[U-Boot] [PATCH v3 07/14] log: Add an implemention of logging
Simon Glass
sjg at chromium.org
Mon Nov 20 22:33:28 UTC 2017
Add the logging header file and implementation with some configuration
options to control it.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v3: None
Changes in v2:
- Add a comment as to why CONFIG_LOG_MAX_LEVEL is not defined
- Drop MAINTAINERS entries for files not added by this patch
- Drop the use of 'continue' in the macro
- Fix LOG_SPL_MAX_LEVEL typo (should be SPL_LOG_MAX_LEVEL)
- Fix up bad use of #if CONFIG_VAL() - use #ifdef instead
- Line up log levels with Linux
MAINTAINERS | 7 ++
common/Kconfig | 56 +++++++++
common/Makefile | 1 +
common/log.c | 244 ++++++++++++++++++++++++++++++++++++++
include/asm-generic/global_data.h | 5 +
include/log.h | 235 ++++++++++++++++++++++++++++++++++++
6 files changed, 548 insertions(+)
create mode 100644 common/log.c
diff --git a/MAINTAINERS b/MAINTAINERS
index b167b028ecf..6814c2fc566 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -291,6 +291,13 @@ S: Maintained
T: git git://git.denx.de/u-boot-i2c.git
F: drivers/i2c/
+LOGGING
+M: Simon Glass <sjg at 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 at monstr.eu>
S: Maintained
diff --git a/common/Kconfig b/common/Kconfig
index c50d6ebb2ad..9747443feb2 100644
--- a/common/Kconfig
+++ b/common/Kconfig
@@ -420,6 +420,62 @@ config SYS_STDIO_DEREGISTER
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
diff --git a/common/Makefile b/common/Makefile
index cec506fe3e1..f4b632761fa 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -128,5 +128,6 @@ obj-y += cli.o
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
diff --git a/common/log.c b/common/log.c
new file mode 100644
index 00000000000..a7d9a548f2a
--- /dev/null
+++ b/common/log.c
@@ -0,0 +1,244 @@
+/*
+ * Logging support
+ *
+ * Copyright (c) 2017 Google, Inc
+ * Written by Simon Glass <sjg at 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 preceeding 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;
+}
diff --git a/include/asm-generic/global_data.h b/include/asm-generic/global_data.h
index 79197acfa42..77755dbb068 100644
--- a/include/asm-generic/global_data.h
+++ b/include/asm-generic/global_data.h
@@ -114,6 +114,11 @@ typedef struct global_data {
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
diff --git a/include/log.h b/include/log.h
index 08ad44cf497..5dced16880b 100644
--- a/include/log.h
+++ b/include/log.h
@@ -10,6 +10,87 @@
#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,
+};
+
+/**
+ * _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(_cat, _l, __FILE__, __LINE__, __func__, \
+ pr_fmt(_fmt), ##_args); \
+ })
+
#ifdef DEBUG
#define _DEBUG 1
#else
@@ -22,6 +103,16 @@
#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 +124,8 @@
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)
@@ -56,4 +149,146 @@ void __assert_fail(const char *assertion, const char *file, unsigned int line,
({ 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
--
2.15.0.448.gf294e3d99a-goog
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