From patchwork Sun Sep 12 16:53:08 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Oded Gabbay X-Patchwork-Id: 76893 Received: from vger.kernel.org ([23.128.96.18]) by www.linuxtv.org with esmtp (Exim 4.92) (envelope-from ) id 1mPSjS-007M6k-P8; Sun, 12 Sep 2021 16:53:31 +0000 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235027AbhILQyf (ORCPT + 1 other); Sun, 12 Sep 2021 12:54:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:48488 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230113AbhILQye (ORCPT ); Sun, 12 Sep 2021 12:54:34 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7D5E660EE7; Sun, 12 Sep 2021 16:53:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631465600; bh=XXqp0AB53GnGXpIu3g+ttsj2JZg0BlQExiR9+JjZlcs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WaTj0eVO59JY/SHAlSifC5Hn+ENsOJ1pBiXYRJrzhGiQVGd31a5zxW1o9/LFjjQpT EueHB4ICpNADm7sAuFfsX1H0PpY+CFsKDudmUx2Ju8DsSr476kK6zaH8ymeYmtmHUs e+GKtGliqBHgyjI6M830WLfkzcSBhNu5CNOIUnqBwo4eh9W092WRhIx1MVwOSBz35g 2/PT2qSNhEbj5/8F1mVRFAxONRbEkIxaMm0CqYZn7YHxBWd0KKzmTRT5WZN509Xj04 KGa8lLvlEtEetVXlEc0tPaLWYfqBllS1CupbYI7c8vVCsEa90CRk7tPezpEkHYqoJk DfrQSlnZ6Nm3w== From: Oded Gabbay To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org, jgg@ziepe.ca 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, airlied@gmail.com, alexander.deucher@amd.com, leonro@nvidia.com, hch@lst.de, amd-gfx@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org Subject: [PATCH v6 1/2] habanalabs: define uAPI to export FD for DMA-BUF Date: Sun, 12 Sep 2021 19:53:08 +0300 Message-Id: <20210912165309.98695-2-ogabbay@kernel.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210912165309.98695-1-ogabbay@kernel.org> References: <20210912165309.98695-1-ogabbay@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-LSpam-Score: -5.4 (-----) X-LSpam-Report: No, score=-5.4 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_MED=-2.3 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 Reviewed-by: Greg Kroah-Hartman --- 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 042e96f99d85..b1def68bf5d3 100644 --- a/include/uapi/misc/habanalabs.h +++ b/include/uapi/misc/habanalabs.h @@ -960,6 +960,10 @@ 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 @@ -1031,11 +1035,26 @@ 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; @@ -1072,6 +1091,13 @@ 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; }; };