[dpdk-dev] [PATCH 04/10] igb_uio: msix cleanups

[Stephen Hemminger]

Since only one MSI-X entry is ever defined, there is no need to
put it as an array in the driver private data structure. One msix_entry
can just be put on the stack and initialized there.

Also remove the unused backport defines related to MSI-X.
I suspect this code was just inherited from some other project and
never cleaned up.

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>


--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c	2014-07-18 08:38:29.291724950 -0700
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c	2014-07-18 08:42:06.460487465 -0700
@@ -37,19 +37,6 @@
 #endif
 #include <rte_pci_dev_features.h>
 
-/**
- * MSI-X related macros, copy from linux/pci_regs.h in kernel 2.6.39,
- * but none of them in kernel 2.6.35.
- */
-#ifndef PCI_MSIX_ENTRY_SIZE
-#define PCI_MSIX_ENTRY_SIZE             16
-#define PCI_MSIX_ENTRY_LOWER_ADDR       0
-#define PCI_MSIX_ENTRY_UPPER_ADDR       4
-#define PCI_MSIX_ENTRY_DATA             8
-#define PCI_MSIX_ENTRY_VECTOR_CTRL      12
-#define PCI_MSIX_ENTRY_CTRL_MASKBIT     1
-#endif
-
 #ifdef RTE_PCI_CONFIG
 #define PCI_SYS_FILE_BUF_SIZE      10
 #define PCI_DEV_CAP_REG            0xA4
@@ -59,8 +46,6 @@
 #define PCI_DEV_CTRL_EXT_TAG_MASK  (1 << PCI_DEV_CTRL_EXT_TAG_SHIFT)
 #endif
 
-#define IGBUIO_NUM_MSI_VECTORS 1
-
 /**
  * A structure describing the private information for a uio device.
  */
@@ -69,8 +54,6 @@ struct rte_uio_pci_dev {
 	struct pci_dev *pdev;
 	spinlock_t lock; /* spinlock for accessing PCI config space or msix data in multi tasks/isr */
 	enum rte_intr_mode mode;
-	struct msix_entry \
-		msix_entries[IGBUIO_NUM_MSI_VECTORS]; /* pointer to the msix vectors to be allocated later */
 };
 
 static char *intr_mode = NULL;
@@ -546,6 +529,7 @@ static int
 igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
 	struct rte_uio_pci_dev *udev;
+	struct msix_entry msix_entry;
 
 	udev = kzalloc(sizeof(struct rte_uio_pci_dev), GFP_KERNEL);
 	if (!udev)
@@ -602,12 +586,8 @@ igbuio_pci_probe(struct pci_dev *dev, co
 
 	/* check if it need to try msix first */
 	if (igbuio_intr_mode_preferred == RTE_INTR_MODE_MSIX) {
-		int vector;
-
-		for (vector = 0; vector < IGBUIO_NUM_MSI_VECTORS; vector ++)
-			udev->msix_entries[vector].entry = vector;
-
-		if (pci_enable_msix(udev->pdev, udev->msix_entries, IGBUIO_NUM_MSI_VECTORS) == 0) {
+		msix_entry.entry = 0;
+		if (pci_enable_msix(dev, &msix_entry, 1) == 0) {
 			udev->mode = RTE_INTR_MODE_MSIX;
 		}
 		else {
@@ -618,7 +598,7 @@ igbuio_pci_probe(struct pci_dev *dev, co
 	switch (udev->mode) {
 	case RTE_INTR_MODE_MSIX:
 		udev->info.irq_flags = 0;
-		udev->info.irq = udev->msix_entries[0].vector;
+		udev->info.irq = msix_entry.vector;
 		break;
 	case RTE_INTR_MODE_MSI:
 		break;