diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-08-14 12:19:59 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-08-14 12:19:59 +0200 |
commit | 8d7ccaa545490cdffdfaff0842436a8dd85cf47b (patch) | |
tree | 8129b5907161bc6ae26deb3645ce1e280c5e1f51 /arch/sparc/include/asm/smpprim.h | |
parent | b2139aa0eec330c711c5a279db361e5ef1178e78 (diff) | |
parent | 30a2f3c60a84092c8084dfe788b710f8d0768cd4 (diff) |
Merge commit 'v2.6.27-rc3' into x86/prototypes
Conflicts:
include/asm-x86/dma-mapping.h
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/sparc/include/asm/smpprim.h')
-rw-r--r-- | arch/sparc/include/asm/smpprim.h | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/arch/sparc/include/asm/smpprim.h b/arch/sparc/include/asm/smpprim.h new file mode 100644 index 000000000000..eb849d862c64 --- /dev/null +++ b/arch/sparc/include/asm/smpprim.h @@ -0,0 +1,54 @@ +/* + * smpprim.h: SMP locking primitives on the Sparc + * + * God knows we won't be actually using this code for some time + * but I thought I'd write it since I knew how. + * + * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + */ + +#ifndef __SPARC_SMPPRIM_H +#define __SPARC_SMPPRIM_H + +/* Test and set the unsigned byte at ADDR to 1. Returns the previous + * value. On the Sparc we use the ldstub instruction since it is + * atomic. + */ + +static inline __volatile__ char test_and_set(void *addr) +{ + char state = 0; + + __asm__ __volatile__("ldstub [%0], %1 ! test_and_set\n\t" + "=r" (addr), "=r" (state) : + "0" (addr), "1" (state) : "memory"); + + return state; +} + +/* Initialize a spin-lock. */ +static inline __volatile__ smp_initlock(void *spinlock) +{ + /* Unset the lock. */ + *((unsigned char *) spinlock) = 0; + + return; +} + +/* This routine spins until it acquires the lock at ADDR. */ +static inline __volatile__ smp_lock(void *addr) +{ + while(test_and_set(addr) == 0xff) + ; + + /* We now have the lock */ + return; +} + +/* This routine releases the lock at ADDR. */ +static inline __volatile__ smp_unlock(void *addr) +{ + *((unsigned char *) addr) = 0; +} + +#endif /* !(__SPARC_SMPPRIM_H) */ |