diff options
author | Oded Gabbay <ogabbay@kernel.org> | 2021-04-11 08:26:50 +0300 |
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committer | Oded Gabbay <ogabbay@kernel.org> | 2021-10-18 12:05:47 +0300 |
commit | a9498ee575fa116e2891d9a6ff4fc7648dd9d7c8 (patch) | |
tree | e0fb3e4c493e0555bee80f7e5685fd33c8a84ed1 /include/uapi/misc | |
parent | 81f8582ec404b2ab3ec1d412e33703e014fc3121 (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.h | 28 |
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; }; }; |