diff options
| author | Matthew Auld <matthew.auld@intel.com> | 2021-09-29 14:26:29 +0100 |
|---|---|---|
| committer | Christian König <christian.koenig@amd.com> | 2021-09-29 16:18:43 +0200 |
| commit | 49e7f76fc514cecf2cad1303fa74d99be7e5d9a6 (patch) | |
| tree | a6d3bbef93cab42511fc29f9fb9b4b86301d74e4 | |
| parent | a5a3dd42fe1314a77972d8682156078de3d0410d (diff) | |
drm/ttm: add TTM_TT_FLAG_EXTERNAL_MAPPABLEdrm-misc-next-2021-09-30
In commit:
commit 667a50db0477d47fdff01c666f5ee1ce26b5264c
Author: Thomas Hellstrom <thellstrom@vmware.com>
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 <matthew.auld@intel.com>
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210929132629.353541-3-matthew.auld@intel.com
Signed-off-by: Christian König <christian.koenig@amd.com>
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_bo_vm.c | 6 | ||||
| -rw-r--r-- | drivers/gpu/drm/ttm/ttm_tt.c | 3 | ||||
| -rw-r--r-- | include/drm/ttm/ttm_tt.h | 19 |
3 files changed, 23 insertions, 5 deletions
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; } diff --git a/include/drm/ttm/ttm_tt.h b/include/drm/ttm/ttm_tt.h index 86d74069be3e..f20832139815 100644 --- a/include/drm/ttm/ttm_tt.h +++ b/include/drm/ttm/ttm_tt.h @@ -67,13 +67,26 @@ struct ttm_tt { * Note that enum ttm_bo_type.ttm_bo_type_sg objects will always enable * this flag. * + * TTM_TT_FLAG_EXTERNAL_MAPPABLE: Same behaviour as + * TTM_TT_FLAG_EXTERNAL, but with the reduced restriction that it is + * still valid to use TTM to map the pages directly. This is useful when + * implementing a ttm_tt backend which still allocates driver owned + * pages underneath(say with shmem). + * + * Note that since this also implies TTM_TT_FLAG_EXTERNAL, the usage + * here should always be: + * + * page_flags = TTM_TT_FLAG_EXTERNAL | + * TTM_TT_FLAG_EXTERNAL_MAPPABLE; + * * TTM_TT_FLAG_PRIV_POPULATED: TTM internal only. DO NOT USE. This is * set by TTM after ttm_tt_populate() has successfully returned, and is * then unset when TTM calls ttm_tt_unpopulate(). */ -#define TTM_TT_FLAG_SWAPPED (1 << 0) -#define TTM_TT_FLAG_ZERO_ALLOC (1 << 1) -#define TTM_TT_FLAG_EXTERNAL (1 << 2) +#define TTM_TT_FLAG_SWAPPED (1 << 0) +#define TTM_TT_FLAG_ZERO_ALLOC (1 << 1) +#define TTM_TT_FLAG_EXTERNAL (1 << 2) +#define TTM_TT_FLAG_EXTERNAL_MAPPABLE (1 << 3) #define TTM_TT_FLAG_PRIV_POPULATED (1 << 31) uint32_t page_flags; |