devargs: add non-variadic parsing function

rte_devargs_parse becomes non-variadic,
rte_devargs_parsef becomes the variadic version, to be used to compose
device strings.

Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
Acked-by: Shreyansh Jain <shreyansh.jain@nxp.com>
Acked-by: Thomas Monjalon <thomas@monjalon.net>

drivers/net/failsafe/failsafe_args.c

@@ -63,7 +63,7 @@ fs_parse_device(struct sub_device *sdev, char *args)
 
 	d = &sdev->devargs;
 	DEBUG("%s", args);
-	ret = rte_devargs_parse(d, "%s", args);
+	ret = rte_devargs_parse(d, args);
 	if (ret) {
 		DEBUG("devargs parsing failed with code %d", ret);
 		return ret;

drivers/net/failsafe/failsafe_eal.c

@@ -86,7 +86,7 @@ fs_bus_init(struct rte_eth_dev *dev)
 			else
 				snprintf(devstr, sizeof(devstr), "%s",
 					 rte_eth_devices[pid].device->name);
-			ret = rte_devargs_parse(da, "%s", devstr);
+			ret = rte_devargs_parse(da, devstr);
 			if (ret) {
 				ERROR("Probed devargs parsing failed with code"
 				      " %d", ret);

lib/librte_eal/common/eal_common_dev.c

@@ -138,8 +138,8 @@ int __rte_experimental rte_eal_hotplug_add(const char *busname, const char *devn
 	if (da == NULL)
 		return -ENOMEM;
 
-	ret = rte_devargs_parse(da, "%s:%s,%s",
-				    busname, devname, devargs);
+	ret = rte_devargs_parsef(da, "%s:%s,%s",
+				 busname, devname, devargs);
 	if (ret)
 		goto err_devarg;
 

lib/librte_eal/common/eal_common_devargs.c

@@ -63,24 +63,18 @@ bus_name_cmp(const struct rte_bus *bus, const void *name)
 	return strncmp(bus->name, name, strlen(bus->name));
 }
 
-int __rte_experimental
-rte_devargs_parse(struct rte_devargs *da, const char *format, ...)
+__rte_experimental
+int
+rte_devargs_parse(struct rte_devargs *da, const char *dev)
 {
 	struct rte_bus *bus = NULL;
-	va_list ap;
-	va_start(ap, format);
-	char dev[vsnprintf(NULL, 0, format, ap) + 1];
 	const char *devname;
 	const size_t maxlen = sizeof(da->name);
 	size_t i;
 
-	va_end(ap);
 	if (da == NULL)
 		return -EINVAL;
 
-	va_start(ap, format);
-	vsnprintf(dev, sizeof(dev), format, ap);
-	va_end(ap);
 	/* Retrieve eventual bus info */
 	do {
 		devname = dev;
@@ -125,6 +119,34 @@ rte_devargs_parse(struct rte_devargs *da, const char *format, ...)
 	return 0;
 }
 
+__rte_experimental
+int
+rte_devargs_parsef(struct rte_devargs *da, const char *format, ...)
+{
+	va_list ap;
+	size_t len;
+	char *dev;
+
+	if (da == NULL)
+		return -EINVAL;
+
+	va_start(ap, format);
+	len = vsnprintf(NULL, 0, format, ap);
+	va_end(ap);
+
+	dev = calloc(1, len + 1);
+	if (dev == NULL) {
+		RTE_LOG(ERR, EAL, "not enough memory to parse device\n");
+		return -ENOMEM;
+	}
+
+	va_start(ap, format);
+	vsnprintf(dev, len, format, ap);
+	va_end(ap);
+
+	return rte_devargs_parse(da, dev);
+}
+
 int __rte_experimental
 rte_devargs_insert(struct rte_devargs *da)
 {
@@ -151,7 +173,7 @@ rte_devargs_add(enum rte_devtype devtype, const char *devargs_str)
 	if (devargs == NULL)
 		goto fail;
 
-	if (rte_devargs_parse(devargs, "%s", dev))
+	if (rte_devargs_parse(devargs, dev))
 		goto fail;
 	devargs->type = devtype;
 	bus = devargs->bus;

lib/librte_eal/common/include/rte_devargs.h

@@ -89,6 +89,42 @@ __rte_deprecated
 int rte_eal_parse_devargs_str(const char *devargs_str,
 				char **drvname, char **drvargs);
 
+/**
+ * Parse a device string.
+ *
+ * Verify that a bus is capable of handling the device passed
+ * in argument. Store which bus will handle the device, its name
+ * and the eventual device parameters.
+ *
+ * The syntax is:
+ *
+ *     bus:device_identifier,arg1=val1,arg2=val2
+ *
+ * where "bus:" is the bus name followed by any character separator.
+ * The bus name is optional. If no bus name is specified, each bus
+ * will attempt to recognize the device identifier. The first one
+ * to succeed will be used.
+ *
+ * Examples:
+ *
+ *     pci:0000:05.00.0,arg=val
+ *     05.00.0,arg=val
+ *     vdev:net_ring0
+ *
+ * @param da
+ *   The devargs structure holding the device information.
+ *
+ * @param dev
+ *   String describing a device.
+ *
+ * @return
+ *   - 0 on success.
+ *   - Negative errno on error.
+ */
+__rte_experimental
+int
+rte_devargs_parse(struct rte_devargs *da, const char *dev);
+
 /**
  * Parse a device string.
  *
@@ -124,8 +160,8 @@ int rte_eal_parse_devargs_str(const char *devargs_str,
  */
 __rte_experimental
 int
-rte_devargs_parse(struct rte_devargs *da,
-		  const char *format, ...)
+rte_devargs_parsef(struct rte_devargs *da,
+		   const char *format, ...)
 __attribute__((format(printf, 2, 0)));
 
 /**

lib/librte_eal/rte_eal_version.map

@@ -264,6 +264,7 @@ EXPERIMENTAL {
 	rte_devargs_insert;
 	rte_devargs_next;
 	rte_devargs_parse;
+	rte_devargs_parsef;
 	rte_devargs_remove;
 	rte_devargs_type_count;
 	rte_eal_cleanup;

lib/librte_ethdev/rte_ethdev.c

@@ -658,7 +658,7 @@ rte_eth_dev_attach(const char *devargs, uint16_t *port_id)
 	}
 
 	/* parse devargs */
-	if (rte_devargs_parse(&da, "%s", devargs))
+	if (rte_devargs_parse(&da, devargs))
 		goto err;
 
 	ret = rte_eal_hotplug_add(da.bus->name, da.name, da.args);