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Message-ID: <20131217234339.2310.68566.stgit@bling.home>
Date: Tue, 17 Dec 2013 16:43:39 -0700
From: Alex Williamson <alex.williamson@...hat.com>
To: bhelgaas@...gle.com, linux-pci@...r.kernel.org
Cc: ddutile@...hat.com, linux-kernel@...r.kernel.org
Subject: [PATCH v2 1/4] pci: Generalize wait loop
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@...hat.com>
---
drivers/pci/pci.c | 54 +++++++++++++++++++++++++++++----------------------
include/linux/pci.h | 1 +
2 files changed, 32 insertions(+), 23 deletions(-)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 07369f3..848023f 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.
+ */
+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");
diff --git a/include/linux/pci.h b/include/linux/pci.h
index a13d682..e661333 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -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);
--
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