backports: add pci_enable_msix_range()

This is needed by drivers/net/ethernet/intel/igb/igb_main.c

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

diff --git a/backport/backport-include/linux/pci.h b/backport/backport-include/linux/pci.h
index 2190831d2f9a52c42b9266cffed08985214f770a..9eeb09be232f1ad3fa9b9102d31134b571107fb4 100644 (file)
--- a/backport/backport-include/linux/pci.h
+++ b/backport/backport-include/linux/pci.h
@@ -245,4 +245,16 @@ static inline int pci_enable_msi_range(struct pci_dev *dev, int minvec,
 #endif
 #endif
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
+#define pci_enable_msix_range LINUX_BACKPORT(pci_enable_msix_range)
+#ifdef CONFIG_PCI_MSI
+int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
+                         int minvec, int maxvec);
+#else
+static inline int pci_enable_msix_range(struct pci_dev *dev,
+                     struct msix_entry *entries, int minvec, int maxvec)
+{ return -ENOSYS; }
+#endif
+#endif
+
 #endif /* _BACKPORT_LINUX_PCI_H */

diff --git a/backport/compat/backport-3.14.c b/backport/compat/backport-3.14.c
index 9e37c58663d83a4bcde86f8affe2d473ca69b4c4..bce50dc55d52a34a914e37c9de14337cc5db698c 100644 (file)
--- a/backport/compat/backport-3.14.c
+++ b/backport/compat/backport-3.14.c
@@ -49,3 +49,44 @@ int pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec)
 EXPORT_SYMBOL(pci_enable_msi_range);
 #endif
 #endif
+
+#ifdef CONFIG_PCI_MSI
+/**
+ * pci_enable_msix_range - configure device's MSI-X capability structure
+ * @dev: pointer to the pci_dev data structure of MSI-X device function
+ * @entries: pointer to an array of MSI-X entries
+ * @minvec: minimum number of MSI-X irqs requested
+ * @maxvec: maximum number of MSI-X irqs requested
+ *
+ * Setup the MSI-X capability structure of device function with a maximum
+ * possible number of interrupts in the range between @minvec and @maxvec
+ * upon its software driver call to request for MSI-X mode enabled on its
+ * hardware device function. It returns a negative errno if an error occurs.
+ * If it succeeds, it returns the actual number of interrupts allocated and
+ * indicates the successful configuration of MSI-X capability structure
+ * with new allocated MSI-X interrupts.
+ **/
+int pci_enable_msix_range(struct pci_dev *dev, struct msix_entry *entries,
+                              int minvec, int maxvec)
+{
+       int nvec = maxvec;
+       int rc;
+
+       if (maxvec < minvec)
+               return -ERANGE;
+
+       do {
+               rc = pci_enable_msix(dev, entries, nvec);
+               if (rc < 0) {
+                       return rc;
+               } else if (rc > 0) {
+                       if (rc < minvec)
+                               return -ENOSPC;
+                       nvec = rc;
+               }
+       } while (rc);
+
+       return nvec;
+}
+EXPORT_SYMBOL(pci_enable_msix_range);
+#endif