From patchwork Thu Apr 7 15:47:17 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 12805410 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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F87EC433EF for ; Thu, 7 Apr 2022 15:49:00 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E01288D0003; Thu, 7 Apr 2022 11:47:58 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BEA5E6B0075; Thu, 7 Apr 2022 11:47:58 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9947D8D0002; Thu, 7 Apr 2022 11:47:58 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 795E98D0001 for ; Thu, 7 Apr 2022 11:47:58 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 5276A6654E for ; Thu, 7 Apr 2022 15:47:48 +0000 (UTC) X-FDA: 79330513416.14.9E1C0EA Received: from ale.deltatee.com (ale.deltatee.com [204.191.154.188]) by imf05.hostedemail.com (Postfix) with ESMTP id CFCC6100002 for ; Thu, 7 Apr 2022 15:47:46 +0000 (UTC) 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=rMmDd7FK89WBPMzhI41Yh5OWeVuvzuwCzfQzO0Mz/AU=; b=iG+EidunEVskeYVIo6imRxDh47 8oq55Yf7ytuhttopUD3lvf6ThM95I2SsX20Tz5UXUkIHMvEUwkiyLww1Y7lHLgPLamVgzzrDt9fYq fpg8LyY+HXCPuc+m5seNIMP6THmXjEpPrwBk+domuzL5vo/nJyqtYtFUTbuonua5YFS70T17/tsyO Pgfwb6Z8/wqY9TNBk0i3thENlVQAP5CwlZXcgv5Mc/wTHtjxESXLnXBUgGBRbumCU/gpb5+oRv96h HcTc43gYK3lYYuIjoveMt+N0WHXfbSbT3dVPExe0nM5REk4BP4aZAir/OaylNhLOLqVjDfa7vIHRS cLi8EOWQ==; Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ncUMI-002BBf-HJ; Thu, 07 Apr 2022 09:47:43 -0600 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.94.2) (envelope-from ) id 1ncUMF-00022U-JJ; Thu, 07 Apr 2022 09:47:39 -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 , Ralph Campbell , Logan Gunthorpe Date: Thu, 7 Apr 2022 09:47:17 -0600 Message-Id: <20220407154717.7695-22-logang@deltatee.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220407154717.7695-1-logang@deltatee.com> References: <20220407154717.7695-1-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, 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, jhubbard@nvidia.com, rcampbell@nvidia.com, logang@deltatee.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH v6 21/21] nvme-pci: allow mmaping the CMB in userspace X-SA-Exim-Version: 4.2.1 (built Sat, 13 Feb 2021 17:57:42 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: CFCC6100002 X-Stat-Signature: n3xqsjocqb3dpm4hjtyfe88qdtrges5h Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=deltatee.com header.s=20200525 header.b=iG+Eidun; dmarc=pass (policy=none) header.from=deltatee.com; spf=pass (imf05.hostedemail.com: domain of gunthorp@deltatee.com designates 204.191.154.188 as permitted sender) smtp.mailfrom=gunthorp@deltatee.com X-Rspam-User: X-HE-Tag: 1649346466-471379 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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 | 17 +++++++++++++++++ 3 files changed, 34 insertions(+) diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c index bbc276dda49f..1fd3372c2c18 100644 --- a/drivers/nvme/host/core.c +++ b/drivers/nvme/host/core.c @@ -3114,6 +3114,10 @@ static int nvme_dev_open(struct inode *inode, struct file *file) } file->private_data = ctrl; + + if (ctrl->ops->cdev_file_open) + ctrl->ops->cdev_file_open(ctrl, file); + return 0; } @@ -3127,12 +3131,23 @@ 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 7d97bfb2a9e2..24fbcd274c64 100644 --- a/drivers/nvme/host/nvme.h +++ b/drivers/nvme/host/nvme.h @@ -497,6 +497,8 @@ 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 (*cdev_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 07412116d4d1..5946244e0295 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -2965,6 +2965,21 @@ static bool nvme_pci_supports_pci_p2pdma(struct nvme_ctrl *ctrl) return dma_pci_p2pdma_supported(dev->dev); } +static void nvme_pci_cdev_file_open(struct nvme_ctrl *ctrl, struct file *file) +{ + struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev); + + pci_p2pdma_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, @@ -2976,6 +2991,8 @@ 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, + .cdev_file_open = nvme_pci_cdev_file_open, + .mmap_cmb = nvme_pci_mmap_cmb, }; static int nvme_dev_map(struct nvme_dev *dev)