Re: [PATCH v3 02/12] drm/ttm: move ttm_tt_{add,clear}_mapping into amdgpu

Am 15.09.21 um 20:59 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.

Signed-off-by: Matthew Auld matthew.auld@intel.com Cc: Thomas Hellström thomas.hellstrom@linux.intel.com Cc: Christian König christian.koenig@amd.com

---

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 27 ++++++++++++++++++++++++- drivers/gpu/drm/ttm/ttm_tt.c | 25 ----------------------- 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c index 1129e17e9f09..c5fa6e62f6ca 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c @@ -1107,6 +1107,24 @@ static struct ttm_tt *amdgpu_ttm_tt_create(struct ttm_buffer_object *bo, return &gtt->ttm; }

+static void amdgpu_ttm_tt_add_mapping(struct ttm_device *bdev,

• 		      struct ttm_tt *ttm)
  

+{

• pgoff_t i;
• for (i = 0; i < ttm->num_pages; ++i)

• ttm->pages[i]->mapping = bdev->dev_mapping;
  

+}

+static void amdgpu_ttm_tt_clear_mapping(struct ttm_tt *ttm) +{

• struct page **page = ttm->pages;
• pgoff_t i;
• for (i = 0; i < ttm->num_pages; ++i)

• (*page)->mapping = NULL;
  

+}

• /*
  • amdgpu_ttm_tt_populate - Map GTT pages visible to the device

@@ -1119,6 +1137,7 @@ 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;

• int ret;

  /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */ if (gtt->userptr) {

@@ -1131,7 +1150,12 @@ 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;
  

• amdgpu_ttm_tt_add_mapping(bdev, ttm);

I don't really see why this needs to be a separate function. Just inline the loop here.

• return 0; }

  /*

@@ -1159,6 +1183,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev, return;

adev = amdgpu_ttm_adev(bdev);

• amdgpu_ttm_tt_clear_mapping(ttm);

Same here of course, apart from that looks good to me.

Christian.

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