[PATCH v8 6/9] ethdev: add common devargs parser

[Declan Doherty <declan.doherty@intel.com>]

From: Remy Horton <remy.horton@intel.com>

Introduces a new structure, rte_eth_devargs, to support generic
ethdev arguments common across NET PMDs, with a new API
rte_eth_devargs_parse API to support PMD parsing these arguments. The
patch add support for a representor argument  passed with passed with
the EAL -w option. The representor parameter allows the user to specify
which representor ports to initialise on a device.

The argument supports passing a single representor port, a list of
port values or a range of port values.

-w BDF,representor=1  # create representor port 1 on pci device BDF
-w BDF,representor=[1,2,5,6,10] # create representor ports in list
-w BDF,representor=[0-31] # create representor ports in range

Signed-off-by: Remy Horton <remy.horton@intel.com>
Signed-off-by: Declan Doherty <declan.doherty@intel.com>
---
 doc/guides/prog_guide/poll_mode_drv.rst |  19 ++++
 lib/Makefile                            |   1 +
 lib/librte_ether/rte_ethdev.c           | 182 ++++++++++++++++++++++++++++++++
 lib/librte_ether/rte_ethdev_driver.h    |  30 ++++++
 lib/librte_ether/rte_ethdev_version.map |   1 +
 5 files changed, 233 insertions(+)

diff --git a/doc/guides/prog_guide/poll_mode_drv.rst b/doc/guides/prog_guide/poll_mode_drv.rst
index e5d01874e..09a93baec 100644
--- a/doc/guides/prog_guide/poll_mode_drv.rst
+++ b/doc/guides/prog_guide/poll_mode_drv.rst
@@ -345,6 +345,25 @@ Ethernet Device API
 
 The Ethernet device API exported by the Ethernet PMDs is described in the *DPDK API Reference*.
 
+Ethernet Device Standard Device Arguments
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Standard Ethernet device arguments allow for a set of commonly used arguments/
+parameters which are applicable to all Ethernet devices to be available to for
+specification of specific device and for passing common configuration
+parameters to those ports.
+
+* ``representor`` for a device which supports the creation of representor ports
+  this argument allows user to specify which switch ports to enable port
+  representors for.::
+
+   -w BDBF,representor=0
+   -w BDBF,representor=[0,4,6,9]
+   -w BDBF,representor=[0-31]
+
+Note: PMDs are not required to support the standard device arguments and users
+should consult the relevant PMD documentation to see support devargs.
+
 Extended Statistics API
 ~~~~~~~~~~~~~~~~~~~~~~~
 
diff --git a/lib/Makefile b/lib/Makefile
index 965be6c8d..536775e59 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -21,6 +21,7 @@ DEPDIRS-librte_cmdline := librte_eal
 DIRS-$(CONFIG_RTE_LIBRTE_ETHER) += librte_ether
 DEPDIRS-librte_ether := librte_net librte_eal librte_mempool librte_ring
 DEPDIRS-librte_ether += librte_mbuf
+DEPDIRS-librte_ether += librte_kvargs
 DIRS-$(CONFIG_RTE_LIBRTE_BBDEV) += librte_bbdev
 DEPDIRS-librte_bbdev := librte_eal librte_mempool librte_mbuf
 DIRS-$(CONFIG_RTE_LIBRTE_CRYPTODEV) += librte_cryptodev
diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 621f8af7f..cb85d8bb7 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -34,6 +34,7 @@
 #include <rte_errno.h>
 #include <rte_spinlock.h>
 #include <rte_string_fns.h>
++#include <rte_kvargs.h>
 
 #include "rte_ether.h"
 #include "rte_ethdev.h"
@@ -4101,6 +4102,187 @@ rte_eth_dev_pool_ops_supported(uint16_t port_id, const char *pool)
 	return (*dev->dev_ops->pool_ops_supported)(dev, pool);
 }
 
+typedef int (*rte_eth_devargs_callback_t)(char *str, void *data);
+
+static int
+rte_eth_devargs_tokenise(struct rte_kvargs *arglist, const char *str_in)
+{
+	int state;
+	struct rte_kvargs_pair *pair;
+	char *letter;
+
+	arglist->str = strdup(str_in);
+	if (arglist->str == NULL)
+		return -ENOMEM;
+
+	letter = arglist->str;
+	state = 0;
+	arglist->count = 0;
+	pair = &arglist->pairs[0];
+	while (1) {
+		switch (state) {
+		case 0: /* Initial */
+			if (*letter == '=')
+				return -EINVAL;
+			else if (*letter == '\0')
+				return 0;
+
+			state = 1;
+			pair->key = letter;
+			/* fall-thru */
+
+		case 1: /* Parsing key */
+			if (*letter == '=') {
+				*letter = '\0';
+				pair->value = letter + 1;
+				state = 2;
+			} else if (*letter == ',' || *letter == '\0')
+				return -EINVAL;
+			break;
+
+
+		case 2: /* Parsing value */
+			if (*letter == '[')
+				state = 3;
+			else if (*letter == ',') {
+				*letter = '\0';
+				arglist->count++;
+				pair = &arglist->pairs[arglist->count];
+				state = 0;
+			} else if (*letter == '\0') {
+				letter--;
+				arglist->count++;
+				pair = &arglist->pairs[arglist->count];
+				state = 0;
+			}
+			break;
+
+		case 3: /* Parsing list */
+			if (*letter == ']')
+				state = 2;
+			else if (*letter == '\0')
+				return -EINVAL;
+			break;
+		}
+		letter++;
+	}
+}
+
+static int
+rte_eth_devargs_parse_list(char *str, rte_eth_devargs_callback_t callback,
+	void *data)
+{
+	char *str_start;
+	int state;
+	int result;
+
+	if (*str != '[')
+		/* Single element, not a list */
+		return callback(str, data);
+
+	/* Sanity check, then strip the brackets */
+	str_start = &str[strlen(str) - 1];
+	if (*str_start != ']') {
+		RTE_LOG(ERR, EAL, "(%s): List does not end with ']'", str);
+		return -EINVAL;
+	}
+	str++;
+	*str_start = '\0';
+
+	/* Process list elements */
+	state = 0;
+	while (1) {
+		if (state == 0) {
+			if (*str == '\0')
+				break;
+			if (*str != ',') {
+				str_start = str;
+				state = 1;
+			}
+		} else if (state == 1) {
+			if (*str == ',' || *str == '\0') {
+				if (str > str_start) {
+					/* Non-empty string fragment */
+					*str = '\0';
+					result = callback(str_start, data);
+					if (result < 0)
+						return result;
+				}
+				state = 0;
+			}
+		}
+		str++;
+	}
+	return 0;
+}
+
+static int
+rte_eth_devargs_process_range(char *str, uint16_t *list, uint16_t *len_list,
+	const uint16_t max_list)
+{
+	uint16_t lo, hi, val;
+	int result;
+
+	result = sscanf(str, "%hu-%hu", &lo, &hi);
+	if (result == 1) {
+		if (*len_list >= max_list)
+			return -ENOMEM;
+		list[(*len_list)++] = lo;
+	} else if (result == 2) {
+		if (lo >= hi || lo > RTE_MAX_ETHPORTS || hi > RTE_MAX_ETHPORTS)
+			return -EINVAL;
+		for (val = lo; val <= hi; val++) {
+			if (*len_list >= max_list)
+				return -ENOMEM;
+			list[(*len_list)++] = val;
+		}
+	} else
+		return -EINVAL;
+	return 0;
+}
+
+
+static int
+rte_eth_devargs_parse_representor_ports(char *str, void *data)
+{
+	struct rte_eth_devargs *eth_da = data;
+
+	return rte_eth_devargs_process_range(str, eth_da->representor_ports,
+		&eth_da->nb_representor_ports, RTE_MAX_ETHPORTS);
+}
+
+int __rte_experimental
+rte_eth_devargs_parse(const char *dargs, struct rte_eth_devargs *eth_da)
+{
+	struct rte_kvargs args;
+	struct rte_kvargs_pair *pair;
+	unsigned int i;
+	int result = 0;
+
+	memset(eth_da, 0, sizeof(*eth_da));
+
+	result = rte_eth_devargs_tokenise(&args, dargs);
+	if (result < 0)
+		goto parse_cleanup;
+
+	for (i = 0; i < args.count; i++) {
+		pair = &args.pairs[i];
+		if (strcmp("representor", pair->key) == 0) {
+			result = rte_eth_devargs_parse_list(pair->value,
+				rte_eth_devargs_parse_representor_ports,
+				eth_da);
+			if (result < 0)
+				goto parse_cleanup;
+		}
+	}
+
+parse_cleanup:
+	if (args.str)
+		free(args.str);
+
+	return result;
+}
+
 RTE_INIT(ethdev_init_log);
 static void
 ethdev_init_log(void)
diff --git a/lib/librte_ether/rte_ethdev_driver.h b/lib/librte_ether/rte_ethdev_driver.h
index 8c61ab2f4..492da754a 100644
--- a/lib/librte_ether/rte_ethdev_driver.h
+++ b/lib/librte_ether/rte_ethdev_driver.h
@@ -189,6 +189,36 @@ rte_eth_linkstatus_get(const struct rte_eth_dev *dev,
 }
 
 
+/** Generic Ethernet device arguments  */
+struct rte_eth_devargs {
+	uint16_t ports[RTE_MAX_ETHPORTS];
+	/** port/s number to enable on a multi-port single function */
+	uint16_t nb_ports;
+	/** number of ports in ports field */
+	uint16_t representor_ports[RTE_MAX_ETHPORTS];
+	/** representor port/s identifier to enable on device */
+	uint16_t nb_representor_ports;
+	/** number of ports in representor port field */
+};
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * PMD helper function to parse ethdev arguments
+ *
+ * @param devargs
+ *  device arguments
+ * @param eth_devargs
+ *  parsed ethdev specific arguments.
+ *
+ * @return
+ *   Negative errno value on error, 0 on success.
+ */
+int __rte_experimental
+rte_eth_devargs_parse(const char *dargs, struct rte_eth_devargs *eth_devargs);
+
+
 typedef int (*ethdev_init_t)(struct rte_eth_dev *ethdev, void *init_params);
 typedef int (*ethdev_bus_specific_init)(struct rte_eth_dev *ethdev,
 	void *bus_specific_init_params);
diff --git a/lib/librte_ether/rte_ethdev_version.map b/lib/librte_ether/rte_ethdev_version.map
index c4380aa31..41c3d2699 100644
--- a/lib/librte_ether/rte_ethdev_version.map
+++ b/lib/librte_ether/rte_ethdev_version.map
@@ -206,6 +206,7 @@ DPDK_18.02 {
 EXPERIMENTAL {
 	global:
 
+	rte_eth_devargs_parse;
 	rte_eth_dev_count_avail;
 	rte_eth_dev_count_total;
 	rte_eth_dev_create;
-- 
2.14.3