Add realtek target files

Signed-off-by: Roman Yeryomin <roman@advem.lv>

1 files changed, 1551 insertions, 0 deletions

diff --git a/target/linux/realtek/files/kernel/printk_log.c b/target/linux/realtek/files/kernel/printk_log.c
new file mode 100644
index 000000000..c53e16bc5
--- /dev/null
+++ b/target/linux/realtek/files/kernel/printk_log.c
@@ -0,0 +1,1551 @@
+/*
+ *  linux/kernel/printk.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *
+ * Modified to make sys_syslog() more flexible: added commands to
+ * return the last 4k of kernel messages, regardless of whether
+ * they've been read or not.  Added option to suppress kernel printk's
+ * to the console.  Added hook for sending the console messages
+ * elsewhere, in preparation for a serial line console (someday).
+ * Ted Ts'o, 2/11/93.
+ * Modified for sysctl support, 1/8/97, Chris Horn.
+ * Fixed SMP synchronization, 08/08/99, Manfred Spraul
+ *     manfred@colorfullife.com
+ * Rewrote bits to get rid of console_lock
+ *	01Mar01 Andrew Morton
+ */
+
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/tty.h>
+#include <linux/tty_driver.h>
+#include <linux/console.h>
+#include <linux/init.h>
+#include <linux/jiffies.h>
+#include <linux/nmi.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/interrupt.h>			/* For in_interrupt() */
+#include <linux/delay.h>
+#include <linux/smp.h>
+#include <linux/security.h>
+#include <linux/bootmem.h>
+#include <linux/syscalls.h>
+#include <linux/kexec.h>
+
+#include <asm/uaccess.h>
+
+/*
+ * Architectures can override it:
+ */
+void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...)
+{
+}
+
+#define __LOG_BUF_LEN	(1 << CONFIG_LOG_BUF_SHIFT)
+
+/* printk's without a loglevel use this.. */
+#define DEFAULT_MESSAGE_LOGLEVEL 4 /* KERN_WARNING */
+
+/* We show everything that is MORE important than this.. */
+#define MINIMUM_CONSOLE_LOGLEVEL 1 /* Minimum loglevel we let people use */
+#define DEFAULT_CONSOLE_LOGLEVEL 7 /* anything MORE serious than KERN_DEBUG */
+
+DECLARE_WAIT_QUEUE_HEAD(log_wait);
+
+int console_printk[4] = {
+	DEFAULT_CONSOLE_LOGLEVEL,	/* console_loglevel */
+	DEFAULT_MESSAGE_LOGLEVEL,	/* default_message_loglevel */
+	MINIMUM_CONSOLE_LOGLEVEL,	/* minimum_console_loglevel */
+	DEFAULT_CONSOLE_LOGLEVEL,	/* default_console_loglevel */
+};
+
+/*
+ * Low level drivers may need that to know if they can schedule in
+ * their unblank() callback or not. So let's export it.
+ */
+int oops_in_progress;
+EXPORT_SYMBOL(oops_in_progress);
+
+/*
+ * console_sem protects the console_drivers list, and also
+ * provides serialisation for access to the entire console
+ * driver system.
+ */
+static DECLARE_MUTEX(console_sem);
+struct console *console_drivers;
+EXPORT_SYMBOL_GPL(console_drivers);
+
+/*
+ * This is used for debugging the mess that is the VT code by
+ * keeping track if we have the console semaphore held. It's
+ * definitely not the perfect debug tool (we don't know if _WE_
+ * hold it are racing, but it helps tracking those weird code
+ * path in the console code where we end up in places I want
+ * locked without the console sempahore held
+ */
+static int console_locked, console_suspended;
+
+/*
+ * logbuf_lock protects log_buf, log_start, log_end, con_start and logged_chars
+ * It is also used in interesting ways to provide interlocking in
+ * release_console_sem().
+ */
+static DEFINE_SPINLOCK(logbuf_lock);
+
+#define LOG_BUF_MASK (log_buf_len-1)
+#define LOG_BUF(idx) (log_buf[(idx) & LOG_BUF_MASK])
+
+/*
+ * The indices into log_buf are not constrained to log_buf_len - they
+ * must be masked before subscripting
+ */
+
+static unsigned log_start;	/* Index into log_buf: next char to be read by syslog() */
+static unsigned con_start;	/* Index into log_buf: next char to be sent to consoles */
+static unsigned log_end;	/* Index into log_buf: most-recently-written-char + 1 */
+
+#if defined (CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+/*
+  * If printk enable, below two indicates the buf to send to consoles
+  */
+static unsigned long prt_start;	/* Index into prt_buf: next char to be sent to consoles */
+static unsigned long prt_end;    /* Index into log_buf: most-recently-written-char + 1 */
+#endif
+/*
+ *	Array of consoles built from command line options (console=)
+ */
+struct console_cmdline
+{
+	char	name[8];			/* Name of the driver	    */
+	int	index;				/* Minor dev. to use	    */
+	char	*options;			/* Options for the driver   */
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+	char	*brl_options;			/* Options for braille driver */
+#endif
+};
+
+#define MAX_CMDLINECONSOLES 1
+
+static struct console_cmdline console_cmdline[MAX_CMDLINECONSOLES];
+static int selected_console = -1;
+static int preferred_console = -1;
+int console_set_on_cmdline;
+EXPORT_SYMBOL(console_set_on_cmdline);
+
+/* Flag: console code may call schedule() */
+static int console_may_schedule;
+
+#ifdef CONFIG_PRINTK_FUNC
+
+static char __log_buf[__LOG_BUF_LEN];
+static char *log_buf = __log_buf;
+static int log_buf_len = __LOG_BUF_LEN;
+static unsigned logged_chars; /* Number of chars produced since last read+clear operation */
+
+#if defined (CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+static char prt_buf[__LOG_BUF_LEN];
+#define PRT_BUF(idx) (prt_buf[(idx) & LOG_BUF_MASK])
+#endif
+
+#ifdef CONFIG_KEXEC
+/*
+ * This appends the listed symbols to /proc/vmcoreinfo
+ *
+ * /proc/vmcoreinfo is used by various utiilties, like crash and makedumpfile to
+ * obtain access to symbols that are otherwise very difficult to locate.  These
+ * symbols are specifically used so that utilities can access and extract the
+ * dmesg log from a vmcore file after a crash.
+ */
+void log_buf_kexec_setup(void)
+{
+	VMCOREINFO_SYMBOL(log_buf);
+	VMCOREINFO_SYMBOL(log_end);
+	VMCOREINFO_SYMBOL(log_buf_len);
+	VMCOREINFO_SYMBOL(logged_chars);
+}
+#endif
+
+static int __init log_buf_len_setup(char *str)
+{
+	unsigned size = memparse(str, &str);
+	unsigned long flags;
+
+	if (size)
+		size = roundup_pow_of_two(size);
+	if (size > log_buf_len) {
+		unsigned start, dest_idx, offset;
+		char *new_log_buf;
+
+		new_log_buf = alloc_bootmem(size);
+		if (!new_log_buf) {
+			printk(KERN_WARNING "log_buf_len: allocation failed\n");
+			goto out;
+		}
+
+		spin_lock_irqsave(&logbuf_lock, flags);
+		log_buf_len = size;
+		log_buf = new_log_buf;
+
+		offset = start = min(con_start, log_start);
+		dest_idx = 0;
+		while (start != log_end) {
+			log_buf[dest_idx] = __log_buf[start & (__LOG_BUF_LEN - 1)];
+			start++;
+			dest_idx++;
+		}
+		log_start -= offset;
+		con_start -= offset;
+		log_end -= offset;
+		spin_unlock_irqrestore(&logbuf_lock, flags);
+
+		printk(KERN_NOTICE "log_buf_len: %d\n", log_buf_len);
+	}
+out:
+	return 1;
+}
+
+__setup("log_buf_len=", log_buf_len_setup);
+
+#ifdef CONFIG_BOOT_PRINTK_DELAY
+
+static unsigned int boot_delay; /* msecs delay after each printk during bootup */
+static unsigned long long printk_delay_msec; /* per msec, based on boot_delay */
+
+static int __init boot_delay_setup(char *str)
+{
+	unsigned long lpj;
+	unsigned long long loops_per_msec;
+
+	lpj = preset_lpj ? preset_lpj : 1000000;	/* some guess */
+	loops_per_msec = (unsigned long long)lpj / 1000 * HZ;
+
+	get_option(&str, &boot_delay);
+	if (boot_delay > 10 * 1000)
+		boot_delay = 0;
+
+	printk_delay_msec = loops_per_msec;
+	printk(KERN_DEBUG "boot_delay: %u, preset_lpj: %ld, lpj: %lu, "
+		"HZ: %d, printk_delay_msec: %llu\n",
+		boot_delay, preset_lpj, lpj, HZ, printk_delay_msec);
+	return 1;
+}
+__setup("boot_delay=", boot_delay_setup);
+
+static void boot_delay_msec(void)
+{
+	unsigned long long k;
+	unsigned long timeout;
+
+	if (boot_delay == 0 || system_state != SYSTEM_BOOTING)
+		return;
+
+	k = (unsigned long long)printk_delay_msec * boot_delay;
+
+	timeout = jiffies + msecs_to_jiffies(boot_delay);
+	while (k) {
+		k--;
+		cpu_relax();
+		/*
+		 * use (volatile) jiffies to prevent
+		 * compiler reduction; loop termination via jiffies
+		 * is secondary and may or may not happen.
+		 */
+		if (time_after(jiffies, timeout))
+			break;
+		touch_nmi_watchdog();
+	}
+}
+#else
+static inline void boot_delay_msec(void)
+{
+}
+#endif
+
+/*
+ * Commands to do_syslog:
+ *
+ * 	0 -- Close the log.  Currently a NOP.
+ * 	1 -- Open the log. Currently a NOP.
+ * 	2 -- Read from the log.
+ * 	3 -- Read all messages remaining in the ring buffer.
+ * 	4 -- Read and clear all messages remaining in the ring buffer
+ * 	5 -- Clear ring buffer.
+ * 	6 -- Disable printk's to console
+ * 	7 -- Enable printk's to console
+ *	8 -- Set level of messages printed to console
+ *	9 -- Return number of unread characters in the log buffer
+ *     10 -- Return size of the log buffer
+ */
+int do_syslog(int type, char __user *buf, int len)
+{
+	unsigned i, j, limit, count;
+	int do_clear = 0;
+	char c;
+	int error = 0;
+
+	error = security_syslog(type);
+	if (error)
+		return error;
+
+	switch (type) {
+	case 0:		/* Close log */
+		break;
+	case 1:		/* Open log */
+		break;
+	case 2:		/* Read from log */
+		error = -EINVAL;
+		if (!buf || len < 0)
+			goto out;
+		error = 0;
+		if (!len)
+			goto out;
+		if (!access_ok(VERIFY_WRITE, buf, len)) {
+			error = -EFAULT;
+			goto out;
+		}
+		error = wait_event_interruptible(log_wait,
+							(log_start - log_end));
+		if (error)
+			goto out;
+		i = 0;
+		spin_lock_irq(&logbuf_lock);
+		while (!error && (log_start != log_end) && i < len) {
+			c = LOG_BUF(log_start);
+			log_start++;
+			spin_unlock_irq(&logbuf_lock);
+			error = __put_user(c,buf);
+			buf++;
+			i++;
+			cond_resched();
+			spin_lock_irq(&logbuf_lock);
+		}
+		spin_unlock_irq(&logbuf_lock);
+		if (!error)
+			error = i;
+		break;
+	case 4:		/* Read/clear last kernel messages */
+		do_clear = 1;
+		/* FALL THRU */
+	case 3:		/* Read last kernel messages */
+		error = -EINVAL;
+		if (!buf || len < 0)
+			goto out;
+		error = 0;
+		if (!len)
+			goto out;
+		if (!access_ok(VERIFY_WRITE, buf, len)) {
+			error = -EFAULT;
+			goto out;
+		}
+		count = len;
+		if (count > log_buf_len)
+			count = log_buf_len;
+		spin_lock_irq(&logbuf_lock);
+		if (count > logged_chars)
+			count = logged_chars;
+		if (do_clear)
+			logged_chars = 0;
+		limit = log_end;
+		/*
+		 * __put_user() could sleep, and while we sleep
+		 * printk() could overwrite the messages
+		 * we try to copy to user space. Therefore
+		 * the messages are copied in reverse. <manfreds>
+		 */
+		for (i = 0; i < count && !error; i++) {
+			j = limit-1-i;
+			if (j + log_buf_len < log_end)
+				break;
+			c = LOG_BUF(j);
+			spin_unlock_irq(&logbuf_lock);
+			error = __put_user(c,&buf[count-1-i]);
+			cond_resched();
+			spin_lock_irq(&logbuf_lock);
+		}
+		spin_unlock_irq(&logbuf_lock);
+		if (error)
+			break;
+		error = i;
+		if (i != count) {
+			int offset = count-error;
+			/* buffer overflow during copy, correct user buffer. */
+			for (i = 0; i < error; i++) {
+				if (__get_user(c,&buf[i+offset]) ||
+				    __put_user(c,&buf[i])) {
+					error = -EFAULT;
+					break;
+				}
+				cond_resched();
+			}
+		}
+		break;
+	case 5:		/* Clear ring buffer */
+		logged_chars = 0;
+		break;
+	case 6:		/* Disable logging to console */
+		console_loglevel = minimum_console_loglevel;
+		break;
+	case 7:		/* Enable logging to console */
+		console_loglevel = default_console_loglevel;
+		break;
+	case 8:		/* Set level of messages printed to console */
+		error = -EINVAL;
+		if (len < 1 || len > 8)
+			goto out;
+		if (len < minimum_console_loglevel)
+			len = minimum_console_loglevel;
+		console_loglevel = len;
+		error = 0;
+		break;
+	case 9:		/* Number of chars in the log buffer */
+		error = log_end - log_start;
+		break;
+	case 10:	/* Size of the log buffer */
+		error = log_buf_len;
+		break;
+	default:
+		error = -EINVAL;
+		break;
+	}
+out:
+	return error;
+}
+
+SYSCALL_DEFINE3(syslog, int, type, char __user *, buf, int, len)
+{
+	return do_syslog(type, buf, len);
+}
+
+/*
+ * Call the console drivers on a range of log_buf
+ */
+static void __call_console_drivers(unsigned start, unsigned end)
+{
+	struct console *con;
+
+	for (con = console_drivers; con; con = con->next) {
+		if ((con->flags & CON_ENABLED) && con->write &&
+				(cpu_online(smp_processor_id()) ||
+				(con->flags & CON_ANYTIME)))
+			{
+			#if defined(CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+			con->write(con, &PRT_BUF(start), end - start);
+			#else
+			//con->write(con, &LOG_BUF(start), end - start);
+			#endif
+			}
+	}
+}
+
+static int __read_mostly ignore_loglevel;
+
+static int __init ignore_loglevel_setup(char *str)
+{
+	ignore_loglevel = 1;
+	printk(KERN_INFO "debug: ignoring loglevel setting.\n");
+
+	return 0;
+}
+
+early_param("ignore_loglevel", ignore_loglevel_setup);
+
+/*
+ * Write out chars from start to end - 1 inclusive
+ */
+static void _call_console_drivers(unsigned start,
+				unsigned end, int msg_log_level)
+{
+	if ((msg_log_level < console_loglevel || ignore_loglevel) &&
+			console_drivers && start != end) {
+		if ((start & LOG_BUF_MASK) > (end & LOG_BUF_MASK)) {
+			/* wrapped write */
+			__call_console_drivers(start & LOG_BUF_MASK,
+						log_buf_len);
+			__call_console_drivers(0, end & LOG_BUF_MASK);
+		} else {
+			__call_console_drivers(start, end);
+		}
+	}
+}
+
+/*
+ * Call the console drivers, asking them to write out
+ * log_buf[start] to log_buf[end - 1].
+ * The console_sem must be held.
+ */
+#if defined (CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+static void call_console_drivers(unsigned start, unsigned end)
+{
+	unsigned cur_index, start_print;
+	static int msg_level = -1;
+
+	BUG_ON(((int)(start - end)) > 0);
+
+	cur_index = start;
+	start_print = start;
+	while (cur_index != end) {
+		if (msg_level < 0 && ((end - cur_index) > 2) &&
+				PRT_BUF(cur_index + 0) == '<' &&
+				PRT_BUF(cur_index + 1) >= '0' &&
+				PRT_BUF(cur_index + 1) <= '7' &&
+				PRT_BUF(cur_index + 2) == '>') {
+			msg_level = PRT_BUF(cur_index + 1) - '0';
+			cur_index += 3;
+			start_print = cur_index;
+		}
+		while (cur_index != end) {
+			char c = PRT_BUF(cur_index);
+
+			cur_index++;
+			if (c == '\n') {
+				if (msg_level < 0) {
+					/*
+					 * printk() has already given us loglevel tags in
+					 * the buffer.  This code is here in case the
+					 * log buffer has wrapped right round and scribbled
+					 * on those tags
+					 */
+					msg_level = default_message_loglevel;
+				}
+				_call_console_drivers(start_print, cur_index, msg_level);
+				msg_level = -1;
+				start_print = cur_index;
+				break;
+			}
+		}
+	}
+	_call_console_drivers(start_print, end, msg_level);
+}
+#else
+static void call_console_drivers(unsigned start, unsigned end)
+{
+	unsigned cur_index, start_print;
+	static int msg_level = -1;
+
+	BUG_ON(((int)(start - end)) > 0);
+
+	cur_index = start;
+	start_print = start;
+	while (cur_index != end) {
+		if (msg_level < 0 && ((end - cur_index) > 2) &&
+				LOG_BUF(cur_index + 0) == '<' &&
+				LOG_BUF(cur_index + 1) >= '0' &&
+				LOG_BUF(cur_index + 1) <= '7' &&
+				LOG_BUF(cur_index + 2) == '>') {
+			msg_level = LOG_BUF(cur_index + 1) - '0';
+			cur_index += 3;
+			start_print = cur_index;
+		}
+		while (cur_index != end) {
+			char c = LOG_BUF(cur_index);
+
+			cur_index++;
+			if (c == '\n') {
+				if (msg_level < 0) {
+					/*
+					 * printk() has already given us loglevel tags in
+					 * the buffer.  This code is here in case the
+					 * log buffer has wrapped right round and scribbled
+					 * on those tags
+					 */
+					msg_level = default_message_loglevel;
+				}
+				_call_console_drivers(start_print, cur_index, msg_level);
+				msg_level = -1;
+				start_print = cur_index;
+				break;
+			}
+		}
+	}
+	_call_console_drivers(start_print, end, msg_level);
+}
+#endif
+
+static void emit_log_char(char c,int prt_to_con)
+{
+	LOG_BUF(log_end) = c;
+	log_end++;
+	if (log_end - log_start > log_buf_len)
+		log_start = log_end - log_buf_len;
+	if (log_end - con_start > log_buf_len)
+		con_start = log_end - log_buf_len;
+	if (logged_chars < log_buf_len)
+		logged_chars++;
+
+#if defined(CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+	if (prt_to_con) {
+		PRT_BUF(prt_end) = c;
+		prt_end++;
+		if (prt_end - prt_start > __LOG_BUF_LEN)
+			prt_start = prt_end - __LOG_BUF_LEN;
+	}
+#endif
+}
+
+/*
+ * Zap console related locks when oopsing. Only zap at most once
+ * every 10 seconds, to leave time for slow consoles to print a
+ * full oops.
+ */
+static void zap_locks(void)
+{
+	static unsigned long oops_timestamp;
+
+	if (time_after_eq(jiffies, oops_timestamp) &&
+			!time_after(jiffies, oops_timestamp + 30 * HZ))
+		return;
+
+	oops_timestamp = jiffies;
+
+	/* If a crash is occurring, make sure we can't deadlock */
+	spin_lock_init(&logbuf_lock);
+	/* And make sure that we print immediately */
+	init_MUTEX(&console_sem);
+}
+
+#if defined(CONFIG_PRINTK_TIME)
+static int printk_time = 1;
+#else
+static int printk_time = 0;
+#endif
+module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
+
+/* Check if we have any console registered that can be called early in boot. */
+static int have_callable_console(void)
+{
+	struct console *con;
+
+	for (con = console_drivers; con; con = con->next)
+		if (con->flags & CON_ANYTIME)
+			return 1;
+
+	return 0;
+}
+
+/**
+ * printk - print a kernel message
+ * @fmt: format string
+ *
+ * This is printk().  It can be called from any context.  We want it to work.
+ *
+ * We try to grab the console_sem.  If we succeed, it's easy - we log the output and
+ * call the console drivers.  If we fail to get the semaphore we place the output
+ * into the log buffer and return.  The current holder of the console_sem will
+ * notice the new output in release_console_sem() and will send it to the
+ * consoles before releasing the semaphore.
+ *
+ * One effect of this deferred printing is that code which calls printk() and
+ * then changes console_loglevel may break. This is because console_loglevel
+ * is inspected when the actual printing occurs.
+ *
+ * See also:
+ * printf(3)
+ *
+ * See the vsnprintf() documentation for format string extensions over C99.
+ */
+
+#if defined (CONFIG_PRINTK)
+asmlinkage int printk(const char *fmt, ...)
+#elif defined(CONFIG_PANIC_PRINTK)
+asmlinkage int panic_printk(const char *fmt, ...)
+#else
+# error "CONFIG_PRINTK or CONFIG_PANIC_PRINTK must be defined"
+#endif
+{
+	va_list args;
+	int r;
+
+	va_start(args, fmt);
+	r = vprintk(fmt, args);
+	va_end(args);
+
+	return r;
+}
+
+/* cpu currently holding logbuf_lock */
+static volatile unsigned int printk_cpu = UINT_MAX;
+
+/*
+ * Can we actually use the console at this time on this cpu?
+ *
+ * Console drivers may assume that per-cpu resources have
+ * been allocated. So unless they're explicitly marked as
+ * being able to cope (CON_ANYTIME) don't call them until
+ * this CPU is officially up.
+ */
+static inline int can_use_console(unsigned int cpu)
+{
+	return cpu_online(cpu) || have_callable_console();
+}
+
+/*
+ * Try to get console ownership to actually show the kernel
+ * messages from a 'printk'. Return true (and with the
+ * console_semaphore held, and 'console_locked' set) if it
+ * is successful, false otherwise.
+ *
+ * This gets called with the 'logbuf_lock' spinlock held and
+ * interrupts disabled. It should return with 'lockbuf_lock'
+ * released but interrupts still disabled.
+ */
+static int acquire_console_semaphore_for_printk(unsigned int cpu)
+{
+	int retval = 0;
+
+	if (!try_acquire_console_sem()) {
+		retval = 1;
+
+		/*
+		 * If we can't use the console, we need to release
+		 * the console semaphore by hand to avoid flushing
+		 * the buffer. We need to hold the console semaphore
+		 * in order to do this test safely.
+		 */
+		if (!can_use_console(cpu)) {
+			console_locked = 0;
+			up(&console_sem);
+			retval = 0;
+		}
+	}
+	printk_cpu = UINT_MAX;
+	spin_unlock(&logbuf_lock);
+	return retval;
+}
+
+#if defined (CONFIG_PRINTK_FUNC)
+static const char recursion_bug_msg [] =
+		KERN_CRIT "BUG: recent printk recursion!\n";
+static int recursion_bug;
+static int new_text_line = 1;
+static char printk_buf[1024];
+#if defined (CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+asmlinkage int vprintk(const char *fmt, va_list args)
+{
+	int printed_len = 0;
+	int current_log_level = default_message_loglevel;
+	unsigned long flags;
+	int this_cpu;
+	char *p;
+
+	boot_delay_msec();
+
+	preempt_disable();
+	/* This stops the holder of console_sem just where we want him */
+	raw_local_irq_save(flags);
+	this_cpu = smp_processor_id();
+
+	/*
+	 * Ouch, printk recursed into itself!
+	 */
+	if (unlikely(printk_cpu == this_cpu)) {
+		/*
+		 * If a crash is occurring during printk() on this CPU,
+		 * then try to get the crash message out but make sure
+		 * we can't deadlock. Otherwise just return to avoid the
+		 * recursion and return - but flag the recursion so that
+		 * it can be printed at the next appropriate moment:
+		 */
+		if (!oops_in_progress) {
+			recursion_bug = 1;
+			goto out_restore_irqs;
+		}
+		zap_locks();
+	}
+
+	lockdep_off();
+	spin_lock(&logbuf_lock);
+	printk_cpu = this_cpu;
+
+	if (recursion_bug) {
+		recursion_bug = 0;
+		strcpy(printk_buf, recursion_bug_msg);
+		printed_len = strlen(recursion_bug_msg);
+	}
+	/* Emit the output into the temporary buffer */
+	printed_len += vscnprintf(printk_buf + printed_len,
+				  sizeof(printk_buf) - printed_len, fmt, args);
+
+
+	/*
+	 * Copy the output into log_buf.  If the caller didn't provide
+	 * appropriate log level tags, we insert them here
+	 */
+	for (p = printk_buf; *p; p++) {
+		if (new_text_line) {
+			/* If a token, set current_log_level and skip over */
+			if (p[0] == '<' && p[1] >= '0' && p[1] <= '7' &&
+			    p[2] == '>') {
+				current_log_level = p[1] - '0';
+				p += 3;
+				printed_len -= 3;
+			}
+
+			/* Always output the token */
+			emit_log_char('<',1);
+			emit_log_char(current_log_level + '0',1);
+			emit_log_char('>',1);
+			printed_len += 3;
+			new_text_line = 0;
+
+			if (printk_time) {
+				/* Follow the token with the time */
+				char tbuf[50], *tp;
+				unsigned tlen;
+				unsigned long long t;
+				unsigned long nanosec_rem;
+
+				t = cpu_clock(printk_cpu);
+				nanosec_rem = do_div(t, 1000000000);
+				tlen = sprintf(tbuf, "[%5lu.%06lu] ",
+						(unsigned long) t,
+						nanosec_rem / 1000);
+
+				for (tp = tbuf; tp < tbuf + tlen; tp++)
+					emit_log_char(*tp,1);
+				printed_len += tlen;
+			}
+
+			if (!*p)
+				break;
+		}
+
+		emit_log_char(*p,1);
+		if (*p == '\n')
+			new_text_line = 1;
+	}
+
+	/*
+	 * Try to acquire and then immediately release the
+	 * console semaphore. The release will do all the
+	 * actual magic (print out buffers, wake up klogd,
+	 * etc). 
+	 *
+	 * The acquire_console_semaphore_for_printk() function
+	 * will release 'logbuf_lock' regardless of whether it
+	 * actually gets the semaphore or not.
+	 */
+	if (acquire_console_semaphore_for_printk(this_cpu))
+		release_console_sem();
+
+	lockdep_on();
+out_restore_irqs:
+	raw_local_irq_restore(flags);
+
+	preempt_enable();
+	return printed_len;
+}
+EXPORT_SYMBOL(printk);
+EXPORT_SYMBOL(vprintk);
+#if defined(CONFIG_PANIC_PRINTK)
+EXPORT_SYMBOL(panic_printk);
+#endif
+
+#endif /*endof CONFIG_PRINTK*/
+
+asmlinkage int scrlog_vprintk(const char *fmt, va_list args)
+{
+	int printed_len = 0;
+	int current_log_level = default_message_loglevel;
+	unsigned long flags;
+	int this_cpu;
+	char *p;
+
+	boot_delay_msec();
+
+	preempt_disable();
+	/* This stops the holder of console_sem just where we want him */
+	raw_local_irq_save(flags);
+	this_cpu = smp_processor_id();
+
+	/*
+	 * Ouch, printk recursed into itself!
+	 */
+	if (unlikely(printk_cpu == this_cpu)) {
+		/*
+		 * If a crash is occurring during printk() on this CPU,
+		 * then try to get the crash message out but make sure
+		 * we can't deadlock. Otherwise just return to avoid the
+		 * recursion and return - but flag the recursion so that
+		 * it can be printed at the next appropriate moment:
+		 */
+		if (!oops_in_progress) {
+			recursion_bug = 1;
+			goto out_restore_irqs;
+		}
+		zap_locks();
+	}
+
+	lockdep_off();
+	spin_lock(&logbuf_lock);
+	printk_cpu = this_cpu;
+
+	if (recursion_bug) {
+		recursion_bug = 0;
+		strcpy(printk_buf, recursion_bug_msg);
+		printed_len = strlen(recursion_bug_msg);
+	}
+	/* Emit the output into the temporary buffer */
+	printed_len += vscnprintf(printk_buf + printed_len,
+				  sizeof(printk_buf) - printed_len, fmt, args);
+
+
+	/*
+	 * Copy the output into log_buf.  If the caller didn't provide
+	 * appropriate log level tags, we insert them here
+	 */
+	for (p = printk_buf; *p; p++) {
+		if (new_text_line) {
+			/* If a token, set current_log_level and skip over */
+			if (p[0] == '<' && p[1] >= '0' && p[1] <= '7' &&
+			    p[2] == '>') {
+				current_log_level = p[1] - '0';
+				p += 3;
+				printed_len -= 3;
+			}
+
+			/* Always output the token */
+			emit_log_char('<',0);
+			emit_log_char(current_log_level + '0',0);
+			emit_log_char('>',0);
+			printed_len += 3;
+			new_text_line = 0;
+
+			if (printk_time) {
+				/* Follow the token with the time */
+				char tbuf[50], *tp;
+				unsigned tlen;
+				unsigned long long t;
+				unsigned long nanosec_rem;
+
+				t = cpu_clock(printk_cpu);
+				nanosec_rem = do_div(t, 1000000000);
+				tlen = sprintf(tbuf, "[%5lu.%06lu] ",
+						(unsigned long) t,
+						nanosec_rem / 1000);
+
+				for (tp = tbuf; tp < tbuf + tlen; tp++)
+					emit_log_char(*tp,0);
+				printed_len += tlen;
+			}
+
+			if (!*p)
+				break;
+		}
+
+		emit_log_char(*p,0);
+		if (*p == '\n')
+			new_text_line = 1;
+	}
+
+	/*
+	 * Try to acquire and then immediately release the
+	 * console semaphore. The release will do all the
+	 * actual magic (print out buffers, wake up klogd,
+	 * etc). 
+	 *
+	 * The acquire_console_semaphore_for_printk() function
+	 * will release 'logbuf_lock' regardless of whether it
+	 * actually gets the semaphore or not.
+	 */
+	if (acquire_console_semaphore_for_printk(this_cpu))
+		release_console_sem();
+
+	lockdep_on();
+out_restore_irqs:
+	raw_local_irq_restore(flags);
+
+	preempt_enable();
+	return printed_len;
+}
+
+asmlinkage int scrlog_printk(const char *fmt, ...)
+{
+	va_list args;
+	int r;
+
+	va_start(args, fmt);
+	r = scrlog_vprintk(fmt, args);
+	va_end(args);
+
+	return r;
+}
+
+EXPORT_SYMBOL(scrlog_vprintk);
+EXPORT_SYMBOL(scrlog_printk);
+
+#endif /*end  CONFIG_PRINTK_FUNC*/
+
+#else
+
+static void call_console_drivers(unsigned start, unsigned end)
+{
+}
+
+#endif
+
+static int __add_preferred_console(char *name, int idx, char *options,
+				   char *brl_options)
+{
+	struct console_cmdline *c;
+	int i;
+
+	/*
+	 *	See if this tty is not yet registered, and
+	 *	if we have a slot free.
+	 */
+	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
+		if (strcmp(console_cmdline[i].name, name) == 0 &&
+			  console_cmdline[i].index == idx) {
+				if (!brl_options)
+					selected_console = i;
+				return 0;
+		}
+	if (i == MAX_CMDLINECONSOLES)
+		return -E2BIG;
+	if (!brl_options)
+		selected_console = i;
+	c = &console_cmdline[i];
+	strlcpy(c->name, name, sizeof(c->name));
+	c->options = options;
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+	c->brl_options = brl_options;
+#endif
+	c->index = idx;
+	return 0;
+}
+/*
+ * Set up a list of consoles.  Called from init/main.c
+ */
+static int __init console_setup(char *str)
+{
+	char buf[sizeof(console_cmdline[0].name) + 4]; /* 4 for index */
+	char *s, *options, *brl_options = NULL;
+	int idx;
+
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+	if (!memcmp(str, "brl,", 4)) {
+		brl_options = "";
+		str += 4;
+	} else if (!memcmp(str, "brl=", 4)) {
+		brl_options = str + 4;
+		str = strchr(brl_options, ',');
+		if (!str) {
+			printk(KERN_ERR "need port name after brl=\n");
+			return 1;
+		}
+		*(str++) = 0;
+	}
+#endif
+
+	/*
+	 * Decode str into name, index, options.
+	 */
+	if (str[0] >= '0' && str[0] <= '9') {
+		strcpy(buf, "ttyS");
+		strncpy(buf + 4, str, sizeof(buf) - 5);
+	} else {
+		strncpy(buf, str, sizeof(buf) - 1);
+	}
+	buf[sizeof(buf) - 1] = 0;
+	if ((options = strchr(str, ',')) != NULL)
+		*(options++) = 0;
+#ifdef __sparc__
+	if (!strcmp(str, "ttya"))
+		strcpy(buf, "ttyS0");
+	if (!strcmp(str, "ttyb"))
+		strcpy(buf, "ttyS1");
+#endif
+	for (s = buf; *s; s++)
+		if ((*s >= '0' && *s <= '9') || *s == ',')
+			break;
+	idx = simple_strtoul(s, NULL, 10);
+	*s = 0;
+
+	__add_preferred_console(buf, idx, options, brl_options);
+	console_set_on_cmdline = 1;
+	return 1;
+}
+__setup("console=", console_setup);
+
+/**
+ * add_preferred_console - add a device to the list of preferred consoles.
+ * @name: device name
+ * @idx: device index
+ * @options: options for this console
+ *
+ * The last preferred console added will be used for kernel messages
+ * and stdin/out/err for init.  Normally this is used by console_setup
+ * above to handle user-supplied console arguments; however it can also
+ * be used by arch-specific code either to override the user or more
+ * commonly to provide a default console (ie from PROM variables) when
+ * the user has not supplied one.
+ */
+int add_preferred_console(char *name, int idx, char *options)
+{
+	return __add_preferred_console(name, idx, options, NULL);
+}
+
+int update_console_cmdline(char *name, int idx, char *name_new, int idx_new, char *options)
+{
+	struct console_cmdline *c;
+	int i;
+
+	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0]; i++)
+		if (strcmp(console_cmdline[i].name, name) == 0 &&
+			  console_cmdline[i].index == idx) {
+				c = &console_cmdline[i];
+				strlcpy(c->name, name_new, sizeof(c->name));
+				c->name[sizeof(c->name) - 1] = 0;
+				c->options = options;
+				c->index = idx_new;
+				return i;
+		}
+	/* not found */
+	return -1;
+}
+
+int console_suspend_enabled = 1;
+EXPORT_SYMBOL(console_suspend_enabled);
+
+static int __init console_suspend_disable(char *str)
+{
+	console_suspend_enabled = 0;
+	return 1;
+}
+__setup("no_console_suspend", console_suspend_disable);
+
+/**
+ * suspend_console - suspend the console subsystem
+ *
+ * This disables printk() while we go into suspend states
+ */
+void suspend_console(void)
+{
+	if (!console_suspend_enabled)
+		return;
+	printk("Suspending console(s) (use no_console_suspend to debug)\n");
+	acquire_console_sem();
+	console_suspended = 1;
+	up(&console_sem);
+}
+
+void resume_console(void)
+{
+	if (!console_suspend_enabled)
+		return;
+	down(&console_sem);
+	console_suspended = 0;
+	release_console_sem();
+}
+
+/**
+ * acquire_console_sem - lock the console system for exclusive use.
+ *
+ * Acquires a semaphore which guarantees that the caller has
+ * exclusive access to the console system and the console_drivers list.
+ *
+ * Can sleep, returns nothing.
+ */
+void acquire_console_sem(void)
+{
+	BUG_ON(in_interrupt());
+	down(&console_sem);
+	if (console_suspended)
+		return;
+	console_locked = 1;
+	console_may_schedule = 1;
+}
+EXPORT_SYMBOL(acquire_console_sem);
+
+int try_acquire_console_sem(void)
+{
+	if (down_trylock(&console_sem))
+		return -1;
+	if (console_suspended) {
+		up(&console_sem);
+		return -1;
+	}
+	console_locked = 1;
+	console_may_schedule = 0;
+	return 0;
+}
+EXPORT_SYMBOL(try_acquire_console_sem);
+
+int is_console_locked(void)
+{
+	return console_locked;
+}
+
+static DEFINE_PER_CPU(int, printk_pending);
+
+void printk_tick(void)
+{
+	if (__get_cpu_var(printk_pending)) {
+		__get_cpu_var(printk_pending) = 0;
+		wake_up_interruptible(&log_wait);
+	}
+}
+
+int printk_needs_cpu(int cpu)
+{
+	return per_cpu(printk_pending, cpu);
+}
+
+void wake_up_klogd(void)
+{
+	if (waitqueue_active(&log_wait))
+		__raw_get_cpu_var(printk_pending) = 1;
+}
+
+/**
+ * release_console_sem - unlock the console system
+ *
+ * Releases the semaphore which the caller holds on the console system
+ * and the console driver list.
+ *
+ * While the semaphore was held, console output may have been buffered
+ * by printk().  If this is the case, release_console_sem() emits
+ * the output prior to releasing the semaphore.
+ *
+ * If there is output waiting for klogd, we wake it up.
+ *
+ * release_console_sem() may be called from any context.
+ */
+void release_console_sem(void)
+{
+	unsigned long flags;
+	unsigned _con_start, _log_end;
+	unsigned wake_klogd = 0;
+
+	if (console_suspended) {
+		up(&console_sem);
+		return;
+	}
+
+	console_may_schedule = 0;
+
+	for ( ; ; ) {
+		spin_lock_irqsave(&logbuf_lock, flags);
+		wake_klogd |= log_start - log_end;
+#if defined(CONFIG_PRINTK) || defined(CONFIG_PANIC_PRINTK)
+		if (prt_start == prt_end)
+			break;
+		_con_start = prt_start;
+		_log_end = prt_end;
+		prt_start = prt_end;
+#else
+		if (con_start == log_end)
+			break;			/* Nothing to print */
+		_con_start = con_start;
+		_log_end = log_end;
+		con_start = log_end;		/* Flush */
+#endif
+		spin_unlock(&logbuf_lock);
+		stop_critical_timings();	/* don't trace print latency */
+		call_console_drivers(_con_start, _log_end);
+		start_critical_timings();
+		local_irq_restore(flags);
+	}
+	console_locked = 0;
+	up(&console_sem);
+	spin_unlock_irqrestore(&logbuf_lock, flags);
+	if (wake_klogd)
+		wake_up_klogd();
+}
+EXPORT_SYMBOL(release_console_sem);
+
+/**
+ * console_conditional_schedule - yield the CPU if required
+ *
+ * If the console code is currently allowed to sleep, and
+ * if this CPU should yield the CPU to another task, do
+ * so here.
+ *
+ * Must be called within acquire_console_sem().
+ */
+void __sched console_conditional_schedule(void)
+{
+	if (console_may_schedule)
+		cond_resched();
+}
+EXPORT_SYMBOL(console_conditional_schedule);
+
+void console_print(const char *s)
+{
+	printk(KERN_EMERG "%s", s);
+}
+EXPORT_SYMBOL(console_print);
+
+void console_unblank(void)
+{
+	struct console *c;
+
+	/*
+	 * console_unblank can no longer be called in interrupt context unless
+	 * oops_in_progress is set to 1..
+	 */
+	if (oops_in_progress) {
+		if (down_trylock(&console_sem) != 0)
+			return;
+	} else
+		acquire_console_sem();
+
+	console_locked = 1;
+	console_may_schedule = 0;
+	for (c = console_drivers; c != NULL; c = c->next)
+		if ((c->flags & CON_ENABLED) && c->unblank)
+			c->unblank();
+	release_console_sem();
+}
+
+/*
+ * Return the console tty driver structure and its associated index
+ */
+struct tty_driver *console_device(int *index)
+{
+	struct console *c;
+	struct tty_driver *driver = NULL;
+
+	acquire_console_sem();
+	for (c = console_drivers; c != NULL; c = c->next) {
+		if (!c->device)
+			continue;
+		driver = c->device(c, index);
+		if (driver)
+			break;
+	}
+	release_console_sem();
+	return driver;
+}
+
+/*
+ * Prevent further output on the passed console device so that (for example)
+ * serial drivers can disable console output before suspending a port, and can
+ * re-enable output afterwards.
+ */
+void console_stop(struct console *console)
+{
+	acquire_console_sem();
+	console->flags &= ~CON_ENABLED;
+	release_console_sem();
+}
+EXPORT_SYMBOL(console_stop);
+
+void console_start(struct console *console)
+{
+	acquire_console_sem();
+	console->flags |= CON_ENABLED;
+	release_console_sem();
+}
+EXPORT_SYMBOL(console_start);
+
+/*
+ * The console driver calls this routine during kernel initialization
+ * to register the console printing procedure with printk() and to
+ * print any messages that were printed by the kernel before the
+ * console driver was initialized.
+ */
+void register_console(struct console *console)
+{
+	int i;
+	unsigned long flags;
+	struct console *bootconsole = NULL;
+
+	if (console_drivers) {
+		if (console->flags & CON_BOOT)
+			return;
+		if (console_drivers->flags & CON_BOOT)
+			bootconsole = console_drivers;
+	}
+
+	if (preferred_console < 0 || bootconsole || !console_drivers)
+		preferred_console = selected_console;
+
+	if (console->early_setup)
+		console->early_setup();
+
+	/*
+	 *	See if we want to use this console driver. If we
+	 *	didn't select a console we take the first one
+	 *	that registers here.
+	 */
+	if (preferred_console < 0) {
+		if (console->index < 0)
+			console->index = 0;
+		if (console->setup == NULL ||
+		    console->setup(console, NULL) == 0) {
+			console->flags |= CON_ENABLED;
+			if (console->device) {
+				console->flags |= CON_CONSDEV;
+				preferred_console = 0;
+			}
+		}
+	}
+
+	/*
+	 *	See if this console matches one we selected on
+	 *	the command line.
+	 */
+	for (i = 0; i < MAX_CMDLINECONSOLES && console_cmdline[i].name[0];
+			i++) {
+		if (strcmp(console_cmdline[i].name, console->name) != 0)
+			continue;
+		if (console->index >= 0 &&
+		    console->index != console_cmdline[i].index)
+			continue;
+		if (console->index < 0)
+			console->index = console_cmdline[i].index;
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+		if (console_cmdline[i].brl_options) {
+			console->flags |= CON_BRL;
+			braille_register_console(console,
+					console_cmdline[i].index,
+					console_cmdline[i].options,
+					console_cmdline[i].brl_options);
+			return;
+		}
+#endif
+		if (console->setup &&
+		    console->setup(console, console_cmdline[i].options) != 0)
+			break;
+		console->flags |= CON_ENABLED;
+		console->index = console_cmdline[i].index;
+		if (i == selected_console) {
+			console->flags |= CON_CONSDEV;
+			preferred_console = selected_console;
+		}
+		break;
+	}
+
+	if (!(console->flags & CON_ENABLED))
+		return;
+
+	if (bootconsole && (console->flags & CON_CONSDEV)) {
+		printk(KERN_INFO "console handover: boot [%s%d] -> real [%s%d]\n",
+		       bootconsole->name, bootconsole->index,
+		       console->name, console->index);
+		unregister_console(bootconsole);
+		console->flags &= ~CON_PRINTBUFFER;
+	} else {
+		printk(KERN_INFO "console [%s%d] enabled\n",
+		       console->name, console->index);
+	}
+
+	/*
+	 *	Put this console in the list - keep the
+	 *	preferred driver at the head of the list.
+	 */
+	acquire_console_sem();
+	if ((console->flags & CON_CONSDEV) || console_drivers == NULL) {
+		console->next = console_drivers;
+		console_drivers = console;
+		if (console->next)
+			console->next->flags &= ~CON_CONSDEV;
+	} else {
+		console->next = console_drivers->next;
+		console_drivers->next = console;
+	}
+	if (console->flags & CON_PRINTBUFFER) {
+		/*
+		 * release_console_sem() will print out the buffered messages
+		 * for us.
+		 */
+		spin_lock_irqsave(&logbuf_lock, flags);
+		con_start = log_start;
+		spin_unlock_irqrestore(&logbuf_lock, flags);
+	}
+	release_console_sem();
+}
+EXPORT_SYMBOL(register_console);
+
+int unregister_console(struct console *console)
+{
+        struct console *a, *b;
+	int res = 1;
+
+#ifdef CONFIG_A11Y_BRAILLE_CONSOLE
+	if (console->flags & CON_BRL)
+		return braille_unregister_console(console);
+#endif
+
+	acquire_console_sem();
+	if (console_drivers == console) {
+		console_drivers=console->next;
+		res = 0;
+	} else if (console_drivers) {
+		for (a=console_drivers->next, b=console_drivers ;
+		     a; b=a, a=b->next) {
+			if (a == console) {
+				b->next = a->next;
+				res = 0;
+				break;
+			}
+		}
+	}
+
+	/*
+	 * If this isn't the last console and it has CON_CONSDEV set, we
+	 * need to set it on the next preferred console.
+	 */
+	if (console_drivers != NULL && console->flags & CON_CONSDEV)
+		console_drivers->flags |= CON_CONSDEV;
+
+	release_console_sem();
+	return res;
+}
+EXPORT_SYMBOL(unregister_console);
+
+static int __init disable_boot_consoles(void)
+{
+	if (console_drivers != NULL) {
+		if (console_drivers->flags & CON_BOOT) {
+			printk(KERN_INFO "turn off boot console %s%d\n",
+				console_drivers->name, console_drivers->index);
+			return unregister_console(console_drivers);
+		}
+	}
+	return 0;
+}
+late_initcall(disable_boot_consoles);
+
+#if defined(CONFIG_PRINTK) && !defined(CONFIG_PANIC_PRINTK)
+
+/*
+ * printk rate limiting, lifted from the networking subsystem.
+ *
+ * This enforces a rate limit: not more than 10 kernel messages
+ * every 5s to make a denial-of-service attack impossible.
+ */
+DEFINE_RATELIMIT_STATE(printk_ratelimit_state, 5 * HZ, 10);
+
+int printk_ratelimit(void)
+{
+	return __ratelimit(&printk_ratelimit_state);
+}
+EXPORT_SYMBOL(printk_ratelimit);
+
+/**
+ * printk_timed_ratelimit - caller-controlled printk ratelimiting
+ * @caller_jiffies: pointer to caller's state
+ * @interval_msecs: minimum interval between prints
+ *
+ * printk_timed_ratelimit() returns true if more than @interval_msecs
+ * milliseconds have elapsed since the last time printk_timed_ratelimit()
+ * returned true.
+ */
+bool printk_timed_ratelimit(unsigned long *caller_jiffies,
+			unsigned int interval_msecs)
+{
+	if (*caller_jiffies == 0
+			|| !time_in_range(jiffies, *caller_jiffies,
+					*caller_jiffies
+					+ msecs_to_jiffies(interval_msecs))) {
+		*caller_jiffies = jiffies;
+		return true;
+	}
+	return false;
+}
+EXPORT_SYMBOL(printk_timed_ratelimit);
+#endif