wimax: allow specifying debug levels as command line option

Add "debug" module options to all the wimax modules (including
drivers) so that the debug levels can be set upon kernel boot or
module load time.

This is needed as currently there was a limitation where the debug
levels could only be set when a device was succesfully
enumerated. This made it difficult to debug issues that made a device
not probe properly.
Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>

drivers/net/wimax/i2400m/driver.c

@@ -90,6 +90,14 @@ MODULE_PARM_DESC(power_save_disabled,
 		 "False by default (so the device is told to do power "
 		 "saving).");
 
+static char i2400m_debug_params[128];
+module_param_string(debug, i2400m_debug_params, sizeof(i2400m_debug_params),
+		    0644);
+MODULE_PARM_DESC(debug,
+		 "String of space-separated NAME:VALUE pairs, where NAMEs "
+		 "are the different debug submodules and VALUE are the "
+		 "initial debug value to set.");
+
 /**
  * i2400m_queue_work - schedule work on a i2400m's queue
  *
@@ -794,6 +802,8 @@ size_t D_LEVEL_SIZE = ARRAY_SIZE(D_LEVEL);
 static
 int __init i2400m_driver_init(void)
 {
+	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400m_debug_params,
+		       "i2400m.debug");
 	return 0;
 }
 module_init(i2400m_driver_init);

drivers/net/wimax/i2400m/sdio.c

@@ -71,6 +71,14 @@
 static int ioe_timeout = 2;
 module_param(ioe_timeout, int, 0);
 
+static char i2400ms_debug_params[128];
+module_param_string(debug, i2400ms_debug_params, sizeof(i2400ms_debug_params),
+		    0644);
+MODULE_PARM_DESC(debug,
+		 "String of space-separated NAME:VALUE pairs, where NAMEs "
+		 "are the different debug submodules and VALUE are the "
+		 "initial debug value to set.");
+
 /* Our firmware file name list */
 static const char *i2400ms_bus_fw_names[] = {
 #define I2400MS_FW_FILE_NAME "i2400m-fw-sdio-1.3.sbcf"
@@ -559,6 +567,8 @@ struct sdio_driver i2400m_sdio_driver = {
 static
 int __init i2400ms_driver_init(void)
 {
+	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400ms_debug_params,
+		       "i2400m_sdio.debug");
 	return sdio_register_driver(&i2400m_sdio_driver);
 }
 module_init(i2400ms_driver_init);

drivers/net/wimax/i2400m/usb.c

@@ -71,6 +71,13 @@
 #define D_SUBMODULE usb
 #include "usb-debug-levels.h"
 
+static char i2400mu_debug_params[128];
+module_param_string(debug, i2400mu_debug_params, sizeof(i2400mu_debug_params),
+		    0644);
+MODULE_PARM_DESC(debug,
+		 "String of space-separated NAME:VALUE pairs, where NAMEs "
+		 "are the different debug submodules and VALUE are the "
+		 "initial debug value to set.");
 
 /* Our firmware file name */
 static const char *i2400mu_bus_fw_names[] = {
@@ -633,6 +640,8 @@ struct usb_driver i2400mu_driver = {
 static
 int __init i2400mu_driver_init(void)
 {
+	d_parse_params(D_LEVEL, D_LEVEL_SIZE, i2400mu_debug_params,
+		       "i2400m_usb.debug");
 	return usb_register(&i2400mu_driver);
 }
 module_init(i2400mu_driver_init);

include/linux/wimax/debug.h

@@ -450,4 +450,76 @@ do {							\
 })
 
 
+static inline
+void d_submodule_set(struct d_level *d_level, size_t d_level_size,
+		     const char *submodule, u8 level, const char *tag)
+{
+	struct d_level *itr, *top;
+	int index = -1;
+
+	for (itr = d_level, top = itr + d_level_size; itr < top; itr++) {
+		index++;
+		if (itr->name == NULL) {
+			printk(KERN_ERR "%s: itr->name NULL?? (%p, #%d)\n",
+			       tag, itr, index);
+			continue;
+		}
+		if (!strcmp(itr->name, submodule)) {
+			itr->level = level;
+			return;
+		}
+	}
+	printk(KERN_ERR "%s: unknown submodule %s\n", tag, submodule);
+}
+
+
+/**
+ * d_parse_params - Parse a string with debug parameters from the
+ * command line
+ *
+ * @d_level: level structure (D_LEVEL)
+ * @d_level_size: number of items in the level structure
+ *     (D_LEVEL_SIZE).
+ * @_params: string with the parameters; this is a space (not tab!)
+ *     separated list of NAME:VALUE, where value is the debug level
+ *     and NAME is the name of the submodule.
+ * @tag: string for error messages (example: MODULE.ARGNAME).
+ */
+static inline
+void d_parse_params(struct d_level *d_level, size_t d_level_size,
+		    const char *_params, const char *tag)
+{
+	char submodule[130], *params, *params_orig, *token, *colon;
+	unsigned level, tokens;
+
+	if (_params == NULL)
+		return;
+	params_orig = kstrdup(_params, GFP_KERNEL);
+	params = params_orig;
+	while (1) {
+		token = strsep(&params, " ");
+		if (token == NULL)
+			break;
+		if (*token == '\0')	/* eat joint spaces */
+			continue;
+		/* kernel's sscanf %s eats until whitespace, so we
+		 * replace : by \n so it doesn't get eaten later by
+		 * strsep */
+		colon = strchr(token, ':');
+		if (colon != NULL)
+			*colon = '\n';
+		tokens = sscanf(token, "%s\n%u", submodule, &level);
+		if (colon != NULL)
+			*colon = ':';	/* set back, for error messages */
+		if (tokens == 2)
+			d_submodule_set(d_level, d_level_size,
+					submodule, level, tag);
+		else
+			printk(KERN_ERR "%s: can't parse '%s' as a "
+			       "SUBMODULE:LEVEL (%d tokens)\n",
+			       tag, token, tokens);
+	}
+	kfree(params_orig);
+}
+
 #endif /* #ifndef __debug__h__ */

net/wimax/stack.c

@@ -60,6 +60,14 @@
 #define D_SUBMODULE stack
 #include "debug-levels.h"
 
+static char wimax_debug_params[128];
+module_param_string(debug, wimax_debug_params, sizeof(wimax_debug_params),
+		    0644);
+MODULE_PARM_DESC(debug,
+		 "String of space-separated NAME:VALUE pairs, where NAMEs "
+		 "are the different debug submodules and VALUE are the "
+		 "initial debug value to set.");
+
 /*
  * Authoritative source for the RE_STATE_CHANGE attribute policy
  *
@@ -562,6 +570,9 @@ int __init wimax_subsys_init(void)
 	int result, cnt;
 
 	d_fnstart(4, NULL, "()\n");
+	d_parse_params(D_LEVEL, D_LEVEL_SIZE, wimax_debug_params,
+		       "wimax.debug");
+
 	snprintf(wimax_gnl_family.name, sizeof(wimax_gnl_family.name),
 		 "WiMAX");
 	result = genl_register_family(&wimax_gnl_family);