[Intel-gfx] [RFC 1/2] drm/i915/ttm: Add extra pages for handling ccs data
Thomas Hellström (Intel)
thomas_os at shipmail.org
Mon Feb 7 10:41:18 UTC 2022
Hi, Ram,
On 2/7/22 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.
Please use imperative form above, Instead of "We are adding..", use "Add"
>
> Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
> Suggested-by: Thomas Hellstorm <thomas.hellstrom at intel.com>
Hellstorm instead of Hellstrom might scare people off. :)
> ---
> 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'd suggest a patch that first adds the functionality to TTM, where even
i915 passes in 0 here, and a follow-up patch for the i915 functionality
where we add the ccs requirement.
> 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.
The name and use-case ccs is driver specific, and TTM knows nothing
about CCS. Hence we should use "additional_pages", "additional_size" or
something similar for this. Christian might have some additional
guidance here.
> *
> * 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);
>
Thanks,
Thomas
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