[PATCH 1/3] pci: Generalize wait loop

From: Alex Williamson
Date: Tue Dec 10 2013 - 13:48:43 EST


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@xxxxxxxxxx>
---
drivers/pci/pci.c | 54 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 31 insertions(+), 23 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 33120d1..05868e4 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -431,6 +431,32 @@ pci_find_parent_resource(const struct pci_dev *dev, struct resource *res)
}

/**
+ * 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.
+ */
+static 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))
- return 1;
- }
+ 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))
- 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");

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/