From mboxrd@z Thu Jan 1 00:00:00 1970 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=-19.2 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=ham 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 7D979C48BE5 for ; Tue, 15 Jun 2021 08:53:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6762661424 for ; Tue, 15 Jun 2021 08:53:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231145AbhFOIzj (ORCPT ); Tue, 15 Jun 2021 04:55:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:45872 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230454AbhFOIzh (ORCPT ); Tue, 15 Jun 2021 04:55:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4C23A61424; Tue, 15 Jun 2021 08:53:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623747213; bh=kKl+dwSE+1mpdV00Nwtq36eOm8r1Np9GR2J4zMKETqw=; h=From:To:Cc:Subject:Date:From; b=iIjqDQCkREsuoyshVjxAlG26ViqPXxn07R7wHtY4bn+ow+zCoRhMDeMg7X6xjcTIA oHspnUL9EWEABb2Po9zPWAn915q1wN4lMnLeFeXDzNOizDvRRN4SQWzUhA/U3PyqvU h1bWVLokIJeSa8rI3kSEB77LS6Im7ZGJqgdd/jf/u/g4Mbnl7bEX9jcCquqdGPFCxm rBur5heW5klvj5nA8No67/s2yg+AAQC7oVBQARt6p4nmliNGdBnhPOUS20E/y96lqc fe7C/x2ru85m8A0Ef+w/7WPrFKBXohH9mDY8L3t6XuqavzCUCQJiTWTP7Xwb8Mbcrn ClhVdqnsMMISQ== From: Oded Gabbay To: linux-kernel@vger.kernel.org Cc: gregkh@linuxfoundation.org, Tomer Tayar Subject: [PATCH v2 1/2] habanalabs: define uAPI to export FD for DMA-BUF Date: Tue, 15 Jun 2021 11:53:25 +0300 Message-Id: <20210615085326.16134-1-ogabbay@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 a47a731e4527..aa3d8e0ba060 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 @@ -878,11 +882,26 @@ 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; @@ -919,6 +938,13 @@ 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; }; }; -- 2.25.1