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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: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
This commit is contained in:
Alex Williamson 2013-12-17 16:43:39 -07:00 committed by Bjorn Helgaas
parent 6ce4eac1f6
commit 157e876ffe
2 changed files with 32 additions and 23 deletions
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54
drivers/pci/pci.c
View File

@ -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;
if (!pci_is_pcie(dev))
return 1;
/* 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))
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))
goto clear;
}
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");

1
include/linux/pci.h
View File

@ -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);