/* * Copyright (C) 2015 Regents of the University of California * Copyright (C) 2017 SiFive * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, version 2. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #ifndef _ASM_RISCV_SPINLOCK_H #define _ASM_RISCV_SPINLOCK_H #include <linux/kernel.h> #include <asm/current.h> #include <asm/fence.h> /* * Simple spin lock operations. These provide no fairness guarantees. */ /* FIXME: Replace this with a ticket lock, like MIPS. */ #define arch_spin_is_locked(x) (READ_ONCE((x)->lock) != 0) static inline void arch_spin_unlock(arch_spinlock_t *lock) { smp_store_release(&lock->lock, 0); } static inline int arch_spin_trylock(arch_spinlock_t *lock) { int tmp = 1, busy; __asm__ __volatile__ ( " amoswap.w %0, %2, %1\n" RISCV_ACQUIRE_BARRIER : "=r" (busy), "+A" (lock->lock) : "r" (tmp) : "memory"); return !busy; } static inline void arch_spin_lock(arch_spinlock_t *lock) { while (1) { if (arch_spin_is_locked(lock)) continue; if (arch_spin_trylock(lock)) break; } } /***********************************************************/ static inline void arch_read_lock(arch_rwlock_t *lock) { int tmp; __asm__ __volatile__( "1: lr.w %1, %0\n" " bltz %1, 1b\n" " addi %1, %1, 1\n" " sc.w %1, %1, %0\n" " bnez %1, 1b\n" RISCV_ACQUIRE_BARRIER : "+A" (lock->lock), "=&r" (tmp) :: "memory"); } static inline void arch_write_lock(arch_rwlock_t *lock) { int tmp; __asm__ __volatile__( "1: lr.w %1, %0\n" " bnez %1, 1b\n" " li %1, -1\n" " sc.w %1, %1, %0\n" " bnez %1, 1b\n" RISCV_ACQUIRE_BARRIER : "+A" (lock->lock), "=&r" (tmp) :: "memory"); } static inline int arch_read_trylock(arch_rwlock_t *lock) { int busy; __asm__ __volatile__( "1: lr.w %1, %0\n" " bltz %1, 1f\n" " addi %1, %1, 1\n" " sc.w %1, %1, %0\n" " bnez %1, 1b\n" RISCV_ACQUIRE_BARRIER "1:\n" : "+A" (lock->lock), "=&r" (busy) :: "memory"); return !busy; } static inline int arch_write_trylock(arch_rwlock_t *lock) { int busy; __asm__ __volatile__( "1: lr.w %1, %0\n" " bnez %1, 1f\n" " li %1, -1\n" " sc.w %1, %1, %0\n" " bnez %1, 1b\n" RISCV_ACQUIRE_BARRIER "1:\n" : "+A" (lock->lock), "=&r" (busy) :: "memory"); return !busy; } static inline void arch_read_unlock(arch_rwlock_t *lock) { __asm__ __volatile__( RISCV_RELEASE_BARRIER " amoadd.w x0, %1, %0\n" : "+A" (lock->lock) : "r" (-1) : "memory"); } static inline void arch_write_unlock(arch_rwlock_t *lock) { smp_store_release(&lock->lock, 0); } #endif /* _ASM_RISCV_SPINLOCK_H */
Name | Type | Size | Permission | Actions |
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Kbuild | File | 1.37 KB | 0644 |
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asm-offsets.h | File | 35 B | 0644 |
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asm-prototypes.h | File | 176 B | 0644 |
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asm.h | File | 1.78 KB | 0644 |
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atomic.h | File | 11.31 KB | 0644 |
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barrier.h | File | 2.59 KB | 0644 |
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bitops.h | File | 6.23 KB | 0644 |
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bug.h | File | 2.12 KB | 0644 |
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cache.h | File | 745 B | 0644 |
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cacheflush.h | File | 1.7 KB | 0644 |
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cmpxchg.h | File | 3.35 KB | 0644 |
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compat.h | File | 924 B | 0644 |
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csr.h | File | 3.8 KB | 0644 |
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current.h | File | 1.27 KB | 0644 |
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delay.h | File | 881 B | 0644 |
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dma-mapping.h | File | 1.19 KB | 0644 |
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elf.h | File | 2.3 KB | 0644 |
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fence.h | File | 279 B | 0644 |
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hwcap.h | File | 1013 B | 0644 |
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io.h | File | 11.81 KB | 0644 |
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irq.h | File | 841 B | 0644 |
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irqflags.h | File | 1.54 KB | 0644 |
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kprobes.h | File | 679 B | 0644 |
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linkage.h | File | 677 B | 0644 |
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mmu.h | File | 829 B | 0644 |
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mmu_context.h | File | 3.14 KB | 0644 |
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page.h | File | 3.76 KB | 0644 |
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pci.h | File | 1.16 KB | 0644 |
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pgalloc.h | File | 3.06 KB | 0644 |
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pgtable-32.h | File | 870 B | 0644 |
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pgtable-64.h | File | 2.08 KB | 0644 |
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pgtable-bits.h | File | 1.81 KB | 0644 |
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pgtable.h | File | 11.17 KB | 0644 |
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processor.h | File | 2.44 KB | 0644 |
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ptrace.h | File | 2.69 KB | 0644 |
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sbi.h | File | 2.6 KB | 0644 |
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smp.h | File | 1.59 KB | 0644 |
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spinlock.h | File | 2.85 KB | 0644 |
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spinlock_types.h | File | 906 B | 0644 |
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string.h | File | 838 B | 0644 |
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switch_to.h | File | 1.86 KB | 0644 |
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syscall.h | File | 2.59 KB | 0644 |
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thread_info.h | File | 3.11 KB | 0644 |
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timex.h | File | 1.29 KB | 0644 |
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tlb.h | File | 717 B | 0644 |
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tlbflush.h | File | 1.83 KB | 0644 |
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uaccess.h | File | 14 KB | 0644 |
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unistd.h | File | 638 B | 0644 |
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vdso.h | File | 1.49 KB | 0644 |
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word-at-a-time.h | File | 1.48 KB | 0644 |
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