fb1c8f93d8
This patch (written by me and also containing many suggestions of Arjan van de Ven) does a major cleanup of the spinlock code. It does the following things: - consolidates and enhances the spinlock/rwlock debugging code - simplifies the asm/spinlock.h files - encapsulates the raw spinlock type and moves generic spinlock features (such as ->break_lock) into the generic code. - cleans up the spinlock code hierarchy to get rid of the spaghetti. Most notably there's now only a single variant of the debugging code, located in lib/spinlock_debug.c. (previously we had one SMP debugging variant per architecture, plus a separate generic one for UP builds) Also, i've enhanced the rwlock debugging facility, it will now track write-owners. There is new spinlock-owner/CPU-tracking on SMP builds too. All locks have lockup detection now, which will work for both soft and hard spin/rwlock lockups. The arch-level include files now only contain the minimally necessary subset of the spinlock code - all the rest that can be generalized now lives in the generic headers: include/asm-i386/spinlock_types.h | 16 include/asm-x86_64/spinlock_types.h | 16 I have also split up the various spinlock variants into separate files, making it easier to see which does what. The new layout is: SMP | UP ----------------------------|----------------------------------- asm/spinlock_types_smp.h | linux/spinlock_types_up.h linux/spinlock_types.h | linux/spinlock_types.h asm/spinlock_smp.h | linux/spinlock_up.h linux/spinlock_api_smp.h | linux/spinlock_api_up.h linux/spinlock.h | linux/spinlock.h /* * here's the role of the various spinlock/rwlock related include files: * * on SMP builds: * * asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the * initializers * * linux/spinlock_types.h: * defines the generic type and initializers * * asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel * implementations, mostly inline assembly code * * (also included on UP-debug builds:) * * linux/spinlock_api_smp.h: * contains the prototypes for the _spin_*() APIs. * * linux/spinlock.h: builds the final spin_*() APIs. * * on UP builds: * * linux/spinlock_type_up.h: * contains the generic, simplified UP spinlock type. * (which is an empty structure on non-debug builds) * * linux/spinlock_types.h: * defines the generic type and initializers * * linux/spinlock_up.h: * contains the __raw_spin_*()/etc. version of UP * builds. (which are NOPs on non-debug, non-preempt * builds) * * (included on UP-non-debug builds:) * * linux/spinlock_api_up.h: * builds the _spin_*() APIs. * * linux/spinlock.h: builds the final spin_*() APIs. */ All SMP and UP architectures are converted by this patch. arm, i386, ia64, ppc, ppc64, s390/s390x, x64 was build-tested via crosscompilers. m32r, mips, sh, sparc, have not been tested yet, but should be mostly fine. From: Grant Grundler <grundler@parisc-linux.org> Booted and lightly tested on a500-44 (64-bit, SMP kernel, dual CPU). Builds 32-bit SMP kernel (not booted or tested). I did not try to build non-SMP kernels. That should be trivial to fix up later if necessary. I converted bit ops atomic_hash lock to raw_spinlock_t. Doing so avoids some ugly nesting of linux/*.h and asm/*.h files. Those particular locks are well tested and contained entirely inside arch specific code. I do NOT expect any new issues to arise with them. If someone does ever need to use debug/metrics with them, then they will need to unravel this hairball between spinlocks, atomic ops, and bit ops that exist only because parisc has exactly one atomic instruction: LDCW (load and clear word). From: "Luck, Tony" <tony.luck@intel.com> ia64 fix Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Arjan van de Ven <arjanv@infradead.org> Signed-off-by: Grant Grundler <grundler@parisc-linux.org> Cc: Matthew Wilcox <willy@debian.org> Signed-off-by: Hirokazu Takata <takata@linux-m32r.org> Signed-off-by: Mikael Pettersson <mikpe@csd.uu.se> Signed-off-by: Benoit Boissinot <benoit.boissinot@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
230 lines
7.5 KiB
C
230 lines
7.5 KiB
C
#ifndef __LINUX_SPINLOCK_H
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#define __LINUX_SPINLOCK_H
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/*
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* include/linux/spinlock.h - generic spinlock/rwlock declarations
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*
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* here's the role of the various spinlock/rwlock related include files:
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*
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* on SMP builds:
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*
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* asm/spinlock_types.h: contains the raw_spinlock_t/raw_rwlock_t and the
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* initializers
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*
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* linux/spinlock_types.h:
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* defines the generic type and initializers
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*
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* asm/spinlock.h: contains the __raw_spin_*()/etc. lowlevel
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* implementations, mostly inline assembly code
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*
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* (also included on UP-debug builds:)
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*
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* linux/spinlock_api_smp.h:
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* contains the prototypes for the _spin_*() APIs.
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*
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* linux/spinlock.h: builds the final spin_*() APIs.
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*
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* on UP builds:
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*
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* linux/spinlock_type_up.h:
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* contains the generic, simplified UP spinlock type.
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* (which is an empty structure on non-debug builds)
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*
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* linux/spinlock_types.h:
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* defines the generic type and initializers
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*
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* linux/spinlock_up.h:
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* contains the __raw_spin_*()/etc. version of UP
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* builds. (which are NOPs on non-debug, non-preempt
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* builds)
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*
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* (included on UP-non-debug builds:)
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*
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* linux/spinlock_api_up.h:
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* builds the _spin_*() APIs.
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*
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* linux/spinlock.h: builds the final spin_*() APIs.
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*/
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#include <linux/config.h>
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#include <linux/preempt.h>
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#include <linux/linkage.h>
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#include <linux/compiler.h>
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#include <linux/thread_info.h>
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#include <linux/kernel.h>
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#include <linux/stringify.h>
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#include <asm/system.h>
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/*
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* Must define these before including other files, inline functions need them
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*/
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#define LOCK_SECTION_NAME \
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".text.lock." __stringify(KBUILD_BASENAME)
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#define LOCK_SECTION_START(extra) \
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".subsection 1\n\t" \
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extra \
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".ifndef " LOCK_SECTION_NAME "\n\t" \
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LOCK_SECTION_NAME ":\n\t" \
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".endif\n"
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#define LOCK_SECTION_END \
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".previous\n\t"
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#define __lockfunc fastcall __attribute__((section(".spinlock.text")))
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/*
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* Pull the raw_spinlock_t and raw_rwlock_t definitions:
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*/
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#include <linux/spinlock_types.h>
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extern int __lockfunc generic__raw_read_trylock(raw_rwlock_t *lock);
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/*
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* Pull the __raw*() functions/declarations (UP-nondebug doesnt need them):
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*/
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#if defined(CONFIG_SMP)
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# include <asm/spinlock.h>
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#else
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# include <linux/spinlock_up.h>
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#endif
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#define spin_lock_init(lock) do { *(lock) = SPIN_LOCK_UNLOCKED; } while (0)
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#define rwlock_init(lock) do { *(lock) = RW_LOCK_UNLOCKED; } while (0)
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#define spin_is_locked(lock) __raw_spin_is_locked(&(lock)->raw_lock)
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/**
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* spin_unlock_wait - wait until the spinlock gets unlocked
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* @lock: the spinlock in question.
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*/
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#define spin_unlock_wait(lock) __raw_spin_unlock_wait(&(lock)->raw_lock)
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/*
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* Pull the _spin_*()/_read_*()/_write_*() functions/declarations:
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*/
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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# include <linux/spinlock_api_smp.h>
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#else
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# include <linux/spinlock_api_up.h>
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#endif
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#ifdef CONFIG_DEBUG_SPINLOCK
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extern void _raw_spin_lock(spinlock_t *lock);
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#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
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extern int _raw_spin_trylock(spinlock_t *lock);
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extern void _raw_spin_unlock(spinlock_t *lock);
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extern void _raw_read_lock(rwlock_t *lock);
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extern int _raw_read_trylock(rwlock_t *lock);
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extern void _raw_read_unlock(rwlock_t *lock);
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extern void _raw_write_lock(rwlock_t *lock);
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extern int _raw_write_trylock(rwlock_t *lock);
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extern void _raw_write_unlock(rwlock_t *lock);
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#else
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# define _raw_spin_unlock(lock) __raw_spin_unlock(&(lock)->raw_lock)
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# define _raw_spin_trylock(lock) __raw_spin_trylock(&(lock)->raw_lock)
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# define _raw_spin_lock(lock) __raw_spin_lock(&(lock)->raw_lock)
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# define _raw_spin_lock_flags(lock, flags) \
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__raw_spin_lock_flags(&(lock)->raw_lock, *(flags))
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# define _raw_read_lock(rwlock) __raw_read_lock(&(rwlock)->raw_lock)
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# define _raw_write_lock(rwlock) __raw_write_lock(&(rwlock)->raw_lock)
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# define _raw_read_unlock(rwlock) __raw_read_unlock(&(rwlock)->raw_lock)
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# define _raw_write_unlock(rwlock) __raw_write_unlock(&(rwlock)->raw_lock)
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# define _raw_read_trylock(rwlock) __raw_read_trylock(&(rwlock)->raw_lock)
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# define _raw_write_trylock(rwlock) __raw_write_trylock(&(rwlock)->raw_lock)
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#endif
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#define read_can_lock(rwlock) __raw_read_can_lock(&(rwlock)->raw_lock)
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#define write_can_lock(rwlock) __raw_write_can_lock(&(rwlock)->raw_lock)
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/*
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* Define the various spin_lock and rw_lock methods. Note we define these
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* regardless of whether CONFIG_SMP or CONFIG_PREEMPT are set. The various
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* methods are defined as nops in the case they are not required.
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*/
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#define spin_trylock(lock) __cond_lock(_spin_trylock(lock))
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#define read_trylock(lock) __cond_lock(_read_trylock(lock))
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#define write_trylock(lock) __cond_lock(_write_trylock(lock))
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#define spin_lock(lock) _spin_lock(lock)
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#define write_lock(lock) _write_lock(lock)
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#define read_lock(lock) _read_lock(lock)
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#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
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#define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock)
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#define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock)
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#define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock)
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#else
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#define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags)
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#define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags)
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#define write_lock_irqsave(lock, flags) _write_lock_irqsave(lock, flags)
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#endif
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#define spin_lock_irq(lock) _spin_lock_irq(lock)
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#define spin_lock_bh(lock) _spin_lock_bh(lock)
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#define read_lock_irq(lock) _read_lock_irq(lock)
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#define read_lock_bh(lock) _read_lock_bh(lock)
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#define write_lock_irq(lock) _write_lock_irq(lock)
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#define write_lock_bh(lock) _write_lock_bh(lock)
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#define spin_unlock(lock) _spin_unlock(lock)
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#define write_unlock(lock) _write_unlock(lock)
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#define read_unlock(lock) _read_unlock(lock)
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#define spin_unlock_irqrestore(lock, flags) \
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_spin_unlock_irqrestore(lock, flags)
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#define spin_unlock_irq(lock) _spin_unlock_irq(lock)
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#define spin_unlock_bh(lock) _spin_unlock_bh(lock)
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#define read_unlock_irqrestore(lock, flags) \
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_read_unlock_irqrestore(lock, flags)
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#define read_unlock_irq(lock) _read_unlock_irq(lock)
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#define read_unlock_bh(lock) _read_unlock_bh(lock)
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#define write_unlock_irqrestore(lock, flags) \
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_write_unlock_irqrestore(lock, flags)
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#define write_unlock_irq(lock) _write_unlock_irq(lock)
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#define write_unlock_bh(lock) _write_unlock_bh(lock)
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#define spin_trylock_bh(lock) __cond_lock(_spin_trylock_bh(lock))
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#define spin_trylock_irq(lock) \
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({ \
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local_irq_disable(); \
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_spin_trylock(lock) ? \
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1 : ({ local_irq_enable(); 0; }); \
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})
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#define spin_trylock_irqsave(lock, flags) \
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({ \
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local_irq_save(flags); \
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_spin_trylock(lock) ? \
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1 : ({ local_irq_restore(flags); 0; }); \
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})
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/*
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* Pull the atomic_t declaration:
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* (asm-mips/atomic.h needs above definitions)
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*/
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#include <asm/atomic.h>
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/**
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* atomic_dec_and_lock - lock on reaching reference count zero
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* @atomic: the atomic counter
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* @lock: the spinlock in question
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*/
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extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock);
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#define atomic_dec_and_lock(atomic, lock) \
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__cond_lock(_atomic_dec_and_lock(atomic, lock))
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/**
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* spin_can_lock - would spin_trylock() succeed?
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* @lock: the spinlock in question.
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*/
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#define spin_can_lock(lock) (!spin_is_locked(lock))
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#endif /* __LINUX_SPINLOCK_H */
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