From 8ec4d41f88872e6a5980558e362c0174dce54e40 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Sat, 1 Jul 2006 04:36:18 -0700 Subject: [PATCH] [PATCH] SMP alternatives: skip with UP kernels Hide the magic in alternative.h and provide some dummy inline functions for the UP case (gcc should manage to optimize away these calls). No changes in module.c. Cc: Dave Jones Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/kernel/alternative.c | 6 ++++++ include/asm-i386/alternative.h | 8 ++++++++ include/asm-x86_64/alternative.h | 9 +++++++++ 3 files changed, 23 insertions(+) diff --git a/arch/i386/kernel/alternative.c b/arch/i386/kernel/alternative.c index 50eb0e03777e..7b421b3a053e 100644 --- a/arch/i386/kernel/alternative.c +++ b/arch/i386/kernel/alternative.c @@ -168,6 +168,8 @@ void apply_alternatives(struct alt_instr *start, struct alt_instr *end) } } +#ifdef CONFIG_SMP + static void alternatives_smp_save(struct alt_instr *start, struct alt_instr *end) { struct alt_instr *a; @@ -328,6 +330,8 @@ void alternatives_smp_switch(int smp) spin_unlock_irqrestore(&smp_alt, flags); } +#endif + void __init alternative_instructions(void) { if (no_replacement) { @@ -349,6 +353,7 @@ void __init alternative_instructions(void) smp_alt_once = 1; #endif +#ifdef CONFIG_SMP if (smp_alt_once) { if (1 == num_possible_cpus()) { printk(KERN_INFO "SMP alternatives: switching to UP code\n"); @@ -370,4 +375,5 @@ void __init alternative_instructions(void) _text, _etext); alternatives_smp_switch(0); } +#endif } diff --git a/include/asm-i386/alternative.h b/include/asm-i386/alternative.h index c61bd1a17f37..96adbabec740 100644 --- a/include/asm-i386/alternative.h +++ b/include/asm-i386/alternative.h @@ -19,11 +19,19 @@ struct alt_instr { extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); struct module; +#ifdef CONFIG_SMP extern void alternatives_smp_module_add(struct module *mod, char *name, void *locks, void *locks_end, void *text, void *text_end); extern void alternatives_smp_module_del(struct module *mod); extern void alternatives_smp_switch(int smp); +#else +static inline void alternatives_smp_module_add(struct module *mod, char *name, + void *locks, void *locks_end, + void *text, void *text_end) {} +static inline void alternatives_smp_module_del(struct module *mod) {} +static inline void alternatives_smp_switch(int smp) {} +#endif #endif diff --git a/include/asm-x86_64/alternative.h b/include/asm-x86_64/alternative.h index 387c8f66af7d..aa67bfd1b3ce 100644 --- a/include/asm-x86_64/alternative.h +++ b/include/asm-x86_64/alternative.h @@ -17,11 +17,20 @@ struct alt_instr { extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end); struct module; + +#ifdef CONFIG_SMP extern void alternatives_smp_module_add(struct module *mod, char *name, void *locks, void *locks_end, void *text, void *text_end); extern void alternatives_smp_module_del(struct module *mod); extern void alternatives_smp_switch(int smp); +#else +static inline void alternatives_smp_module_add(struct module *mod, char *name, + void *locks, void *locks_end, + void *text, void *text_end) {} +static inline void alternatives_smp_module_del(struct module *mod) {} +static inline void alternatives_smp_switch(int smp) {} +#endif #endif -- 2.30.2