alt_printk must be enabled on systems that have CONFIG_PRINTK set, while NMI related functions must depend on CONFIG_PRINTK_NMI.
Signed-off-by: Sergey Senozhatsky <[email protected]> --- include/linux/printk.h | 21 +++++++++++++++------ kernel/printk/Makefile | 2 +- kernel/printk/alt_printk.c | 30 +++++++++++++++++++++++++----- 3 files changed, 41 insertions(+), 12 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 7510613..068a124 100644 --- a/include/linux/printk.h +++ b/include/linux/printk.h @@ -131,17 +131,11 @@ void early_printk(const char *s, ...) { } #endif #ifdef CONFIG_PRINTK_NMI -extern void alt_printk_init(void); extern void printk_nmi_enter(void); extern void printk_nmi_exit(void); -extern void alt_printk_flush(void); -extern void alt_printk_flush_on_panic(void); #else -static inline void alt_printk_init(void) { } static inline void printk_nmi_enter(void) { } static inline void printk_nmi_exit(void) { } -static inline void alt_printk_flush(void) { } -static inline void alt_printk_flush_on_panic(void) { } #endif /* PRINTK_NMI */ #ifdef CONFIG_PRINTK @@ -193,6 +187,9 @@ void __init setup_log_buf(int early); __printf(1, 2) void dump_stack_set_arch_desc(const char *fmt, ...); void dump_stack_print_info(const char *log_lvl); void show_regs_print_info(const char *log_lvl); +extern void alt_printk_init(void); +extern void alt_printk_flush(void); +extern void alt_printk_flush_on_panic(void); #else static inline __printf(1, 0) int vprintk(const char *s, va_list args) @@ -252,6 +249,18 @@ static inline void dump_stack_print_info(const char *log_lvl) static inline void show_regs_print_info(const char *log_lvl) { } + +static inline void alt_printk_init(void) +{ +} + +static inline void alt_printk_flush(void) +{ +} + +static inline void alt_printk_flush_on_panic(void) +{ +} #endif extern asmlinkage void dump_stack(void) __cold; diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile index 3fc5e4e..d11838c 100644 --- a/kernel/printk/Makefile +++ b/kernel/printk/Makefile @@ -1,3 +1,3 @@ obj-y = printk.o -obj-$(CONFIG_PRINTK_NMI) += alt_printk.o +obj-$(CONFIG_PRINTK) += alt_printk.o obj-$(CONFIG_A11Y_BRAILLE_CONSOLE) += braille.o diff --git a/kernel/printk/alt_printk.c b/kernel/printk/alt_printk.c index 4bc1e7d..db0bfc8 100644 --- a/kernel/printk/alt_printk.c +++ b/kernel/printk/alt_printk.c @@ -40,7 +40,6 @@ * were handled or when IRQs are blocked. */ static int alt_printk_irq_ready; -atomic_t nmi_message_lost; #define ALT_LOG_BUF_LEN ((1 << CONFIG_ALT_PRINTK_LOG_BUF_SHIFT) - \ sizeof(atomic_t) - sizeof(struct irq_work)) @@ -50,12 +49,16 @@ struct alt_printk_seq_buf { struct irq_work work; /* IRQ work that flushes the buffer */ unsigned char buffer[ALT_LOG_BUF_LEN]; }; -static DEFINE_PER_CPU(struct alt_printk_seq_buf, nmi_print_seq); static DEFINE_PER_CPU(struct alt_printk_seq_buf, alt_print_seq); static DEFINE_PER_CPU(int, alt_printk_ctx); static DEFINE_PER_CPU(unsigned long, alt_printk_irq_flags); +#ifdef CONFIG_PRINTK_NMI +static DEFINE_PER_CPU(struct alt_printk_seq_buf, nmi_print_seq); +atomic_t nmi_message_lost; +#endif + static int alt_printk_log_store(struct alt_printk_seq_buf *s, const char *fmt, va_list args) { @@ -204,8 +207,12 @@ void alt_printk_flush(void) { int cpu; - for_each_possible_cpu(cpu) + for_each_possible_cpu(cpu) { +#ifdef CONFIG_PRINTK_NMI __alt_printk_flush(&per_cpu(nmi_print_seq, cpu).work); +#endif + __alt_printk_flush(&per_cpu(alt_print_seq, cpu).work); + } } /** @@ -235,6 +242,8 @@ void alt_printk_flush_on_panic(void) alt_printk_flush(); } +#ifdef CONFIG_PRINTK_NMI + /* * Safe printk() for NMI context. It uses a per-CPU buffer to * store the message. NMIs are not nested, so there is always only @@ -263,6 +272,15 @@ void printk_nmi_exit(void) this_cpu_and(alt_printk_ctx, ~ALT_PRINTK_NMI_CONTEXT_MASK); } +#else + +static int vprintk_nmi(const char *fmt, va_list args) +{ + return 0; +} + +#endif /* CONFIG_PRINTK_NMI */ + /* * Lockless printk(), to avoid deadlocks should the printk() recurse * into itself. It uses a per-CPU buffer to store the message, just like @@ -317,12 +335,14 @@ void __init alt_printk_init(void) int cpu; for_each_possible_cpu(cpu) { - struct alt_printk_seq_buf *s = &per_cpu(nmi_print_seq, cpu); + struct alt_printk_seq_buf *s = &per_cpu(alt_print_seq, cpu); init_irq_work(&s->work, __alt_printk_flush); - s = &per_cpu(alt_print_seq, cpu); +#ifdef CONFIG_PRINTK_NMI + s = &per_cpu(nmi_print_seq, cpu); init_irq_work(&s->work, __alt_printk_flush); +#endif } /* Make sure that IRQ works are initialized before enabling. */ -- 2.10.0.372.g6fe1b14
