diff options
| author | Nick Piggin <nickpiggin@yahoo.com.au> | 2005-11-13 16:07:23 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-11-13 18:14:15 -0800 |
| commit | 53e86b91b7ae66d4c2757195cbd42e00d9199cf2 (patch) | |
| tree | 80c44aeb046ac91a5bc7465da91a7b2519c53096 /arch/i386 | |
| parent | dbdf65b1b7f8ec48bda1604cfea7ac09ce583d6b (diff) | |
[PATCH] i386: generic cmpxchg
- Make cmpxchg generally available on the i386 platform.
- Provide emulation of cmpxchg suitable for uniprocessor if built and run on
386.
From: Christoph Lameter <clameter@sgi.com>
- Cut down patch and small style changes.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/i386')
| -rw-r--r-- | arch/i386/kernel/cpu/intel.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/intel.c b/arch/i386/kernel/cpu/intel.c index 43601de0f63..c28d26fb5f2 100644 --- a/arch/i386/kernel/cpu/intel.c +++ b/arch/i386/kernel/cpu/intel.c @@ -6,6 +6,7 @@ #include <linux/bitops.h> #include <linux/smp.h> #include <linux/thread_info.h> +#include <linux/module.h> #include <asm/processor.h> #include <asm/msr.h> @@ -264,5 +265,52 @@ __init int intel_cpu_init(void) return 0; } +#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 + // arch_initcall(intel_cpu_init); |