From patchwork Thu Sep 16 23:41:00 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12500549 X-Patchwork-Delegate: bhelgaas@google.com 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,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 58425C28CAF for ; Thu, 16 Sep 2021 23:41:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 35A8661130 for ; Thu, 16 Sep 2021 23:41:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241789AbhIPXmy (ORCPT ); Thu, 16 Sep 2021 19:42:54 -0400 Received: from ale.deltatee.com ([204.191.154.188]:40954 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241859AbhIPXmp (ORCPT ); Thu, 16 Sep 2021 19:42:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=deltatee.com; s=20200525; h=Subject:MIME-Version:References:In-Reply-To: Message-Id:Date:Cc:To:From:content-disposition; bh=DCe73G/87iDXLgvKp651BN9RlPv5YM0qiz8R3mNA2S8=; b=hN6uw/EdGbq0EBEeo9SVGMf1N/ uuccSiV6x4AlIRsHAycfNcHtP0J9xZaZqKfwq0x7kPrUaCr0xKBFHh5S57JZ2/MENkhiLWLPIDwoj ZLSfDZRcjpGhjVH4ZGvhYGJf7++1l3whp1kdgiNwd0nE8fhTCduxy2vDmaeTPpc10YNnprEgUWfC1 o5XUV6dEkQ1zRk2gYrQYUWr2wzpOVTkGxDChsmAwu9l0CPtW9PfwL3FYuwyfeQvb7/84ST7otdSWh tbMyTw1hL3+DUq1pb5+EUubk2QMB+kTHd5dyphoFznGpfOCrACya0xmAJO9cDItVH9Bf3K0z51OBh pE0qZEEA==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mR108-0008I2-IM; Thu, 16 Sep 2021 17:41:23 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1mR106-000Vry-PT; Thu, 16 Sep 2021 17:41:06 -0600 From: Logan Gunthorpe To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Cc: Stephen Bates , Christoph Hellwig , Dan Williams , Jason Gunthorpe , =?utf-8?q?Christian_K=C3=B6nig?= , John Hubbard , Don Dutile , Matthew Wilcox , Daniel Vetter , Jakowski Andrzej , Minturn Dave B , Jason Ekstrand , Dave Hansen , Xiong Jianxin , Bjorn Helgaas , Ira Weiny , Robin Murphy , Martin Oliveira , Chaitanya Kulkarni , Logan Gunthorpe Date: Thu, 16 Sep 2021 17:41:00 -0600 Message-Id: <20210916234100.122368-21-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210916234100.122368-1-logang@deltatee.com> References: <20210916234100.122368-1-logang@deltatee.com> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-pci@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org, sbates@raithlin.com, hch@lst.de, jgg@ziepe.ca, christian.koenig@amd.com, jhubbard@nvidia.com, ddutile@redhat.com, willy@infradead.org, daniel.vetter@ffwll.ch, jason@jlekstrand.net, dave.hansen@linux.intel.com, helgaas@kernel.org, dan.j.williams@intel.com, andrzej.jakowski@intel.com, dave.b.minturn@intel.com, jianxin.xiong@intel.com, ira.weiny@intel.com, robin.murphy@arm.com, martin.oliveira@eideticom.com, ckulkarnilinux@gmail.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v3 20/20] nvme-pci: allow mmaping the CMB in userspace X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Allow userspace to obtain CMB memory by mmaping the controller's char device. The mmap call allocates and returns a hunk of CMB memory, (the offset is ignored) so userspace does not have control over the address within the CMB. A VMA allocated in this way will only be usable by drivers that set FOLL_PCI_P2PDMA when calling GUP. And inter-device support will be checked the first time the pages are mapped for DMA. Currently this is only supported by O_DIRECT to an PCI NVMe device or through the NVMe passthrough IOCTL. Signed-off-by: Logan Gunthorpe --- drivers/nvme/host/core.c | 15 +++++++++++++++ drivers/nvme/host/nvme.h | 2 ++ drivers/nvme/host/pci.c | 18 ++++++++++++++++++ 3 files changed, 35 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index 916750a54f60..dfc18f0bdeee 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3075,6 +3075,10 @@ static int nvme_dev_open(struct inode *inode, struct file *file) } file->private_data = ctrl; + + if (ctrl->ops->mmap_file_open) + ctrl->ops->mmap_file_open(ctrl, file); + return 0; } @@ -3088,12 +3092,23 @@ static int nvme_dev_release(struct inode *inode, struct file *file) return 0; } +static int nvme_dev_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct nvme_ctrl *ctrl = file->private_data; + + if (!ctrl->ops->mmap_cmb) + return -ENODEV; + + return ctrl->ops->mmap_cmb(ctrl, vma); +} + static const struct file_operations nvme_dev_fops = { .owner = THIS_MODULE, .open = nvme_dev_open, .release = nvme_dev_release, .unlocked_ioctl = nvme_dev_ioctl, .compat_ioctl = compat_ptr_ioctl, + .mmap = nvme_dev_mmap, }; static ssize_t nvme_sysfs_reset(struct device *dev, diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h index fb9bfc52a6d7..1cc721290d4c 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -485,6 +485,8 @@ struct nvme_ctrl_ops { void (*delete_ctrl)(struct nvme_ctrl *ctrl); int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size); bool (*supports_pci_p2pdma)(struct nvme_ctrl *ctrl); + void (*mmap_file_open)(struct nvme_ctrl *ctrl, struct file *file); + int (*mmap_cmb)(struct nvme_ctrl *ctrl, struct vm_area_struct *vma); }; /* diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index e2cd73129a88..9d69e4a3d62e 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2870,6 +2870,22 @@ static bool nvme_pci_supports_pci_p2pdma(struct nvme_ctrl *ctrl) return dma_pci_p2pdma_supported(dev->dev); } +static void nvme_pci_mmap_file_open(struct nvme_ctrl *ctrl, + struct file *file) +{ + struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev); + + pci_p2pdma_mmap_file_open(pdev, file); +} + +static int nvme_pci_mmap_cmb(struct nvme_ctrl *ctrl, + struct vm_area_struct *vma) +{ + struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev); + + return pci_mmap_p2pmem(pdev, vma); +} + static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = { .name = "pcie", .module = THIS_MODULE, @@ -2881,6 +2897,8 @@ static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = { .submit_async_event = nvme_pci_submit_async_event, .get_address = nvme_pci_get_address, .supports_pci_p2pdma = nvme_pci_supports_pci_p2pdma, + .mmap_file_open = nvme_pci_mmap_file_open, + .mmap_cmb = nvme_pci_mmap_cmb, }; static int nvme_dev_map(struct nvme_dev *dev)