Replace pci_enable_msix() with pci_alloc_irq_vectors()

Since kernel version 4.8. pci_enable_msix() isn't available any more.
Therefore it is replaced with pci_alloc_irq_vectors() if used
kernel version is >= 4.8

Signed-off-by: Andreas Rollbühler <andreas.rollbuehler@siemens.com>

Author: andreas-rollbuehler

kernel_module/uio/uio_ivshmem.c

@@ -3,6 +3,7 @@
  *
  * (C) 2009 Cam Macdonell
  * (C) 2014 Henning Schild
+ * (C) 2017 Andreas Rollbühler
  * based on Hilscher CIF card driver (C) 2007 Hans J. Koch <hjk@linutronix.de>
  *
  * Licensed under GPL version 2 only.
@@ -15,6 +16,8 @@
 #include <linux/uio_driver.h>
 #include <linux/io.h>
 
+#include <linux/version.h>
+
 #define IntrStatus 0x04
 #define IntrMask 0x00
 
@@ -59,7 +62,12 @@ static void free_msix_vectors(struct ivshmem_info *ivs_info,
 	int i;
 
 	for (i = 0; i < max_vector; i++)
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,8,0)
 		free_irq(ivs_info->msix_entries[i].vector, ivs_info->uio);
+#else
+		free_irq(pci_irq_vector(ivs_info->dev, ivs_info->msix_entries[i].entry),
+			ivs_info->uio);
+#endif
 }
 
 static int request_msix_vectors(struct ivshmem_info *ivs_info, int nvectors)
@@ -85,6 +93,8 @@ static int request_msix_vectors(struct ivshmem_info *ivs_info, int nvectors)
 	for (i = 0; i < nvectors; ++i)
 		ivs_info->msix_entries[i].entry = i;
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,8,0)
+
 	err = pci_enable_msix(ivs_info->dev, ivs_info->msix_entries,
 					ivs_info->nvectors);
 	if (err > 0) {
@@ -101,12 +111,27 @@ static int request_msix_vectors(struct ivshmem_info *ivs_info, int nvectors)
 
 	if (err)
 		goto error;
+#else
+	err = pci_alloc_irq_vectors(ivs_info->dev, 1, ivs_info->nvectors,
+			PCI_IRQ_MSIX);
+
+	if (err <= 0) {
+		dev_info(&ivs_info->dev->dev,
+			 "no MSI (%d). Back to INTx.\n", err);
+		goto error;
+	} else {
+		ivs_info->nvectors = err;
+	}
+#endif
+
 
 	for (i = 0; i < ivs_info->nvectors; i++) {
 
 		snprintf(ivs_info->msix_names[i], sizeof(*ivs_info->msix_names),
 			"%s-config", name);
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4,8,0)
+
 		err = request_irq(ivs_info->msix_entries[i].vector,
 			ivshmem_msix_handler, 0,
 			ivs_info->msix_names[i], ivs_info->uio);
@@ -115,14 +140,26 @@ static int request_msix_vectors(struct ivshmem_info *ivs_info, int nvectors)
 			free_msix_vectors(ivs_info, i - 1);
 			goto error;
 		}
+#else
+		err = request_irq(pci_irq_vector(ivs_info->dev,
+			ivs_info->msix_entries[i].entry), ivshmem_msix_handler, 0,
+			ivs_info->msix_names[i], ivs_info->uio);
 
+		if (err < 0) {
+			free_msix_vectors(ivs_info, i - 1);
+			goto error;
+		}
+#endif
 	}
 
 	return 0;
 error:
 	kfree(ivs_info->msix_entries);
 	kfree(ivs_info->msix_names);
 	ivs_info->nvectors = 0;
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,8,0)
+	pci_free_irq_vectors(ivs_info->dev);
+#endif
 	return err;
 
 }