From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- include/asm-sparc/smpprim.h | 54 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 include/asm-sparc/smpprim.h (limited to 'include/asm-sparc/smpprim.h') diff --git a/include/asm-sparc/smpprim.h b/include/asm-sparc/smpprim.h new file mode 100644 index 000000000000..9b9c28ed748e --- /dev/null +++ b/include/asm-sparc/smpprim.h @@ -0,0 +1,54 @@ +/* $Id: smpprim.h,v 1.5 1996/08/29 09:48:49 davem Exp $ + * 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. + */ + +extern __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. */ +extern __inline__ __volatile__ smp_initlock(void *spinlock) +{ + /* Unset the lock. */ + *((unsigned char *) spinlock) = 0; + + return; +} + +/* This routine spins until it acquires the lock at ADDR. */ +extern __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. */ +extern __inline__ __volatile__ smp_unlock(void *addr) +{ + *((unsigned char *) addr) = 0; +} + +#endif /* !(__SPARC_SMPPRIM_H) */ -- cgit v1.2.3