From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ale.deltatee.com (ale.deltatee.com [207.54.116.67]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 763F22110783B for ; Thu, 30 Aug 2018 11:54:09 -0700 (PDT) From: Logan Gunthorpe Date: Thu, 30 Aug 2018 12:53:43 -0600 Message-Id: <20180830185352.3369-5-logang@deltatee.com> In-Reply-To: <20180830185352.3369-1-logang@deltatee.com> References: <20180830185352.3369-1-logang@deltatee.com> Subject: [PATCH v5 04/13] PCI/P2PDMA: Introduce configfs/sysfs enable attribute helpers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org, linux-nvdimm@lists.01.org, linux-block@vger.kernel.org Cc: =?UTF-8?q?Christian=20K=C3=B6nig?= , Benjamin Herrenschmidt , Alex Williamson , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jason Gunthorpe , Bjorn Helgaas , Max Gurtovoy , Christoph Hellwig List-ID: Users of the P2PDMA infrastructure will typically need a way for the user to tell the kernel to use P2P resources. Typically this will be a simple on/off boolean operation but sometimes it may be desirable for the user to specify the exact device to use for the P2P operation. Add new helpers for attributes which take a boolean or a PCI device. Any boolean, or the word 'auto' turn P2P on or off. Specifying a full PCI device name/BDF will select the specific device. Signed-off-by: Logan Gunthorpe --- drivers/pci/p2pdma.c | 83 ++++++++++++++++++++++++++++++++++++++++++++++ include/linux/pci-p2pdma.h | 15 +++++++++ 2 files changed, 98 insertions(+) diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 29bd40a87768..3da848f3fe72 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -9,6 +9,7 @@ */ #define pr_fmt(fmt) "pci-p2pdma: " fmt +#include #include #include #include @@ -856,3 +857,85 @@ int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, return nents; } EXPORT_SYMBOL_GPL(pci_p2pdma_map_sg); + +/** + * pci_p2pdma_enable_store - parse a configfs/sysfs attribute store + * to enable p2pdma + * @page: contents of the value to be stored + * @p2p_dev: returns the PCI device that was selected to be used + * (if 'auto', 'none or a boolean isn't the store value) + * @use_p2pdma: returns whether to enable p2pdma or not + * + * Parses an attribute value to decide whether to enable p2pdma. + * The value can select a PCI device (using it's full BDF device + * name), a boolean, or 'auto'. 'auto' and a true boolean value + * have the same meaning. A false value disables p2pdma and + * a PCI device enables it to use a specific device as the + * backing provider. + * + * pci_p2pdma_enable_show() should be used as the show operation for + * the attribute. + * + * Returns 0 on success + */ +int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, + bool *use_p2pdma) +{ + struct device *dev; + + dev = bus_find_device_by_name(&pci_bus_type, NULL, page); + if (dev) { + *use_p2pdma = true; + *p2p_dev = to_pci_dev(dev); + + if (!pci_has_p2pmem(*p2p_dev)) { + pr_err("PCI device has no peer-to-peer memory: %s\n", + page); + pci_dev_put(*p2p_dev); + return -ENODEV; + } + + return 0; + } else if (sysfs_streq(page, "auto")) { + *use_p2pdma = true; + return 0; + } else if ((page[0] == '0' || page[0] == '1') && !iscntrl(page[1])) { + /* + * If the user enters a PCI device that doesn't exist + * like "0000:01:00.1", we don't want strtobool to think + * it's a '0' when it's clearly not what the user wanted. + * So we require 0's and 1's to be exactly one character. + */ + } else if (!strtobool(page, use_p2pdma)) { + return 0; + } + + pr_err("No such PCI device: %.*s\n", (int)strcspn(page, "\n"), page); + return -ENODEV; +} +EXPORT_SYMBOL_GPL(pci_p2pdma_enable_store); + +/** + * pci_p2pdma_enable_show - show a configfs/sysfs attribute indicating + * whether p2pdma is enabled + * @page: contents of the stored value + * @p2p_dev: the selected p2p device (NULL if no device is selected) + * @use_p2pdma: whether p2pdme has been enabled + * + * Attributes that use pci_p2pdma_enable_store() should use this function + * to show the value of the attribute. + * + * Returns 0 on success + */ +ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, + bool use_p2pdma) +{ + if (!use_p2pdma) + return sprintf(page, "none\n"); + + if (!p2p_dev) + return sprintf(page, "auto\n"); + + return sprintf(page, "%s\n", pci_name(p2p_dev)); +} +EXPORT_SYMBOL_GPL(pci_p2pdma_enable_show); diff --git a/include/linux/pci-p2pdma.h b/include/linux/pci-p2pdma.h index 2f03dbbf5af6..377de4d73767 100644 --- a/include/linux/pci-p2pdma.h +++ b/include/linux/pci-p2pdma.h @@ -38,6 +38,10 @@ void pci_p2pmem_free_sgl(struct pci_dev *pdev, struct scatterlist *sgl); void pci_p2pmem_publish(struct pci_dev *pdev, bool publish); int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents, enum dma_data_direction dir); +int pci_p2pdma_enable_store(const char *page, struct pci_dev **p2p_dev, + bool *use_p2pdma); +ssize_t pci_p2pdma_enable_show(char *page, struct pci_dev *p2p_dev, + bool use_p2pdma); #else /* CONFIG_PCI_P2PDMA */ static inline int pci_p2pdma_add_resource(struct pci_dev *pdev, int bar, size_t size, u64 offset) @@ -105,5 +109,16 @@ static inline int pci_p2pdma_map_sg(struct device *dev, { return 0; } +static inline int pci_p2pdma_enable_store(const char *page, + struct pci_dev **p2p_dev, bool *use_p2pdma) +{ + *use_p2pdma = false; + return 0; +} +static inline ssize_t pci_p2pdma_enable_show(char *page, + struct pci_dev *p2p_dev, bool use_p2pdma) +{ + return sprintf(page, "none\n"); +} #endif /* CONFIG_PCI_P2PDMA */ #endif /* _LINUX_PCI_P2P_H */ -- 2.11.0 _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm