From 7d08df5d0bd3d12d14dcec773fcddbe3eed3a8e8 Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Tue, 26 Nov 2024 09:46:09 -0800 Subject: [PATCH] drm/ttm: Add ttm_bo_access MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Non-contiguous VRAM cannot easily be mapped in TTM nor can non-visible VRAM easily be accessed. Add ttm_bo_access, which is similar to ttm_bo_vm_access, to access such memory. v4: - Fix checkpatch warnings (CI) v5: - Fix checkpatch warnings (CI) v6: - Fix kernel doc (Auld) v7: - Move ttm_bo_access to ttm_bo_vm.c (Christian) Cc: Christian König Reported-by: Christoph Manszewski Suggested-by: Thomas Hellström Signed-off-by: Matthew Brost Tested-by: Mika Kuoppala Reviewed-by: Matthew Auld Reviewed-by: Christian König Link: https://patchwork.freedesktop.org/patch/msgid/20241126174615.2665852-3-matthew.brost@intel.com --- drivers/gpu/drm/ttm/ttm_bo_vm.c | 40 ++++++++++++++++++++++++++------- include/drm/ttm/ttm_bo.h | 2 ++ 2 files changed, 34 insertions(+), 8 deletions(-) diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c index 2c699ed1963a6..f02d3966cc840 100644 --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c @@ -405,13 +405,25 @@ static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo, return len; } -int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, - void *buf, int len, int write) +/** + * ttm_bo_access - Helper to access a buffer object + * + * @bo: ttm buffer object + * @offset: access offset into buffer object + * @buf: pointer to caller memory to read into or write from + * @len: length of access + * @write: write access + * + * Utility function to access a buffer object. Useful when buffer object cannot + * be easily mapped (non-contiguous, non-visible, etc...). Should not directly + * be exported to user space via a peak / poke interface. + * + * Returns: + * @len if successful, negative error code on failure. + */ +int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset, + void *buf, int len, int write) { - struct ttm_buffer_object *bo = vma->vm_private_data; - unsigned long offset = (addr) - vma->vm_start + - ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node)) - << PAGE_SHIFT); int ret; if (len < 1 || (offset + len) > bo->base.size) @@ -429,8 +441,8 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, break; default: if (bo->bdev->funcs->access_memory) - ret = bo->bdev->funcs->access_memory( - bo, offset, buf, len, write); + ret = bo->bdev->funcs->access_memory + (bo, offset, buf, len, write); else ret = -EIO; } @@ -439,6 +451,18 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, return ret; } +EXPORT_SYMBOL(ttm_bo_access); + +int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr, + void *buf, int len, int write) +{ + struct ttm_buffer_object *bo = vma->vm_private_data; + unsigned long offset = (addr) - vma->vm_start + + ((vma->vm_pgoff - drm_vma_node_start(&bo->base.vma_node)) + << PAGE_SHIFT); + + return ttm_bo_access(bo, offset, buf, len, write); +} EXPORT_SYMBOL(ttm_bo_vm_access); static const struct vm_operations_struct ttm_bo_vm_ops = { diff --git a/include/drm/ttm/ttm_bo.h b/include/drm/ttm/ttm_bo.h index 5804408815bed..8ea11cd8df397 100644 --- a/include/drm/ttm/ttm_bo.h +++ b/include/drm/ttm/ttm_bo.h @@ -421,6 +421,8 @@ void ttm_bo_unpin(struct ttm_buffer_object *bo); int ttm_bo_evict_first(struct ttm_device *bdev, struct ttm_resource_manager *man, struct ttm_operation_ctx *ctx); +int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset, + void *buf, int len, int write); vm_fault_t ttm_bo_vm_reserve(struct ttm_buffer_object *bo, struct vm_fault *vmf); vm_fault_t ttm_bo_vm_fault_reserved(struct vm_fault *vmf, -- 2.47.2