From: Christoph Hellwig Subject: [PATCH 1/7] PCI: export pcie_flr Date: Fri, 14 Apr 2017 21:11:25 +0200 Message-ID: <20170414191131.14286-2-hch@lst.de> References: <20170414191131.14286-1-hch@lst.de> Cc: linux-pci@vger.kernel.org, qat-linux@intel.com, linux-crypto@vger.kernel.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: Bjorn Helgaas , Giovanni Cabiddu , Salvatore Benedetto , Mike Marciniszyn , Dennis Dalessandro , Derek Chickles , Satanand Burla , Felix Manlunas , Raghu Vatsavayi , Jeff Kirsher Return-path: In-Reply-To: <20170414191131.14286-1-hch@lst.de> Sender: linux-pci-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org Currently we opencode the FLR sequence in lots of place, export a core helper instead. We split out the probing for FLR support as all the non-core callers already know their hardware. Note that in the new pci_has_flr function the quirk check has been moved before the capability check as there is no point in reading the capability in this case. Signed-off-by: Christoph Hellwig Acked-by: Bjorn Helgaas --- drivers/pci/pci.c | 39 ++++++++++++++++++++++++++++----------- include/linux/pci.h | 1 + 2 files changed, 29 insertions(+), 11 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index bef14777bb30..957a11a6a840 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3773,27 +3773,41 @@ static void pci_flr_wait(struct pci_dev *dev) (i - 1) * 100); } -static int pcie_flr(struct pci_dev *dev, int probe) +/** + * pcie_has_flr - check if a device supports function level resets + * @dev: device to check + * + * Returns true if the device advertises support for PCIe function level + * resets. + */ +static bool pcie_has_flr(struct pci_dev *dev) { u32 cap; - pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); - if (!(cap & PCI_EXP_DEVCAP_FLR)) - return -ENOTTY; - if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) - return -ENOTTY; + return false; - if (probe) - return 0; + pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); + return cap & PCI_EXP_DEVCAP_FLR; +} +/** + * pcie_flr - initiate a PCIe function level reset + * @dev: device to reset + * + * Initiate a function level reset on @dev. The caller should ensure the + * device supports FLR before calling this function, e.g. by using the + * pcie_has_flr() helper. + */ +void pcie_flr(struct pci_dev *dev) +{ if (!pci_wait_for_pending_transaction(dev)) dev_err(&dev->dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); pci_flr_wait(dev); - return 0; } +EXPORT_SYMBOL_GPL(pcie_flr); static int pci_af_flr(struct pci_dev *dev, int probe) { @@ -3977,9 +3991,12 @@ static int __pci_dev_reset(struct pci_dev *dev, int probe) if (rc != -ENOTTY) goto done; - rc = pcie_flr(dev, probe); - if (rc != -ENOTTY) + if (pcie_has_flr(dev)) { + if (!probe) + pcie_flr(dev); + rc = 0; goto done; + } rc = pci_af_flr(dev, probe); if (rc != -ENOTTY) diff --git a/include/linux/pci.h b/include/linux/pci.h index 20e1865233a4..60162f51227a 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1054,6 +1054,7 @@ int pcie_get_mps(struct pci_dev *dev); int pcie_set_mps(struct pci_dev *dev, int mps); int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, enum pcie_link_width *width); +void pcie_flr(struct pci_dev *dev); int __pci_reset_function(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); -- 2.11.0