common/cmd_ethsw: Add generic commands for Ethernet Switches

This patch creates a flexible parser for Ethernet Switch
configurations that should support complex commands.
The parser searches for predefined keywords in the command
and calls the proper function when a match is found.
Also, the parser allows for optional keywords, such as
"port", to apply the command on a port
or on all ports. For now, the defined commands are:
ethsw [port <port_no>] { enable | disable | show }

Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>

1 files changed, 347 insertions, 0 deletions

diff --git a/common/cmd_ethsw.c b/common/cmd_ethsw.c
new file mode 100644
index 0000000..9a7ae74
--- /dev/null
+++ b/common/cmd_ethsw.c
@@ -0,0 +1,347 @@
+/*
+ * Copyright 2015 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:      GPL-2.0+
+ *
+ * Ethernet Switch commands
+ */
+
+#include <common.h>
+#include <command.h>
+#include <errno.h>
+#include <ethsw.h>
+
+static const char *ethsw_name;
+
+static struct keywords_to_function {
+	enum ethsw_keyword_id cmd_keyword[ETHSW_MAX_CMD_PARAMS];
+	int cmd_func_offset;
+	int (*keyword_function)(struct ethsw_command_def *parsed_cmd);
+} ethsw_cmd_def[] = {
+		{
+			.cmd_keyword = {
+					ethsw_id_enable,
+					ethsw_id_key_end,
+			},
+			.cmd_func_offset = offsetof(struct ethsw_command_func,
+						    port_enable),
+			.keyword_function = NULL,
+		}, {
+			.cmd_keyword = {
+					ethsw_id_disable,
+					ethsw_id_key_end,
+			},
+			.cmd_func_offset = offsetof(struct ethsw_command_func,
+						    port_disable),
+			.keyword_function = NULL,
+		}, {
+			.cmd_keyword = {
+					ethsw_id_show,
+					ethsw_id_key_end,
+			},
+			.cmd_func_offset = offsetof(struct ethsw_command_func,
+						    port_show),
+			.keyword_function = NULL,
+		},
+};
+
+struct keywords_optional {
+	int cmd_keyword[ETHSW_MAX_CMD_PARAMS];
+} cmd_opt_def[] = {
+		{
+				.cmd_keyword = {
+						ethsw_id_port,
+						ethsw_id_port_no,
+						ethsw_id_key_end,
+				},
+		},
+};
+
+static int keyword_match_gen(enum ethsw_keyword_id key_id, int argc, char
+			     *const argv[], int *argc_nr,
+			     struct ethsw_command_def *parsed_cmd);
+static int keyword_match_port(enum ethsw_keyword_id key_id, int argc,
+			      char *const argv[], int *argc_nr,
+			      struct ethsw_command_def *parsed_cmd);
+
+/*
+ * Define properties for each keyword;
+ * keep the order synced with enum ethsw_keyword_id
+ */
+struct keyword_def {
+	const char *keyword_name;
+	int (*match)(enum ethsw_keyword_id key_id, int argc, char *const argv[],
+		     int *argc_nr, struct ethsw_command_def *parsed_cmd);
+} keyword[] = {
+		{
+				.keyword_name = "help",
+				.match = &keyword_match_gen,
+		}, {
+				.keyword_name = "show",
+				.match = &keyword_match_gen,
+		}, {
+				.keyword_name = "port",
+				.match = &keyword_match_port
+		},  {
+				.keyword_name = "enable",
+				.match = &keyword_match_gen,
+		}, {
+				.keyword_name = "disable",
+				.match = &keyword_match_gen,
+		},
+};
+
+/*
+ * Function used by an Ethernet Switch driver to set the functions
+ * that must be called by the parser when an ethsw command is given
+ */
+int ethsw_define_functions(const struct ethsw_command_func *cmd_func)
+{
+	int i;
+	void **aux_p;
+	int (*cmd_func_aux)(struct ethsw_command_def *);
+
+	if (!cmd_func->ethsw_name)
+		return -EINVAL;
+
+	ethsw_name = cmd_func->ethsw_name;
+
+	for (i = 0; i < ARRAY_SIZE(ethsw_cmd_def); i++) {
+		/*
+		 * get the pointer to the function send by the Ethernet Switch
+		 * driver that corresponds to the proper ethsw command
+		 */
+		if (ethsw_cmd_def[i].keyword_function)
+			continue;
+
+		aux_p = (void *)cmd_func + ethsw_cmd_def[i].cmd_func_offset;
+
+		cmd_func_aux = (int (*)(struct ethsw_command_def *)) *aux_p;
+		ethsw_cmd_def[i].keyword_function = cmd_func_aux;
+	}
+
+	return 0;
+}
+
+/* Generic function used to match a keyword only by a string */
+static int keyword_match_gen(enum ethsw_keyword_id key_id, int argc,
+			     char *const argv[], int *argc_nr,
+			     struct ethsw_command_def *parsed_cmd)
+{
+	if (strcmp(argv[*argc_nr], keyword[key_id].keyword_name) == 0) {
+		parsed_cmd->cmd_to_keywords[*argc_nr] = key_id;
+
+		return 1;
+	}
+	return 0;
+}
+
+/* Function used to match the command's port */
+static int keyword_match_port(enum ethsw_keyword_id key_id, int argc,
+			      char *const argv[], int *argc_nr,
+			      struct ethsw_command_def *parsed_cmd)
+{
+	unsigned long val;
+
+	if (!keyword_match_gen(key_id, argc, argv, argc_nr, parsed_cmd))
+		return 0;
+
+	if (*argc_nr + 1 >= argc)
+		return 0;
+
+	if (strict_strtoul(argv[*argc_nr + 1], 10, &val) != -EINVAL) {
+		parsed_cmd->port = val;
+		(*argc_nr)++;
+		parsed_cmd->cmd_to_keywords[*argc_nr] = ethsw_id_port_no;
+		return 1;
+	}
+
+	return 0;
+}
+
+/* Finds optional keywords and modifies *argc_va to skip them */
+static void cmd_keywords_opt_check(const struct ethsw_command_def *parsed_cmd,
+				   int *argc_val)
+{
+	int i;
+	int keyw_opt_matched;
+	int argc_val_max;
+	int const *cmd_keyw_p;
+	int const *cmd_keyw_opt_p;
+
+	/* remember the best match */
+	argc_val_max = *argc_val;
+
+	/*
+	 * check if our command's optional keywords match the optional
+	 * keywords of an available command
+	 */
+	for (i = 0; i < ARRAY_SIZE(ethsw_cmd_def); i++) {
+		keyw_opt_matched = 0;
+		cmd_keyw_p = &parsed_cmd->cmd_to_keywords[keyw_opt_matched];
+		cmd_keyw_opt_p = &cmd_opt_def[i].cmd_keyword[keyw_opt_matched];
+
+		/*
+		 * increase the number of keywords that
+		 * matched with a command
+		 */
+		while (keyw_opt_matched + *argc_val <
+		       parsed_cmd->cmd_keywords_nr &&
+		       *cmd_keyw_opt_p != ethsw_id_key_end &&
+		       *(cmd_keyw_p + *argc_val) == *cmd_keyw_opt_p) {
+			keyw_opt_matched++;
+			cmd_keyw_p++;
+			cmd_keyw_opt_p++;
+		}
+
+		/*
+		 * if all our optional command's keywords perfectly match an
+		 * optional pattern, then we can move to the next defined
+		 * keywords in our command; remember the one that matched the
+		 * greatest number of keywords
+		 */
+		if (keyw_opt_matched + *argc_val <=
+		    parsed_cmd->cmd_keywords_nr &&
+		    *cmd_keyw_opt_p == ethsw_id_key_end &&
+		    *argc_val + keyw_opt_matched > argc_val_max)
+			argc_val_max = *argc_val + keyw_opt_matched;
+	}
+
+	*argc_val = argc_val_max;
+}
+
+/*
+ * Finds the function to call based on keywords and
+ * modifies *argc_va to skip them
+ */
+static void cmd_keywords_check(struct ethsw_command_def *parsed_cmd,
+			       int *argc_val)
+{
+	int i;
+	int keyw_matched;
+	int *cmd_keyw_p;
+	int *cmd_keyw_def_p;
+
+	/*
+	 * check if our command's keywords match the
+	 * keywords of an available command
+	 */
+	for (i = 0; i < ARRAY_SIZE(ethsw_cmd_def); i++) {
+		keyw_matched = 0;
+		cmd_keyw_p = &parsed_cmd->cmd_to_keywords[keyw_matched];
+		cmd_keyw_def_p = &ethsw_cmd_def[i].cmd_keyword[keyw_matched];
+
+		/*
+		 * increase the number of keywords that
+		 * matched with a command
+		 */
+		while (keyw_matched + *argc_val < parsed_cmd->cmd_keywords_nr &&
+		       *cmd_keyw_def_p != ethsw_id_key_end &&
+		       *(cmd_keyw_p + *argc_val) == *cmd_keyw_def_p) {
+			keyw_matched++;
+			cmd_keyw_p++;
+			cmd_keyw_def_p++;
+		}
+
+		/*
+		 * if all our command's keywords perfectly match an
+		 * available command, then we get the function we need to call
+		 * to configure the Ethernet Switch
+		 */
+		if (keyw_matched && keyw_matched + *argc_val ==
+		    parsed_cmd->cmd_keywords_nr &&
+		    *cmd_keyw_def_p == ethsw_id_key_end) {
+			*argc_val += keyw_matched;
+			parsed_cmd->cmd_function =
+					ethsw_cmd_def[i].keyword_function;
+			return;
+		}
+	}
+}
+
+/* find all the keywords in the command */
+static int keywords_find(int argc, char * const argv[],
+			 struct ethsw_command_def *parsed_cmd)
+{
+	int i;
+	int j;
+	int argc_val;
+	int rc = CMD_RET_SUCCESS;
+
+	for (i = 1; i < argc; i++) {
+		for (j = 0; j < ethsw_id_count; j++) {
+			if (keyword[j].match(j, argc, argv, &i, parsed_cmd))
+				break;
+		}
+	}
+
+	/* if there is no keyword match for a word, the command is invalid */
+	for (i = 1; i < argc; i++)
+		if (parsed_cmd->cmd_to_keywords[i] == ethsw_id_key_end)
+			rc = CMD_RET_USAGE;
+
+	parsed_cmd->cmd_keywords_nr = argc;
+	argc_val = 1;
+
+	/* get optional parameters first */
+	cmd_keywords_opt_check(parsed_cmd, &argc_val);
+
+	if (argc_val == parsed_cmd->cmd_keywords_nr)
+		return CMD_RET_USAGE;
+
+	/*
+	 * check the keywords and if a match is found,
+	 * get the function to call
+	 */
+	cmd_keywords_check(parsed_cmd, &argc_val);
+
+	/* error if not all commands' parameters were matched */
+	if (argc_val == parsed_cmd->cmd_keywords_nr) {
+		if (!parsed_cmd->cmd_function) {
+			printf("Command not available for: %s\n", ethsw_name);
+			rc = CMD_RET_FAILURE;
+		}
+	} else {
+		rc = CMD_RET_USAGE;
+	}
+
+	return rc;
+}
+
+static void command_def_init(struct ethsw_command_def *parsed_cmd)
+{
+	int i;
+
+	for (i = 0; i < ETHSW_MAX_CMD_PARAMS; i++)
+		parsed_cmd->cmd_to_keywords[i] = ethsw_id_key_end;
+
+	parsed_cmd->port = ETHSW_CMD_PORT_ALL;
+	parsed_cmd->cmd_function = NULL;
+}
+
+/* function to interpret commands starting with "ethsw " */
+static int do_ethsw(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	struct ethsw_command_def parsed_cmd;
+	int rc = CMD_RET_SUCCESS;
+
+	if (argc == 1 || argc >= ETHSW_MAX_CMD_PARAMS)
+		return CMD_RET_USAGE;
+
+	command_def_init(&parsed_cmd);
+
+	rc = keywords_find(argc, argv, &parsed_cmd);
+
+	if (rc == CMD_RET_SUCCESS)
+		rc = parsed_cmd.cmd_function(&parsed_cmd);
+
+	return rc;
+}
+
+#define ETHSW_PORT_CONF_HELP "[port <port_no>] { enable | disable | show } " \
+"- enable/disable a port; show shows a port's configuration"
+
+U_BOOT_CMD(ethsw, ETHSW_MAX_CMD_PARAMS, 0, do_ethsw,
+	   "Ethernet l2 switch commands",
+	   ETHSW_PORT_CONF_HELP"\n"
+);