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#ifndef _ASM_IA64_SPINLOCK_H
#define _ASM_IA64_SPINLOCK_H
/*
* Copyright (C) 1998, 1999 Hewlett-Packard Co
* Copyright (C) 1998, 1999 David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
*
* This file is used for SMP configurations only.
*/
#include <asm/system.h>
#include <asm/bitops.h>
#include <asm/atomic.h>
typedef struct {
volatile unsigned int lock;
} spinlock_t;
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
#define spin_lock_init(x) ((x)->lock = 0)
/* Streamlined test_and_set_bit(0, (x)) */
#define spin_lock(x) __asm__ __volatile__ ( \
"mov ar.ccv = r0\n" \
"mov r29 = 1\n" \
";;\n" \
"1:\n" \
"ld4 r2 = [%0]\n" \
";;\n" \
"cmp4.eq p0,p7 = r0,r2\n" \
"(p7) br.cond.dptk.few 1b \n" \
"cmpxchg4.acq r2 = [%0], r29, ar.ccv\n" \
";;\n" \
"cmp4.eq p0,p7 = r0, r2\n" \
"(p7) br.cond.dptk.few 1b\n" \
";;\n" \
:: "m" __atomic_fool_gcc((x)) : "r2", "r29")
#define spin_unlock(x) __asm__ __volatile__ ("st4.rel [%0] = r0;;" : "=m" (__atomic_fool_gcc((x))))
#define spin_trylock(x) (!test_and_set_bit(0, (x)))
#define spin_unlock_wait(x) \
({ do { barrier(); } while(((volatile spinlock_t *)x)->lock); })
typedef struct {
volatile int read_counter:31;
volatile int write_lock:1;
} rwlock_t;
#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
#define read_lock(rw) \
do { \
int tmp = 0; \
__asm__ __volatile__ ("1:\tfetchadd4.acq %0 = %1, 1\n" \
";;\n" \
"tbit.nz p6,p0 = %0, 31\n" \
"(p6) br.cond.sptk.few 2f\n" \
".section .text.lock,\"ax\"\n" \
"2:\tfetchadd4.rel %0 = %1, -1\n" \
";;\n" \
"3:\tld4.acq %0 = %1\n" \
";;\n" \
"tbit.nz p6,p0 = %0, 31\n" \
"(p6) br.cond.sptk.few 3b\n" \
"br.cond.sptk.few 1b\n" \
";;\n" \
".previous\n": "=r" (tmp), "=m" (__atomic_fool_gcc(rw))); \
} while(0)
#define read_unlock(rw) \
do { \
int tmp = 0; \
__asm__ __volatile__ ("fetchadd4.rel %0 = %1, -1\n" \
: "=r" (tmp) : "m" (__atomic_fool_gcc(rw))); \
} while(0)
/*
* These may need to be rewhacked in asm().
* XXX FIXME SDV - This may have a race on real hardware but is sufficient for SoftSDV
*/
#define write_lock(rw) \
while(1) {\
do { \
} while (!test_and_set_bit(31, (rw))); \
if ((rw)->read_counter) { \
clear_bit(31, (rw)); \
while ((rw)->read_counter) \
; \
} else { \
break; \
} \
}
#define write_unlock(x) (clear_bit(31, (x)))
#endif /* _ASM_IA64_SPINLOCK_H */
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