Merge tag 'fbdev-fixes-3.9-rc4' of git://gitorious.org/linux-omap-dss2/linux

[firefly-linux-kernel-4.4.55.git] / kernel / printk.c

diff --git a/kernel/printk.c b/kernel/printk.c
index 267ce780abe8dd0c18b3c6f1d93f3974b75697ed..abbdd9e2ac82c423a3dc6c778632c37887241b41 100644 (file)
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -42,6 +42,7 @@
 #include <linux/notifier.h>
 #include <linux/rculist.h>
 #include <linux/poll.h>
+#include <linux/irq_work.h>
 
 #include <asm/uaccess.h>
 
@@ -62,8 +63,6 @@ void asmlinkage __attribute__((weak)) early_printk(const char *fmt, ...)
 #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 */
@@ -87,6 +86,12 @@ 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
@@ -217,6 +222,7 @@ struct log {
 static DEFINE_RAW_SPINLOCK(logbuf_lock);
 
 #ifdef CONFIG_PRINTK
+DECLARE_WAIT_QUEUE_HEAD(log_wait);
 /* the next printk record to read by syslog(READ) or /proc/kmsg */
 static u64 syslog_seq;
 static u32 syslog_idx;
@@ -1918,6 +1924,7 @@ void console_lock(void)
                return;
        console_locked = 1;
        console_may_schedule = 1;
+       mutex_acquire(&console_lock_dep_map, 0, 0, _RET_IP_);
 }
 EXPORT_SYMBOL(console_lock);
 
@@ -1939,6 +1946,7 @@ int console_trylock(void)
        }
        console_locked = 1;
        console_may_schedule = 0;
+       mutex_acquire(&console_lock_dep_map, 0, 1, _RET_IP_);
        return 1;
 }
 EXPORT_SYMBOL(console_trylock);
@@ -1948,43 +1956,6 @@ int is_console_locked(void)
        return console_locked;
 }
 
-/*
- * Delayed printk version, for scheduler-internal messages:
- */
-#define PRINTK_BUF_SIZE                512
-
-#define PRINTK_PENDING_WAKEUP  0x01
-#define PRINTK_PENDING_SCHED   0x02
-
-static DEFINE_PER_CPU(int, printk_pending);
-static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
-
-void printk_tick(void)
-{
-       if (__this_cpu_read(printk_pending)) {
-               int pending = __this_cpu_xchg(printk_pending, 0);
-               if (pending & PRINTK_PENDING_SCHED) {
-                       char *buf = __get_cpu_var(printk_sched_buf);
-                       printk(KERN_WARNING "[sched_delayed] %s", buf);
-               }
-               if (pending & PRINTK_PENDING_WAKEUP)
-                       wake_up_interruptible(&log_wait);
-       }
-}
-
-int printk_needs_cpu(int cpu)
-{
-       if (cpu_is_offline(cpu))
-               printk_tick();
-       return __this_cpu_read(printk_pending);
-}
-
-void wake_up_klogd(void)
-{
-       if (waitqueue_active(&log_wait))
-               this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
-}
-
 static void console_cont_flush(char *text, size_t size)
 {
        unsigned long flags;
@@ -2099,6 +2070,7 @@ skip:
                local_irq_restore(flags);
        }
        console_locked = 0;
+       mutex_release(&console_lock_dep_map, 1, _RET_IP_);
 
        /* Release the exclusive_console once it is used */
        if (unlikely(exclusive_console))
@@ -2446,6 +2418,44 @@ static int __init printk_late_init(void)
 late_initcall(printk_late_init);
 
 #if defined CONFIG_PRINTK
+/*
+ * Delayed printk version, for scheduler-internal messages:
+ */
+#define PRINTK_BUF_SIZE                512
+
+#define PRINTK_PENDING_WAKEUP  0x01
+#define PRINTK_PENDING_SCHED   0x02
+
+static DEFINE_PER_CPU(int, printk_pending);
+static DEFINE_PER_CPU(char [PRINTK_BUF_SIZE], printk_sched_buf);
+
+static void wake_up_klogd_work_func(struct irq_work *irq_work)
+{
+       int pending = __this_cpu_xchg(printk_pending, 0);
+
+       if (pending & PRINTK_PENDING_SCHED) {
+               char *buf = __get_cpu_var(printk_sched_buf);
+               printk(KERN_WARNING "[sched_delayed] %s", buf);
+       }
+
+       if (pending & PRINTK_PENDING_WAKEUP)
+               wake_up_interruptible(&log_wait);
+}
+
+static DEFINE_PER_CPU(struct irq_work, wake_up_klogd_work) = {
+       .func = wake_up_klogd_work_func,
+       .flags = IRQ_WORK_LAZY,
+};
+
+void wake_up_klogd(void)
+{
+       preempt_disable();
+       if (waitqueue_active(&log_wait)) {
+               this_cpu_or(printk_pending, PRINTK_PENDING_WAKEUP);
+               irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
+       }
+       preempt_enable();
+}
 
 int printk_sched(const char *fmt, ...)
 {
@@ -2462,6 +2472,7 @@ int printk_sched(const char *fmt, ...)
        va_end(args);
 
        __this_cpu_or(printk_pending, PRINTK_PENDING_SCHED);
+       irq_work_queue(&__get_cpu_var(wake_up_klogd_work));
        local_irq_restore(flags);
 
        return r;