From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934237AbcI0OZU (ORCPT ); Tue, 27 Sep 2016 10:25:20 -0400 Received: from mail-pa0-f67.google.com ([209.85.220.67]:34840 "EHLO mail-pa0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932963AbcI0OXy (ORCPT ); Tue, 27 Sep 2016 10:23:54 -0400 From: Sergey Senozhatsky To: Petr Mladek , Jan Kara Cc: Andrew Morton , Tejun Heo , Calvin Owens , linux-kernel@vger.kernel.org, Sergey Senozhatsky , Sergey Senozhatsky Subject: [RFC][PATCH 4/7] printk: make alt_printk available when config printk set Date: Tue, 27 Sep 2016 23:22:34 +0900 Message-Id: <20160927142237.5539-5-sergey.senozhatsky@gmail.com> X-Mailer: git-send-email 2.10.0.372.g6fe1b14 In-Reply-To: <20160927142237.5539-1-sergey.senozhatsky@gmail.com> References: <20160927142237.5539-1-sergey.senozhatsky@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 --- include/linux/printk.h | 14 ++++++++------ kernel/printk/Makefile | 2 +- kernel/printk/alt_printk.c | 23 +++++++++++++++++------ kernel/printk/internal.h | 31 +++++++++++++------------------ 4 files changed, 39 insertions(+), 31 deletions(-) diff --git a/include/linux/printk.h b/include/linux/printk.h index 7510613..fae308a 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 +187,10 @@ 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 +250,10 @@ 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 8978390..8ac1daa 100644 --- a/kernel/printk/alt_printk.c +++ b/kernel/printk/alt_printk.c @@ -40,7 +40,6 @@ */ DEFINE_PER_CPU(printk_func_t, printk_func) = vprintk_default; 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)) @@ -50,7 +49,11 @@ struct alt_printk_seq_buf { struct irq_work work; /* IRQ work that flushes the buffer */ unsigned char buffer[ALT_LOG_BUF_LEN]; }; + +#ifdef CONFIG_PRINTK_NMI static DEFINE_PER_CPU(struct alt_printk_seq_buf, nmi_print_seq); +atomic_t nmi_message_lost; +#endif /* * There can be two alt_printk contexts at most - a `normal' alt_printk @@ -320,8 +323,12 @@ void alt_printk_flush(void) { int cpu; - for_each_possible_cpu(cpu) - __alt_printk_flush(&per_cpu(nmi_print_seq, cpu).work); + for_each_possible_cpu(cpu) { + if (IS_ENABLED(CONFIG_PRINTK_NMI)) + __alt_printk_flush(&per_cpu(nmi_print_seq, cpu).work); + + __alt_printk_flush(&per_cpu(alt_print_seq, cpu).work); + } } /** @@ -356,12 +363,14 @@ 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); - init_irq_work(&s->work, __alt_printk_flush); + if (IS_ENABLED(CONFIG_PRINTK_NMI)) { + s = &per_cpu(nmi_print_seq, cpu); + init_irq_work(&s->work, __alt_printk_flush); + } } /* Make sure that IRQ works are initialized before enabling. */ @@ -372,6 +381,7 @@ void __init alt_printk_init(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 @@ -399,3 +409,4 @@ void printk_nmi_exit(void) { __lockless_printk_exit(); } +#endif /* CONFIG_PRINTK_NMI */ diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index c5f970e..3eebf6d 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -18,21 +18,9 @@ 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 -void alt_printk_enter(void); -void alt_printk_exit(void); - -#else - -void alt_printk_enter(void) { } -void alt_printk_exit(void) { } - -#endif /* CONFIG_PRINTK */ - -#ifdef CONFIG_PRINTK_NMI +int __printf(1, 0) vprintk_default(const char *fmt, va_list args); extern raw_spinlock_t logbuf_lock; @@ -48,6 +36,18 @@ static inline __printf(1, 0) int vprintk_func(const char *fmt, va_list args) return this_cpu_read(printk_func)(fmt, args); } +void alt_printk_enter(void); +void alt_printk_exit(void); + +#else + +void alt_printk_enter(void) { } +void alt_printk_exit(void) { } + +#endif /* CONFIG_PRINTK */ + +#ifdef CONFIG_PRINTK_NMI + extern atomic_t nmi_message_lost; static inline int get_nmi_message_lost(void) { @@ -56,11 +56,6 @@ 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; -- 2.10.0.372.g6fe1b14