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>

2 files changed, 32 insertions, 23 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 33120d156668..bb257b975a8f 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 1084a15175e0..211ce43ba483 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);