From 77cb985ad4acbe66a92ead1bb826deffa47dd33f Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Thu, 8 Aug 2013 14:09:49 -0600 Subject: [PATCH] PCI: Split out pci_dev lock/unlock and save/restore Only cosmetic code changes to existing paths. Expand the comment in the new pci_dev_save_and_disable() function since there's a lot hidden in that Command register write. Signed-off-by: Alex Williamson Signed-off-by: Bjorn Helgaas --- drivers/pci/pci.c | 55 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 38 insertions(+), 17 deletions(-) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 9407aabc77a3..d48d9febc241 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3317,22 +3317,49 @@ done: return rc; } +static void pci_dev_lock(struct pci_dev *dev) +{ + pci_cfg_access_lock(dev); + /* block PM suspend, driver probe, etc. */ + device_lock(&dev->dev); +} + +static void pci_dev_unlock(struct pci_dev *dev) +{ + device_unlock(&dev->dev); + pci_cfg_access_unlock(dev); +} + +static void pci_dev_save_and_disable(struct pci_dev *dev) +{ + pci_save_state(dev); + /* + * Disable the device by clearing the Command register, except for + * INTx-disable which is set. This not only disables MMIO and I/O port + * BARs, but also prevents the device from being Bus Master, preventing + * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3 + * compliant devices, INTx-disable prevents legacy interrupts. + */ + pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); +} + +static void pci_dev_restore(struct pci_dev *dev) +{ + pci_restore_state(dev); +} + static int pci_dev_reset(struct pci_dev *dev, int probe) { int rc; - if (!probe) { - pci_cfg_access_lock(dev); - /* block PM suspend, driver probe, etc. */ - device_lock(&dev->dev); - } + if (!probe) + pci_dev_lock(dev); rc = __pci_dev_reset(dev, probe); - if (!probe) { - device_unlock(&dev->dev); - pci_cfg_access_unlock(dev); - } + if (!probe) + pci_dev_unlock(dev); + return rc; } /** @@ -3423,17 +3450,11 @@ int pci_reset_function(struct pci_dev *dev) if (rc) return rc; - pci_save_state(dev); - - /* - * both INTx and MSI are disabled after the Interrupt Disable bit - * is set and the Bus Master bit is cleared. - */ - pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); + pci_dev_save_and_disable(dev); rc = pci_dev_reset(dev, 0); - pci_restore_state(dev); + pci_dev_restore(dev); return rc; } -- 2.39.2