On Xe-HP and later devices, dedicated compression control state (CCS) stored in local memory is used for each surface, to support the 3D and media compression formats.
The memory required for the CCS of the entire local memory is 1/256 of the local memory size. So before the kernel boot, the required memory is reserved for the CCS data and a secure register will be programmed with the CCS base address
So when an object is allocated in local memory, dont need to explicitly allocate the space for ccs data. But when the obj is evicted into the smem, to hold the compression related data along with the obj extra space is needed in smem. i.e obj_size + (obj_size/256).
Hence when a smem pages are allocated for an obj with lmem placement possibility we create with the extra pages required for the ccs data for the obj size.
v2: Used imperative wording [Thomas] v3: Inflate the pages only when obj's placement is lmem only
Signed-off-by: Ramalingam C ramalingam.c@intel.com cc: Christian Koenig christian.koenig@amd.com cc: Hellstrom Thomas thomas.hellstrom@intel.com Reviewed-by: Thomas Hellström thomas.hellstrom@linux.intel.com --- drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 29 ++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c index 3b9f99c765c4..0305a150b9d4 100644 --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c @@ -20,6 +20,7 @@ #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 @@ -262,12 +263,33 @@ static const struct i915_refct_sgt_ops tt_rsgt_ops = { .release = i915_ttm_tt_release };
+static inline bool +i915_gem_object_needs_ccs_pages(struct drm_i915_gem_object *obj) +{ + bool lmem_placement = false; + int i; + + for (i = 0; i < obj->mm.n_placements; i++) { + /* Compression is not allowed for the objects with smem placement */ + if (obj->mm.placements[i]->type == INTEL_MEMORY_SYSTEM) + return false; + if (!lmem_placement && + obj->mm.placements[i]->type == INTEL_MEMORY_LOCAL) + lmem_placement = true; + } + + return lmem_placement; +} + 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 = 0; enum ttm_caching caching; struct i915_ttm_tt *i915_tt; int ret; @@ -290,7 +312,12 @@ 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, 0); + if (HAS_FLAT_CCS(i915) && i915_gem_object_needs_ccs_pages(obj)) + ccs_pages = DIV_ROUND_UP(DIV_ROUND_UP(bo->base.size, + NUM_BYTES_PER_CCS_BYTE), + PAGE_SIZE); + + ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, ccs_pages); if (ret) goto err_free;