diff options
Diffstat (limited to 'kernel/printk/internal.h')
-rw-r--r-- | kernel/printk/internal.h | 76 |
1 files changed, 53 insertions, 23 deletions
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index 7fd2838fa417..c65e36509f3b 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -16,26 +16,8 @@ */ #include <linux/percpu.h> -typedef __printf(1, 0) int (*printk_func_t)(const char *fmt, va_list args); - -int __printf(1, 0) vprintk_default(const char *fmt, va_list args); - #ifdef CONFIG_PRINTK_NMI -extern raw_spinlock_t logbuf_lock; - -/* - * printk() could not take logbuf_lock in NMI context. Instead, - * it temporary stores the strings into a per-CPU buffer. - * The alternative implementation is chosen transparently - * via per-CPU variable. - */ -DECLARE_PER_CPU(printk_func_t, printk_func); -static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args) -{ - return this_cpu_read(printk_func)(fmt, args); -} - extern atomic_t nmi_message_lost; static inline int get_nmi_message_lost(void) { @@ -44,14 +26,62 @@ static inline int get_nmi_message_lost(void) #else /* CONFIG_PRINTK_NMI */ -static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args) -{ - return vprintk_default(fmt, args); -} - static inline int get_nmi_message_lost(void) { return 0; } #endif /* CONFIG_PRINTK_NMI */ + +#ifdef CONFIG_PRINTK + +#define PRINTK_SAFE_CONTEXT_MASK 0x7fffffff +#define PRINTK_NMI_CONTEXT_MASK 0x80000000 + +extern raw_spinlock_t logbuf_lock; + +__printf(1, 0) int vprintk_default(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) + +#else + +__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 */ |