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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 21:48:02 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-12 21:48:02 +0300
commit6cdf89b1ca803b2d2d097466516431b1fc5bf985 (patch)
tree37c980180dcfdfbed004ae079c7da0fd58b8ecf4 /arch/x86/include/asm/mutex_64.h
parent3940cf0b3d3c6c5817bb86f61a02277cd33f953a (diff)
parent11f254dbb3a2e3f0d8552d0dd37f4faa432b6b16 (diff)
downloadlinux-6cdf89b1ca803b2d2d097466516431b1fc5bf985.tar.xz
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar: "The tree got pretty big in this development cycle, but the net effect is pretty good: 115 files changed, 673 insertions(+), 1522 deletions(-) The main changes were: - Rework and generalize the mutex code to remove per arch mutex primitives. (Peter Zijlstra) - Add vCPU preemption support: add an interface to query the preemption status of vCPUs and use it in locking primitives - this optimizes paravirt performance. (Pan Xinhui, Juergen Gross, Christian Borntraeger) - Introduce cpu_relax_yield() and remov cpu_relax_lowlatency() to clean up and improve the s390 lock yielding machinery and its core kernel impact. (Christian Borntraeger) - Micro-optimize mutexes some more. (Waiman Long) - Reluctantly add the to-be-deprecated mutex_trylock_recursive() interface on a temporary basis, to give the DRM code more time to get rid of its locking hacks. Any other users will be NAK-ed on sight. (We turned off the deprecation warning for the time being to not pollute the build log.) (Peter Zijlstra) - Improve the rtmutex code a bit, in light of recent long lived bugs/races. (Thomas Gleixner) - Misc fixes, cleanups" * 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits) x86/paravirt: Fix bool return type for PVOP_CALL() x86/paravirt: Fix native_patch() locking/ww_mutex: Use relaxed atomics locking/rtmutex: Explain locking rules for rt_mutex_proxy_unlock()/init_proxy_locked() locking/rtmutex: Get rid of RT_MUTEX_OWNER_MASKALL x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted() locking/mutex: Break out of expensive busy-loop on {mutex,rwsem}_spin_on_owner() when owner vCPU is preempted locking/osq: Break out of spin-wait busy waiting loop for a preempted vCPU in osq_lock() Documentation/virtual/kvm: Support the vCPU preemption check x86/xen: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check x86/kvm: Support the vCPU preemption check kvm: Introduce kvm_write_guest_offset_cached() locking/core, x86/paravirt: Implement vcpu_is_preempted(cpu) for KVM and Xen guests locking/spinlocks, s390: Implement vcpu_is_preempted(cpu) locking/core, powerpc: Implement vcpu_is_preempted(cpu) sched/core: Introduce the vcpu_is_preempted(cpu) interface sched/wake_q: Rename WAKE_Q to DEFINE_WAKE_Q locking/core: Provide common cpu_relax_yield() definition locking/mutex: Don't mark mutex_trylock_recursive() as deprecated, temporarily ...
Diffstat (limited to 'arch/x86/include/asm/mutex_64.h')
-rw-r--r--arch/x86/include/asm/mutex_64.h127
1 files changed, 0 insertions, 127 deletions
diff --git a/arch/x86/include/asm/mutex_64.h b/arch/x86/include/asm/mutex_64.h
deleted file mode 100644
index d9850758464e..000000000000
--- a/arch/x86/include/asm/mutex_64.h
+++ /dev/null
@@ -1,127 +0,0 @@
-/*
- * Assembly implementation of the mutex fastpath, based on atomic
- * decrement/increment.
- *
- * started by Ingo Molnar:
- *
- * Copyright (C) 2004, 2005, 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- */
-#ifndef _ASM_X86_MUTEX_64_H
-#define _ASM_X86_MUTEX_64_H
-
-/**
- * __mutex_fastpath_lock - decrement and call function if negative
- * @v: pointer of type atomic_t
- * @fail_fn: function to call if the result is negative
- *
- * Atomically decrements @v and calls <fail_fn> if the result is negative.
- */
-#ifdef CC_HAVE_ASM_GOTO
-static inline void __mutex_fastpath_lock(atomic_t *v,
- void (*fail_fn)(atomic_t *))
-{
- asm_volatile_goto(LOCK_PREFIX " decl %0\n"
- " jns %l[exit]\n"
- : : "m" (v->counter)
- : "memory", "cc"
- : exit);
- fail_fn(v);
-exit:
- return;
-}
-#else
-#define __mutex_fastpath_lock(v, fail_fn) \
-do { \
- unsigned long dummy; \
- \
- typecheck(atomic_t *, v); \
- typecheck_fn(void (*)(atomic_t *), fail_fn); \
- \
- asm volatile(LOCK_PREFIX " decl (%%rdi)\n" \
- " jns 1f \n" \
- " call " #fail_fn "\n" \
- "1:" \
- : "=D" (dummy) \
- : "D" (v) \
- : "rax", "rsi", "rdx", "rcx", \
- "r8", "r9", "r10", "r11", "memory"); \
-} while (0)
-#endif
-
-/**
- * __mutex_fastpath_lock_retval - try to take the lock by moving the count
- * from 1 to a 0 value
- * @count: pointer of type atomic_t
- *
- * Change the count from 1 to a value lower than 1. This function returns 0
- * if the fastpath succeeds, or -1 otherwise.
- */
-static inline int __mutex_fastpath_lock_retval(atomic_t *count)
-{
- if (unlikely(atomic_dec_return(count) < 0))
- return -1;
- else
- return 0;
-}
-
-/**
- * __mutex_fastpath_unlock - increment and call function if nonpositive
- * @v: pointer of type atomic_t
- * @fail_fn: function to call if the result is nonpositive
- *
- * Atomically increments @v and calls <fail_fn> if the result is nonpositive.
- */
-#ifdef CC_HAVE_ASM_GOTO
-static inline void __mutex_fastpath_unlock(atomic_t *v,
- void (*fail_fn)(atomic_t *))
-{
- asm_volatile_goto(LOCK_PREFIX " incl %0\n"
- " jg %l[exit]\n"
- : : "m" (v->counter)
- : "memory", "cc"
- : exit);
- fail_fn(v);
-exit:
- return;
-}
-#else
-#define __mutex_fastpath_unlock(v, fail_fn) \
-do { \
- unsigned long dummy; \
- \
- typecheck(atomic_t *, v); \
- typecheck_fn(void (*)(atomic_t *), fail_fn); \
- \
- asm volatile(LOCK_PREFIX " incl (%%rdi)\n" \
- " jg 1f\n" \
- " call " #fail_fn "\n" \
- "1:" \
- : "=D" (dummy) \
- : "D" (v) \
- : "rax", "rsi", "rdx", "rcx", \
- "r8", "r9", "r10", "r11", "memory"); \
-} while (0)
-#endif
-
-#define __mutex_slowpath_needs_to_unlock() 1
-
-/**
- * __mutex_fastpath_trylock - try to acquire the mutex, without waiting
- *
- * @count: pointer of type atomic_t
- * @fail_fn: fallback function
- *
- * Change the count from 1 to 0 and return 1 (success), or return 0 (failure)
- * if it wasn't 1 originally. [the fallback function is never used on
- * x86_64, because all x86_64 CPUs have a CMPXCHG instruction.]
- */
-static inline int __mutex_fastpath_trylock(atomic_t *count,
- int (*fail_fn)(atomic_t *))
-{
- if (likely(atomic_read(count) == 1 && atomic_cmpxchg(count, 1, 0) == 1))
- return 1;
-
- return 0;
-}
-
-#endif /* _ASM_X86_MUTEX_64_H */