Re: [Intel-gfx] [PATCH v4 03/14] drm/ttm: move ttm_tt_{add, clear}_mapping into amdgpu

Christian König
2021-09-21T11:29:43Z

Am 21.09.21 um 13:01 schrieb Matthew Auld:
> Now that setting page->index shouldn't be needed anymore, we are just
> left with setting page->mapping, and here it looks like amdgpu is the
> only user, where pointing the page->mapping at the dev_mapping is used
> to verify that the pages do indeed belong to the device, if userspace
> later tries to touch them.
>
> v2(Christian):
> - Drop the functions altogether and just inline modifying
> the page->mapping
>
> Signed-off-by: Matthew Auld <matthew.auld@intel.com>
> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Cc: Christian König <christian.koenig@amd.com>

Reviewed-by: Christian König <christian.koenig@amd.com>

> ---
> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 15 ++++++++++++++-
> drivers/gpu/drm/ttm/ttm_tt.c | 25 -------------------------
> 2 files changed, 14 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> index 820fcb24231f..438377a89aa3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> @@ -1119,6 +1119,8 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
> {
> struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
> + pgoff_t i;
> + int ret;
>
> /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
> if (gtt->userptr) {
> @@ -1131,7 +1133,14 @@ static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> return 0;
>
> - return ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
> + ret = ttm_pool_alloc(&adev->mman.bdev.pool, ttm, ctx);
> + if (ret)
> + return ret;
> +
> + for (i = 0; i < ttm->num_pages; ++i)
> + ttm->pages[i]->mapping = bdev->dev_mapping;
> +
> + return 0;
> }
>
> /*
> @@ -1145,6 +1154,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
> {
> struct amdgpu_ttm_tt *gtt = (void *)ttm;
> struct amdgpu_device *adev;
> + pgoff_t i;
>
> amdgpu_ttm_backend_unbind(bdev, ttm);
>
> @@ -1158,6 +1168,9 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
> if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> return;
>
> + for (i = 0; i < ttm->num_pages; ++i)
> + ttm->pages[i]->mapping = NULL;
> +
> adev = amdgpu_ttm_adev(bdev);
> return ttm_pool_free(&adev->mman.bdev.pool, ttm);
> }
> diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c
> index 1cc04c224988..980ecb079b2c 100644
> --- a/drivers/gpu/drm/ttm/ttm_tt.c
> +++ b/drivers/gpu/drm/ttm/ttm_tt.c
> @@ -289,17 +289,6 @@ int ttm_tt_swapout(struct ttm_device *bdev, struct ttm_tt *ttm,
> return ret;
> }
>
> -static void ttm_tt_add_mapping(struct ttm_device *bdev, struct ttm_tt *ttm)
> -{
> - pgoff_t i;
> -
> - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> - return;
> -
> - for (i = 0; i < ttm->num_pages; ++i)
> - ttm->pages[i]->mapping = bdev->dev_mapping;
> -}
> -
> int ttm_tt_populate(struct ttm_device *bdev,
> struct ttm_tt *ttm, struct ttm_operation_ctx *ctx)
> {
> @@ -336,7 +325,6 @@ int ttm_tt_populate(struct ttm_device *bdev,
> if (ret)
> goto error;
>
> - ttm_tt_add_mapping(bdev, ttm);
> ttm->page_flags |= TTM_PAGE_FLAG_PRIV_POPULATED;
> if (unlikely(ttm->page_flags & TTM_PAGE_FLAG_SWAPPED)) {
> ret = ttm_tt_swapin(ttm);
> @@ -359,24 +347,11 @@ int ttm_tt_populate(struct ttm_device *bdev,
> }
> EXPORT_SYMBOL(ttm_tt_populate);
>
> -static void ttm_tt_clear_mapping(struct ttm_tt *ttm)
> -{
> - pgoff_t i;
> - struct page **page = ttm->pages;
> -
> - if (ttm->page_flags & TTM_PAGE_FLAG_SG)
> - return;
> -
> - for (i = 0; i < ttm->num_pages; ++i)
> - (*page)->mapping = NULL;
> -}
> -
> void ttm_tt_unpopulate(struct ttm_device *bdev, struct ttm_tt *ttm)
> {
> if (!ttm_tt_is_populated(ttm))
> return;
>
> - ttm_tt_clear_mapping(ttm);
> if (bdev->funcs->ttm_tt_unpopulate)
> bdev->funcs->ttm_tt_unpopulate(bdev, ttm);
> else