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| 1 | +/* SPDX-License-Identifier: GPL-2.0-or-later */ |
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| 1 | 2 | #ifndef __ASM_SPINLOCK_H |
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| 2 | 3 | #define __ASM_SPINLOCK_H |
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| 3 | 4 | #ifdef __KERNEL__ |
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| 4 | 5 | |
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| 5 | | -/* |
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| 6 | | - * Simple spin lock operations. |
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| 7 | | - * |
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| 8 | | - * Copyright (C) 2001-2004 Paul Mackerras <paulus@au.ibm.com>, IBM |
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| 9 | | - * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM |
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| 10 | | - * Copyright (C) 2002 Dave Engebretsen <engebret@us.ibm.com>, IBM |
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| 11 | | - * Rework to support virtual processors |
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| 12 | | - * |
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| 13 | | - * Type of int is used as a full 64b word is not necessary. |
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| 14 | | - * |
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| 15 | | - * This program is free software; you can redistribute it and/or |
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| 16 | | - * modify it under the terms of the GNU General Public License |
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| 17 | | - * as published by the Free Software Foundation; either version |
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| 18 | | - * 2 of the License, or (at your option) any later version. |
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| 19 | | - * |
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| 20 | | - * (the type definitions are in asm/spinlock_types.h) |
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| 21 | | - */ |
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| 22 | | -#include <linux/jump_label.h> |
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| 23 | | -#include <linux/irqflags.h> |
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| 24 | | -#ifdef CONFIG_PPC64 |
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| 25 | | -#include <asm/paca.h> |
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| 26 | | -#include <asm/hvcall.h> |
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| 27 | | -#endif |
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| 28 | | -#include <asm/synch.h> |
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| 29 | | -#include <asm/ppc-opcode.h> |
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| 30 | | -#include <asm/asm-405.h> |
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| 31 | | - |
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| 32 | | -#ifdef CONFIG_PPC64 |
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| 33 | | -/* use 0x800000yy when locked, where yy == CPU number */ |
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| 34 | | -#ifdef __BIG_ENDIAN__ |
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| 35 | | -#define LOCK_TOKEN (*(u32 *)(&get_paca()->lock_token)) |
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| 6 | +#ifdef CONFIG_PPC_QUEUED_SPINLOCKS |
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| 7 | +#include <asm/qspinlock.h> |
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| 8 | +#include <asm/qrwlock.h> |
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| 36 | 9 | #else |
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| 37 | | -#define LOCK_TOKEN (*(u32 *)(&get_paca()->paca_index)) |
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| 38 | | -#endif |
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| 39 | | -#else |
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| 40 | | -#define LOCK_TOKEN 1 |
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| 10 | +#include <asm/simple_spinlock.h> |
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| 41 | 11 | #endif |
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| 42 | 12 | |
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| 43 | | -#if defined(CONFIG_PPC64) && defined(CONFIG_SMP) |
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| 44 | | -#define CLEAR_IO_SYNC (get_paca()->io_sync = 0) |
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| 45 | | -#define SYNC_IO do { \ |
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| 46 | | - if (unlikely(get_paca()->io_sync)) { \ |
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| 47 | | - mb(); \ |
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| 48 | | - get_paca()->io_sync = 0; \ |
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| 49 | | - } \ |
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| 50 | | - } while (0) |
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| 51 | | -#else |
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| 52 | | -#define CLEAR_IO_SYNC |
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| 53 | | -#define SYNC_IO |
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| 13 | +#ifndef CONFIG_PARAVIRT_SPINLOCKS |
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| 14 | +static inline void pv_spinlocks_init(void) { } |
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| 54 | 15 | #endif |
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| 55 | | - |
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| 56 | | -#ifdef CONFIG_PPC_PSERIES |
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| 57 | | -DECLARE_STATIC_KEY_FALSE(shared_processor); |
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| 58 | | - |
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| 59 | | -#define vcpu_is_preempted vcpu_is_preempted |
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| 60 | | -static inline bool vcpu_is_preempted(int cpu) |
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| 61 | | -{ |
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| 62 | | - if (!static_branch_unlikely(&shared_processor)) |
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| 63 | | - return false; |
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| 64 | | - return !!(be32_to_cpu(lppaca_of(cpu).yield_count) & 1); |
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| 65 | | -} |
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| 66 | | -#endif |
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| 67 | | - |
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| 68 | | -static __always_inline int arch_spin_value_unlocked(arch_spinlock_t lock) |
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| 69 | | -{ |
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| 70 | | - return lock.slock == 0; |
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| 71 | | -} |
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| 72 | | - |
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| 73 | | -static inline int arch_spin_is_locked(arch_spinlock_t *lock) |
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| 74 | | -{ |
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| 75 | | - smp_mb(); |
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| 76 | | - return !arch_spin_value_unlocked(*lock); |
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| 77 | | -} |
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| 78 | | - |
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| 79 | | -/* |
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| 80 | | - * This returns the old value in the lock, so we succeeded |
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| 81 | | - * in getting the lock if the return value is 0. |
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| 82 | | - */ |
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| 83 | | -static inline unsigned long __arch_spin_trylock(arch_spinlock_t *lock) |
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| 84 | | -{ |
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| 85 | | - unsigned long tmp, token; |
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| 86 | | - |
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| 87 | | - token = LOCK_TOKEN; |
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| 88 | | - __asm__ __volatile__( |
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| 89 | | -"1: " PPC_LWARX(%0,0,%2,1) "\n\ |
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| 90 | | - cmpwi 0,%0,0\n\ |
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| 91 | | - bne- 2f\n\ |
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| 92 | | - stwcx. %1,0,%2\n\ |
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| 93 | | - bne- 1b\n" |
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| 94 | | - PPC_ACQUIRE_BARRIER |
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| 95 | | -"2:" |
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| 96 | | - : "=&r" (tmp) |
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| 97 | | - : "r" (token), "r" (&lock->slock) |
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| 98 | | - : "cr0", "memory"); |
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| 99 | | - |
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| 100 | | - return tmp; |
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| 101 | | -} |
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| 102 | | - |
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| 103 | | -static inline int arch_spin_trylock(arch_spinlock_t *lock) |
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| 104 | | -{ |
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| 105 | | - CLEAR_IO_SYNC; |
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| 106 | | - return __arch_spin_trylock(lock) == 0; |
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| 107 | | -} |
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| 108 | | - |
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| 109 | | -/* |
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| 110 | | - * On a system with shared processors (that is, where a physical |
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| 111 | | - * processor is multiplexed between several virtual processors), |
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| 112 | | - * there is no point spinning on a lock if the holder of the lock |
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| 113 | | - * isn't currently scheduled on a physical processor. Instead |
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| 114 | | - * we detect this situation and ask the hypervisor to give the |
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| 115 | | - * rest of our timeslice to the lock holder. |
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| 116 | | - * |
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| 117 | | - * So that we can tell which virtual processor is holding a lock, |
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| 118 | | - * we put 0x80000000 | smp_processor_id() in the lock when it is |
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| 119 | | - * held. Conveniently, we have a word in the paca that holds this |
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| 120 | | - * value. |
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| 121 | | - */ |
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| 122 | | - |
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| 123 | | -#if defined(CONFIG_PPC_SPLPAR) |
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| 124 | | -/* We only yield to the hypervisor if we are in shared processor mode */ |
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| 125 | | -#define SHARED_PROCESSOR (lppaca_shared_proc(local_paca->lppaca_ptr)) |
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| 126 | | -extern void __spin_yield(arch_spinlock_t *lock); |
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| 127 | | -extern void __rw_yield(arch_rwlock_t *lock); |
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| 128 | | -#else /* SPLPAR */ |
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| 129 | | -#define __spin_yield(x) barrier() |
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| 130 | | -#define __rw_yield(x) barrier() |
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| 131 | | -#define SHARED_PROCESSOR 0 |
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| 132 | | -#endif |
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| 133 | | - |
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| 134 | | -static inline void arch_spin_lock(arch_spinlock_t *lock) |
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| 135 | | -{ |
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| 136 | | - CLEAR_IO_SYNC; |
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| 137 | | - while (1) { |
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| 138 | | - if (likely(__arch_spin_trylock(lock) == 0)) |
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| 139 | | - break; |
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| 140 | | - do { |
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| 141 | | - HMT_low(); |
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| 142 | | - if (SHARED_PROCESSOR) |
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| 143 | | - __spin_yield(lock); |
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| 144 | | - } while (unlikely(lock->slock != 0)); |
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| 145 | | - HMT_medium(); |
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| 146 | | - } |
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| 147 | | -} |
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| 148 | | - |
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| 149 | | -static inline |
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| 150 | | -void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) |
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| 151 | | -{ |
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| 152 | | - unsigned long flags_dis; |
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| 153 | | - |
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| 154 | | - CLEAR_IO_SYNC; |
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| 155 | | - while (1) { |
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| 156 | | - if (likely(__arch_spin_trylock(lock) == 0)) |
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| 157 | | - break; |
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| 158 | | - local_save_flags(flags_dis); |
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| 159 | | - local_irq_restore(flags); |
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| 160 | | - do { |
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| 161 | | - HMT_low(); |
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| 162 | | - if (SHARED_PROCESSOR) |
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| 163 | | - __spin_yield(lock); |
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| 164 | | - } while (unlikely(lock->slock != 0)); |
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| 165 | | - HMT_medium(); |
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| 166 | | - local_irq_restore(flags_dis); |
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| 167 | | - } |
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| 168 | | -} |
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| 169 | | -#define arch_spin_lock_flags arch_spin_lock_flags |
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| 170 | | - |
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| 171 | | -static inline void arch_spin_unlock(arch_spinlock_t *lock) |
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| 172 | | -{ |
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| 173 | | - SYNC_IO; |
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| 174 | | - __asm__ __volatile__("# arch_spin_unlock\n\t" |
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| 175 | | - PPC_RELEASE_BARRIER: : :"memory"); |
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| 176 | | - lock->slock = 0; |
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| 177 | | -} |
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| 178 | | - |
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| 179 | | -/* |
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| 180 | | - * Read-write spinlocks, allowing multiple readers |
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| 181 | | - * but only one writer. |
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| 182 | | - * |
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| 183 | | - * NOTE! it is quite common to have readers in interrupts |
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| 184 | | - * but no interrupt writers. For those circumstances we |
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| 185 | | - * can "mix" irq-safe locks - any writer needs to get a |
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| 186 | | - * irq-safe write-lock, but readers can get non-irqsafe |
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| 187 | | - * read-locks. |
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| 188 | | - */ |
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| 189 | | - |
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| 190 | | -#ifdef CONFIG_PPC64 |
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| 191 | | -#define __DO_SIGN_EXTEND "extsw %0,%0\n" |
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| 192 | | -#define WRLOCK_TOKEN LOCK_TOKEN /* it's negative */ |
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| 193 | | -#else |
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| 194 | | -#define __DO_SIGN_EXTEND |
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| 195 | | -#define WRLOCK_TOKEN (-1) |
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| 196 | | -#endif |
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| 197 | | - |
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| 198 | | -/* |
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| 199 | | - * This returns the old value in the lock + 1, |
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| 200 | | - * so we got a read lock if the return value is > 0. |
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| 201 | | - */ |
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| 202 | | -static inline long __arch_read_trylock(arch_rwlock_t *rw) |
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| 203 | | -{ |
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| 204 | | - long tmp; |
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| 205 | | - |
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| 206 | | - __asm__ __volatile__( |
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| 207 | | -"1: " PPC_LWARX(%0,0,%1,1) "\n" |
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| 208 | | - __DO_SIGN_EXTEND |
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| 209 | | -" addic. %0,%0,1\n\ |
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| 210 | | - ble- 2f\n" |
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| 211 | | - PPC405_ERR77(0,%1) |
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| 212 | | -" stwcx. %0,0,%1\n\ |
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| 213 | | - bne- 1b\n" |
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| 214 | | - PPC_ACQUIRE_BARRIER |
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| 215 | | -"2:" : "=&r" (tmp) |
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| 216 | | - : "r" (&rw->lock) |
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| 217 | | - : "cr0", "xer", "memory"); |
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| 218 | | - |
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| 219 | | - return tmp; |
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| 220 | | -} |
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| 221 | | - |
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| 222 | | -/* |
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| 223 | | - * This returns the old value in the lock, |
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| 224 | | - * so we got the write lock if the return value is 0. |
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| 225 | | - */ |
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| 226 | | -static inline long __arch_write_trylock(arch_rwlock_t *rw) |
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| 227 | | -{ |
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| 228 | | - long tmp, token; |
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| 229 | | - |
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| 230 | | - token = WRLOCK_TOKEN; |
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| 231 | | - __asm__ __volatile__( |
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| 232 | | -"1: " PPC_LWARX(%0,0,%2,1) "\n\ |
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| 233 | | - cmpwi 0,%0,0\n\ |
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| 234 | | - bne- 2f\n" |
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| 235 | | - PPC405_ERR77(0,%1) |
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| 236 | | -" stwcx. %1,0,%2\n\ |
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| 237 | | - bne- 1b\n" |
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| 238 | | - PPC_ACQUIRE_BARRIER |
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| 239 | | -"2:" : "=&r" (tmp) |
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| 240 | | - : "r" (token), "r" (&rw->lock) |
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| 241 | | - : "cr0", "memory"); |
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| 242 | | - |
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| 243 | | - return tmp; |
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| 244 | | -} |
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| 245 | | - |
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| 246 | | -static inline void arch_read_lock(arch_rwlock_t *rw) |
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| 247 | | -{ |
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| 248 | | - while (1) { |
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| 249 | | - if (likely(__arch_read_trylock(rw) > 0)) |
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| 250 | | - break; |
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| 251 | | - do { |
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| 252 | | - HMT_low(); |
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| 253 | | - if (SHARED_PROCESSOR) |
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| 254 | | - __rw_yield(rw); |
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| 255 | | - } while (unlikely(rw->lock < 0)); |
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| 256 | | - HMT_medium(); |
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| 257 | | - } |
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| 258 | | -} |
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| 259 | | - |
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| 260 | | -static inline void arch_write_lock(arch_rwlock_t *rw) |
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| 261 | | -{ |
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| 262 | | - while (1) { |
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| 263 | | - if (likely(__arch_write_trylock(rw) == 0)) |
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| 264 | | - break; |
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| 265 | | - do { |
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| 266 | | - HMT_low(); |
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| 267 | | - if (SHARED_PROCESSOR) |
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| 268 | | - __rw_yield(rw); |
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| 269 | | - } while (unlikely(rw->lock != 0)); |
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| 270 | | - HMT_medium(); |
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| 271 | | - } |
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| 272 | | -} |
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| 273 | | - |
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| 274 | | -static inline int arch_read_trylock(arch_rwlock_t *rw) |
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| 275 | | -{ |
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| 276 | | - return __arch_read_trylock(rw) > 0; |
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| 277 | | -} |
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| 278 | | - |
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| 279 | | -static inline int arch_write_trylock(arch_rwlock_t *rw) |
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| 280 | | -{ |
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| 281 | | - return __arch_write_trylock(rw) == 0; |
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| 282 | | -} |
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| 283 | | - |
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| 284 | | -static inline void arch_read_unlock(arch_rwlock_t *rw) |
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| 285 | | -{ |
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| 286 | | - long tmp; |
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| 287 | | - |
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| 288 | | - __asm__ __volatile__( |
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| 289 | | - "# read_unlock\n\t" |
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| 290 | | - PPC_RELEASE_BARRIER |
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| 291 | | -"1: lwarx %0,0,%1\n\ |
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| 292 | | - addic %0,%0,-1\n" |
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| 293 | | - PPC405_ERR77(0,%1) |
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| 294 | | -" stwcx. %0,0,%1\n\ |
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| 295 | | - bne- 1b" |
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| 296 | | - : "=&r"(tmp) |
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| 297 | | - : "r"(&rw->lock) |
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| 298 | | - : "cr0", "xer", "memory"); |
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| 299 | | -} |
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| 300 | | - |
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| 301 | | -static inline void arch_write_unlock(arch_rwlock_t *rw) |
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| 302 | | -{ |
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| 303 | | - __asm__ __volatile__("# write_unlock\n\t" |
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| 304 | | - PPC_RELEASE_BARRIER: : :"memory"); |
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| 305 | | - rw->lock = 0; |
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| 306 | | -} |
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| 307 | | - |
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| 308 | | -#define arch_spin_relax(lock) __spin_yield(lock) |
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| 309 | | -#define arch_read_relax(lock) __rw_yield(lock) |
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| 310 | | -#define arch_write_relax(lock) __rw_yield(lock) |
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| 311 | | - |
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| 312 | | -/* See include/linux/spinlock.h */ |
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| 313 | | -#define smp_mb__after_spinlock() smp_mb() |
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| 314 | 16 | |
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| 315 | 17 | #endif /* __KERNEL__ */ |
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| 316 | 18 | #endif /* __ASM_SPINLOCK_H */ |
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