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PCI: Export pcie_flr()

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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 <hch@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Christoph Hellwig
2017-04-14 21:11:25 +02:00
committed by Bjorn Helgaas
parent 0e7df22401
commit a60a2b73ba
2 changed files with 29 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

39
drivers/pci/pci.c
View File

@@ -3773,27 +3773,41 @@ static void pci_flr_wait(struct pci_dev *dev)
(i - 1) * 100); (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; 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) if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
return -ENOTTY; return false;
if (probe) pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
return 0; 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)) if (!pci_wait_for_pending_transaction(dev))
dev_err(&dev->dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); 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); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR);
pci_flr_wait(dev); pci_flr_wait(dev);
return 0;
} }
EXPORT_SYMBOL_GPL(pcie_flr);
static int pci_af_flr(struct pci_dev *dev, int probe) 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) if (rc != -ENOTTY)
goto done; goto done;
rc = pcie_flr(dev, probe); if (pcie_has_flr(dev)) {
if (rc != -ENOTTY) if (!probe)
pcie_flr(dev);
rc = 0;
goto done; goto done;
}
rc = pci_af_flr(dev, probe); rc = pci_af_flr(dev, probe);
if (rc != -ENOTTY) if (rc != -ENOTTY)

1
include/linux/pci.h
View File

@@ -1054,6 +1054,7 @@ int pcie_get_mps(struct pci_dev *dev);
int pcie_set_mps(struct pci_dev *dev, int mps); int pcie_set_mps(struct pci_dev *dev, int mps);
int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed,
enum pcie_link_width *width); enum pcie_link_width *width);
void pcie_flr(struct pci_dev *dev);
int __pci_reset_function(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_locked(struct pci_dev *dev);
int pci_reset_function(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev);