From patchwork Fri Jun 18 12:36:13 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oded Gabbay X-Patchwork-Id: 12331243 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=-16.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 A0F92C48BE8 for ; Fri, 18 Jun 2021 12:36:29 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2BCFB610A3 for ; Fri, 18 Jun 2021 12:36:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2BCFB610A3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 2DD376E114; Fri, 18 Jun 2021 12:36:28 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by gabe.freedesktop.org (Postfix) with ESMTPS id 4CEE36E114 for ; Fri, 18 Jun 2021 12:36:26 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 93FB8613EC; Fri, 18 Jun 2021 12:36:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1624019785; bh=kKl+dwSE+1mpdV00Nwtq36eOm8r1Np9GR2J4zMKETqw=; h=From:To:Cc:Subject:Date:From; b=k5YrrBAxdE8zUmY8WvvE6MJEHD4yCIfdhvVUBlI/qsUYJjYXfbKU78ApJg64xU1w0 7qVG5t7WmchDe1sFQazK5BroSYVUpuwWCeJQjZKn+NVSZEZR83wuOrbwgzND8hO6xj LeGInqvzq3wnMOuT582NCuDiz8hpEMnM5/fItlJtMGeIUVem4IjyF9PZlr21qPYRcw 1OrO4AmqhBJCzw7ReLn/CQ97OKXWmWIWJekrO+4rgfXkdFWmthIQCpPPjZbYiMWg6S v8GMav3uPaH40/Rv2M1px0v63R1WEz2KC51rodtiVAv48rOedfjrayds0BLFUoeUOa G8T2S2M7U15bw== From: Oded Gabbay To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org Subject: [PATCH v3 1/2] habanalabs: define uAPI to export FD for DMA-BUF Date: Fri, 18 Jun 2021 15:36:13 +0300 Message-Id: <20210618123615.11456-1-ogabbay@kernel.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: daniel.vetter@ffwll.ch, sleybo@amazon.com, galpress@amazon.com, dri-devel@lists.freedesktop.org, christian.koenig@amd.com, Tomer Tayar Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" 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; }; };