From patchwork Sun Oct 3 09:07:55 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oded Gabbay X-Patchwork-Id: 12532657 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6A41FC433EF for ; Sun, 3 Oct 2021 09:08:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4F3AD61B3E for ; Sun, 3 Oct 2021 09:08:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229918AbhJCJJ5 (ORCPT ); Sun, 3 Oct 2021 05:09:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:57054 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229823AbhJCJJ4 (ORCPT ); Sun, 3 Oct 2021 05:09:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4DCEF61B3E; Sun, 3 Oct 2021 09:08:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633252089; bh=6pWomhfOVahVZykDCvLCYpB4y+neaQ61MPumOZ0Coto=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fial3gyhd0UyvBLkkezOJEHLMLCxz9nxiRFA0+PHBWN9cSsqVrHD9mtm/5tuPOGT1 ZQiMGHHHgszzi88Z+CJ/MGC4kPFGsOhpdxs/L//NDW30YTbn9P7uQFEc0HQXloUii9 IjzQxXvaQSXYzGqhFuBCqj+RZvO1vh1pBaTIPIM7vvqhk6GsRYHBRLrSXPbTp9c7jc aFBtUfwz75Qqf3Qy1qZZd1eCH6wwB6JSdj1hymPhkv2DfZLBr+aFj5kG5n2B5RBQdl IQf9/aJfKRtwHfOCZj6UgyRSaDkbTCgLzCh3VqFlK2U3DQ4IKlUVpNNiJw9dwzvj+K anSrML0NFY1CA== From: Oded Gabbay To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, jgg@ziepe.ca, airlied@gmail.com Cc: 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, alexander.deucher@amd.com, leonro@nvidia.com, hch@lst.de, amd-gfx@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Subject: [PATCH v7 1/2] habanalabs: define uAPI to export FD for DMA-BUF Date: Sun, 3 Oct 2021 12:07:55 +0300 Message-Id: <20211003090756.117809-2-ogabbay@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20211003090756.117809-1-ogabbay@kernel.org> References: <20211003090756.117809-1-ogabbay@kernel.org> 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 Reviewed-by: Greg Kroah-Hartman Acked-by: Daniel Vetter --- Changes in v7: - Change the type of the fd variable returned from IOCTL to be __s32 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 ccfcb4d188fc..f980fbfb1a0e 100644 --- a/include/uapi/misc/habanalabs.h +++ b/include/uapi/misc/habanalabs.h @@ -959,6 +959,10 @@ 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 @@ -1030,11 +1034,26 @@ 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; @@ -1071,6 +1090,13 @@ 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; }; };