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 <christian.koenig@xxxxxxx>
Reported-by: Christoph Manszewski <christoph.manszewski@xxxxxxxxx>
Suggested-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
Tested-by: Mika Kuoppala <mika.kuoppala@xxxxxxxxxxxxxxx>
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
---
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 2c699ed1963a..f02d3966cc84 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 5804408815be..8ea11cd8df39 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,
--
2.34.1
