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

["Thomas Hellström" <thomas.hellstrom@linux.intel.com>]

On Wed, 2022-03-02 at 03:23 +0530, Ramalingam C wrote:
> When a driver needs extra pages in ttm_tt, to facilidate such
> requirement, parameter called "extra_pages" is added for
> ttm_tt_init

nit: Please use imperative wording in commit title and description,
"Add a parameter to add extra pages.."

> 
> Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
> cc: Christian Koenig <christian.koenig@amd.com>
> cc: Hellstrom Thomas <thomas.hellstrom@intel.com>

Otherwise LGTM.
Reviewed-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>


> ---
>  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);
>