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authorOded Gabbay <ogabbay@kernel.org>2021-04-11 08:26:50 +0300
committerOded Gabbay <ogabbay@kernel.org>2021-10-18 12:05:47 +0300
commita9498ee575fa116e2891d9a6ff4fc7648dd9d7c8 (patch)
treee0fb3e4c493e0555bee80f7e5685fd33c8a84ed1 /include/uapi/misc
parent81f8582ec404b2ab3ec1d412e33703e014fc3121 (diff)
habanalabs: define uAPI to export FD for DMA-BUF
User process might want to share the device memory with another driver/device, and to allow it to access it over PCIe (P2P). To enable this, we utilize the dma-buf mechanism and add a dma-buf exporter support, so the other driver can import the device memory and access it. The device memory is allocated using our existing allocation uAPI, where the user will get a handle that represents the allocation. The user will then need to call the new uAPI (HL_MEM_OP_EXPORT_DMABUF_FD) and give the handle as a parameter. The driver will return a FD that represents the DMA-BUF object that was created to match that allocation. Signed-off-by: Oded Gabbay <ogabbay@kernel.org> Reviewed-by: Tomer Tayar <ttayar@habana.ai> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'include/uapi/misc')
-rw-r--r--include/uapi/misc/habanalabs.h28
1 files changed, 27 insertions, 1 deletions
diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h
index fe73630e1a05..00b309590499 100644
--- a/include/uapi/misc/habanalabs.h
+++ b/include/uapi/misc/habanalabs.h
@@ -960,6 +960,10 @@ union hl_wait_cs_args {
#define HL_MEM_OP_UNMAP 3
/* Opcode to map a hw block */
#define HL_MEM_OP_MAP_BLOCK 4
+/* Opcode to create DMA-BUF object for an existing device memory allocation
+ * and to export an FD of that DMA-BUF back to the caller
+ */
+#define HL_MEM_OP_EXPORT_DMABUF_FD 5
/* Memory flags */
#define HL_MEM_CONTIGUOUS 0x1
@@ -1031,11 +1035,26 @@ struct hl_mem_in {
/* Virtual address returned from HL_MEM_OP_MAP */
__u64 device_virt_addr;
} unmap;
+
+ /* HL_MEM_OP_EXPORT_DMABUF_FD */
+ struct {
+ /* 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.
+ */
+ __u64 handle;
+ /* Size of memory allocation. Relevant only for GAUDI */
+ __u64 mem_size;
+ } export_dmabuf_fd;
};
/* HL_MEM_OP_* */
__u32 op;
- /* HL_MEM_* flags */
+ /* HL_MEM_* flags.
+ * For the HL_MEM_OP_EXPORT_DMABUF_FD opcode, this field holds the
+ * DMA-BUF file/FD flags.
+ */
__u32 flags;
/* Context ID - Currently not in use */
__u32 ctx_id;
@@ -1072,6 +1091,13 @@ struct hl_mem_out {
__u32 pad;
};
+
+ /* Returned in HL_MEM_OP_EXPORT_DMABUF_FD. Represents the
+ * DMA-BUF object that was created to describe a memory
+ * allocation on the device's memory space. The FD should be
+ * passed to the importer driver
+ */
+ __s32 fd;
};
};