MSI: Expand pci_msi_supported()

pci_enable_msi() and pci_enable_msix() both search for the MSI/MSI-X
capability, we can fold this into pci_msi_supported() by passing the
type in.

Update the code to match the comment for pci_msi_supported(). That is
it returns 0 on success, and anything else indicates an error.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 8 insertions, 11 deletions

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 762bff18187d..d5b9b94a2ac5 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -459,12 +459,13 @@ static int msix_capability_init(struct pci_dev *dev,
 /**
  * pci_msi_supported - check whether MSI may be enabled on device
  * @dev: pointer to the pci_dev data structure of MSI device function
+ * @type: are we checking for MSI or MSI-X ?
  *
  * Look at global flags, the device itself, and its parent busses
  * to return 0 if MSI are supported for the device.
  **/
 static
-int pci_msi_supported(struct pci_dev * dev)
+int pci_msi_supported(struct pci_dev * dev, int type)
 {
         struct pci_bus *bus;
 
@@ -482,6 +483,9 @@ int pci_msi_supported(struct pci_dev * dev)
                 if (bus->bus_flags & PCI_BUS_FLAGS_NO_MSI)
                         return -EINVAL;
 
+        if (!pci_find_capability(dev, type))
+                return -EINVAL;
+
         return 0;
 }
 
@@ -497,13 +501,9 @@ int pci_msi_supported(struct pci_dev * dev)
  **/
 int pci_enable_msi(struct pci_dev* dev)
 {
-        int pos, status;
+        int status;
 
-        if (pci_msi_supported(dev) < 0)
-                return -EINVAL;
-
-        pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
-        if (!pos)
+        if (pci_msi_supported(dev, PCI_CAP_ID_MSI))
                 return -EINVAL;
 
         WARN_ON(!!dev->msi_enabled);
@@ -606,13 +606,10 @@ int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec)
         int i, j;
         u16 control;
 
-        if (!entries || pci_msi_supported(dev) < 0)
+        if (!entries || pci_msi_supported(dev, PCI_CAP_ID_MSIX))
                 return -EINVAL;
 
         pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
-        if (!pos)
-                return -EINVAL;
-
         pci_read_config_word(dev, msi_control_reg(pos), &control);
         nr_entries = multi_msix_capable(control);
         if (nvec > nr_entries)