2005-04-17 02:20:36 +04:00
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/*
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* S390 version
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2012-07-20 13:15:04 +04:00
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* Copyright IBM Corp. 1999
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2005-04-17 02:20:36 +04:00
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* Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
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*
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* Derived from "include/asm-i386/spinlock.h"
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*/
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#ifndef __ASM_SPINLOCK_H
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#define __ASM_SPINLOCK_H
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2006-10-01 10:27:45 +04:00
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#include <linux/smp.h>
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2016-05-26 11:35:03 +03:00
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#include <asm/barrier.h>
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#include <asm/processor.h>
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2006-10-01 10:27:45 +04:00
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2014-04-07 20:25:23 +04:00
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#define SPINLOCK_LOCKVAL (S390_lowcore.spinlock_lockval)
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2011-10-30 18:17:13 +04:00
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extern int spin_retry;
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2006-09-28 18:56:43 +04:00
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static inline int
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2014-04-07 20:25:23 +04:00
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_raw_compare_and_swap(unsigned int *lock, unsigned int old, unsigned int new)
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2006-09-28 18:56:43 +04:00
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{
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2014-10-29 14:50:31 +03:00
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return __sync_bool_compare_and_swap(lock, old, new);
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2006-09-28 18:56:43 +04:00
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}
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2005-04-17 02:20:36 +04:00
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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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* We make no fairness assumptions. They have a cost.
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[PATCH] spinlock consolidation
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>
2005-09-10 11:25:56 +04:00
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*
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* (the type definitions are in asm/spinlock_types.h)
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2005-04-17 02:20:36 +04:00
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*/
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2014-09-19 16:29:31 +04:00
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void arch_lock_relax(unsigned int cpu);
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2014-04-07 20:25:23 +04:00
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void arch_spin_lock_wait(arch_spinlock_t *);
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int arch_spin_trylock_retry(arch_spinlock_t *);
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void arch_spin_lock_wait_flags(arch_spinlock_t *, unsigned long flags);
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2005-07-27 22:44:57 +04:00
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2014-09-19 16:29:31 +04:00
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static inline void arch_spin_relax(arch_spinlock_t *lock)
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{
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arch_lock_relax(lock->lock);
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}
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2014-04-07 20:25:23 +04:00
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static inline u32 arch_spin_lockval(int cpu)
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{
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return ~cpu;
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}
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2013-09-05 15:26:17 +04:00
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static inline int arch_spin_value_unlocked(arch_spinlock_t lock)
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{
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2014-04-07 20:25:23 +04:00
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return lock.lock == 0;
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2013-09-05 15:26:17 +04:00
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}
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2014-04-07 20:25:23 +04:00
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static inline int arch_spin_is_locked(arch_spinlock_t *lp)
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{
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return ACCESS_ONCE(lp->lock) != 0;
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}
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static inline int arch_spin_trylock_once(arch_spinlock_t *lp)
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2005-04-17 02:20:36 +04:00
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{
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2014-05-15 13:00:44 +04:00
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barrier();
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return likely(arch_spin_value_unlocked(*lp) &&
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_raw_compare_and_swap(&lp->lock, 0, SPINLOCK_LOCKVAL));
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2005-04-17 02:20:36 +04:00
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}
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2014-04-07 20:25:23 +04:00
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static inline void arch_spin_lock(arch_spinlock_t *lp)
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2005-04-17 02:20:36 +04:00
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{
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2014-05-15 13:00:44 +04:00
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if (!arch_spin_trylock_once(lp))
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2014-04-07 20:25:23 +04:00
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arch_spin_lock_wait(lp);
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}
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2005-07-27 22:44:57 +04:00
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2014-04-07 20:25:23 +04:00
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static inline void arch_spin_lock_flags(arch_spinlock_t *lp,
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unsigned long flags)
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{
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2014-05-15 13:00:44 +04:00
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if (!arch_spin_trylock_once(lp))
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2014-04-07 20:25:23 +04:00
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arch_spin_lock_wait_flags(lp, flags);
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}
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static inline int arch_spin_trylock(arch_spinlock_t *lp)
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{
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2014-05-15 13:00:44 +04:00
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if (!arch_spin_trylock_once(lp))
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2014-04-07 20:25:23 +04:00
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return arch_spin_trylock_retry(lp);
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return 1;
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2005-04-17 02:20:36 +04:00
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}
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2009-12-02 22:01:25 +03:00
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static inline void arch_spin_unlock(arch_spinlock_t *lp)
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2005-04-17 02:20:36 +04:00
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{
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2014-09-08 10:20:43 +04:00
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typecheck(unsigned int, lp->lock);
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asm volatile(
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"st %1,%0\n"
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: "+Q" (lp->lock)
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: "d" (0)
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: "cc", "memory");
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2005-04-17 02:20:36 +04:00
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}
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2014-04-07 20:25:23 +04:00
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static inline void arch_spin_unlock_wait(arch_spinlock_t *lock)
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{
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while (arch_spin_is_locked(lock))
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arch_spin_relax(lock);
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2016-05-26 11:35:03 +03:00
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smp_acquire__after_ctrl_dep();
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2014-04-07 20:25:23 +04:00
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}
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2005-04-17 02:20:36 +04:00
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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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/**
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* read_can_lock - would read_trylock() succeed?
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* @lock: the rwlock in question.
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*/
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2009-12-03 22:08:46 +03:00
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#define arch_read_can_lock(x) ((int)(x)->lock >= 0)
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2005-04-17 02:20:36 +04:00
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/**
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* write_can_lock - would write_trylock() succeed?
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* @lock: the rwlock in question.
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*/
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2009-12-03 22:08:46 +03:00
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#define arch_write_can_lock(x) ((x)->lock == 0)
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2005-04-17 02:20:36 +04:00
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2014-09-22 16:45:11 +04:00
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extern int _raw_read_trylock_retry(arch_rwlock_t *lp);
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2009-12-03 22:01:19 +03:00
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extern int _raw_write_trylock_retry(arch_rwlock_t *lp);
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2014-09-22 16:45:11 +04:00
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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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2014-05-15 13:00:44 +04:00
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static inline int arch_read_trylock_once(arch_rwlock_t *rw)
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{
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unsigned int old = ACCESS_ONCE(rw->lock);
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return likely((int) old >= 0 &&
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_raw_compare_and_swap(&rw->lock, old, old + 1));
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}
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static inline int arch_write_trylock_once(arch_rwlock_t *rw)
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{
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unsigned int old = ACCESS_ONCE(rw->lock);
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return likely(old == 0 &&
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_raw_compare_and_swap(&rw->lock, 0, 0x80000000));
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}
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2014-09-22 18:34:38 +04:00
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#ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
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#define __RAW_OP_OR "lao"
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#define __RAW_OP_AND "lan"
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#define __RAW_OP_ADD "laa"
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#define __RAW_LOCK(ptr, op_val, op_string) \
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({ \
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unsigned int old_val; \
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\
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typecheck(unsigned int *, ptr); \
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asm volatile( \
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op_string " %0,%2,%1\n" \
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"bcr 14,0\n" \
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: "=d" (old_val), "+Q" (*ptr) \
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: "d" (op_val) \
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: "cc", "memory"); \
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old_val; \
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})
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#define __RAW_UNLOCK(ptr, op_val, op_string) \
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({ \
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unsigned int old_val; \
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\
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typecheck(unsigned int *, ptr); \
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asm volatile( \
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op_string " %0,%2,%1\n" \
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: "=d" (old_val), "+Q" (*ptr) \
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: "d" (op_val) \
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: "cc", "memory"); \
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old_val; \
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})
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extern void _raw_read_lock_wait(arch_rwlock_t *lp);
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extern void _raw_write_lock_wait(arch_rwlock_t *lp, unsigned int prev);
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static inline void arch_read_lock(arch_rwlock_t *rw)
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{
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unsigned int old;
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old = __RAW_LOCK(&rw->lock, 1, __RAW_OP_ADD);
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if ((int) old < 0)
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_raw_read_lock_wait(rw);
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}
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static inline void arch_read_unlock(arch_rwlock_t *rw)
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{
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__RAW_UNLOCK(&rw->lock, -1, __RAW_OP_ADD);
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}
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static inline void arch_write_lock(arch_rwlock_t *rw)
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{
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unsigned int old;
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old = __RAW_LOCK(&rw->lock, 0x80000000, __RAW_OP_OR);
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if (old != 0)
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_raw_write_lock_wait(rw, old);
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rw->owner = SPINLOCK_LOCKVAL;
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}
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static inline void arch_write_unlock(arch_rwlock_t *rw)
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{
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rw->owner = 0;
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__RAW_UNLOCK(&rw->lock, 0x7fffffff, __RAW_OP_AND);
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}
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#else /* CONFIG_HAVE_MARCH_Z196_FEATURES */
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extern void _raw_read_lock_wait(arch_rwlock_t *lp);
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extern void _raw_write_lock_wait(arch_rwlock_t *lp);
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2009-12-03 22:08:46 +03:00
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static inline void arch_read_lock(arch_rwlock_t *rw)
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2005-07-27 22:44:57 +04:00
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{
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2014-05-15 13:00:44 +04:00
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if (!arch_read_trylock_once(rw))
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2005-07-27 22:44:57 +04:00
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_raw_read_lock_wait(rw);
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}
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2009-12-03 22:08:46 +03:00
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static inline void arch_read_unlock(arch_rwlock_t *rw)
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2005-07-27 22:44:57 +04:00
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{
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2014-04-07 20:25:23 +04:00
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unsigned int old;
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2005-07-27 22:44:57 +04:00
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do {
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2014-04-07 20:25:23 +04:00
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old = ACCESS_ONCE(rw->lock);
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} while (!_raw_compare_and_swap(&rw->lock, old, old - 1));
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2005-07-27 22:44:57 +04:00
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}
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2009-12-03 22:08:46 +03:00
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static inline void arch_write_lock(arch_rwlock_t *rw)
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2005-07-27 22:44:57 +04:00
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{
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2014-05-15 13:00:44 +04:00
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if (!arch_write_trylock_once(rw))
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2005-07-27 22:44:57 +04:00
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_raw_write_lock_wait(rw);
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2014-09-19 16:29:31 +04:00
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rw->owner = SPINLOCK_LOCKVAL;
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2005-07-27 22:44:57 +04:00
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}
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2009-12-03 22:08:46 +03:00
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static inline void arch_write_unlock(arch_rwlock_t *rw)
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2005-07-27 22:44:57 +04:00
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{
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2014-09-08 10:20:43 +04:00
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typecheck(unsigned int, rw->lock);
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2014-09-19 16:29:31 +04:00
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rw->owner = 0;
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2014-09-08 10:20:43 +04:00
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asm volatile(
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"st %1,%0\n"
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: "+Q" (rw->lock)
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: "d" (0)
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: "cc", "memory");
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2005-07-27 22:44:57 +04:00
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}
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2014-09-22 18:34:38 +04:00
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#endif /* CONFIG_HAVE_MARCH_Z196_FEATURES */
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2009-12-03 22:08:46 +03:00
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static inline int arch_read_trylock(arch_rwlock_t *rw)
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2005-07-27 22:44:57 +04:00
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{
|
2014-05-15 13:00:44 +04:00
|
|
|
if (!arch_read_trylock_once(rw))
|
|
|
|
return _raw_read_trylock_retry(rw);
|
|
|
|
return 1;
|
2005-07-27 22:44:57 +04:00
|
|
|
}
|
|
|
|
|
2009-12-03 22:08:46 +03:00
|
|
|
static inline int arch_write_trylock(arch_rwlock_t *rw)
|
2005-04-17 02:20:36 +04:00
|
|
|
{
|
2014-09-19 16:29:31 +04:00
|
|
|
if (!arch_write_trylock_once(rw) && !_raw_write_trylock_retry(rw))
|
|
|
|
return 0;
|
|
|
|
rw->owner = SPINLOCK_LOCKVAL;
|
2014-05-15 13:00:44 +04:00
|
|
|
return 1;
|
2005-04-17 02:20:36 +04:00
|
|
|
}
|
|
|
|
|
2014-09-19 16:29:31 +04:00
|
|
|
static inline void arch_read_relax(arch_rwlock_t *rw)
|
|
|
|
{
|
|
|
|
arch_lock_relax(rw->owner);
|
|
|
|
}
|
|
|
|
|
|
|
|
static inline void arch_write_relax(arch_rwlock_t *rw)
|
|
|
|
{
|
|
|
|
arch_lock_relax(rw->owner);
|
|
|
|
}
|
2006-10-01 10:27:43 +04:00
|
|
|
|
2005-04-17 02:20:36 +04:00
|
|
|
#endif /* __ASM_SPINLOCK_H */
|