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author | Jiri Kosina <jkosina@suse.cz> | 2010-08-10 15:22:08 +0400 |
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committer | Jiri Kosina <jkosina@suse.cz> | 2010-08-10 15:22:08 +0400 |
commit | fb8231a8b139035476f2a8aaac837d0099b66dad (patch) | |
tree | 2875806beb96ea0cdab292146767a5085721dc6a /arch/x86/lib/cmpxchg.c | |
parent | 426d31071ac476ea62c62656b242930c17b58c00 (diff) | |
parent | f6cec0ae58c17522a7bc4e2f39dae19f199ab534 (diff) | |
download | linux-fb8231a8b139035476f2a8aaac837d0099b66dad.tar.xz |
Merge branch 'master' into for-next
Conflicts:
arch/arm/mach-omap1/board-nokia770.c
Diffstat (limited to 'arch/x86/lib/cmpxchg.c')
-rw-r--r-- | arch/x86/lib/cmpxchg.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/x86/lib/cmpxchg.c b/arch/x86/lib/cmpxchg.c new file mode 100644 index 000000000000..5d619f6df3ee --- /dev/null +++ b/arch/x86/lib/cmpxchg.c @@ -0,0 +1,54 @@ +/* + * cmpxchg*() fallbacks for CPU not supporting these instructions + */ + +#include <linux/kernel.h> +#include <linux/smp.h> +#include <linux/module.h> + +#ifndef CONFIG_X86_CMPXCHG +unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new) +{ + u8 prev; + unsigned long flags; + + /* Poor man's cmpxchg for 386. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u8 *)ptr; + if (prev == old) + *(u8 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_386_u8); + +unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new) +{ + u16 prev; + unsigned long flags; + + /* Poor man's cmpxchg for 386. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u16 *)ptr; + if (prev == old) + *(u16 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_386_u16); + +unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new) +{ + u32 prev; + unsigned long flags; + + /* Poor man's cmpxchg for 386. Unsuitable for SMP */ + local_irq_save(flags); + prev = *(u32 *)ptr; + if (prev == old) + *(u32 *)ptr = new; + local_irq_restore(flags); + return prev; +} +EXPORT_SYMBOL(cmpxchg_386_u32); +#endif |