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Diffstat (limited to 'arch/ia64/include/asm/spinlock.h')
-rw-r--r-- | arch/ia64/include/asm/spinlock.h | 265 |
1 files changed, 0 insertions, 265 deletions
diff --git a/arch/ia64/include/asm/spinlock.h b/arch/ia64/include/asm/spinlock.h deleted file mode 100644 index 0e5c1ad323..0000000000 --- a/arch/ia64/include/asm/spinlock.h +++ /dev/null @@ -1,265 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#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 <linux/bitops.h> - -#include <linux/atomic.h> -#include <asm/intrinsics.h> -#include <asm/barrier.h> -#include <asm/processor.h> - -#define arch_spin_lock_init(x) ((x)->lock = 0) - -/* - * Ticket locks are conceptually two parts, one indicating the current head of - * the queue, and the other indicating the current tail. The lock is acquired - * by atomically noting the tail and incrementing it by one (thus adding - * ourself to the queue and noting our position), then waiting until the head - * becomes equal to the initial value of the tail. - * The pad bits in the middle are used to prevent the next_ticket number - * overflowing into the now_serving number. - * - * 31 17 16 15 14 0 - * +----------------------------------------------------+ - * | now_serving | padding | next_ticket | - * +----------------------------------------------------+ - */ - -#define TICKET_SHIFT 17 -#define TICKET_BITS 15 -#define TICKET_MASK ((1 << TICKET_BITS) - 1) - -static __always_inline void __ticket_spin_lock(arch_spinlock_t *lock) -{ - int *p = (int *)&lock->lock, ticket, serve; - - ticket = ia64_fetchadd(1, p, acq); - - if (!(((ticket >> TICKET_SHIFT) ^ ticket) & TICKET_MASK)) - return; - - ia64_invala(); - - for (;;) { - asm volatile ("ld4.c.nc %0=[%1]" : "=r"(serve) : "r"(p) : "memory"); - - if (!(((serve >> TICKET_SHIFT) ^ ticket) & TICKET_MASK)) - return; - cpu_relax(); - } -} - -static __always_inline int __ticket_spin_trylock(arch_spinlock_t *lock) -{ - int tmp = READ_ONCE(lock->lock); - - if (!(((tmp >> TICKET_SHIFT) ^ tmp) & TICKET_MASK)) - return ia64_cmpxchg(acq, &lock->lock, tmp, tmp + 1, sizeof (tmp)) == tmp; - return 0; -} - -static __always_inline void __ticket_spin_unlock(arch_spinlock_t *lock) -{ - unsigned short *p = (unsigned short *)&lock->lock + 1, tmp; - - /* This could be optimised with ARCH_HAS_MMIOWB */ - mmiowb(); - asm volatile ("ld2.bias %0=[%1]" : "=r"(tmp) : "r"(p)); - WRITE_ONCE(*p, (tmp + 2) & ~1); -} - -static inline int __ticket_spin_is_locked(arch_spinlock_t *lock) -{ - long tmp = READ_ONCE(lock->lock); - - return !!(((tmp >> TICKET_SHIFT) ^ tmp) & TICKET_MASK); -} - -static inline int __ticket_spin_is_contended(arch_spinlock_t *lock) -{ - long tmp = READ_ONCE(lock->lock); - - return ((tmp - (tmp >> TICKET_SHIFT)) & TICKET_MASK) > 1; -} - -static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) -{ - return !(((lock.lock >> TICKET_SHIFT) ^ lock.lock) & TICKET_MASK); -} - -static inline int arch_spin_is_locked(arch_spinlock_t *lock) -{ - return __ticket_spin_is_locked(lock); -} - -static inline int arch_spin_is_contended(arch_spinlock_t *lock) -{ - return __ticket_spin_is_contended(lock); -} -#define arch_spin_is_contended arch_spin_is_contended - -static __always_inline void arch_spin_lock(arch_spinlock_t *lock) -{ - __ticket_spin_lock(lock); -} - -static __always_inline int arch_spin_trylock(arch_spinlock_t *lock) -{ - return __ticket_spin_trylock(lock); -} - -static __always_inline void arch_spin_unlock(arch_spinlock_t *lock) -{ - __ticket_spin_unlock(lock); -} - -#ifdef ASM_SUPPORTED - -static __always_inline void -arch_read_lock(arch_rwlock_t *lock) -{ - unsigned long flags = 0; - - __asm__ __volatile__ ( - "tbit.nz p6, p0 = %1,%2\n" - "br.few 3f\n" - "1:\n" - "fetchadd4.rel r2 = [%0], -1;;\n" - "(p6) ssm psr.i\n" - "2:\n" - "hint @pause\n" - "ld4 r2 = [%0];;\n" - "cmp4.lt p7,p0 = r2, r0\n" - "(p7) br.cond.spnt.few 2b\n" - "(p6) rsm psr.i\n" - ";;\n" - "3:\n" - "fetchadd4.acq r2 = [%0], 1;;\n" - "cmp4.lt p7,p0 = r2, r0\n" - "(p7) br.cond.spnt.few 1b\n" - : : "r"(lock), "r"(flags), "i"(IA64_PSR_I_BIT) - : "p6", "p7", "r2", "memory"); -} - -#else /* !ASM_SUPPORTED */ - -#define arch_read_lock(rw) \ -do { \ - arch_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) - -#endif /* !ASM_SUPPORTED */ - -#define arch_read_unlock(rw) \ -do { \ - arch_rwlock_t *__read_lock_ptr = (rw); \ - ia64_fetchadd(-1, (int *) __read_lock_ptr, rel); \ -} while (0) - -#ifdef ASM_SUPPORTED - -static __always_inline void -arch_write_lock(arch_rwlock_t *lock) -{ - unsigned long flags = 0; - - __asm__ __volatile__ ( - "tbit.nz p6, p0 = %1, %2\n" - "mov ar.ccv = r0\n" - "dep r29 = -1, r0, 31, 1\n" - "br.few 3f;;\n" - "1:\n" - "(p6) ssm psr.i\n" - "2:\n" - "hint @pause\n" - "ld4 r2 = [%0];;\n" - "cmp4.eq p0,p7 = r0, r2\n" - "(p7) br.cond.spnt.few 2b\n" - "(p6) rsm psr.i\n" - ";;\n" - "3:\n" - "cmpxchg4.acq r2 = [%0], r29, ar.ccv;;\n" - "cmp4.eq p0,p7 = r0, r2\n" - "(p7) br.cond.spnt.few 1b;;\n" - : : "r"(lock), "r"(flags), "i"(IA64_PSR_I_BIT) - : "ar.ccv", "p6", "p7", "r2", "r29", "memory"); -} - -#define arch_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); \ -}) - -static inline void arch_write_unlock(arch_rwlock_t *x) -{ - u8 *y = (u8 *)x; - barrier(); - asm volatile ("st1.rel.nta [%0] = r0\n\t" :: "r"(y+3) : "memory" ); -} - -#else /* !ASM_SUPPORTED */ - -#define arch_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 arch_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); \ -}) - -static inline void arch_write_unlock(arch_rwlock_t *x) -{ - barrier(); - x->write_lock = 0; -} - -#endif /* !ASM_SUPPORTED */ - -static inline int arch_read_trylock(arch_rwlock_t *x) -{ - union { - arch_rwlock_t lock; - __u32 word; - } old, new; - old.lock = new.lock = *x; - old.lock.write_lock = new.lock.write_lock = 0; - ++new.lock.read_counter; - return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word; -} - -#endif /* _ASM_IA64_SPINLOCK_H */ |