[dpdk-dev] [PATCH v2 05/10] Subjec: igb_uio: msix cleanups

[Stephen Hemminger <stephen@networkplumber.org>]

[-- Attachment #1: igb_uio-msix-vector.patch --]
[-- Type: text/plain, Size: 2212 bytes --]

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@networkplumber.org>


--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
@@ -36,21 +36,6 @@
 #include <xen/xen.h>
 #endif
 
-/**
- * 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
-
-#define IGBUIO_NUM_MSI_VECTORS 1
-
 /* interrupt mode */
 enum igbuio_intr_mode {
 	IGBUIO_LEGACY_INTR_MODE = 0,
@@ -67,8 +52,6 @@
 	struct pci_dev *pdev;
 	spinlock_t lock; /* spinlock for accessing PCI config space or msix data in multi tasks/isr */
 	enum igbuio_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;
@@ -526,17 +509,16 @@
 
 	/* check if it need to try msix first */
 	if (igbuio_intr_mode_preferred == IGBUIO_MSIX_INTR_MODE) {
-		int vector;
-
-		for (vector = 0; vector < IGBUIO_NUM_MSI_VECTORS; vector ++)
-			udev->msix_entries[vector].entry = vector;
+		/* only one MSIX vector needed */
+		struct msix_entry msix_entry = {
+			.entry = 0,
+		};
 
-		if (pci_enable_msix(udev->pdev, udev->msix_entries, IGBUIO_NUM_MSI_VECTORS) == 0) {
+		if (pci_enable_msix(udev->pdev, &msix_entry, 1) == 0) {
 			udev->mode = IGBUIO_MSIX_INTR_MODE;
-		}
-		else {
-			pci_disable_msix(udev->pdev);
-			pr_info("fail to enable pci msix, or not enough msix entries\n");
+		} else {
+			pr_err("failed to enable pci msix, or not enough msix entries\n");
+			udev->mode = IGBUIO_LEGACY_INTR_MODE;
 		}
 	}
 	switch (udev->mode) {