bf67fd3142
This patch introduces a wfe-based polling loop for spinning on contended MCS locks and waking up corresponding waiters when the lock is released. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
23 lines
531 B
C
23 lines
531 B
C
#ifndef __ASM_MCS_LOCK_H
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#define __ASM_MCS_LOCK_H
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#ifdef CONFIG_SMP
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#include <asm/spinlock.h>
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/* MCS spin-locking. */
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#define arch_mcs_spin_lock_contended(lock) \
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do { \
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/* Ensure prior stores are observed before we enter wfe. */ \
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smp_mb(); \
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while (!(smp_load_acquire(lock))) \
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wfe(); \
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} while (0) \
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#define arch_mcs_spin_unlock_contended(lock) \
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do { \
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smp_store_release(lock, 1); \
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dsb_sev(); \
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} while (0)
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#endif /* CONFIG_SMP */
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#endif /* __ASM_MCS_LOCK_H */
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