Re: [PATCH v6 1/2] habanalabs: define uAPI to export FD for DMA-BUF

From: Jason Gunthorpe <jgg@ziepe.ca>
To: Oded Gabbay <ogabbay@kernel.org>
Cc: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org,
	christian.koenig@amd.com, daniel.vetter@ffwll.ch,
	galpress@amazon.com, sleybo@amazon.com,
	dri-devel@lists.freedesktop.org, linux-rdma@vger.kernel.org,
	linux-media@vger.kernel.org, dledford@redhat.com,
	airlied@gmail.com, alexander.deucher@amd.com, leonro@nvidia.com,
	hch@lst.de, amd-gfx@lists.freedesktop.org,
	linaro-mm-sig@lists.linaro.org
Subject: Re: [PATCH v6 1/2] habanalabs: define uAPI to export FD for DMA-BUF
Date: Tue, 28 Sep 2021 14:13:29 -0300	[thread overview]
Message-ID: <20210928171329.GF3544071@ziepe.ca> (raw)
In-Reply-To: <20210912165309.98695-2-ogabbay@kernel.org>

On Sun, Sep 12, 2021 at 07:53:08PM +0300, Oded Gabbay wrote:
>  	/* 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
> +		 */
> +		__u64 fd;

fd's should be a s32 type in a fixed width uapi.

I usually expect to see the uapi changes inside the commit that
consumes them, splitting the patch like this seems strange but
harmless.

Jason