Re: [PATCH v6 8/8] drm/xe/migrate: Parameterize ccs and bo data clear in xe_migrate_clear()

[Matthew Brost <matthew.brost@intel.com>]

On Wed, Jul 17, 2024 at 05:21:33AM +0000, Akshata Jahagirdar wrote:
> Parameterize clearing ccs and bo data in xe_migrate_clear() which  higher
> layers can utilize. This patch will be used later on when doing bo data
> clear for igfx as well.
> 
> v2: Moved 2 bool arguments to a flag argument
> 
> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
> Signed-off-by: Akshata Jahagirdar <akshata.jahagirdar@intel.com>
> ---
>  drivers/gpu/drm/xe/tests/xe_bo.c      |  3 ++-
>  drivers/gpu/drm/xe/tests/xe_migrate.c |  8 +++----
>  drivers/gpu/drm/xe/xe_bo.c            | 10 +++++++--
>  drivers/gpu/drm/xe/xe_migrate.c       | 32 ++++++++++++++++++---------
>  drivers/gpu/drm/xe/xe_migrate.h       |  3 ++-
>  5 files changed, 37 insertions(+), 19 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/tests/xe_bo.c b/drivers/gpu/drm/xe/tests/xe_bo.c
> index e2e0ea24757a..c6db62a07276 100644
> --- a/drivers/gpu/drm/xe/tests/xe_bo.c
> +++ b/drivers/gpu/drm/xe/tests/xe_bo.c
> @@ -35,7 +35,8 @@ static int ccs_test_migrate(struct xe_tile *tile, struct xe_bo *bo,
>  
>  	/* Optionally clear bo *and* CCS data in VRAM. */
>  	if (clear) {
> -		fence = xe_migrate_clear(tile->migrate, bo, bo->ttm.resource);
> +		fence = xe_migrate_clear(tile->migrate, bo, bo->ttm.resource,
> +					 BIT(2) | BIT(3));

Use defines everywhere. e.g. s/BIT(2)/CLEAR_BO_DATA_FLAG

>  		if (IS_ERR(fence)) {
>  			KUNIT_FAIL(test, "Failed to submit bo clear.\n");
>  			return PTR_ERR(fence);
> diff --git a/drivers/gpu/drm/xe/tests/xe_migrate.c b/drivers/gpu/drm/xe/tests/xe_migrate.c
> index 4929af88e75c..ac52bc4d2c51 100644
> --- a/drivers/gpu/drm/xe/tests/xe_migrate.c
> +++ b/drivers/gpu/drm/xe/tests/xe_migrate.c
> @@ -104,7 +104,7 @@ static void test_copy(struct xe_migrate *m, struct xe_bo *bo,
>  	}
>  
>  	xe_map_memset(xe, &remote->vmap, 0, 0xd0, remote->size);
> -	fence = xe_migrate_clear(m, remote, remote->ttm.resource);
> +	fence = xe_migrate_clear(m, remote, remote->ttm.resource, BIT(2) | BIT(3));
>  	if (!sanity_fence_failed(xe, fence, big ? "Clearing remote big bo" :
>  				 "Clearing remote small bo", test)) {
>  		retval = xe_map_rd(xe, &remote->vmap, 0, u64);
> @@ -278,7 +278,7 @@ static void xe_migrate_sanity_test(struct xe_migrate *m, struct kunit *test)
>  	kunit_info(test, "Clearing small buffer object\n");
>  	xe_map_memset(xe, &tiny->vmap, 0, 0x22, tiny->size);
>  	expected = 0;
> -	fence = xe_migrate_clear(m, tiny, tiny->ttm.resource);
> +	fence = xe_migrate_clear(m, tiny, tiny->ttm.resource, BIT(2) | BIT(3));
>  	if (sanity_fence_failed(xe, fence, "Clearing small bo", test))
>  		goto out;
>  
> @@ -299,7 +299,7 @@ static void xe_migrate_sanity_test(struct xe_migrate *m, struct kunit *test)
>  	kunit_info(test, "Clearing big buffer object\n");
>  	xe_map_memset(xe, &big->vmap, 0, 0x11, big->size);
>  	expected = 0;
> -	fence = xe_migrate_clear(m, big, big->ttm.resource);
> +	fence = xe_migrate_clear(m, big, big->ttm.resource, BIT(2) | BIT(3));
>  	if (sanity_fence_failed(xe, fence, "Clearing big bo", test))
>  		goto out;
>  
> @@ -598,7 +598,7 @@ static void test_clear(struct xe_device *xe, struct xe_tile *tile,
>  
>  	kunit_info(test, "Clear vram buffer object\n");
>  	expected = 0x0000000000000000;
> -	fence = xe_migrate_clear(tile->migrate, vram_bo, vram_bo->ttm.resource);
> +	fence = xe_migrate_clear(tile->migrate, vram_bo, vram_bo->ttm.resource, BIT(2) | BIT(3));
>  	if (sanity_fence_failed(xe, fence, "Clear vram_bo", test))
>  		return;
>  	dma_fence_put(fence);
> diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> index 31192d983d9e..22b16a0006c5 100644
> --- a/drivers/gpu/drm/xe/xe_bo.c
> +++ b/drivers/gpu/drm/xe/xe_bo.c
> @@ -793,8 +793,14 @@ static int xe_bo_move(struct ttm_buffer_object *ttm_bo, bool evict,
>  			}
>  		}
>  	} else {
> -		if (move_lacks_source)
> -			fence = xe_migrate_clear(migrate, bo, new_mem);
> +		if (move_lacks_source) {
> +			u32 clear_flags = mem_type_is_vram(new_mem->mem_type) ?
> +						BIT(2) : 0;
> +			clear_flags |= mem_type_is_vram(new_mem->mem_type) || handle_system_ccs ?
> +						BIT(3) : 0;
> +			fence = xe_migrate_clear(migrate, bo, new_mem,
> +						 clear_flags);
> +		}
>  		else
>  			fence = xe_migrate_copy(migrate, bo, bo, old_mem,
>  						new_mem, handle_system_ccs);
> diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
> index efd64af4f8cd..da06b434b9eb 100644
> --- a/drivers/gpu/drm/xe/xe_migrate.c
> +++ b/drivers/gpu/drm/xe/xe_migrate.c
> @@ -518,15 +518,15 @@ static bool xe_migrate_allow_identity(u64 size, const struct xe_res_cursor *cur)
>  #define PTE_UPDATE_FLAG_IS_COMP_PTE	BIT(1)
>  
>  static u32 pte_update_size(struct xe_migrate *m,
> -			   u32 flags,
> +			   u32 pte_flags,

Looks unrelated.

>  			   struct ttm_resource *res,
>  			   struct xe_res_cursor *cur,
>  			   u64 *L0, u64 *L0_ofs, u32 *L0_pt,
>  			   u32 cmd_size, u32 pt_ofs, u32 avail_pts)
>  {
>  	u32 cmds = 0;
> -	bool is_vram = PTE_UPDATE_FLAG_IS_VRAM & flags;
> -	bool is_comp_pte = PTE_UPDATE_FLAG_IS_COMP_PTE & flags;
> +	bool is_vram = PTE_UPDATE_FLAG_IS_VRAM & pte_flags;
> +	bool is_comp_pte = PTE_UPDATE_FLAG_IS_COMP_PTE & pte_flags;
>  
>  	*L0_pt = pt_ofs;
>  	if (is_vram && xe_migrate_allow_identity(*L0, cur)) {
> @@ -1032,14 +1032,19 @@ static void emit_clear(struct xe_gt *gt, struct xe_bb *bb, u64 src_ofs,
>  				     is_vram);
>  }
>  
> +#define CLEAR_BO_DATA_FLAG	BIT(2)
> +#define CLEAR_CCS_DATA_FLAG	BIT(3)
> +

BIT(0), BIT(1)

Also since this is a public function, define these in xe_migrate.h.

Since public define, probably normalize too (see xe_bo.h XE_BO_FLAG_*).

So...

s/CLEAR_BO_DATA_FLAG/XE_MIGRATE_CLEAR_FLAG_BO_DATA
s/CLEAR_BO_DATA_FLAG/XE_MIGRATE_CLEAR_FLAG_CCS_DATA

>  /**
>   * xe_migrate_clear() - Copy content of TTM resources.
>   * @m: The migration context.
>   * @bo: The buffer object @dst is currently bound to.
>   * @dst: The dst TTM resource to be cleared.
> + * @flags: flags to clear_bo_data and ccs metadata

Mismatch variable names flags & clear_flags. CI hooks is complaining about this.

>   *
> - * Clear the contents of @dst to zero. On flat CCS devices,
> - * the CCS metadata is cleared to zero as well on VRAM destinations.
> + * Clear the contents of @dst to zero when clear_bo_data_flag is set.
> + * On flat CCS devices, the CCS metadata is cleared to zero with clear_ccs_flag.
> + * Set both, clear_bo_data_flag and clear_ccs_flag to clear bo as well as CCS metadata
>   * TODO: Eliminate the @bo argument.
>   *
>   * Return: Pointer to a dma_fence representing the last clear batch, or
> @@ -1048,18 +1053,23 @@ static void emit_clear(struct xe_gt *gt, struct xe_bb *bb, u64 src_ofs,
>   */
>  struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>  				   struct xe_bo *bo,
> -				   struct ttm_resource *dst)
> +				   struct ttm_resource *dst,
> +				   u32 clear_flags)
>  {
>  	bool clear_vram = mem_type_is_vram(dst->mem_type);
> +	bool clear_bo_data = CLEAR_BO_DATA_FLAG & clear_flags;
> +	bool clear_ccs = CLEAR_CCS_DATA_FLAG & clear_flags;
>  	struct xe_gt *gt = m->tile->primary_gt;
>  	struct xe_device *xe = gt_to_xe(gt);
> -	bool clear_system_ccs = (xe_bo_needs_ccs_pages(bo) && !IS_DGFX(xe)) ? true : false;

I'm not familar enough with this code to know if this change is correct...

I'd check with Matt Auld or Thomas (but he is out for 3 more weeks),
don't feel comfortable RBing this one as I'm unfamilar.

>  	struct dma_fence *fence = NULL;
>  	u64 size = bo->size;
>  	struct xe_res_cursor src_it;
>  	struct ttm_resource *src = dst;
>  	int err;
>  
> +	if (WARN_ON(!clear_bo_data && !clear_ccs))
> +		return NULL;
> +
>  	if (!clear_vram)
>  		xe_res_first_sg(xe_bo_sg(bo), 0, bo->size, &src_it);
>  	else
> @@ -1085,7 +1095,7 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>  		batch_size = 2 +
>  			pte_update_size(m, pte_flags, src, &src_it,
>  					&clear_L0, &clear_L0_ofs, &clear_L0_pt,
> -					clear_system_ccs ? 0 : emit_clear_cmd_len(gt), 0,
> +					clear_bo_data ? emit_clear_cmd_len(gt) : 0, 0,
>  					avail_pts);
>  
>  		if (xe_migrate_needs_ccs_emit(xe))
> @@ -1107,13 +1117,13 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>  		if (clear_vram && xe_migrate_allow_identity(clear_L0, &src_it))
>  			xe_res_next(&src_it, clear_L0);
>  		else
> -			emit_pte(m, bb, clear_L0_pt, clear_vram, clear_system_ccs,
> +			emit_pte(m, bb, clear_L0_pt, clear_vram, clear_ccs,
>  				 &src_it, clear_L0, dst);
>  
>  		bb->cs[bb->len++] = MI_BATCH_BUFFER_END;
>  		update_idx = bb->len;
>  
> -		if (!clear_system_ccs)
> +		if (clear_bo_data)
>  			emit_clear(gt, bb, clear_L0_ofs, clear_L0, XE_PAGE_SIZE, clear_vram);
>  
>  		if (xe_migrate_needs_ccs_emit(xe)) {
> @@ -1172,7 +1182,7 @@ struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>  		return ERR_PTR(err);
>  	}
>  
> -	if (clear_system_ccs)
> +	if (clear_ccs)
>  		bo->ccs_cleared = true;
>  
>  	return fence;
> diff --git a/drivers/gpu/drm/xe/xe_migrate.h b/drivers/gpu/drm/xe/xe_migrate.h
> index 453e0ecf5034..0d19bfe02a23 100644
> --- a/drivers/gpu/drm/xe/xe_migrate.h
> +++ b/drivers/gpu/drm/xe/xe_migrate.h
> @@ -104,7 +104,8 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
>  
>  struct dma_fence *xe_migrate_clear(struct xe_migrate *m,
>  				   struct xe_bo *bo,
> -				   struct ttm_resource *dst);
> +				   struct ttm_resource *dst,
> +				   u32 clear_flags);
>  
>  struct xe_vm *xe_migrate_get_vm(struct xe_migrate *m);
>  
> -- 
> 2.34.1
>