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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/alpha/include/asm/spinlock.h | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/alpha/include/asm/spinlock.h')
-rw-r--r-- | arch/alpha/include/asm/spinlock.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/spinlock.h b/arch/alpha/include/asm/spinlock.h new file mode 100644 index 000000000..1221cbb86 --- /dev/null +++ b/arch/alpha/include/asm/spinlock.h @@ -0,0 +1,163 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ALPHA_SPINLOCK_H +#define _ALPHA_SPINLOCK_H + +#include <linux/kernel.h> +#include <asm/current.h> +#include <asm/barrier.h> +#include <asm/processor.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) ((x)->lock != 0) + +static inline int arch_spin_value_unlocked(arch_spinlock_t lock) +{ + return lock.lock == 0; +} + +static inline void arch_spin_unlock(arch_spinlock_t * lock) +{ + mb(); + lock->lock = 0; +} + +static inline void arch_spin_lock(arch_spinlock_t * lock) +{ + long tmp; + + __asm__ __volatile__( + "1: ldl_l %0,%1\n" + " bne %0,2f\n" + " lda %0,1\n" + " stl_c %0,%1\n" + " beq %0,2f\n" + " mb\n" + ".subsection 2\n" + "2: ldl %0,%1\n" + " bne %0,2b\n" + " br 1b\n" + ".previous" + : "=&r" (tmp), "=m" (lock->lock) + : "m"(lock->lock) : "memory"); +} + +static inline int arch_spin_trylock(arch_spinlock_t *lock) +{ + return !test_and_set_bit(0, &lock->lock); +} + +/***********************************************************/ + +static inline void arch_read_lock(arch_rwlock_t *lock) +{ + long regx; + + __asm__ __volatile__( + "1: ldl_l %1,%0\n" + " blbs %1,6f\n" + " subl %1,2,%1\n" + " stl_c %1,%0\n" + " beq %1,6f\n" + " mb\n" + ".subsection 2\n" + "6: ldl %1,%0\n" + " blbs %1,6b\n" + " br 1b\n" + ".previous" + : "=m" (*lock), "=&r" (regx) + : "m" (*lock) : "memory"); +} + +static inline void arch_write_lock(arch_rwlock_t *lock) +{ + long regx; + + __asm__ __volatile__( + "1: ldl_l %1,%0\n" + " bne %1,6f\n" + " lda %1,1\n" + " stl_c %1,%0\n" + " beq %1,6f\n" + " mb\n" + ".subsection 2\n" + "6: ldl %1,%0\n" + " bne %1,6b\n" + " br 1b\n" + ".previous" + : "=m" (*lock), "=&r" (regx) + : "m" (*lock) : "memory"); +} + +static inline int arch_read_trylock(arch_rwlock_t * lock) +{ + long regx; + int success; + + __asm__ __volatile__( + "1: ldl_l %1,%0\n" + " lda %2,0\n" + " blbs %1,2f\n" + " subl %1,2,%2\n" + " stl_c %2,%0\n" + " beq %2,6f\n" + "2: mb\n" + ".subsection 2\n" + "6: br 1b\n" + ".previous" + : "=m" (*lock), "=&r" (regx), "=&r" (success) + : "m" (*lock) : "memory"); + + return success; +} + +static inline int arch_write_trylock(arch_rwlock_t * lock) +{ + long regx; + int success; + + __asm__ __volatile__( + "1: ldl_l %1,%0\n" + " lda %2,0\n" + " bne %1,2f\n" + " lda %2,1\n" + " stl_c %2,%0\n" + " beq %2,6f\n" + "2: mb\n" + ".subsection 2\n" + "6: br 1b\n" + ".previous" + : "=m" (*lock), "=&r" (regx), "=&r" (success) + : "m" (*lock) : "memory"); + + return success; +} + +static inline void arch_read_unlock(arch_rwlock_t * lock) +{ + long regx; + __asm__ __volatile__( + " mb\n" + "1: ldl_l %1,%0\n" + " addl %1,2,%1\n" + " stl_c %1,%0\n" + " beq %1,6f\n" + ".subsection 2\n" + "6: br 1b\n" + ".previous" + : "=m" (*lock), "=&r" (regx) + : "m" (*lock) : "memory"); +} + +static inline void arch_write_unlock(arch_rwlock_t * lock) +{ + mb(); + lock->lock = 0; +} + +#endif /* _ALPHA_SPINLOCK_H */ |