From patchwork Mon Jul 5 13:03:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oded Gabbay X-Patchwork-Id: 75566 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1m0OG8-00BpoK-AZ; Mon, 05 Jul 2021 13:03:36 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231376AbhGENGL (ORCPT + 1 other); Mon, 5 Jul 2021 09:06:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:53310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230188AbhGENGJ (ORCPT ); Mon, 5 Jul 2021 09:06:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B57D46144E; Mon, 5 Jul 2021 13:03:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625490212; bh=O9tVDHLp82fxI8fp4sMu7i3QoMxUxxqqvrdNLqZSB4Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RJb2d9bAZPcATE7ZkmAgKxPie7inq7+8E7R7lygyLai9dkK8trzjd0dyLEwICJ2qh ni6advReSuykJSlS9P1XylPPeV+FYHuFsunmaPicFSHF8y8qyT0/YWho83oOfO630f KejUpdsmj35ghZLZHA3U0J/zodkRBCpLtilpZxLKYUt3GvD8gIuq0MRqcSak5F6YxK ZPG/ZVWA+bQEzfDo0WXd8uIpKEvvTQ9fypDDkZwPOUhebEslDweEfELtQdr2goFKbN KM6PVxUAl7nBCyc7TTcGVhARPqE/idoN4xFLd4vGXOYa8Gr84Q6V1acrp6ZFxMsNH0 Zd08u93kl0xAg== From: Oded Gabbay To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org Cc: sumit.semwal@linaro.org, christian.koenig@amd.com, daniel.vetter@ffwll.ch, galpress@amazon.com, sleybo@amazon.com, dri-devel@lists.freedesktop.org, jgg@ziepe.ca, 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, Tomer Tayar Subject: [PATCH v4 1/2] habanalabs: define uAPI to export FD for DMA-BUF Date: Mon, 5 Jul 2021 16:03:13 +0300 Message-Id: <20210705130314.11519-2-ogabbay@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210705130314.11519-1-ogabbay@kernel.org> References: <20210705130314.11519-1-ogabbay@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -3.1 (---) X-LSpam-Report: No, score=-3.1 required=5.0 tests=BAYES_00=-1.9,DKIMWL_WL_HIGH=0.001,DKIM_SIGNED=0.1,DKIM_VALID=-0.1,DKIM_VALID_AU=-0.1,DKIM_VALID_EF=-0.1,MAILING_LIST_MULTI=-1,RCVD_IN_DNSWL_NONE=-0.0001 autolearn=ham autolearn_force=no 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 Reviewed-by: Tomer Tayar --- include/uapi/misc/habanalabs.h | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) diff --git a/include/uapi/misc/habanalabs.h b/include/uapi/misc/habanalabs.h index 18765eb75b65..c5cbd60696d7 100644 --- a/include/uapi/misc/habanalabs.h +++ b/include/uapi/misc/habanalabs.h @@ -808,6 +808,10 @@ 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 @@ -879,11 +883,26 @@ 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; @@ -920,6 +939,13 @@ 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; }; };