[RFC][PATCHv2 2/4] printk: move printk_safe macros to printk header

Sergey Senozhatsky
2018-10-16T05:04:26Z

Make printk_safe_enter_irqsave()/etc macros available to the
rest of the kernel.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
---
include/linux/printk.h | 40 +++++++++++++++++++++++++++++++++++++
kernel/printk/internal.h | 37 ----------------------------------
kernel/printk/printk_safe.c | 6 ++++--
3 files changed, 44 insertions(+), 39 deletions(-)

diff --git a/include/linux/printk.h b/include/linux/printk.h
index cf3eccfe1543..75f99441fd54 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -157,6 +157,46 @@ static inline void printk_nmi_direct_enter(void) { }
static inline void printk_nmi_direct_exit(void) { }
#endif /* PRINTK_NMI */

+#ifdef CONFIG_PRINTK
+extern void printk_safe_enter(void);
+extern void printk_safe_exit(void);
+
+#define printk_safe_enter_irqsave(flags) \
+ do { \
+ local_irq_save(flags); \
+ printk_safe_enter(); \
+ } while (0)
+
+#define printk_safe_exit_irqrestore(flags) \
+ do { \
+ printk_safe_exit(); \
+ local_irq_restore(flags); \
+ } while (0)
+
+#define printk_safe_enter_irq() \
+ do { \
+ local_irq_disable(); \
+ printk_safe_enter(); \
+ } while (0)
+
+#define printk_safe_exit_irq() \
+ do { \
+ printk_safe_exit(); \
+ local_irq_enable(); \
+ } while (0)
+#else
+/*
+ * On !PRINTK builds we still export console output related locks
+ * and some functions (console_unlock()/tty/etc.), so printk-safe
+ * must preserve the existing local IRQ guarantees.
+ */
+#define printk_safe_enter_irqsave(flags) local_irq_save(flags)
+#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
+
+#define printk_safe_enter_irq() local_irq_disable()
+#define printk_safe_exit_irq() local_irq_enable()
+#endif
+
#ifdef CONFIG_PRINTK
asmlinkage __printf(5, 0)
int vprintk_emit(int facility, int level,
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h
index 0f1898820cba..03c10f361a15 100644
--- a/kernel/printk/internal.h
+++ b/kernel/printk/internal.h
@@ -32,32 +32,6 @@ int vprintk_store(int facility, int level,
__printf(1, 0) int vprintk_default(const char *fmt, va_list args);
__printf(1, 0) int vprintk_deferred(const char *fmt, va_list args);
__printf(1, 0) int vprintk_func(const char *fmt, va_list args);
-void __printk_safe_enter(void);
-void __printk_safe_exit(void);
-
-#define printk_safe_enter_irqsave(flags) \
- do { \
- local_irq_save(flags); \
- __printk_safe_enter(); \
- } while (0)
-
-#define printk_safe_exit_irqrestore(flags) \
- do { \
- __printk_safe_exit(); \
- local_irq_restore(flags); \
- } while (0)
-
-#define printk_safe_enter_irq() \
- do { \
- local_irq_disable(); \
- __printk_safe_enter(); \
- } while (0)
-
-#define printk_safe_exit_irq() \
- do { \
- __printk_safe_exit(); \
- local_irq_enable(); \
- } while (0)

void defer_console_output(void);

@@ -65,15 +39,4 @@ void defer_console_output(void);

__printf(1, 0) int vprintk_func(const char *fmt, va_list args) { return 0; }

-/*
- * In !PRINTK builds we still export logbuf_lock spin_lock, console_sem
- * semaphore and some of console functions (console_unlock()/etc.), so
- * printk-safe must preserve the existing local IRQ guarantees.
- */
-#define printk_safe_enter_irqsave(flags) local_irq_save(flags)
-#define printk_safe_exit_irqrestore(flags) local_irq_restore(flags)
-
-#define printk_safe_enter_irq() local_irq_disable()
-#define printk_safe_exit_irq() local_irq_enable()
-
#endif /* CONFIG_PRINTK */
diff --git a/kernel/printk/printk_safe.c b/kernel/printk/printk_safe.c
index 0913b4d385de..367fcb2c39f0 100644
--- a/kernel/printk/printk_safe.c
+++ b/kernel/printk/printk_safe.c
@@ -359,16 +359,18 @@ static __printf(1, 0) int vprintk_safe(const char *fmt, va_list args)
}

/* Can be preempted by NMI. */
-void __printk_safe_enter(void)
+void printk_safe_enter(void)
{
this_cpu_inc(printk_context);
}
+EXPORT_SYMBOL_GPL(printk_safe_enter);

/* Can be preempted by NMI. */
-void __printk_safe_exit(void)
+void printk_safe_exit(void)
{
this_cpu_dec(printk_context);
}
+EXPORT_SYMBOL_GPL(printk_safe_exit);

__printf(1, 0) int vprintk_func(const char *fmt, va_list args)
{
--
2.19.1