Allows gdb to access contents of user mode mapped BOs. VRAM access
requires the driver to implement a new callback in ttm_bo_driver.
Signed-off-by: Felix Kuehling <Felix.Kuehling at amd.com>
---
drivers/gpu/drm/ttm/ttm_bo_vm.c | 66 ++++++++++++++++++++++++++++++++++++++++-
include/drm/ttm/ttm_bo_driver.h | 12 ++++++++
2 files changed, 77 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
index 9f53df9..0ef2eb9 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
@@ -294,10 +294,74 @@ static void ttm_bo_vm_close(struct vm_area_struct *vma)
vma->vm_private_data = NULL;
}
+static int ttm_bo_vm_access_kmap(struct ttm_buffer_object *bo,
+ unsigned long offset,
+ void *buf, int len, int write)
+{
+ unsigned long first_page = offset >> PAGE_SHIFT;
+ unsigned long last_page = (offset + len - 1) >> PAGE_SHIFT;
+ unsigned long num_pages = last_page - first_page + 1;
+ struct ttm_bo_kmap_obj map;
+ void *ptr;
+ bool is_iomem;
+ int ret;
+
+ ret = ttm_bo_kmap(bo, first_page, num_pages, &map);
+ if (ret)
+ return ret;
+
+ offset -= first_page << PAGE_SHIFT;
+ ptr = (uint8_t *)ttm_kmap_obj_virtual(&map, &is_iomem) + offset;
+ WARN_ON(is_iomem);
+ if (write)
+ memcpy(ptr, buf, len);
+ else
+ memcpy(buf, ptr, len);
+ ttm_bo_kunmap(&map);
+
+ return len;
+}
+
+static int ttm_bo_vm_access(struct vm_area_struct *vma, unsigned long addr,
+ void *buf, int len, int write)
+{
+ unsigned long offset = (addr) - vma->vm_start;
+ struct ttm_buffer_object *bo = vma->vm_private_data;
+ int ret;
+
+ if (len < 1 || (offset + len) >> PAGE_SHIFT > bo->num_pages)
+ return -EIO;
+
+ ret = ttm_bo_reserve(bo, true, false, NULL);
+ if (ret)
+ return ret;
+
+ switch(bo->mem.mem_type) {
+ case TTM_PL_SYSTEM:
+ case TTM_PL_TT:
+ ret = ttm_bo_vm_access_kmap(bo, offset, buf, len, write);
+ break;
+ case TTM_PL_VRAM:
+ if (bo->bdev->driver->access_vram)
+ ret = bo->bdev->driver->access_vram(
+ bo, offset, buf, len, write);
+ else
+ ret = -EIO;
+ break;
+ default:
+ ret = -EIO;
+ }
+
+ ttm_bo_unreserve(bo);
+
+ return ret;
+}
+
static const struct vm_operations_struct ttm_bo_vm_ops = {
.fault = ttm_bo_vm_fault,
.open = ttm_bo_vm_open,
- .close = ttm_bo_vm_close
+ .close = ttm_bo_vm_close,
+ .access = ttm_bo_vm_access
};
static struct ttm_buffer_object *ttm_bo_vm_lookup(struct ttm_bo_device *bdev,
diff --git a/include/drm/ttm/ttm_bo_driver.h b/include/drm/ttm/ttm_bo_driver.h
index 6bbd34d..6ce5094 100644
--- a/include/drm/ttm/ttm_bo_driver.h
+++ b/include/drm/ttm/ttm_bo_driver.h
@@ -471,6 +471,18 @@ struct ttm_bo_driver {
*/
unsigned long (*io_mem_pfn)(struct ttm_buffer_object *bo,
unsigned long page_offset);
+
+ /**
+ * Read/write VRAM buffers for ptrace access
+ *
+ * @bo: the BO to access
+ * @offset: the offset from the start of the BO
+ * @buf: pointer to source/destination buffer
+ * @len: number of bytes to copy
+ * @write: whether to read (0) from or write (non-0) to BO
+ */
+ int (*access_vram)(struct ttm_buffer_object *bo, unsigned long offset,
+ void *buf, int len, int write);
};
/**
--
1.9.1
