Re: [Intel-gfx] [RFC 1/2] drm/i915/ttm: Add extra pages for handling ccs data

On 07/02/2022 10:37, Ramalingam C wrote:

While evicting the local memory data on flat-ccs capable platform we need to evict the ccs data associated to the data. For this, we are adding extra pages ((size / 256) >> PAGE_SIZE) into the ttm_tt.

To achieve this we are adding a new param into the ttm_tt_init as ccs_pages_needed, which will be added into the ttm_tt->num_pages.

Signed-off-by: Ramalingam C ramalingam.c@intel.com Suggested-by: Thomas Hellstorm thomas.hellstrom@intel.com

---

drivers/gpu/drm/drm_gem_vram_helper.c | 2 +- drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 23 +++++++++++++++++++++- drivers/gpu/drm/qxl/qxl_ttm.c | 2 +- drivers/gpu/drm/ttm/ttm_agp_backend.c | 2 +- drivers/gpu/drm/ttm/ttm_tt.c | 12 ++++++----- drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c | 2 +- include/drm/ttm/ttm_tt.h | 4 +++- 7 files changed, 36 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c index 3f00192215d1..eef1f4dc7232 100644 --- a/drivers/gpu/drm/drm_gem_vram_helper.c +++ b/drivers/gpu/drm/drm_gem_vram_helper.c @@ -864,7 +864,7 @@ static struct ttm_tt *bo_driver_ttm_tt_create(struct ttm_buffer_object *bo, if (!tt) return NULL;

• ret = ttm_tt_init(tt, bo, page_flags, ttm_cached);

• ret = ttm_tt_init(tt, bo, page_flags, ttm_cached, 0); if (ret < 0) goto err_ttm_tt_init;

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index 84cae740b4a5..bb71aa6d66c0 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -16,6 +16,7 @@ #include "gem/i915_gem_ttm.h" #include "gem/i915_gem_ttm_move.h" #include "gem/i915_gem_ttm_pm.h" +#include "gt/intel_gpu_commands.h"

#define I915_TTM_PRIO_PURGE 0 #define I915_TTM_PRIO_NO_PAGES 1 @@ -242,12 +243,27 @@ static const struct i915_refct_sgt_ops tt_rsgt_ops = { .release = i915_ttm_tt_release };

+static inline bool +i915_gem_object_has_lmem_placement(struct drm_i915_gem_object *obj) +{

• int i;
• for (i = 0; i < obj->mm.n_placements; i++)

• if (obj->mm.placements[i]->type == INTEL_MEMORY_LOCAL)
  

• 	return true;
  

• return false;

+}

• static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, uint32_t page_flags) {
• struct drm_i915_private *i915 = container_of(bo->bdev, typeof(*i915),

• 				     bdev);
  

  struct ttm_resource_manager *man = ttm_manager_type(bo->bdev, bo->resource->mem_type); struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
• unsigned long ccs_pages_needed = 0; enum ttm_caching caching; struct i915_ttm_tt *i915_tt; int ret;

@@ -270,7 +286,12 @@ static struct ttm_tt *i915_ttm_tt_create(struct ttm_buffer_object *bo, i915_tt->is_shmem = true; }

• ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching);

• if (HAS_FLAT_CCS(i915) && i915_gem_object_has_lmem_placement(obj))

• ccs_pages_needed = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size,
  

• 			       NUM_CCS_BYTES_PER_BLOCK), PAGE_SIZE);
  

• ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags,

• 	  caching, ccs_pages_needed);
  

I am wondering if we should do this in the driver itself and pass ttm->num_pages with CCS size included.

Regards,

Nirmoy

if (ret) goto err_free;

diff --git a/drivers/gpu/drm/qxl/qxl_ttm.c b/drivers/gpu/drm/qxl/qxl_ttm.c index b2e33d5ba5d0..52156b54498f 100644 --- a/drivers/gpu/drm/qxl/qxl_ttm.c +++ b/drivers/gpu/drm/qxl/qxl_ttm.c @@ -113,7 +113,7 @@ static struct ttm_tt *qxl_ttm_tt_create(struct ttm_buffer_object *bo, ttm = kzalloc(sizeof(struct ttm_tt), GFP_KERNEL); if (ttm == NULL) return NULL;

• if (ttm_tt_init(ttm, bo, page_flags, ttm_cached)) {

• if (ttm_tt_init(ttm, bo, page_flags, ttm_cached, 0)) { kfree(ttm); return NULL; }

diff --git a/drivers/gpu/drm/ttm/ttm_agp_backend.c b/drivers/gpu/drm/ttm/ttm_agp_backend.c index 6ddc16f0fe2b..d27691f2e451 100644 --- a/drivers/gpu/drm/ttm/ttm_agp_backend.c +++ b/drivers/gpu/drm/ttm/ttm_agp_backend.c @@ -134,7 +134,7 @@ struct ttm_tt *ttm_agp_tt_create(struct ttm_buffer_object *bo, agp_be->mem = NULL; agp_be->bridge = bridge;

• if (ttm_tt_init(&agp_be->ttm, bo, page_flags, ttm_write_combined)) {

• if (ttm_tt_init(&agp_be->ttm, bo, page_flags, ttm_write_combined, 0)) { kfree(agp_be); return NULL; }

diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c index 79c870a3bef8..80355465f717 100644 --- a/drivers/gpu/drm/ttm/ttm_tt.c +++ b/drivers/gpu/drm/ttm/ttm_tt.c @@ -134,9 +134,10 @@ void ttm_tt_destroy(struct ttm_device *bdev, struct ttm_tt *ttm) static void ttm_tt_init_fields(struct ttm_tt *ttm, struct ttm_buffer_object *bo, uint32_t page_flags,

• 	       enum ttm_caching caching)
  

• 	       enum ttm_caching caching,
  

• 	       unsigned long ccs_pages)
  

  {

• ttm->num_pages = PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT;

• ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + ccs_pages; ttm->caching = ttm_cached; ttm->page_flags = page_flags; ttm->dma_address = NULL;

@@ -146,9 +147,10 @@ static void ttm_tt_init_fields(struct ttm_tt *ttm, }

int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,

• uint32_t page_flags, enum ttm_caching caching)
  

• uint32_t page_flags, enum ttm_caching caching,
  

• unsigned long ccs_pages)
  

  {

• ttm_tt_init_fields(ttm, bo, page_flags, caching);

• ttm_tt_init_fields(ttm, bo, page_flags, caching, ccs_pages);

  if (ttm_tt_alloc_page_directory(ttm)) { pr_err("Failed allocating page table\n");

@@ -180,7 +182,7 @@ int ttm_sg_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo, { int ret;

• ttm_tt_init_fields(ttm, bo, page_flags, caching);

• ttm_tt_init_fields(ttm, bo, page_flags, caching, 0);

  if (page_flags & TTM_TT_FLAG_EXTERNAL) ret = ttm_sg_tt_alloc_page_directory(ttm);

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c index b84ecc6d6611..4e3938e62c08 100644 --- a/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_ttm_buffer.c @@ -517,7 +517,7 @@ static struct ttm_tt *vmw_ttm_tt_create(struct ttm_buffer_object *bo, ttm_cached); else ret = ttm_tt_init(&vmw_be->dma_ttm, bo, page_flags,

• 		  ttm_cached);
  

• 		  ttm_cached, 0);
  

  if (unlikely(ret != 0)) goto out_no_init;

diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h index f20832139815..2c4ff08ea354 100644 --- a/include/drm/ttm/ttm_tt.h +++ b/include/drm/ttm/ttm_tt.h @@ -140,6 +140,7 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc);

• @bo: The buffer object we create the ttm for.
• @page_flags: Page flags as identified by TTM_TT_FLAG_XX flags.
• @caching: the desired caching state of the pages

• • @ccs_pages_needed: Extra pages needed for the ccs data of compression.
  • Create a struct ttm_tt to back data with system memory pages.
  • No pages are actually allocated.

@@ -147,7 +148,8 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc);

• NULL: Out of memory.

*/ int ttm_tt_init(struct ttm_tt *ttm, struct ttm_buffer_object *bo,

• uint32_t page_flags, enum ttm_caching caching);
  

• uint32_t page_flags, enum ttm_caching caching,
  

• unsigned long ccs_pages_needed);
  

  int ttm_sg_tt_init(struct ttm_tt *ttm_dma, struct ttm_buffer_object *bo, uint32_t page_flags, enum ttm_caching caching);