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Commit 157e876f authored by Alex Williamson's avatar Alex Williamson Committed by Bjorn Helgaas
Browse files

PCI: Add pci_wait_for_pending() (refactor pci_wait_for_pending_transaction()) 



We currently have two instance of this loop which waits for a pending bit
to clear in a status dword.  Generalize the function for future users.

Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 6ce4eac1

drivers/pci/pci.c

+31 −23
Original line number Diff line number Diff line
@@ -430,6 +430,32 @@ pci_find_parent_resource(const struct pci_dev *dev, struct resource *res) 
	return best;

}



/**

 * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos

 * @dev: the PCI device to operate on

 * @pos: config space offset of status word

 * @mask: mask of bit(s) to care about in status word

 *

 * Return 1 when mask bit(s) in status word clear, 0 otherwise.

 */

int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask)

{

	int i;



	/* Wait for Transaction Pending bit clean */

	for (i = 0; i < 4; i++) {

		u16 status;

		if (i)

			msleep((1 << (i - 1)) * 100);



		pci_read_config_word(dev, pos, &status);

		if (!(status & mask))

			return 1;

	}



	return 0;

}



/**

 * pci_restore_bars - restore a devices BAR values (e.g. after wake-up)

 * @dev: PCI device to have its BARs restored
@@ -3204,20 +3230,10 @@ EXPORT_SYMBOL(pci_set_dma_seg_boundary); 
 */

int pci_wait_for_pending_transaction(struct pci_dev *dev)

{

	int i;

	u16 status;



	/* Wait for Transaction Pending bit clean */

	for (i = 0; i < 4; i++) {

		if (i)

			msleep((1 << (i - 1)) * 100);



		pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &status);

		if (!(status & PCI_EXP_DEVSTA_TRPND))

	if (!pci_is_pcie(dev))

		return 1;

	}



	return 0;

	return pci_wait_for_pending(dev, PCI_EXP_DEVSTA, PCI_EXP_DEVSTA_TRPND);

}

EXPORT_SYMBOL(pci_wait_for_pending_transaction);
@@ -3244,10 +3260,8 @@ static int pcie_flr(struct pci_dev *dev, int probe) 


static int pci_af_flr(struct pci_dev *dev, int probe)

{

	int i;

	int pos;

	u8 cap;

	u8 status;



	pos = pci_find_capability(dev, PCI_CAP_ID_AF);

	if (!pos)
@@ -3261,14 +3275,8 @@ static int pci_af_flr(struct pci_dev *dev, int probe) 
		return 0;



	/* Wait for Transaction Pending bit clean */

	for (i = 0; i < 4; i++) {

		if (i)

			msleep((1 << (i - 1)) * 100);



		pci_read_config_byte(dev, pos + PCI_AF_STATUS, &status);

		if (!(status & PCI_AF_STATUS_TP))

	if (pci_wait_for_pending(dev, PCI_AF_STATUS, PCI_AF_STATUS_TP))

		goto clear;

	}



	dev_err(&dev->dev, "transaction is not cleared; "

			"proceeding with reset anyway\n");

include/linux/pci.h

+1 −0
Original line number Diff line number Diff line
@@ -938,6 +938,7 @@ bool pci_check_and_unmask_intx(struct pci_dev *dev); 
void pci_msi_off(struct pci_dev *dev);

int pci_set_dma_max_seg_size(struct pci_dev *dev, unsigned int size);

int pci_set_dma_seg_boundary(struct pci_dev *dev, unsigned long mask);

int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask);

int pci_wait_for_pending_transaction(struct pci_dev *dev);

int pcix_get_max_mmrbc(struct pci_dev *dev);

int pcix_get_mmrbc(struct pci_dev *dev);