From 49e7f76fc514cecf2cad1303fa74d99be7e5d9a6 Mon Sep 17 00:00:00 2001 From: Matthew Auld Date: Wed, 29 Sep 2021 14:26:29 +0100 Subject: drm/ttm: add TTM_TT_FLAG_EXTERNAL_MAPPABLE MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In commit: commit 667a50db0477d47fdff01c666f5ee1ce26b5264c Author: Thomas Hellstrom Date: Fri Jan 3 11:17:18 2014 +0100 drm/ttm: Refuse to fault (prime-) imported pages we introduced the restriction that imported pages should not be directly mappable through TTM(this also extends to userptr). In the next patch we want to introduce a shmem_tt backend, which should follow all the existing rules with TTM_PAGE_FLAG_EXTERNAL, since it will need to handle swapping itself, but with the above mapping restriction lifted. v2(Christian): - Don't OR together EXTERNAL and EXTERNAL_MAPPABLE in the definition of EXTERNAL_MAPPABLE, just leave it the caller to handle this correctly, otherwise we might encounter subtle issues. Signed-off-by: Matthew Auld Cc: Thomas Hellström Cc: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20210929132629.353541-3-matthew.auld@intel.com Signed-off-by: Christian König --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 6 ++++-- drivers/gpu/drm/ttm/ttm_tt.c | 3 +++ 2 files changed, 7 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/drm/ttm') diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 950f4f132802..33680c94127c 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -163,8 +163,10 @@ vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, * (if at all) by redirecting mmap to the exporter. */ if (bo->ttm && (bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)) { - dma_resv_unlock(bo->base.resv); - return VM_FAULT_SIGBUS; + if (!(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE)) { + dma_resv_unlock(bo->base.resv); + return VM_FAULT_SIGBUS; + } } return 0; diff --git a/drivers/gpu/drm/ttm/ttm_tt.c b/drivers/gpu/drm/ttm/ttm_tt.c index 86f31fde6e35..7e83c00a3f48 100644 --- a/drivers/gpu/drm/ttm/ttm_tt.c +++ b/drivers/gpu/drm/ttm/ttm_tt.c @@ -84,6 +84,9 @@ int ttm_tt_create(struct ttm_buffer_object *bo, bool zero_alloc) if (unlikely(bo->ttm == NULL)) return -ENOMEM; + WARN_ON(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL_MAPPABLE && + !(bo->ttm->page_flags & TTM_TT_FLAG_EXTERNAL)); + return 0; } -- cgit v1.2.3