@ static int amdgpu_vram_mgr_new(struct
> ttm_resource_manager *man,
> }
> mutex_unlock(&mgr->lock);
>
> + if (bo->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS &&
> + bo->flags & AMDGPU_GEM_CREATE_GFX12_DCC) {
> + struct drm_buddy_block *dcc_block;
> + u64 dcc_start, alignment;
> +
> + dcc_block = amdgpu_vram_mgr_first_block(&vres->blocks);
> + dcc_start = amdgpu_vram_mgr_block_start(dcc_block);
> +
> + if (adev->gmc.gmc_funcs->get_dcc_alignment) {
> + alignment = amdgpu_gmc_get_dcc_alignment(adev);
> + /* Adjust the start address for DCC buffers only */
> + dcc_start = roundup(dcc_start, alignment);
> + drm_buddy_block_trim(mm, &dcc_start,
> + (u64)vres->base.size,
> + &vres->blocks);
> + }
> + }
> +
> vres->base.start = 0;
> size = max_t(u64, amdgpu_vram_mgr_blocks_size(&vres->blocks),
> vres->base.size);
> diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> index fd3ac483760e..4259edcdec8a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/gmc_v12_0.c
> @@ -542,6 +542,20 @@ static unsigned gmc_v12_0_get_vbios_fb_size(struct
> amdgpu_device *adev)
> return 0;
> }
>
> +static u64 gmc_v12_0_get_dcc_alignment(struct amdgpu_device *adev)
> +{
> + u64 max_tex_channel_caches, alignment;
> +
> + max_tex_channel_caches =
> adev->gfx.config.max_texture_channel_caches;
> + if (is_power_of_2(max_tex_channel_caches))
> + alignment = (max_tex_channel_caches / SZ_4) *
> max_tex_channel_caches;
> + else
> + alignment = roundup_pow_of_two(max_tex_channel_caches) *
> + max_tex_channel_caches;
> +
> + return (u64)alignment * SZ_1K;
> +}
> +
> static const struct amdgpu_gmc_funcs gmc_v12_0_gmc_funcs = {
> .flush_gpu_tlb = gmc_v12_0_flush_gpu_tlb,
> .flush_gpu_tlb_pasid = gmc_v12_0_flush_gpu_tlb_pasid,
> @@ -551,6 +565,7 @@ static const struct amdgpu_gmc_funcs
> gmc_v12_0_gmc_funcs = {
> .get_vm_pde = gmc_v12_0_get_vm_pde,
> .get_vm_pte = gmc_v12_0_get_vm_pte,
> .get_vbios_fb_size = gmc_v12_0_get_vbios_fb_size,
> + .get_dcc_alignment = gmc_v12_0_get_dcc_alignment,
> };
>
> static void gmc_v12_0_set_gmc_funcs(struct amdgpu_device *adev)
> --
> 2.25.1
>
>
