PCI/MSI: Add pci_msix_vec_count()

[firefly-linux-kernel-4.4.55.git] / drivers / pci / msi.c

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 76507ab13bebafe2ab9138bde1df1ea069048fb4..bd18ecf74c55d07eceaf7a214511f72717df38e1 100644 (file)
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -948,19 +948,25 @@ void pci_disable_msi(struct pci_dev *dev)
 EXPORT_SYMBOL(pci_disable_msi);
 
 /**
- * pci_msix_table_size - return the number of device's MSI-X table entries
+ * pci_msix_vec_count - return the number of device's MSI-X table entries
  * @dev: pointer to the pci_dev data structure of MSI-X device function
- */
-int pci_msix_table_size(struct pci_dev *dev)
+
+ * This function returns the number of device's MSI-X table entries and
+ * therefore the number of MSI-X vectors device is capable of sending.
+ * It returns a negative errno if the device is not capable of sending MSI-X
+ * interrupts.
+ **/
+int pci_msix_vec_count(struct pci_dev *dev)
 {
        u16 control;
 
        if (!dev->msix_cap)
-               return 0;
+               return -EINVAL;
 
        pci_read_config_word(dev, dev->msix_cap + PCI_MSIX_FLAGS, &control);
        return msix_table_size(control);
 }
+EXPORT_SYMBOL(pci_msix_vec_count);
 
 /**
  * pci_enable_msix - configure device's MSI-X capability structure
@@ -989,7 +995,9 @@ int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
        if (status)
                return status;
 
-       nr_entries = pci_msix_table_size(dev);
+       nr_entries = pci_msix_vec_count(dev);
+       if (nr_entries < 0)
+               return nr_entries;
        if (nvec > nr_entries)
                return nr_entries;