habanalabs: modify export dmabuf API

A previous commit deprecated the option to export from handle, leaving
the code with no support for devices with virtual memory.

This commit modifies the export API in a way that unifies the uAPI to
user address for both cases (i.e. with and without MMU support) and add
the actual support for devices with virtual memory.

Signed-off-by: Ohad Sharabi <osharabi@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

1 files changed, 15 insertions, 6 deletions

diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
index 3b995e841eb8..c67d18901c1d 100644
--- a/include/uapi/misc/habanalabs.h
+++ b/include/uapi/misc/habanalabs.h
@@ -1851,15 +1851,24 @@ struct hl_mem_in {
 		/**
 		 * structure for exporting DMABUF object (used with
 		 * the HL_MEM_OP_EXPORT_DMABUF_FD op)
-		 * @handle: handle returned from HL_MEM_OP_ALLOC.
-		 *          in Gaudi, where we don't have MMU for the device memory, the
-		 *          driver expects a physical address (instead of a handle) in the
-		 *          device memory space.
-		 * @mem_size: size of memory allocation. Relevant only for GAUDI
+		 * @addr: for Gaudi1, the driver expects a physical address
+		 *        inside the device's DRAM. this is because in Gaudi1
+		 *        we don't have MMU that covers the device's DRAM.
+		 *        for all other ASICs, the driver expects a device
+		 *        virtual address that represents the start address of
+		 *        a mapped DRAM memory area inside the device.
+		 *        the address must be the same as was received from the
+		 *        driver during a previous HL_MEM_OP_MAP operation.
+		 * @mem_size: size of memory to export.
+		 * @offset: for Gaudi1, this value must be 0. For all other ASICs,
+		 *          the driver expects an offset inside of the memory area
+		 *          describe by addr. the offset represents the start
+		 *          address of that the exported dma-buf object describes.
 		 */
 		struct {
-			__u64 handle;
+			__u64 addr;
 			__u64 mem_size;
+			__u64 offset;
 		} export_dmabuf_fd;
 	};