diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-07-29 00:07:55 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-29 00:07:55 +0200 |
commit | cb28a1bbdb4790378e7366d6c9ee1d2340b84f92 (patch) | |
tree | 316436f77dac75335fd2c3ef5f109e71606c50d3 /arch/sparc/include/asm/smpprim.h | |
parent | b6d4f7e3ef25beb8c658c97867d98883e69dc544 (diff) | |
parent | f934fb19ef34730263e6afc01e8ec27a8a71470f (diff) |
Merge branch 'linus' into core/generic-dma-coherent
Conflicts:
arch/x86/Kconfig
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 00000000000..eb849d862c6 --- /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) */ |