/* MN10300 spinlock support * * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public Licence * as published by the Free Software Foundation; either version * 2 of the Licence, or (at your option) any later version. */ #ifndef _ASM_SPINLOCK_H #define _ASM_SPINLOCK_H #include <linux/atomic.h> #include <asm/barrier.h> #include <asm/processor.h> #include <asm/rwlock.h> #include <asm/page.h> /* * Simple spin lock operations. There are two variants, one clears IRQ's * on the local processor, one does not. * * We make no fairness assumptions. They have a cost. */ #define arch_spin_is_locked(x) (*(volatile signed char *)(&(x)->slock) != 0) static inline void arch_spin_unlock(arch_spinlock_t *lock) { asm volatile( " bclr 1,(0,%0) \n" : : "a"(&lock->slock) : "memory", "cc"); } static inline int arch_spin_trylock(arch_spinlock_t *lock) { int ret; asm volatile( " mov 1,%0 \n" " bset %0,(%1) \n" " bne 1f \n" " clr %0 \n" "1: xor 1,%0 \n" : "=d"(ret) : "a"(&lock->slock) : "memory", "cc"); return ret; } static inline void arch_spin_lock(arch_spinlock_t *lock) { asm volatile( "1: bset 1,(0,%0) \n" " bne 1b \n" : : "a"(&lock->slock) : "memory", "cc"); } static inline void arch_spin_lock_flags(arch_spinlock_t *lock, unsigned long flags) { int temp; asm volatile( "1: bset 1,(0,%2) \n" " beq 3f \n" " mov %1,epsw \n" "2: mov (0,%2),%0 \n" " or %0,%0 \n" " bne 2b \n" " mov %3,%0 \n" " mov %0,epsw \n" " nop \n" " nop \n" " bra 1b\n" "3: \n" : "=&d" (temp) : "d" (flags), "a"(&lock->slock), "i"(EPSW_IE | MN10300_CLI_LEVEL) : "memory", "cc"); } #define arch_spin_lock_flags arch_spin_lock_flags #ifdef __KERNEL__ /* * Read-write spinlocks, allowing multiple readers * but only one writer. * * NOTE! it is quite common to have readers in interrupts * but no interrupt writers. For those circumstances we * can "mix" irq-safe locks - any writer needs to get a * irq-safe write-lock, but readers can get non-irqsafe * read-locks. */ /* * On mn10300, we implement read-write locks as a 32-bit counter * with the high bit (sign) being the "contended" bit. */ static inline void arch_read_lock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_read_lock(rw, "__read_lock_failed"); #else { atomic_t *count = (atomic_t *)rw; while (atomic_dec_return(count) < 0) atomic_inc(count); } #endif } static inline void arch_write_lock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_write_lock(rw, "__write_lock_failed"); #else { atomic_t *count = (atomic_t *)rw; while (!atomic_sub_and_test(RW_LOCK_BIAS, count)) atomic_add(RW_LOCK_BIAS, count); } #endif } static inline void arch_read_unlock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_read_unlock(rw); #else { atomic_t *count = (atomic_t *)rw; atomic_inc(count); } #endif } static inline void arch_write_unlock(arch_rwlock_t *rw) { #if 0 //def CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT __build_write_unlock(rw); #else { atomic_t *count = (atomic_t *)rw; atomic_add(RW_LOCK_BIAS, count); } #endif } static inline int arch_read_trylock(arch_rwlock_t *lock) { atomic_t *count = (atomic_t *)lock; atomic_dec(count); if (atomic_read(count) >= 0) return 1; atomic_inc(count); return 0; } static inline int arch_write_trylock(arch_rwlock_t *lock) { atomic_t *count = (atomic_t *)lock; if (atomic_sub_and_test(RW_LOCK_BIAS, count)) return 1; atomic_add(RW_LOCK_BIAS, count); return 0; } #define _raw_spin_relax(lock) cpu_relax() #define _raw_read_relax(lock) cpu_relax() #define _raw_write_relax(lock) cpu_relax() #endif /* __KERNEL__ */ #endif /* _ASM_SPINLOCK_H */
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asm-offsets.h | File | 35 B | 0644 |
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atomic.h | File | 4.02 KB | 0644 |
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bitops.h | File | 5.42 KB | 0644 |
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bug.h | File | 864 B | 0644 |
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bugs.h | File | 561 B | 0644 |
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busctl-regs.h | File | 7.8 KB | 0644 |
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cacheflush.h | File | 7.6 KB | 0644 |
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checksum.h | File | 2.09 KB | 0644 |
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cmpxchg.h | File | 2.65 KB | 0644 |
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cpu-regs.h | File | 16.61 KB | 0644 |
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current.h | File | 922 B | 0644 |
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debugger.h | File | 1.2 KB | 0644 |
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delay.h | File | 597 B | 0644 |
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div64.h | File | 3.21 KB | 0644 |
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dma-mapping.h | File | 636 B | 0644 |
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dma.h | File | 3.09 KB | 0644 |
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dmactl-regs.h | File | 532 B | 0644 |
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elf.h | File | 4.49 KB | 0644 |
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emergency-restart.h | File | 43 B | 0644 |
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fpu.h | File | 3.57 KB | 0644 |
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frame.inc | File | 2.37 KB | 0644 |
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ftrace.h | File | 12 B | 0644 |
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futex.h | File | 31 B | 0644 |
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gdb-stub.h | File | 5.42 KB | 0644 |
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hardirq.h | File | 1.68 KB | 0644 |
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highmem.h | File | 3.01 KB | 0644 |
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hw_irq.h | File | 483 B | 0644 |
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intctl-regs.h | File | 2.26 KB | 0644 |
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io.h | File | 7.67 KB | 0644 |
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irq.h | File | 1.11 KB | 0644 |
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irq_regs.h | File | 751 B | 0644 |
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irqflags.h | File | 4.05 KB | 0644 |
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kdebug.h | File | 561 B | 0644 |
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kgdb.h | File | 1.7 KB | 0644 |
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kmap_types.h | File | 160 B | 0644 |
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kprobes.h | File | 1.59 KB | 0644 |
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linkage.h | File | 593 B | 0644 |
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local.h | File | 31 B | 0644 |
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local64.h | File | 33 B | 0644 |
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mc146818rtc.h | File | 26 B | 0644 |
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mmu.h | File | 434 B | 0644 |
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mmu_context.h | File | 4.44 KB | 0644 |
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module.h | File | 677 B | 0644 |
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nmi.h | File | 500 B | 0644 |
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page.h | File | 3.63 KB | 0644 |
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page_offset.h | File | 302 B | 0644 |
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pci.h | File | 2.17 KB | 0644 |
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percpu.h | File | 32 B | 0644 |
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pgalloc.h | File | 1.49 KB | 0644 |
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pgtable.h | File | 15.68 KB | 0644 |
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pio-regs.h | File | 7.53 KB | 0644 |
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processor.h | File | 4.12 KB | 0644 |
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ptrace.h | File | 805 B | 0644 |
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reset-regs.h | File | 1.8 KB | 0644 |
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rtc-regs.h | File | 3.57 KB | 0644 |
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rtc.h | File | 692 B | 0644 |
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rwlock.h | File | 2.98 KB | 0644 |
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serial-regs.h | File | 8.85 KB | 0644 |
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serial.h | File | 1.02 KB | 0644 |
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setup.h | File | 574 B | 0644 |
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shmparam.h | File | 182 B | 0644 |
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signal.h | File | 888 B | 0644 |
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smp.h | File | 3.06 KB | 0644 |
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smsc911x.h | File | 27 B | 0644 |
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spinlock.h | File | 3.84 KB | 0644 |
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spinlock_types.h | File | 445 B | 0644 |
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string.h | File | 1.03 KB | 0644 |
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switch_to.h | File | 1.49 KB | 0644 |
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syscall.h | File | 2.38 KB | 0644 |
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termios.h | File | 387 B | 0644 |
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thread_info.h | File | 4.36 KB | 0644 |
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timer-regs.h | File | 20.72 KB | 0644 |
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timex.h | File | 843 B | 0644 |
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tlb.h | File | 941 B | 0644 |
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tlbflush.h | File | 3.45 KB | 0644 |
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topology.h | File | 34 B | 0644 |
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types.h | File | 620 B | 0644 |
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uaccess.h | File | 7.78 KB | 0644 |
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ucontext.h | File | 673 B | 0644 |
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unaligned.h | File | 678 B | 0644 |
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unistd.h | File | 1.34 KB | 0644 |
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user.h | File | 1.91 KB | 0644 |
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