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Commit a60a2b73 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Bjorn Helgaas
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PCI: Export pcie_flr() 



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: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 0e7df224

drivers/pci/pci.c

+28 −11
Original line number Diff line number Diff line
@@ -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)

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -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);