Re: [PATCH v2 2/4] drm/ttm: parameter to add extra pages into ttm_tt

[Christian König <christian.koenig@xxxxxxx>]

Am 01.03.22 um 22:53 schrieb Ramalingam C:
> When a driver needs extra pages in ttm_tt, to facilidate such
> requirement, parameter called "extra_pages" is added for
> ttm_tt_init
>
> Signed-off-by: Ramalingam C <ramalingam.c@xxxxxxxxx>
> cc: Christian Koenig <christian.koenig@xxxxxxx>
> cc: Hellstrom Thomas <thomas.hellstrom@xxxxxxxxx>

With the nits pointed out by Thomas the patch is Reviewed-by: Christian 
König <christian.koenig@xxxxxxx> as well.

Let me know through which branch you want to push this upstream (i915 or 
drm-misc-next).

Thanks,
Christian.

> ---
>   drivers/gpu/drm/drm_gem_vram_helper.c      |  2 +-
>   drivers/gpu/drm/i915/gem/i915_gem_ttm.c    |  2 +-
>   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, 15 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c b/drivers/gpu/drm/drm_gem_vram_helper.c
> index dc7f938bfff2..123045b58fec 100644
> --- a/drivers/gpu/drm/drm_gem_vram_helper.c
> +++ b/drivers/gpu/drm/drm_gem_vram_helper.c
> @@ -867,7 +867,7 @@ 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 45cc5837ce00..1a8262f5f692 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
> @@ -283,7 +283,7 @@ 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);
> +	ret = ttm_tt_init(&i915_tt->ttm, bo, page_flags, caching, 0);
>   	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 d234aab800a0..1a66d9fc589a 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 extra_pages)
>   {
> -	ttm->num_pages = PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT;
> +	ttm->num_pages = (PAGE_ALIGN(bo->base.size) >> PAGE_SHIFT) + extra_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 extra_pages)
>   {
> -	ttm_tt_init_fields(ttm, bo, page_flags, caching);
> +	ttm_tt_init_fields(ttm, bo, page_flags, caching, extra_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..17a0310e8aaa 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
> + * @extra_pages: Extra pages needed for the driver.
>    *
>    * 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 extra_pages);
>   int ttm_sg_tt_init(struct ttm_tt *ttm_dma, struct ttm_buffer_object *bo,
>   		   uint32_t page_flags, enum ttm_caching caching);
>