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author | Alex Williamson <alex.williamson@redhat.com> | 2013-08-08 20:09:49 (GMT) |
---|---|---|
committer | Bjorn Helgaas <bhelgaas@google.com> | 2013-08-14 21:19:46 (GMT) |
commit | 77cb985ad4acbe66a92ead1bb826deffa47dd33f (patch) | |
tree | 788d6b9ec8f701d952c84552fd4d33483c200611 /drivers/pci | |
parent | 608c388122c72e1bf11ba8113434eb3d0c40c32d (diff) | |
download | linux-fsl-qoriq-77cb985ad4acbe66a92ead1bb826deffa47dd33f.tar.xz |
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 <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers/pci')
-rw-r--r-- | drivers/pci/pci.c | 55 |
1 files changed, 38 insertions, 17 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 9407aab..d48d9fe 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; } |