From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga09.intel.com ([134.134.136.24]:64714 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756626AbbFCSrA (ORCPT ); Wed, 3 Jun 2015 14:47:00 -0400 Subject: [PATCH V3 1/2] pci: Add dev_flags bit to access VPD through function 0 From: Mark D Rustad To: bhelgaas@google.com Cc: linux-pci@vger.kernel.org, intel-wired-lan@lists.osuosl.org, netdev@vger.kernel.org Date: Wed, 03 Jun 2015 11:46:59 -0700 Message-ID: <20150603184659.109080.6915.stgit@mdrustad-wks.jf.intel.com> In-Reply-To: <20150603184445.109080.36387.stgit@mdrustad-wks.jf.intel.com> References: <20150603184445.109080.36387.stgit@mdrustad-wks.jf.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-pci-owner@vger.kernel.org List-ID: Add a dev_flags bit, PCI_DEV_FLAGS_VPD_REF_F0, to access VPD through function 0 to provide VPD access on other functions. This solves concurrent access problems on many devices without changing the attributes exposed in sysfs. Never set this bit on function 0 or there will be an infinite recursion. Signed-off-by: Mark Rustad --- Changes in V2: - Corrected spelling in log message - Added checks to see that the referenced function 0 is reasonable Changes in V3: - Don't leak a device reference - Check that function 0 has VPD - Make a helper for the function 0 checks - Do multifunction check in the quirk --- drivers/pci/access.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 60 insertions(+), 1 deletion(-) diff --git a/drivers/pci/access.c b/drivers/pci/access.c index d9b64a175990..b965c12168b7 100644 --- a/drivers/pci/access.c +++ b/drivers/pci/access.c @@ -439,6 +439,56 @@ static const struct pci_vpd_ops pci_vpd_pci22_ops = { .release = pci_vpd_pci22_release, }; +static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count, + void *arg) +{ + struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn)); + ssize_t ret; + + if (!tdev) + return -ENODEV; + + ret = pci_read_vpd(tdev, pos, count, arg); + pci_dev_put(tdev); + return ret; +} + +static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count, + const void *arg) +{ + struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn)); + ssize_t ret; + + if (!tdev) + return -ENODEV; + + ret = pci_write_vpd(tdev, pos, count, arg); + pci_dev_put(tdev); + return ret; +} + +static const struct pci_vpd_ops pci_vpd_f0_ops = { + .read = pci_vpd_f0_read, + .write = pci_vpd_f0_write, + .release = pci_vpd_pci22_release, +}; + +static int pci_vpd_f0_dev_check(struct pci_dev *dev) +{ + struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn)); + int ret = 0; + + if (!tdev) + return -ENODEV; + if (!tdev->vpd || !tdev->multifunction || + dev->class != tdev->class || dev->vendor != tdev->vendor || + dev->device != tdev->device) + ret = -ENODEV; + + pci_dev_put(tdev); + return ret; +} + int pci_vpd_pci22_init(struct pci_dev *dev) { struct pci_vpd_pci22 *vpd; @@ -447,12 +497,21 @@ int pci_vpd_pci22_init(struct pci_dev *dev) cap = pci_find_capability(dev, PCI_CAP_ID_VPD); if (!cap) return -ENODEV; + if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { + int ret = pci_vpd_f0_dev_check(dev); + + if (ret) + return ret; + } vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC); if (!vpd) return -ENOMEM; vpd->base.len = PCI_VPD_PCI22_SIZE; - vpd->base.ops = &pci_vpd_pci22_ops; + if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) + vpd->base.ops = &pci_vpd_f0_ops; + else + vpd->base.ops = &pci_vpd_pci22_ops; mutex_init(&vpd->lock); vpd->cap = cap; vpd->busy = false; diff --git a/include/linux/pci.h b/include/linux/pci.h index 353db8dc4c6e..194df6d635e6 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -180,6 +180,8 @@ enum pci_dev_flags { PCI_DEV_FLAGS_NO_BUS_RESET = (__force pci_dev_flags_t) (1 << 6), /* Do not use PM reset even if device advertises NoSoftRst- */ PCI_DEV_FLAGS_NO_PM_RESET = (__force pci_dev_flags_t) (1 << 7), + /* Get VPD from function 0 VPD */ + PCI_DEV_FLAGS_VPD_REF_F0 = (__force pci_dev_flags_t) (1 << 8), }; enum pci_irq_reroute_variant {