- Updating dpdk_iface.ko module which now supports dynamic allocation of major numbers.

dpdk-iface-kmod/dpdk_iface.c

@@ -33,6 +33,7 @@
 /*--------------------------------------------------------------------------*/
 struct stats_struct sarrays[MAX_DEVICES][MAX_QID] = {{{0, 0, 0, 0, 0, 0, 0, 0, 0}}};
 struct stats_struct old_sarrays[MAX_DEVICES][MAX_QID] = {{{0, 0, 0, 0, 0, 0, 0, 0, 0}}};
+static int major_no = -1;
 /*--------------------------------------------------------------------------*/
 static int
 update_stats(struct stats_struct *stats)
@@ -245,7 +246,7 @@ iface_pci_init_module(void)
 {
 	int ret;
 
-	ret = register_chrdev(MAJOR_NO /* MAJOR */,
+	ret = register_chrdev(0, /* MAJOR */,
 			      DEV_NAME /*NAME*/,
 			      &igb_net_fops);
 	if (ret < 0) {
@@ -256,6 +257,10 @@ iface_pci_init_module(void)
 
 	printk(KERN_INFO "%s: Loaded\n",
 	       THIS_MODULE->name);
+
+	/* record major number */
+	major_no = ret;
+	
 	return 0;
 }
 /*--------------------------------------------------------------------------*/
@@ -263,7 +268,7 @@ static void __exit
 iface_pci_exit_module(void)
 {
 	clear_all_netdevices();
-	unregister_chrdev(MAJOR_NO, DEV_NAME);
+	unregister_chrdev(major_no, DEV_NAME);
 }
 /*--------------------------------------------------------------------------*/
 module_init(iface_pci_init_module);

dpdk-iface-kmod/dpdk_iface_common.h

@@ -5,12 +5,12 @@
 #ifndef __KERNEL__
 #include <net/if.h>
 #endif
+#include <asm/bitsperlong.h>
 /*--------------------------------------------------------------------------*/
-/* major number */
-#define MAJOR_NO		511 //1110
 /* dev name */
 #define DEV_NAME		"dpdk-iface"
 #define DEV_PATH		"/dev/"DEV_NAME
+#define DEV_PROC_PATH		"/proc/devices"
 /* ioctl# */
 #define SEND_STATS		 0
 #define CREATE_IFACE		 1
@@ -40,6 +40,6 @@ typedef struct PciDevice {
 		char ifname[IFNAMSIZ];
 	};
 	PciAddress pa;
-} PciDevice __attribute__((aligned(64)));
+} PciDevice __attribute__((aligned(__BITS_PER_LONG)));
 /*--------------------------------------------------------------------------*/
 #endif /* __DPDK_IFACE_COMMON_H__ */

dpdk-iface-kmod/dpdk_iface_main.c

@@ -12,12 +12,12 @@
 #include <rte_ethdev.h>
 #include "dpdk_iface_common.h"
 /*--------------------------------------------------------------------------*/
-//#define DEBUG			1
-#define SYSFS_PCI_DRIVER_PATH	"/sys/bus/pci/drivers/"
-#define SYSFS_PCI_IGB_UIO	SYSFS_PCI_DRIVER_PATH"igb_uio"
-#define SYSFS_PCI_VFIO_PCI	SYSFS_PCI_DRIVER_PATH"vfio-pci"
-#define SYSFS_PCI_UIOPCIGEN	SYSFS_PCI_DRIVER_PATH"uio_pci_generic"
-#define RTE_ARGC_MAX		(RTE_MAX_ETHPORTS << 1) + 7
+//#define DEBUG				1
+#define SYSFS_PCI_DRIVER_PATH		"/sys/bus/pci/drivers/"
+#define SYSFS_PCI_IGB_UIO		SYSFS_PCI_DRIVER_PATH"igb_uio"
+#define SYSFS_PCI_VFIO_PCI		SYSFS_PCI_DRIVER_PATH"vfio-pci"
+#define SYSFS_PCI_UIOPCIGEN		SYSFS_PCI_DRIVER_PATH"uio_pci_generic"
+#define RTE_ARGC_MAX			(RTE_MAX_ETHPORTS << 1) + 7
 /*--------------------------------------------------------------------------*/
 typedef struct {
 	PciDevice pd;
@@ -144,6 +144,43 @@ probe_all_rte_devices(char **argv, int *argc)
 }
 /*--------------------------------------------------------------------------*/
 int
+fetch_major_no()
+{
+	FILE *f;
+	int major_no;
+	char *line;
+	size_t len;
+	char dummy[512];
+
+	major_no = -1;
+	len = 0;
+	line = NULL;
+	
+	f = fopen(DEV_PROC_PATH, "r");
+	if (f == NULL) {
+		fprintf(stderr, "Can't open %s file\n", DEV_PROC_PATH);
+		return -1;
+	}
+
+	while (getline(&line, &len, f) != -1) {
+		if (strstr(line, DEV_NAME) != NULL) {
+			if (sscanf(line, "%d %s", &major_no, dummy) == 2) {
+				free(line);
+				break;
+			}
+		}
+		free(line);
+		line = NULL;
+		len = 0;
+	}
+	
+	/* close the file descriptor */
+	fclose(f);
+
+	return major_no;
+}
+/*--------------------------------------------------------------------------*/
+int
 main(int argc, char **argv)
 {
 	int ret, fd, num_devices, i;
@@ -183,7 +220,11 @@ main(int argc, char **argv)
 		"\033[32m not present. \033[0m \n");
 
 	/* create dpdk-iface device node entry */
+#if 0
 	dev = makedev(MAJOR_NO, 0);
+#else
+	dev = makedev(fetch_major_no(), 0);
+#endif
 	ret = mknod(DEV_PATH, S_IFCHR | O_RDWR, dev);
 	if (ret == 0)
 		fprintf(stderr, "Creating device node entry...");