printk: move to separate directory for easier modification

Make it easier to break up printk into bite-sized chunks.

Remove printk path/filename from comment.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

2 files changed, 2925 insertions, 0 deletions

diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
new file mode 100644
index 000000000000..36d306d9273c
--- /dev/null
+++ b/kernel/printk/Makefile
@@ -0,0 +1 @@
+obj-y   = printk.o
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
new file mode 100644
index 000000000000..69b0890ed7e5
--- /dev/null
+++ b/kernel/printk/printk.c
@@ -0,0 +1,2924 @@
+/*
+ *  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/memblock.h>
+#include <linux/aio.h>
+#include <linux/syscalls.h>
+#include <linux/kexec.h>
+#include <linux/kdb.h>
+#include <linux/ratelimit.h>
+#include <linux/kmsg_dump.h>
+#include <linux/syslog.h>
+#include <linux/cpu.h>
+#include <linux/notifier.h>
+#include <linux/rculist.h>
+#include <linux/poll.h>
+#include <linux/irq_work.h>
+#include <linux/utsname.h>
+
+#include <asm/uaccess.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/printk.h>
+
+/* printk's without a loglevel use this.. */
+#define DEFAULT_MESSAGE_LOGLEVEL CONFIG_DEFAULT_MESSAGE_LOGLEVEL
+
+/* 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 */
+
+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 DEFINE_SEMAPHORE(console_sem);
+struct console *console_drivers;
+EXPORT_SYMBOL_GPL(console_drivers);
+
+#ifdef CONFIG_LOCKDEP
+static struct lockdep_map console_lock_dep_map = {
+        .name = "console_lock"
+};
+#endif
+
+/*
+ * 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;
+
+/*
+ * If exclusive_console is non-NULL then only this console is to be printed to.
+ */
+static struct console *exclusive_console;
+
+/*
+ *      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 8
+
+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;
+
+/*
+ * The printk log buffer consists of a chain of concatenated variable
+ * length records. Every record starts with a record header, containing
+ * the overall length of the record.
+ *
+ * The heads to the first and last entry in the buffer, as well as the
+ * sequence numbers of these both entries are maintained when messages
+ * are stored..
+ *
+ * If the heads indicate available messages, the length in the header
+ * tells the start next message. A length == 0 for the next message
+ * indicates a wrap-around to the beginning of the buffer.
+ *
+ * Every record carries the monotonic timestamp in microseconds, as well as
+ * the standard userspace syslog level and syslog facility. The usual
+ * kernel messages use LOG_KERN; userspace-injected messages always carry
+ * a matching syslog facility, by default LOG_USER. The origin of every
+ * message can be reliably determined that way.
+ *
+ * The human readable log message directly follows the message header. The
+ * length of the message text is stored in the header, the stored message
+ * is not terminated.
+ *
+ * Optionally, a message can carry a dictionary of properties (key/value pairs),
+ * to provide userspace with a machine-readable message context.
+ *
+ * Examples for well-defined, commonly used property names are:
+ *   DEVICE=b12:8               device identifier
+ *                                b12:8         block dev_t
+ *                                c127:3        char dev_t
+ *                                n8            netdev ifindex
+ *                                +sound:card0  subsystem:devname
+ *   SUBSYSTEM=pci              driver-core subsystem name
+ *
+ * Valid characters in property names are [a-zA-Z0-9.-_]. The plain text value
+ * follows directly after a '=' character. Every property is terminated by
+ * a '\0' character. The last property is not terminated.
+ *
+ * Example of a message structure:
+ *   0000  ff 8f 00 00 00 00 00 00      monotonic time in nsec
+ *   0008  34 00                        record is 52 bytes long
+ *   000a        0b 00                  text is 11 bytes long
+ *   000c              1f 00            dictionary is 23 bytes long
+ *   000e                    03 00      LOG_KERN (facility) LOG_ERR (level)
+ *   0010  69 74 27 73 20 61 20 6c      "it's a l"
+ *         69 6e 65                     "ine"
+ *   001b           44 45 56 49 43      "DEVIC"
+ *         45 3d 62 38 3a 32 00 44      "E=b8:2\0D"
+ *         52 49 56 45 52 3d 62 75      "RIVER=bu"
+ *         67                           "g"
+ *   0032     00 00 00                  padding to next message header
+ *
+ * The 'struct log' buffer header must never be directly exported to
+ * userspace, it is a kernel-private implementation detail that might
+ * need to be changed in the future, when the requirements change.
+ *
+ * /dev/kmsg exports the structured data in the following line format:
+ *   "level,sequnum,timestamp;<message text>\n"
+ *
+ * The optional key/value pairs are attached as continuation lines starting
+ * with a space character and terminated by a newline. All possible
+ * non-prinatable characters are escaped in the "\xff" notation.
+ *