On 21/10/2024 22:18, Matthew Brost wrote:
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)
Reported-by: Christoph Manszewski <christoph.manszewski@xxxxxxxxx>
Suggested-by: Thomas Hellström <thomas.hellstrom@xxxxxxxxxxxxxxx>
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/ttm/ttm_bo_util.c | 86 +++++++++++++++++++++++++++++++
drivers/gpu/drm/ttm/ttm_bo_vm.c | 65 +----------------------
include/drm/ttm/ttm_bo.h | 2 +
3 files changed, 89 insertions(+), 64 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index d939925efa81..41bb5a7477d3 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -919,3 +919,89 @@ s64 ttm_lru_walk_for_evict(struct ttm_lru_walk *walk, struct ttm_device *bdev,
return progress;
}
+
+static int ttm_bo_access_kmap(struct ttm_buffer_object *bo,
+ unsigned long offset,
+ void *buf, int len, int write)
+{
+ unsigned long page = offset >> PAGE_SHIFT;
+ unsigned long bytes_left = len;
+ int ret;
+
+ /* Copy a page at a time, that way no extra virtual address
+ * mapping is needed
+ */
+ offset -= page << PAGE_SHIFT;
+ do {
+ unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
+ struct ttm_bo_kmap_obj map;
+ void *ptr;
+ bool is_iomem;
+
+ ret = ttm_bo_kmap(bo, page, 1, &map);
+ if (ret)
+ return ret;
+
+ ptr = (void *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
+ WARN_ON_ONCE(is_iomem);
+ if (write)
+ memcpy(ptr, buf, bytes);
+ else
+ memcpy(buf, ptr, bytes);
+ ttm_bo_kunmap(&map);
+
+ page++;
+ buf += bytes;
+ bytes_left -= bytes;
+ offset = 0;
+ } while (bytes_left);
+
+ return len;
+}
+
+/**
+ * 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...).
+ *
+ * Returns:
+ * 0 if successful, negative error code on failure.
@len if successful
Reviewed-by: Matthew Auld <matthew.auld@xxxxxxxxx>
+ */
+int ttm_bo_access(struct ttm_buffer_object *bo, unsigned long offset,
+ void *buf, int len, int write)
+{
+ int ret;
+
+ if (len < 1 || (offset + len) > bo->base.size)
+ return -EIO;
+
+ ret = ttm_bo_reserve(bo, true, false, NULL);
+ if (ret)
+ return ret;
+
+ switch (bo->resource->mem_type) {
+ case TTM_PL_SYSTEM:
+ fallthrough;
+ case TTM_PL_TT:
+ ret = ttm_bo_access_kmap(bo, offset, buf, len, write);
+ break;
+ default:
+ if (bo->bdev->funcs->access_memory)
+ ret = bo->bdev->funcs->access_memory
+ (bo, offset, buf, len, write);
+ else
+ ret = -EIO;
+ }
+
+ ttm_bo_unreserve(bo);
+
+ return ret;
+}
+EXPORT_SYMBOL(ttm_bo_access);
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 2c699ed1963a..20b1e5f78684 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -366,45 +366,6 @@ void ttm_bo_vm_close(struct vm_area_struct *vma)
}
EXPORT_SYMBOL(ttm_bo_vm_close);
-static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
- unsigned long offset,
- uint8_t *buf, int len, int write)
-{
- unsigned long page = offset >> PAGE_SHIFT;
- unsigned long bytes_left = len;
- int ret;
-
- /* Copy a page at a time, that way no extra virtual address
- * mapping is needed
- */
- offset -= page << PAGE_SHIFT;
- do {
- unsigned long bytes = min(bytes_left, PAGE_SIZE - offset);
- struct ttm_bo_kmap_obj map;
- void *ptr;
- bool is_iomem;
-
- ret = ttm_bo_kmap(bo, page, 1, &map);
- if (ret)
- return ret;
-
- ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
- WARN_ON_ONCE(is_iomem);
- if (write)
- memcpy(ptr, buf, bytes);
- else
- memcpy(buf, ptr, bytes);
- ttm_bo_kunmap(&map);
-
- page++;
- buf += bytes;
- bytes_left -= bytes;
- offset = 0;
- } while (bytes_left);
-
- return len;
-}
-
int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
void *buf, int len, int write)
{
@@ -412,32 +373,8 @@ int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
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)
- return -EIO;
- ret = ttm_bo_reserve(bo, true, false, NULL);
- if (ret)
- return ret;
-
- switch (bo->resource->mem_type) {
- case TTM_PL_SYSTEM:
- fallthrough;
- case TTM_PL_TT:
- ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
- break;
- default:
- if (bo->bdev->funcs->access_memory)
- ret = bo->bdev->funcs->access_memory(
- bo, offset, buf, len, write);
- else
- ret = -EIO;
- }
-
- ttm_bo_unreserve(bo);
-
- return ret;
+ return ttm_bo_access(bo, offset, buf, len, write);
}
EXPORT_SYMBOL(ttm_bo_vm_access);
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,
