log: Add an implementation of logging

Add the logging header file and implementation with some configuration options to control it. Signed-off-by: Simon Glass <sjg@chromium.org>

log: Add an implementation of logging
Add the logging header file and implementation with some configuration options to control it. Signed-off-by: Simon Glass <sjg@chromium.org>
Simon Glass · Tom Rini · Eric Lee
1 parent c5404b64fb
Showing 6 changed files with 555 additions and 0 deletions Side-by-side Diff
MAINTAINERS
common/Kconfig
common/Makefile
common/log.c
include/asm-generic/global_data.h
include/log.h
@@ -310,6 +310,13 @@
 T:	git git://git.denx.de/u-boot-i2c.git
 F:	drivers/i2c/
  
+LOGGING
+M:	Simon Glass <sjg@chromium.org>
+S:	Maintained
+T:	git git://git.denx.de/u-boot.git
+F:	common/log.c
+F:	cmd/log.c
+
 MICROBLAZE
 M:	Michal Simek <monstr@monstr.eu>
 S:	Maintained
@@ -420,6 +420,62 @@
  
 endmenu
  
+menu "Logging"
+
+config LOG
+	bool "Enable logging support"
+	help
+	  This enables support for logging of status and debug messages. These
+	  can be displayed on the console, recorded in a memory buffer, or
+	  discarded if not needed. Logging supports various categories and
+	  levels of severity.
+
+config SPL_LOG
+	bool "Enable logging support in SPL"
+	help
+	  This enables support for logging of status and debug messages. These
+	  can be displayed on the console, recorded in a memory buffer, or
+	  discarded if not needed. Logging supports various categories and
+	  levels of severity.
+
+config LOG_MAX_LEVEL
+	int "Maximum log level to record"
+	depends on LOG
+	default 5
+	help
+	  This selects the maximum log level that will be recorded. Any value
+	  higher than this will be ignored. If possible log statements below
+	  this level will be discarded at build time. Levels:
+
+	    0 - panic
+	    1 - critical
+	    2 - error
+	    3 - warning
+	    4 - note
+	    5 - info
+	    6 - detail
+	    7 - debug
+
+config SPL_LOG_MAX_LEVEL
+	int "Maximum log level to record in SPL"
+	depends on SPL_LOG
+	default 3
+	help
+	  This selects the maximum log level that will be recorded. Any value
+	  higher than this will be ignored. If possible log statements below
+	  this level will be discarded at build time. Levels:
+
+	    0 - panic
+	    1 - critical
+	    2 - error
+	    3 - warning
+	    4 - note
+	    5 - info
+	    6 - detail
+	    7 - debug
+
+endmenu
+
 config DEFAULT_FDT_FILE
 	string "Default fdt file"
 	help
@@ -128,6 +128,7 @@
 obj-$(CONFIG_FSL_DDR_INTERACTIVE) += cli_simple.o cli_readline.o
 obj-$(CONFIG_CMD_DFU) += dfu.o
 obj-y += command.o
+obj-$(CONFIG_$(SPL_)LOG) += log.o
 obj-y += s_record.o
 obj-y += xyzModem.o
+/*
+ * Logging support
+ *
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg@chromium.org>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <log.h>
+#include <malloc.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static struct log_device *log_device_find_by_name(const char *drv_name)
+{
+	struct log_device *ldev;
+
+	list_for_each_entry(ldev, &gd->log_head, sibling_node) {
+		if (!strcmp(drv_name, ldev->drv->name))
+			return ldev;
+	}
+
+	return NULL;
+}
+
+/**
+ * log_has_cat() - check if a log category exists within a list
+ *
+ * @cat_list: List of categories to check, at most LOGF_MAX_CATEGORIES entries
+ *	long, terminated by LC_END if fewer
+ * @cat: Category to search for
+ * @return true if @cat is in @cat_list, else false
+ */
+static bool log_has_cat(enum log_category_t cat_list[], enum log_category_t cat)
+{
+	int i;
+
+	for (i = 0; i < LOGF_MAX_CATEGORIES && cat_list[i] != LOGC_END; i++) {
+		if (cat_list[i] == cat)
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * log_has_file() - check if a file is with a list
+ *
+ * @file_list: List of files to check, separated by comma
+ * @file: File to check for. This string is matched against the end of each
+ *	file in the list, i.e. ignoring any preceding path. The list is
+ *	intended to consist of relative pathnames, e.g. common/main.c,cmd/log.c
+ * @return true if @file is in @file_list, else false
+ */
+static bool log_has_file(const char *file_list, const char *file)
+{
+	int file_len = strlen(file);
+	const char *s, *p;
+	int substr_len;
+
+	for (s = file_list; *s; s = p + (*p != '\0')) {
+		p = strchrnul(s, ',');
+		substr_len = p - s;
+		if (file_len >= substr_len &&
+		    !strncmp(file + file_len - substr_len, s, substr_len))
+			return true;
+	}
+
+	return false;
+}
+
+/**
+ * log_passes_filters() - check if a log record passes the filters for a device
+ *
+ * @ldev: Log device to check
+ * @rec: Log record to check
+ * @return true if @rec is not blocked by the filters in @ldev, false if it is
+ */
+static bool log_passes_filters(struct log_device *ldev, struct log_rec *rec)
+{
+	struct log_filter *filt;
+
+	/* If there are no filters, filter on the default log level */
+	if (list_empty(&ldev->filter_head)) {
+		if (rec->level > gd->default_log_level)
+			return false;
+		return true;
+	}
+
+	list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
+		if (rec->level > filt->max_level)
+			continue;
+		if ((filt->flags & LOGFF_HAS_CAT) &&
+		    !log_has_cat(filt->cat_list, rec->cat))
+			continue;
+		if (filt->file_list &&
+		    !log_has_file(filt->file_list, rec->file))
+			continue;
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * log_dispatch() - Send a log record to all log devices for processing
+ *
+ * The log record is sent to each log device in turn, skipping those which have
+ * filters which block the record
+ *
+ * @rec: Log record to dispatch
+ * @return 0 (meaning success)
+ */
+static int log_dispatch(struct log_rec *rec)
+{
+	struct log_device *ldev;
+
+	list_for_each_entry(ldev, &gd->log_head, sibling_node) {
+		if (log_passes_filters(ldev, rec))
+			ldev->drv->emit(ldev, rec);
+	}
+
+	return 0;
+}
+
+int _log(enum log_category_t cat, enum log_level_t level, const char *file,
+	 int line, const char *func, const char *fmt, ...)
+{
+	char buf[CONFIG_SYS_CBSIZE];
+	struct log_rec rec;
+	va_list args;
+
+	rec.cat = cat;
+	rec.level = level;
+	rec.file = file;
+	rec.line = line;
+	rec.func = func;
+	va_start(args, fmt);
+	vsnprintf(buf, sizeof(buf), fmt, args);
+	va_end(args);
+	rec.msg = buf;
+	if (!gd || !(gd->flags & GD_FLG_LOG_READY)) {
+		if (gd)
+			gd->log_drop_count++;
+		return -ENOSYS;
+	}
+	log_dispatch(&rec);
+
+	return 0;
+}
+
+int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
+		   enum log_level_t max_level, const char *file_list)
+{
+	struct log_filter *filt;
+	struct log_device *ldev;
+	int i;
+
+	ldev = log_device_find_by_name(drv_name);
+	if (!ldev)
+		return -ENOENT;
+	filt = (struct log_filter *)calloc(1, sizeof(*filt));
+	if (!filt)
+		return -ENOMEM;
+
+	if (cat_list) {
+		filt->flags |= LOGFF_HAS_CAT;
+		for (i = 0; ; i++) {
+			if (i == ARRAY_SIZE(filt->cat_list))
+				return -ENOSPC;
+			filt->cat_list[i] = cat_list[i];
+			if (cat_list[i] == LOGC_END)
+				break;
+		}
+	}
+	filt->max_level = max_level;
+	if (file_list) {
+		filt->file_list = strdup(file_list);
+		if (!filt->file_list)
+			goto nomem;
+	}
+	filt->filter_num = ldev->next_filter_num++;
+	list_add_tail(&filt->sibling_node, &ldev->filter_head);
+
+	return filt->filter_num;
+
+nomem:
+	free(filt);
+	return -ENOMEM;
+}
+
+int log_remove_filter(const char *drv_name, int filter_num)
+{
+	struct log_filter *filt;
+	struct log_device *ldev;
+
+	ldev = log_device_find_by_name(drv_name);
+	if (!ldev)
+		return -ENOENT;
+
+	list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
+		if (filt->filter_num == filter_num) {
+			list_del(&filt->sibling_node);
+			free(filt);
+
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+int log_init(void)
+{
+	struct log_driver *drv = ll_entry_start(struct log_driver, log_driver);
+	const int count = ll_entry_count(struct log_driver, log_driver);
+	struct log_driver *end = drv + count;
+
+	/*
+	 * We cannot add runtime data to the driver since it is likely stored
+	 * in rodata. Instead, set up a 'device' corresponding to each driver.
+	 * We only support having a single device.
+	 */
+	INIT_LIST_HEAD((struct list_head *)&gd->log_head);
+	while (drv < end) {
+		struct log_device *ldev;
+
+		ldev = calloc(1, sizeof(*ldev));
+		if (!ldev) {
+			debug("%s: Cannot allocate memory\n", __func__);
+			return -ENOMEM;
+		}
+		INIT_LIST_HEAD(&ldev->filter_head);
+		ldev->drv = drv;
+		list_add_tail(&ldev->sibling_node,
+			      (struct list_head *)&gd->log_head);
+		drv++;
+	}
+	gd->default_log_level = LOGL_INFO;
+
+	return 0;
+}
@@ -114,6 +114,11 @@
 	struct bootstage_data *bootstage;	/* Bootstage information */
 	struct bootstage_data *new_bootstage;	/* Relocated bootstage info */
 #endif
+#ifdef CONFIG_LOG
+	int log_drop_count;		/* Number of dropped log messages */
+	int default_log_level;		/* For devices with no filters */
+	struct list_head log_head;	/* List of struct log_device */
+#endif
 } gd_t;
 #endif
  
@@ -10,6 +10,94 @@
 #ifndef __LOG_H
 #define __LOG_H
  
+#include <dm/uclass-id.h>
+#include <linux/list.h>
+
+/** Log levels supported, ranging from most to least important */
+enum log_level_t {
+	LOGL_EMERG = 0,		/*U-Boot is unstable */
+	LOGL_ALERT,		/* Action must be taken immediately */
+	LOGL_CRIT,		/* Critical conditions */
+	LOGL_ERR,		/* Error that prevents something from working */
+	LOGL_WARNING,		/* Warning may prevent optimial operation */
+	LOGL_NOTICE,		/* Normal but significant condition, printf() */
+	LOGL_INFO,		/* General information message */
+	LOGL_DEBUG,		/* Basic debug-level message */
+	LOGL_DEBUG_CONTENT,	/* Debug message showing full message content */
+	LOGL_DEBUG_IO,		/* Debug message showing hardware I/O access */
+
+	LOGL_COUNT,
+	LOGL_FIRST = LOGL_EMERG,
+	LOGL_MAX = LOGL_DEBUG,
+};
+
+/**
+ * Log categories supported. Most of these correspond to uclasses (i.e.
+ * enum uclass_id) but there are also some more generic categories
+ */
+enum log_category_t {
+	LOGC_FIRST = 0,	/* First part mirrors UCLASS_... */
+
+	LOGC_NONE = UCLASS_COUNT,
+	LOGC_ARCH,
+	LOGC_BOARD,
+	LOGC_CORE,
+	LOGC_DT,
+
+	LOGC_COUNT,
+	LOGC_END,
+};
+
+/* Helper to cast a uclass ID to a log category */
+static inline int log_uc_cat(enum uclass_id id)
+{
+	return (enum log_category_t)id;
+}
+
+/**
+ * _log() - Internal function to emit a new log record
+ *
+ * @cat: Category of log record (indicating which subsystem generated it)
+ * @level: Level of log record (indicating its severity)
+ * @file: File name of file where log record was generated
+ * @line: Line number in file where log record was generated
+ * @func: Function where log record was generated
+ * @fmt: printf() format string for log record
+ * @...: Optional parameters, according to the format string @fmt
+ * @return 0 if log record was emitted, -ve on error
+ */
+int _log(enum log_category_t cat, enum log_level_t level, const char *file,
+	 int line, const char *func, const char *fmt, ...);
+
+/* Define this at the top of a file to add a prefix to debug messages */
+#ifndef pr_fmt
+#define pr_fmt(fmt) fmt
+#endif
+
+/* Use a default category if this file does not supply one */
+#ifndef LOG_CATEGORY
+#define LOG_CATEGORY LOGC_NONE
+#endif
+
+/*
+ * This header may be including when CONFIG_LOG is disabled, in which case
+ * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
+ */
+#if CONFIG_IS_ENABLED(LOG)
+#define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
+#else
+#define _LOG_MAX_LEVEL LOGL_INFO
+#endif
+
+/* Emit a log record if the level is less that the maximum */
+#define log(_cat, _level, _fmt, _args...) ({ \
+	int _l = _level; \
+	if (_l <= _LOG_MAX_LEVEL) \
+		_log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
+		      __func__, \
+		      pr_fmt(_fmt), ##_args); \
+	})
+
 #ifdef DEBUG
 #define _DEBUG	1
 #else
@@ -22,6 +110,16 @@
 #define _SPL_BUILD	0
 #endif
  
+#if !_DEBUG && CONFIG_IS_ENABLED(LOG)
+
+#define debug_cond(cond, fmt, args...)			\
+	do {						\
+		if (1)					\
+			log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
+	} while (0)
+
+#else /* _DEBUG */
+
 /*
  * Output a debug text when condition "cond" is met. The "cond" should be
  * computed by a preprocessor in the best case, allowing for the best
@@ -33,6 +131,8 @@
 			printf(pr_fmt(fmt), ##args);	\
 	} while (0)
  
+#endif /* _DEBUG */
+
 /* Show a message if DEBUG is defined in a file */
 #define debug(fmt, args...)			\
 	debug_cond(_DEBUG, fmt, ##args)
@@ -55,6 +155,148 @@
 #define assert(x) \
 	({ if (!(x) && _DEBUG) \
 		__assert_fail(#x, __FILE__, __LINE__, __func__); })
+
+/**
+ * struct log_rec - a single log record
+ *
+ * Holds information about a single record in the log
+ *
+ * Members marked as 'not allocated' are stored as pointers and the caller is
+ * responsible for making sure that the data pointed to is not overwritten.
+ * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
+ * system.
+ *
+ * @cat: Category, representing a uclass or part of U-Boot
+ * @level: Severity level, less severe is higher
+ * @file: Name of file where the log record was generated (not allocated)
+ * @line: Line number where the log record was generated
+ * @func: Function where the log record was generated (not allocated)
+ * @msg: Log message (allocated)
+ */
+struct log_rec {
+	enum log_category_t cat;
+	enum log_level_t level;
+	const char *file;
+	int line;
+	const char *func;
+	const char *msg;
+};
+
+struct log_device;
+
+/**
+ * struct log_driver - a driver which accepts and processes log records
+ *
+ * @name: Name of driver
+ */
+struct log_driver {
+	const char *name;
+	/**
+	 * emit() - emit a log record
+	 *
+	 * Called by the log system to pass a log record to a particular driver
+	 * for processing. The filter is checked before calling this function.
+	 */
+	int (*emit)(struct log_device *ldev, struct log_rec *rec);
+};
+
+/**
+ * struct log_device - an instance of a log driver
+ *
+ * Since drivers are set up at build-time we need to have a separate device for
+ * the run-time aspects of drivers (currently just a list of filters to apply
+ * to records send to this device).
+ *
+ * @next_filter_num: Seqence number of next filter filter added (0=no filters
+ *	yet). This increments with each new filter on the device, but never
+ *	decrements
+ * @drv: Pointer to driver for this device
+ * @filter_head: List of filters for this device
+ * @sibling_node: Next device in the list of all devices
+ */
+struct log_device {
+	int next_filter_num;
+	struct log_driver *drv;
+	struct list_head filter_head;
+	struct list_head sibling_node;
+};
+
+enum {
+	LOGF_MAX_CATEGORIES = 5,	/* maximum categories per filter */
+};
+
+enum log_filter_flags {
+	LOGFF_HAS_CAT		= 1 << 0,	/* Filter has a category list */
+};
+
+/**
+ * struct log_filter - criterial to filter out log messages
+ *
+ * @filter_num: Sequence number of this filter.  This is returned when adding a
+ *	new filter, and must be provided when removing a previously added
+ *	filter.
+ * @flags: Flags for this filter (LOGFF_...)
+ * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
+ *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
+ *	can be provided
+ * @max_level: Maximum log level to allow
+ * @file_list: List of files to allow, separated by comma. If NULL then all
+ *	files are permitted
+ * @sibling_node: Next filter in the list of filters for this log device
+ */
+struct log_filter {
+	int filter_num;
+	int flags;
+	enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
+	enum log_level_t max_level;
+	const char *file_list;
+	struct list_head sibling_node;
+};
+
+#define LOG_DRIVER(_name) \
+	ll_entry_declare(struct log_driver, _name, log_driver)
+
+/**
+ * log_add_filter() - Add a new filter to a log device
+ *
+ * @drv_name: Driver name to add the filter to (since each driver only has a
+ *	single device)
+ * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
+ *	then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
+ *	can be provided
+ * @max_level: Maximum log level to allow
+ * @file_list: List of files to allow, separated by comma. If NULL then all
+ *	files are permitted
+ * @return the sequence number of the new filter (>=0) if the filter was added,
+ *	or a -ve value on error
+ */
+int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
+		   enum log_level_t max_level, const char *file_list);
+
+/**
+ * log_remove_filter() - Remove a filter from a log device
+ *
+ * @drv_name: Driver name to remove the filter from (since each driver only has
+ *	a single device)
+ * @filter_num: Filter number to remove (as returned by log_add_filter())
+ * @return 0 if the filter was removed, -ENOENT if either the driver or the
+ *	filter number was not found
+ */
+int log_remove_filter(const char *drv_name, int filter_num);
+
+#if CONFIG_IS_ENABLED(LOG)
+/**
+ * log_init() - Set up the log system ready for use
+ *
+ * @return 0 if OK, -ENOMEM if out of memory
+ */
+int log_init(void);
+#else
+static inline int log_init(void)
+{
+	return 0;
+}
+#endif
  
 #endif
...	...	@@ -310,6 +310,13 @@
310	310	T: git git://git.denx.de/u-boot-i2c.git
311	311	F: drivers/i2c/
312	312
	313	+LOGGING
	314	+M: Simon Glass <sjg@chromium.org>
	315	+S: Maintained
	316	+T: git git://git.denx.de/u-boot.git
	317	+F: common/log.c
	318	+F: cmd/log.c
	319	+
313	320	MICROBLAZE
314	321	M: Michal Simek <monstr@monstr.eu>
315	322	S: Maintained
...	...	@@ -420,6 +420,62 @@
420	420
421	421	endmenu
422	422
	423	+menu "Logging"
	424	+
	425	+config LOG
	426	+ bool "Enable logging support"
	427	+ help
	428	+ This enables support for logging of status and debug messages. These
	429	+ can be displayed on the console, recorded in a memory buffer, or
	430	+ discarded if not needed. Logging supports various categories and
	431	+ levels of severity.
	432	+
	433	+config SPL_LOG
	434	+ bool "Enable logging support in SPL"
	435	+ help
	436	+ This enables support for logging of status and debug messages. These
	437	+ can be displayed on the console, recorded in a memory buffer, or
	438	+ discarded if not needed. Logging supports various categories and
	439	+ levels of severity.
	440	+
	441	+config LOG_MAX_LEVEL
	442	+ int "Maximum log level to record"
	443	+ depends on LOG
	444	+ default 5
	445	+ help
	446	+ This selects the maximum log level that will be recorded. Any value
	447	+ higher than this will be ignored. If possible log statements below
	448	+ this level will be discarded at build time. Levels:
	449	+
	450	+ 0 - panic
	451	+ 1 - critical
	452	+ 2 - error
	453	+ 3 - warning
	454	+ 4 - note
	455	+ 5 - info
	456	+ 6 - detail
	457	+ 7 - debug
	458	+
	459	+config SPL_LOG_MAX_LEVEL
	460	+ int "Maximum log level to record in SPL"
	461	+ depends on SPL_LOG
	462	+ default 3
	463	+ help
	464	+ This selects the maximum log level that will be recorded. Any value
	465	+ higher than this will be ignored. If possible log statements below
	466	+ this level will be discarded at build time. Levels:
	467	+
	468	+ 0 - panic
	469	+ 1 - critical
	470	+ 2 - error
	471	+ 3 - warning
	472	+ 4 - note
	473	+ 5 - info
	474	+ 6 - detail
	475	+ 7 - debug
	476	+
	477	+endmenu
	478	+
423	479	config DEFAULT_FDT_FILE
424	480	string "Default fdt file"
425	481	help
...	...	@@ -128,6 +128,7 @@
128	128	obj-$(CONFIG_FSL_DDR_INTERACTIVE) += cli_simple.o cli_readline.o
129	129	obj-$(CONFIG_CMD_DFU) += dfu.o
130	130	obj-y += command.o
	131	+obj-$(CONFIG_$(SPL_)LOG) += log.o
131	132	obj-y += s_record.o
132	133	obj-y += xyzModem.o
	1	+/*
	2	+ * Logging support
	3	+ *
	4	+ * Copyright (c) 2017 Google, Inc
	5	+ * Written by Simon Glass <sjg@chromium.org>
	6	+ *
	7	+ * SPDX-License-Identifier: GPL-2.0+
	8	+ */
	9	+
	10	+#include <common.h>
	11	+#include <log.h>
	12	+#include <malloc.h>
	13	+
	14	+DECLARE_GLOBAL_DATA_PTR;
	15	+
	16	+static struct log_device log_device_find_by_name(const char drv_name)
	17	+{
	18	+ struct log_device *ldev;
	19	+
	20	+ list_for_each_entry(ldev, &gd->log_head, sibling_node) {
	21	+ if (!strcmp(drv_name, ldev->drv->name))
	22	+ return ldev;
	23	+ }
	24	+
	25	+ return NULL;
	26	+}
	27	+
	28	+/**
	29	+ * log_has_cat() - check if a log category exists within a list
	30	+ *
	31	+ * @cat_list: List of categories to check, at most LOGF_MAX_CATEGORIES entries
	32	+ * long, terminated by LC_END if fewer
	33	+ * @cat: Category to search for
	34	+ * @return true if @cat is in @cat_list, else false
	35	+ */
	36	+static bool log_has_cat(enum log_category_t cat_list[], enum log_category_t cat)
	37	+{
	38	+ int i;
	39	+
	40	+ for (i = 0; i < LOGF_MAX_CATEGORIES && cat_list[i] != LOGC_END; i++) {
	41	+ if (cat_list[i] == cat)
	42	+ return true;
	43	+ }
	44	+
	45	+ return false;
	46	+}
	47	+
	48	+/**
	49	+ * log_has_file() - check if a file is with a list
	50	+ *
	51	+ * @file_list: List of files to check, separated by comma
	52	+ * @file: File to check for. This string is matched against the end of each
	53	+ * file in the list, i.e. ignoring any preceding path. The list is
	54	+ * intended to consist of relative pathnames, e.g. common/main.c,cmd/log.c
	55	+ * @return true if @file is in @file_list, else false
	56	+ */
	57	+static bool log_has_file(const char file_list, const char file)
	58	+{
	59	+ int file_len = strlen(file);
	60	+ const char s, p;
	61	+ int substr_len;
	62	+
	63	+ for (s = file_list; s; s = p + (p != '\0')) {
	64	+ p = strchrnul(s, ',');
	65	+ substr_len = p - s;
	66	+ if (file_len >= substr_len &&
	67	+ !strncmp(file + file_len - substr_len, s, substr_len))
	68	+ return true;
	69	+ }
	70	+
	71	+ return false;
	72	+}
	73	+
	74	+/**
	75	+ * log_passes_filters() - check if a log record passes the filters for a device
	76	+ *
	77	+ * @ldev: Log device to check
	78	+ * @rec: Log record to check
	79	+ * @return true if @rec is not blocked by the filters in @ldev, false if it is
	80	+ */
	81	+static bool log_passes_filters(struct log_device ldev, struct log_rec rec)
	82	+{
	83	+ struct log_filter *filt;
	84	+
	85	+ /* If there are no filters, filter on the default log level */
	86	+ if (list_empty(&ldev->filter_head)) {
	87	+ if (rec->level > gd->default_log_level)
	88	+ return false;
	89	+ return true;
	90	+ }
	91	+
	92	+ list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
	93	+ if (rec->level > filt->max_level)
	94	+ continue;
	95	+ if ((filt->flags & LOGFF_HAS_CAT) &&
	96	+ !log_has_cat(filt->cat_list, rec->cat))
	97	+ continue;
	98	+ if (filt->file_list &&
	99	+ !log_has_file(filt->file_list, rec->file))
	100	+ continue;
	101	+ return true;
	102	+ }
	103	+
	104	+ return false;
	105	+}
	106	+
	107	+/**
	108	+ * log_dispatch() - Send a log record to all log devices for processing
	109	+ *
	110	+ * The log record is sent to each log device in turn, skipping those which have
	111	+ * filters which block the record
	112	+ *
	113	+ * @rec: Log record to dispatch
	114	+ * @return 0 (meaning success)
	115	+ */
	116	+static int log_dispatch(struct log_rec *rec)
	117	+{
	118	+ struct log_device *ldev;
	119	+
	120	+ list_for_each_entry(ldev, &gd->log_head, sibling_node) {
	121	+ if (log_passes_filters(ldev, rec))
	122	+ ldev->drv->emit(ldev, rec);
	123	+ }
	124	+
	125	+ return 0;
	126	+}
	127	+
	128	+int _log(enum log_category_t cat, enum log_level_t level, const char *file,
	129	+ int line, const char func, const char fmt, ...)
	130	+{
	131	+ char buf[CONFIG_SYS_CBSIZE];
	132	+ struct log_rec rec;
	133	+ va_list args;
	134	+
	135	+ rec.cat = cat;
	136	+ rec.level = level;
	137	+ rec.file = file;
	138	+ rec.line = line;
	139	+ rec.func = func;
	140	+ va_start(args, fmt);
	141	+ vsnprintf(buf, sizeof(buf), fmt, args);
	142	+ va_end(args);
	143	+ rec.msg = buf;
	144	+ if (!gd \|\| !(gd->flags & GD_FLG_LOG_READY)) {
	145	+ if (gd)
	146	+ gd->log_drop_count++;
	147	+ return -ENOSYS;
	148	+ }
	149	+ log_dispatch(&rec);
	150	+
	151	+ return 0;
	152	+}
	153	+
	154	+int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
	155	+ enum log_level_t max_level, const char *file_list)
	156	+{
	157	+ struct log_filter *filt;
	158	+ struct log_device *ldev;
	159	+ int i;
	160	+
	161	+ ldev = log_device_find_by_name(drv_name);
	162	+ if (!ldev)
	163	+ return -ENOENT;
	164	+ filt = (struct log_filter )calloc(1, sizeof(filt));
	165	+ if (!filt)
	166	+ return -ENOMEM;
	167	+
	168	+ if (cat_list) {
	169	+ filt->flags \|= LOGFF_HAS_CAT;
	170	+ for (i = 0; ; i++) {
	171	+ if (i == ARRAY_SIZE(filt->cat_list))
	172	+ return -ENOSPC;
	173	+ filt->cat_list[i] = cat_list[i];
	174	+ if (cat_list[i] == LOGC_END)
	175	+ break;
	176	+ }
	177	+ }
	178	+ filt->max_level = max_level;
	179	+ if (file_list) {
	180	+ filt->file_list = strdup(file_list);
	181	+ if (!filt->file_list)
	182	+ goto nomem;
	183	+ }
	184	+ filt->filter_num = ldev->next_filter_num++;
	185	+ list_add_tail(&filt->sibling_node, &ldev->filter_head);
	186	+
	187	+ return filt->filter_num;
	188	+
	189	+nomem:
	190	+ free(filt);
	191	+ return -ENOMEM;
	192	+}
	193	+
	194	+int log_remove_filter(const char *drv_name, int filter_num)
	195	+{
	196	+ struct log_filter *filt;
	197	+ struct log_device *ldev;
	198	+
	199	+ ldev = log_device_find_by_name(drv_name);
	200	+ if (!ldev)
	201	+ return -ENOENT;
	202	+
	203	+ list_for_each_entry(filt, &ldev->filter_head, sibling_node) {
	204	+ if (filt->filter_num == filter_num) {
	205	+ list_del(&filt->sibling_node);
	206	+ free(filt);
	207	+
	208	+ return 0;
	209	+ }
	210	+ }
	211	+
	212	+ return -ENOENT;
	213	+}
	214	+
	215	+int log_init(void)
	216	+{
	217	+ struct log_driver *drv = ll_entry_start(struct log_driver, log_driver);
	218	+ const int count = ll_entry_count(struct log_driver, log_driver);
	219	+ struct log_driver *end = drv + count;
	220	+
	221	+ /*
	222	+ * We cannot add runtime data to the driver since it is likely stored
	223	+ * in rodata. Instead, set up a 'device' corresponding to each driver.
	224	+ * We only support having a single device.
	225	+ */
	226	+ INIT_LIST_HEAD((struct list_head *)&gd->log_head);
	227	+ while (drv < end) {
	228	+ struct log_device *ldev;
	229	+
	230	+ ldev = calloc(1, sizeof(*ldev));
	231	+ if (!ldev) {
	232	+ debug("%s: Cannot allocate memory\n", __func__);
	233	+ return -ENOMEM;
	234	+ }
	235	+ INIT_LIST_HEAD(&ldev->filter_head);
	236	+ ldev->drv = drv;
	237	+ list_add_tail(&ldev->sibling_node,
	238	+ (struct list_head *)&gd->log_head);
	239	+ drv++;
	240	+ }
	241	+ gd->default_log_level = LOGL_INFO;
	242	+
	243	+ return 0;
	244	+}
...	...	@@ -114,6 +114,11 @@
114	114	struct bootstage_data bootstage; / Bootstage information */
115	115	struct bootstage_data new_bootstage; / Relocated bootstage info */
116	116	#endif
	117	+#ifdef CONFIG_LOG
	118	+ int log_drop_count; /* Number of dropped log messages */
	119	+ int default_log_level; /* For devices with no filters */
	120	+ struct list_head log_head; /* List of struct log_device */
	121	+#endif
117	122	} gd_t;
118	123	#endif
119	124
...	...	@@ -10,6 +10,94 @@
10	10	#ifndef __LOG_H
11	11	#define __LOG_H
12	12
	13	+#include <dm/uclass-id.h>
	14	+#include <linux/list.h>
	15	+
	16	+/** Log levels supported, ranging from most to least important */
	17	+enum log_level_t {
	18	+ LOGL_EMERG = 0, /U-Boot is unstable /
	19	+ LOGL_ALERT, /* Action must be taken immediately */
	20	+ LOGL_CRIT, /* Critical conditions */
	21	+ LOGL_ERR, /* Error that prevents something from working */
	22	+ LOGL_WARNING, /* Warning may prevent optimial operation */
	23	+ LOGL_NOTICE, /* Normal but significant condition, printf() */
	24	+ LOGL_INFO, /* General information message */
	25	+ LOGL_DEBUG, /* Basic debug-level message */
	26	+ LOGL_DEBUG_CONTENT, /* Debug message showing full message content */
	27	+ LOGL_DEBUG_IO, /* Debug message showing hardware I/O access */
	28	+
	29	+ LOGL_COUNT,
	30	+ LOGL_FIRST = LOGL_EMERG,
	31	+ LOGL_MAX = LOGL_DEBUG,
	32	+};
	33	+
	34	+/**
	35	+ * Log categories supported. Most of these correspond to uclasses (i.e.
	36	+ * enum uclass_id) but there are also some more generic categories
	37	+ */
	38	+enum log_category_t {
	39	+ LOGC_FIRST = 0, /* First part mirrors UCLASS_... */
	40	+
	41	+ LOGC_NONE = UCLASS_COUNT,
	42	+ LOGC_ARCH,
	43	+ LOGC_BOARD,
	44	+ LOGC_CORE,
	45	+ LOGC_DT,
	46	+
	47	+ LOGC_COUNT,
	48	+ LOGC_END,
	49	+};
	50	+
	51	+/* Helper to cast a uclass ID to a log category */
	52	+static inline int log_uc_cat(enum uclass_id id)
	53	+{
	54	+ return (enum log_category_t)id;
	55	+}
	56	+
	57	+/**
	58	+ * _log() - Internal function to emit a new log record
	59	+ *
	60	+ * @cat: Category of log record (indicating which subsystem generated it)
	61	+ * @level: Level of log record (indicating its severity)
	62	+ * @file: File name of file where log record was generated
	63	+ * @line: Line number in file where log record was generated
	64	+ * @func: Function where log record was generated
	65	+ * @fmt: printf() format string for log record
	66	+ * @...: Optional parameters, according to the format string @fmt
	67	+ * @return 0 if log record was emitted, -ve on error
	68	+ */
	69	+int _log(enum log_category_t cat, enum log_level_t level, const char *file,
	70	+ int line, const char func, const char fmt, ...);
	71	+
	72	+/* Define this at the top of a file to add a prefix to debug messages */
	73	+#ifndef pr_fmt
	74	+#define pr_fmt(fmt) fmt
	75	+#endif
	76	+
	77	+/* Use a default category if this file does not supply one */
	78	+#ifndef LOG_CATEGORY
	79	+#define LOG_CATEGORY LOGC_NONE
	80	+#endif
	81	+
	82	+/*
	83	+ * This header may be including when CONFIG_LOG is disabled, in which case
	84	+ * CONFIG_LOG_MAX_LEVEL is not defined. Add a check for this.
	85	+ */
	86	+#if CONFIG_IS_ENABLED(LOG)
	87	+#define _LOG_MAX_LEVEL CONFIG_VAL(LOG_MAX_LEVEL)
	88	+#else
	89	+#define _LOG_MAX_LEVEL LOGL_INFO
	90	+#endif
	91	+
	92	+/* Emit a log record if the level is less that the maximum */
	93	+#define log(_cat, _level, _fmt, _args...) ({ \
	94	+ int _l = _level; \
	95	+ if (_l <= _LOG_MAX_LEVEL) \
	96	+ _log((enum log_category_t)(_cat), _l, __FILE__, __LINE__, \
	97	+ __func__, \
	98	+ pr_fmt(_fmt), ##_args); \
	99	+ })
	100	+
13	101	#ifdef DEBUG
14	102	#define _DEBUG 1
15	103	#else
...	...	@@ -22,6 +110,16 @@
22	110	#define _SPL_BUILD 0
23	111	#endif
24	112
	113	+#if !_DEBUG && CONFIG_IS_ENABLED(LOG)
	114	+
	115	+#define debug_cond(cond, fmt, args...) \
	116	+ do { \
	117	+ if (1) \
	118	+ log(LOG_CATEGORY, LOGL_DEBUG, fmt, ##args); \
	119	+ } while (0)
	120	+
	121	+#else /* _DEBUG */
	122	+
25	123	/*
26	124	* Output a debug text when condition "cond" is met. The "cond" should be
27	125	* computed by a preprocessor in the best case, allowing for the best
...	...	@@ -33,6 +131,8 @@
33	131	printf(pr_fmt(fmt), ##args); \
34	132	} while (0)
35	133
	134	+#endif /* _DEBUG */
	135	+
36	136	/* Show a message if DEBUG is defined in a file */
37	137	#define debug(fmt, args...) \
38	138	debug_cond(_DEBUG, fmt, ##args)
...	...	@@ -55,6 +155,148 @@
55	155	#define assert(x) \
56	156	({ if (!(x) && _DEBUG) \
57	157	__assert_fail(#x, __FILE__, __LINE__, __func__); })
	158	+
	159	+/**
	160	+ * struct log_rec - a single log record
	161	+ *
	162	+ * Holds information about a single record in the log
	163	+ *
	164	+ * Members marked as 'not allocated' are stored as pointers and the caller is
	165	+ * responsible for making sure that the data pointed to is not overwritten.
	166	+ * Memebers marked as 'allocated' are allocated (e.g. via strdup()) by the log
	167	+ * system.
	168	+ *
	169	+ * @cat: Category, representing a uclass or part of U-Boot
	170	+ * @level: Severity level, less severe is higher
	171	+ * @file: Name of file where the log record was generated (not allocated)
	172	+ * @line: Line number where the log record was generated
	173	+ * @func: Function where the log record was generated (not allocated)
	174	+ * @msg: Log message (allocated)
	175	+ */
	176	+struct log_rec {
	177	+ enum log_category_t cat;
	178	+ enum log_level_t level;
	179	+ const char *file;
	180	+ int line;
	181	+ const char *func;
	182	+ const char *msg;
	183	+};
	184	+
	185	+struct log_device;
	186	+
	187	+/**
	188	+ * struct log_driver - a driver which accepts and processes log records
	189	+ *
	190	+ * @name: Name of driver
	191	+ */
	192	+struct log_driver {
	193	+ const char *name;
	194	+ /**
	195	+ * emit() - emit a log record
	196	+ *
	197	+ * Called by the log system to pass a log record to a particular driver
	198	+ * for processing. The filter is checked before calling this function.
	199	+ */
	200	+ int (emit)(struct log_device ldev, struct log_rec *rec);
	201	+};
	202	+
	203	+/**
	204	+ * struct log_device - an instance of a log driver
	205	+ *
	206	+ * Since drivers are set up at build-time we need to have a separate device for
	207	+ * the run-time aspects of drivers (currently just a list of filters to apply
	208	+ * to records send to this device).
	209	+ *
	210	+ * @next_filter_num: Seqence number of next filter filter added (0=no filters
	211	+ * yet). This increments with each new filter on the device, but never
	212	+ * decrements
	213	+ * @drv: Pointer to driver for this device
	214	+ * @filter_head: List of filters for this device
	215	+ * @sibling_node: Next device in the list of all devices
	216	+ */
	217	+struct log_device {
	218	+ int next_filter_num;
	219	+ struct log_driver *drv;
	220	+ struct list_head filter_head;
	221	+ struct list_head sibling_node;
	222	+};
	223	+
	224	+enum {
	225	+ LOGF_MAX_CATEGORIES = 5, /* maximum categories per filter */
	226	+};
	227	+
	228	+enum log_filter_flags {
	229	+ LOGFF_HAS_CAT = 1 << 0, /* Filter has a category list */
	230	+};
	231	+
	232	+/**
	233	+ * struct log_filter - criterial to filter out log messages
	234	+ *
	235	+ * @filter_num: Sequence number of this filter. This is returned when adding a
	236	+ * new filter, and must be provided when removing a previously added
	237	+ * filter.
	238	+ * @flags: Flags for this filter (LOGFF_...)
	239	+ * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
	240	+ * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
	241	+ * can be provided
	242	+ * @max_level: Maximum log level to allow
	243	+ * @file_list: List of files to allow, separated by comma. If NULL then all
	244	+ * files are permitted
	245	+ * @sibling_node: Next filter in the list of filters for this log device
	246	+ */
	247	+struct log_filter {
	248	+ int filter_num;
	249	+ int flags;
	250	+ enum log_category_t cat_list[LOGF_MAX_CATEGORIES];
	251	+ enum log_level_t max_level;
	252	+ const char *file_list;
	253	+ struct list_head sibling_node;
	254	+};
	255	+
	256	+#define LOG_DRIVER(_name) \
	257	+ ll_entry_declare(struct log_driver, _name, log_driver)
	258	+
	259	+/**
	260	+ * log_add_filter() - Add a new filter to a log device
	261	+ *
	262	+ * @drv_name: Driver name to add the filter to (since each driver only has a
	263	+ * single device)
	264	+ * @cat_list: List of categories to allow (terminated by LOGC_none). If empty
	265	+ * then all categories are permitted. Up to LOGF_MAX_CATEGORIES entries
	266	+ * can be provided
	267	+ * @max_level: Maximum log level to allow
	268	+ * @file_list: List of files to allow, separated by comma. If NULL then all
	269	+ * files are permitted
	270	+ * @return the sequence number of the new filter (>=0) if the filter was added,
	271	+ * or a -ve value on error
	272	+ */
	273	+int log_add_filter(const char *drv_name, enum log_category_t cat_list[],
	274	+ enum log_level_t max_level, const char *file_list);
	275	+
	276	+/**
	277	+ * log_remove_filter() - Remove a filter from a log device
	278	+ *
	279	+ * @drv_name: Driver name to remove the filter from (since each driver only has
	280	+ * a single device)
	281	+ * @filter_num: Filter number to remove (as returned by log_add_filter())
	282	+ * @return 0 if the filter was removed, -ENOENT if either the driver or the
	283	+ * filter number was not found
	284	+ */
	285	+int log_remove_filter(const char *drv_name, int filter_num);
	286	+
	287	+#if CONFIG_IS_ENABLED(LOG)
	288	+/**
	289	+ * log_init() - Set up the log system ready for use
	290	+ *
	291	+ * @return 0 if OK, -ENOMEM if out of memory
	292	+ */
	293	+int log_init(void);
	294	+#else
	295	+static inline int log_init(void)
	296	+{
	297	+ return 0;
	298	+}
	299	+#endif
58	300
59	301	#endif