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Diffstat (limited to 'include/asm-ia64/spinlock.h')
| -rw-r--r-- | include/asm-ia64/spinlock.h | 208 |
1 files changed, 208 insertions, 0 deletions
diff --git a/include/asm-ia64/spinlock.h b/include/asm-ia64/spinlock.h new file mode 100644 index 00000000000..909936f2551 --- /dev/null +++ b/include/asm-ia64/spinlock.h @@ -0,0 +1,208 @@ +#ifndef _ASM_IA64_SPINLOCK_H +#define _ASM_IA64_SPINLOCK_H + +/* + * Copyright (C) 1998-2003 Hewlett-Packard Co + * David Mosberger-Tang <davidm@hpl.hp.com> + * Copyright (C) 1999 Walt Drummond <drummond@valinux.com> + * + * This file is used for SMP configurations only. + */ + +#include <linux/compiler.h> +#include <linux/kernel.h> + +#include <asm/atomic.h> +#include <asm/bitops.h> +#include <asm/intrinsics.h> +#include <asm/system.h> + +typedef struct { + volatile unsigned int lock; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +} spinlock_t; + +#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } +#define spin_lock_init(x) ((x)->lock = 0) + +#ifdef ASM_SUPPORTED +/* + * Try to get the lock. If we fail to get the lock, make a non-standard call to + * ia64_spinlock_contention(). We do not use a normal call because that would force all + * callers of spin_lock() to be non-leaf routines. Instead, ia64_spinlock_contention() is + * carefully coded to touch only those registers that spin_lock() marks "clobbered". + */ + +#define IA64_SPINLOCK_CLOBBERS "ar.ccv", "ar.pfs", "p14", "p15", "r27", "r28", "r29", "r30", "b6", "memory" + +static inline void +_raw_spin_lock_flags (spinlock_t *lock, unsigned long flags) +{ + register volatile unsigned int *ptr asm ("r31") = &lock->lock; + +#if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 3) +# ifdef CONFIG_ITANIUM + /* don't use brl on Itanium... */ + asm volatile ("{\n\t" + " mov ar.ccv = r0\n\t" + " mov r28 = ip\n\t" + " mov r30 = 1;;\n\t" + "}\n\t" + "cmpxchg4.acq r30 = [%1], r30, ar.ccv\n\t" + "movl r29 = ia64_spinlock_contention_pre3_4;;\n\t" + "cmp4.ne p14, p0 = r30, r0\n\t" + "mov b6 = r29;;\n\t" + "mov r27=%2\n\t" + "(p14) br.cond.spnt.many b6" + : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); +# else + asm volatile ("{\n\t" + " mov ar.ccv = r0\n\t" + " mov r28 = ip\n\t" + " mov r30 = 1;;\n\t" + "}\n\t" + "cmpxchg4.acq r30 = [%1], r30, ar.ccv;;\n\t" + "cmp4.ne p14, p0 = r30, r0\n\t" + "mov r27=%2\n\t" + "(p14) brl.cond.spnt.many ia64_spinlock_contention_pre3_4;;" + : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); +# endif /* CONFIG_MCKINLEY */ +#else +# ifdef CONFIG_ITANIUM + /* don't use brl on Itanium... */ + /* mis-declare, so we get the entry-point, not it's function descriptor: */ + asm volatile ("mov r30 = 1\n\t" + "mov r27=%2\n\t" + "mov ar.ccv = r0;;\n\t" + "cmpxchg4.acq r30 = [%0], r30, ar.ccv\n\t" + "movl r29 = ia64_spinlock_contention;;\n\t" + "cmp4.ne p14, p0 = r30, r0\n\t" + "mov b6 = r29;;\n\t" + "(p14) br.call.spnt.many b6 = b6" + : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); +# else + asm volatile ("mov r30 = 1\n\t" + "mov r27=%2\n\t" + "mov ar.ccv = r0;;\n\t" + "cmpxchg4.acq r30 = [%0], r30, ar.ccv;;\n\t" + "cmp4.ne p14, p0 = r30, r0\n\t" + "(p14) brl.call.spnt.many b6=ia64_spinlock_contention;;" + : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS); +# endif /* CONFIG_MCKINLEY */ +#endif +} +#define _raw_spin_lock(lock) _raw_spin_lock_flags(lock, 0) +#else /* !ASM_SUPPORTED */ +#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) +# define _raw_spin_lock(x) \ +do { \ + __u32 *ia64_spinlock_ptr = (__u32 *) (x); \ + __u64 ia64_spinlock_val; \ + ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0); \ + if (unlikely(ia64_spinlock_val)) { \ + do { \ + while (*ia64_spinlock_ptr) \ + ia64_barrier(); \ + ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0); \ + } while (ia64_spinlock_val); \ + } \ +} while (0) +#endif /* !ASM_SUPPORTED */ + +#define spin_is_locked(x) ((x)->lock != 0) +#define _raw_spin_unlock(x) do { barrier(); ((spinlock_t *) x)->lock = 0; } while (0) +#define _raw_spin_trylock(x) (cmpxchg_acq(&(x)->lock, 0, 1) == 0) +#define spin_unlock_wait(x) do { barrier(); } while ((x)->lock) + +typedef struct { + volatile unsigned int read_counter : 31; + volatile unsigned int write_lock : 1; +#ifdef CONFIG_PREEMPT + unsigned int break_lock; +#endif +} rwlock_t; +#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 } + +#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0) +#define read_can_lock(rw) (*(volatile int *)(rw) >= 0) +#define write_can_lock(rw) (*(volatile int *)(rw) == 0) + +#define _raw_read_lock(rw) \ +do { \ + rwlock_t *__read_lock_ptr = (rw); \ + \ + while (unlikely(ia64_fetchadd(1, (int *) __read_lock_ptr, acq) < 0)) { \ + ia64_fetchadd(-1, (int *) __read_lock_ptr, rel); \ + while (*(volatile int *)__read_lock_ptr < 0) \ + cpu_relax(); \ + } \ +} while (0) + +#define _raw_read_unlock(rw) \ +do { \ + rwlock_t *__read_lock_ptr = (rw); \ + ia64_fetchadd(-1, (int *) __read_lock_ptr, rel); \ +} while (0) + +#ifdef ASM_SUPPORTED +#define _raw_write_lock(rw) \ +do { \ + __asm__ __volatile__ ( \ + "mov ar.ccv = r0\n" \ + "dep r29 = -1, r0, 31, 1;;\n" \ + "1:\n" \ + "ld4 r2 = [%0];;\n" \ + "cmp4.eq p0,p7 = r0,r2\n" \ + "(p7) br.cond.spnt.few 1b \n" \ + "cmpxchg4.acq r2 = [%0], r29, ar.ccv;;\n" \ + "cmp4.eq p0,p7 = r0, r2\n" \ + "(p7) br.cond.spnt.few 1b;;\n" \ + :: "r"(rw) : "ar.ccv", "p7", "r2", "r29", "memory"); \ +} while(0) + +#define _raw_write_trylock(rw) \ +({ \ + register long result; \ + \ + __asm__ __volatile__ ( \ + "mov ar.ccv = r0\n" \ + "dep r29 = -1, r0, 31, 1;;\n" \ + "cmpxchg4.acq %0 = [%1], r29, ar.ccv\n" \ + : "=r"(result) : "r"(rw) : "ar.ccv", "r29", "memory"); \ + (result == 0); \ +}) + +#else /* !ASM_SUPPORTED */ + +#define _raw_write_lock(l) \ +({ \ + __u64 ia64_val, ia64_set_val = ia64_dep_mi(-1, 0, 31, 1); \ + __u32 *ia64_write_lock_ptr = (__u32 *) (l); \ + do { \ + while (*ia64_write_lock_ptr) \ + ia64_barrier(); \ + ia64_val = ia64_cmpxchg4_acq(ia64_write_lock_ptr, ia64_set_val, 0); \ + } while (ia64_val); \ +}) + +#define _raw_write_trylock(rw) \ +({ \ + __u64 ia64_val; \ + __u64 ia64_set_val = ia64_dep_mi(-1, 0, 31,1); \ + ia64_val = ia64_cmpxchg4_acq((__u32 *)(rw), ia64_set_val, 0); \ + (ia64_val == 0); \ +}) + +#endif /* !ASM_SUPPORTED */ + +#define _raw_read_trylock(lock) generic_raw_read_trylock(lock) + +#define _raw_write_unlock(x) \ +({ \ + smp_mb__before_clear_bit(); /* need barrier before releasing lock... */ \ + clear_bit(31, (x)); \ +}) + +#endif /* _ASM_IA64_SPINLOCK_H */ |