From 930ce6e142354268d11ec9fe5cf6f4fc66a8f1f0 Mon Sep 17 00:00:00 2001
From: Sascha Hauer <s.hauer@pengutronix.de>
Date: Tue, 30 Sep 2014 10:26:20 +0200
Subject: Introduce message logging support

This adds a buffer for log messages and a 'dmesg' command to
print the messages. The log buffer is implemented as log objects
rather than a string buffer. This makes it easy to implement
limiting the messages, cleaning the buffer and timestamping
the messages.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
 common/console_common.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 126 insertions(+), 3 deletions(-)

(limited to 'common/console_common.c')

diff --git a/common/console_common.c b/common/console_common.c
index cc184dfaef..cc25f97d9d 100644
--- a/common/console_common.c
+++ b/common/console_common.c
@@ -27,6 +27,9 @@
 #include <globalvar.h>
 #include <magicvar.h>
 #include <password.h>
+#include <clock.h>
+#include <malloc.h>
+#include <asm-generic/div64.h>
 
 #ifndef CONFIG_CONSOLE_NONE
 
@@ -59,31 +62,151 @@ void console_allow_input(bool val)
 
 int barebox_loglevel = CONFIG_DEFAULT_LOGLEVEL;
 
+LIST_HEAD(barebox_logbuf);
+static int barebox_logbuf_num_messages;
+static int barebox_log_max_messages = 1000;
+
+static void log_del(struct log_entry *log)
+{
+	free(log->msg);
+	list_del(&log->list);
+	free(log);
+	barebox_logbuf_num_messages--;
+}
+
+/**
+ * log_clean - delete log messages from buffer
+ *
+ * @limit:	The maximum messages left in the buffer after
+ *		calling this function.
+ *
+ * This function deletes all messages in the logbuf exeeding
+ * the limit.
+ */
+void log_clean(unsigned int limit)
+{
+	struct log_entry *log, *tmp;
+
+	if (list_empty(&barebox_logbuf))
+		return;
+
+	list_for_each_entry_safe(log, tmp, &barebox_logbuf, list) {
+		if (barebox_logbuf_num_messages <= limit)
+			break;
+		log_del(log);
+	}
+}
+
+void pr_puts(int level, const char *str)
+{
+	struct log_entry *log;
+
+	if (IS_ENABLED(CONFIG_LOGBUF)) {
+		if (barebox_log_max_messages > 0)
+			log_clean(barebox_log_max_messages - 1);
+
+		if (barebox_log_max_messages >= 0) {
+			log = xzalloc(sizeof(*log));
+			log->msg = xstrdup(str);
+			log->timestamp = get_time_ns();
+			log->level = level;
+			list_add_tail(&log->list, &barebox_logbuf);
+			barebox_logbuf_num_messages++;
+		}
+	}
+
+	if (level > barebox_loglevel)
+		return;
+
+	puts(str);
+}
+
 int pr_print(int level, const char *fmt, ...)
 {
 	va_list args;
 	uint i;
 	char printbuffer[CFG_PBSIZE];
 
-	if (level > barebox_loglevel)
+	if (!IS_ENABLED(CONFIG_LOGBUF) && level > barebox_loglevel)
 		return 0;
 
 	va_start(args, fmt);
 	i = vsprintf(printbuffer, fmt, args);
 	va_end(args);
 
-	/* Print the string */
-	puts(printbuffer);
+	pr_puts(level, printbuffer);
 
 	return i;
 }
 
+int dev_printf(int level, const struct device_d *dev, const char *format, ...)
+{
+	va_list args;
+	int ret = 0;
+	char printbuffer[CFG_PBSIZE];
+
+	if (!IS_ENABLED(CONFIG_LOGBUF) && level > barebox_loglevel)
+		return 0;
+
+	if (dev->driver && dev->driver->name)
+		ret += sprintf(printbuffer, "%s ", dev->driver->name);
+
+	ret += sprintf(printbuffer + ret, "%s: ", dev_name(dev));
+
+	va_start(args, format);
+
+	ret += vsprintf(printbuffer + ret, format, args);
+
+	va_end(args);
+
+	pr_puts(level, printbuffer);
+
+	return ret;
+}
+
 static int loglevel_init(void)
 {
+	if (IS_ENABLED(CONFIG_LOGBUF))
+		globalvar_add_simple_int("log_max_messages",
+				&barebox_log_max_messages, "%d");
+
 	return globalvar_add_simple_int("loglevel", &barebox_loglevel, "%d");
 }
 device_initcall(loglevel_init);
 
+void log_print(unsigned flags)
+{
+	struct log_entry *log;
+	unsigned long last = 0;
+
+	list_for_each_entry(log, &barebox_logbuf, list) {
+		uint64_t diff = log->timestamp - time_beginning;
+		unsigned long difful;
+
+		do_div(diff, 1000);
+		difful = diff;
+
+		if (!log->timestamp)
+			difful = 0;
+
+		if (flags & (BAREBOX_LOG_PRINT_TIME | BAREBOX_LOG_DIFF_TIME))
+			printf("[");
+
+		if (flags & BAREBOX_LOG_PRINT_TIME)
+			printf("%10luus", difful);
+
+		if (flags & BAREBOX_LOG_DIFF_TIME) {
+			printf(" < %10luus", difful - last);
+			last = difful;
+		}
+
+		if (flags & (BAREBOX_LOG_PRINT_TIME | BAREBOX_LOG_DIFF_TIME))
+			printf("] ");
+
+		printf("%s", log->msg);
+	}
+}
+
 int printf(const char *fmt, ...)
 {
 	va_list args;
-- 
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