From patchwork Sun Jul 11 14:06:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oded Gabbay X-Patchwork-Id: 12369163 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 46C24C07E9B for ; Sun, 11 Jul 2021 14:06:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AB3C611BF for ; Sun, 11 Jul 2021 14:06:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233036AbhGKOJ3 (ORCPT ); Sun, 11 Jul 2021 10:09:29 -0400 Received: from mail.kernel.org ([198.145.29.99]:56462 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232917AbhGKOJ2 (ORCPT ); Sun, 11 Jul 2021 10:09:28 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id C3B0161167; Sun, 11 Jul 2021 14:06:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626012402; bh=O9tVDHLp82fxI8fp4sMu7i3QoMxUxxqqvrdNLqZSB4Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=p9A0Ei8dPsg1DNaCpk7G4RuK71EXQYBF7LHUVKCn2n8NeG/O+FES5kIHnQSsjk3/R +6nCAGAQst90jIXY/FjHBojN5YMxVUS2yLCtduWv5uRz9yYS+DO1RFiZ0qcV/30uHC h+wVerXhO7/hZ5wDKPNee+NJjH6/00ogzQjXOgeDdXTH/+dGimPUb8SsOWUhX5JrUV DIRtpE/swWmRNryMQHAXimG0UnhP7notK5wELq4HA8T2SXUXzvBQ+j6EJK/ZtI/GRa 5HdxVa+BEDJvd2rrtQXUi0uLU3lmlNSLKhowOArfKBUZLlEoQKadSU5+TeapU2zVDb biusiMgX2Zx3A== From: Oded Gabbay To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, jgg@ziepe.ca Cc: sumit.semwal@linaro.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, Tomer Tayar Subject: [PATCH v5 1/2] habanalabs: define uAPI to export FD for DMA-BUF Date: Sun, 11 Jul 2021 17:06:00 +0300 Message-Id: <20210711140601.7472-2-ogabbay@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210711140601.7472-1-ogabbay@kernel.org> References: <20210711140601.7472-1-ogabbay@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org 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; }; };