08dbd0f8ef
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 and only version 2 as published by the free software foundation 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 you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 94 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141334.043630402@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
159 lines
3.2 KiB
C
159 lines
3.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Spinlock support for the Hexagon architecture
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*
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* Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
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*/
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#ifndef _ASM_SPINLOCK_H
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#define _ASM_SPINLOCK_H
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#include <asm/irqflags.h>
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#include <asm/barrier.h>
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#include <asm/processor.h>
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/*
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* This file is pulled in for SMP builds.
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* Really need to check all the barrier stuff for "true" SMP
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*/
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/*
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* Read locks:
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* - load the lock value
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* - increment it
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* - if the lock value is still negative, go back and try again.
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* - unsuccessful store is unsuccessful. Go back and try again. Loser.
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* - successful store new lock value if positive -> lock acquired
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*/
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static inline void arch_read_lock(arch_rwlock_t *lock)
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{
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__asm__ __volatile__(
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"1: R6 = memw_locked(%0);\n"
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" { P3 = cmp.ge(R6,#0); R6 = add(R6,#1);}\n"
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" { if !P3 jump 1b; }\n"
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" memw_locked(%0,P3) = R6;\n"
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" { if !P3 jump 1b; }\n"
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:
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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}
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static inline void arch_read_unlock(arch_rwlock_t *lock)
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{
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__asm__ __volatile__(
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"1: R6 = memw_locked(%0);\n"
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" R6 = add(R6,#-1);\n"
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" memw_locked(%0,P3) = R6\n"
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" if !P3 jump 1b;\n"
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:
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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}
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/* I think this returns 0 on fail, 1 on success. */
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static inline int arch_read_trylock(arch_rwlock_t *lock)
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{
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int temp;
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__asm__ __volatile__(
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" R6 = memw_locked(%1);\n"
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" { %0 = #0; P3 = cmp.ge(R6,#0); R6 = add(R6,#1);}\n"
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" { if !P3 jump 1f; }\n"
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" memw_locked(%1,P3) = R6;\n"
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" { %0 = P3 }\n"
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"1:\n"
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: "=&r" (temp)
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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return temp;
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}
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/* Stuffs a -1 in the lock value? */
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static inline void arch_write_lock(arch_rwlock_t *lock)
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{
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__asm__ __volatile__(
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"1: R6 = memw_locked(%0)\n"
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" { P3 = cmp.eq(R6,#0); R6 = #-1;}\n"
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" { if !P3 jump 1b; }\n"
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" memw_locked(%0,P3) = R6;\n"
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" { if !P3 jump 1b; }\n"
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:
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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}
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static inline int arch_write_trylock(arch_rwlock_t *lock)
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{
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int temp;
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__asm__ __volatile__(
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" R6 = memw_locked(%1)\n"
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" { %0 = #0; P3 = cmp.eq(R6,#0); R6 = #-1;}\n"
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" { if !P3 jump 1f; }\n"
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" memw_locked(%1,P3) = R6;\n"
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" %0 = P3;\n"
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"1:\n"
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: "=&r" (temp)
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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return temp;
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}
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static inline void arch_write_unlock(arch_rwlock_t *lock)
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{
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smp_mb();
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lock->lock = 0;
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}
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static inline void arch_spin_lock(arch_spinlock_t *lock)
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{
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__asm__ __volatile__(
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"1: R6 = memw_locked(%0);\n"
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" P3 = cmp.eq(R6,#0);\n"
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" { if !P3 jump 1b; R6 = #1; }\n"
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" memw_locked(%0,P3) = R6;\n"
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" { if !P3 jump 1b; }\n"
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:
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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}
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static inline void arch_spin_unlock(arch_spinlock_t *lock)
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{
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smp_mb();
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lock->lock = 0;
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}
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static inline unsigned int arch_spin_trylock(arch_spinlock_t *lock)
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{
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int temp;
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__asm__ __volatile__(
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" R6 = memw_locked(%1);\n"
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" P3 = cmp.eq(R6,#0);\n"
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" { if !P3 jump 1f; R6 = #1; %0 = #0; }\n"
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" memw_locked(%1,P3) = R6;\n"
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" %0 = P3;\n"
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"1:\n"
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: "=&r" (temp)
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: "r" (&lock->lock)
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: "memory", "r6", "p3"
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);
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return temp;
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}
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/*
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* SMP spinlocks are intended to allow only a single CPU at the lock
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*/
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#define arch_spin_is_locked(x) ((x)->lock != 0)
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#endif
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