forked from Minki/linux
cfd8983f03
We've unconditionally used the queued spinlock for many releases now. Its time to remove the old ticket lock code. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <waiman.long@hpe.com> Cc: Waiman.Long@hpe.com Cc: david.vrabel@citrix.com Cc: dhowells@redhat.com Cc: pbonzini@redhat.com Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/20160518184302.GO3193@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
#ifndef _ASM_X86_SPINLOCK_H
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#define _ASM_X86_SPINLOCK_H
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#include <linux/jump_label.h>
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#include <linux/atomic.h>
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#include <asm/page.h>
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#include <asm/processor.h>
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#include <linux/compiler.h>
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#include <asm/paravirt.h>
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#include <asm/bitops.h>
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/*
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* Your basic SMP spinlocks, allowing only a single CPU anywhere
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*
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* Simple spin lock operations. There are two variants, one clears IRQ's
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* on the local processor, one does not.
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*
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* These are fair FIFO ticket locks, which support up to 2^16 CPUs.
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*
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* (the type definitions are in asm/spinlock_types.h)
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*/
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/* How long a lock should spin before we consider blocking */
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#define SPIN_THRESHOLD (1 << 15)
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extern struct static_key paravirt_ticketlocks_enabled;
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static __always_inline bool static_key_false(struct static_key *key);
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#include <asm/qspinlock.h>
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/*
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* Read-write spinlocks, allowing multiple readers
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* but only one writer.
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*
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* NOTE! it is quite common to have readers in interrupts
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* but no interrupt writers. For those circumstances we
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* can "mix" irq-safe locks - any writer needs to get a
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* irq-safe write-lock, but readers can get non-irqsafe
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* read-locks.
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*
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* On x86, we implement read-write locks using the generic qrwlock with
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* x86 specific optimization.
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*/
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#include <asm/qrwlock.h>
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#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
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#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
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#define arch_spin_relax(lock) cpu_relax()
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#define arch_read_relax(lock) cpu_relax()
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#define arch_write_relax(lock) cpu_relax()
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#endif /* _ASM_X86_SPINLOCK_H */
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