From fb1c8f93d869b34cacb8b8932e2b83d96a19d720 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sat, 10 Sep 2005 00:25:56 -0700 Subject: [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 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" ia64 fix Signed-off-by: Ingo Molnar Signed-off-by: Arjan van de Ven Signed-off-by: Grant Grundler Cc: Matthew Wilcox Signed-off-by: Hirokazu Takata Signed-off-by: Mikael Pettersson Signed-off-by: Benoit Boissinot Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/asm-sparc/spinlock.h | 140 ++++++------------------------------- include/asm-sparc/spinlock_types.h | 20 ++++++ 2 files changed, 41 insertions(+), 119 deletions(-) create mode 100644 include/asm-sparc/spinlock_types.h (limited to 'include/asm-sparc') diff --git a/include/asm-sparc/spinlock.h b/include/asm-sparc/spinlock.h index 0cbd87ad491..111727a2bb4 100644 --- a/include/asm-sparc/spinlock.h +++ b/include/asm-sparc/spinlock.h @@ -12,96 +12,12 @@ #include -#ifdef CONFIG_DEBUG_SPINLOCK -struct _spinlock_debug { - unsigned char lock; - unsigned long owner_pc; -#ifdef CONFIG_PREEMPT - unsigned int break_lock; -#endif -}; -typedef struct _spinlock_debug spinlock_t; - -#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0, 0 } -#define spin_lock_init(lp) do { *(lp)= SPIN_LOCK_UNLOCKED; } while(0) -#define spin_is_locked(lp) (*((volatile unsigned char *)(&((lp)->lock))) != 0) -#define spin_unlock_wait(lp) do { barrier(); } while(*(volatile unsigned char *)(&(lp)->lock)) - -extern void _do_spin_lock(spinlock_t *lock, char *str); -extern int _spin_trylock(spinlock_t *lock); -extern void _do_spin_unlock(spinlock_t *lock); - -#define _raw_spin_trylock(lp) _spin_trylock(lp) -#define _raw_spin_lock(lock) _do_spin_lock(lock, "spin_lock") -#define _raw_spin_unlock(lock) _do_spin_unlock(lock) - -struct _rwlock_debug { - volatile unsigned int lock; - unsigned long owner_pc; - unsigned long reader_pc[NR_CPUS]; -#ifdef CONFIG_PREEMPT - unsigned int break_lock; -#endif -}; -typedef struct _rwlock_debug rwlock_t; - -#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0, {0} } - -#define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0) - -extern void _do_read_lock(rwlock_t *rw, char *str); -extern void _do_read_unlock(rwlock_t *rw, char *str); -extern void _do_write_lock(rwlock_t *rw, char *str); -extern void _do_write_unlock(rwlock_t *rw); - -#define _raw_read_lock(lock) \ -do { unsigned long flags; \ - local_irq_save(flags); \ - _do_read_lock(lock, "read_lock"); \ - local_irq_restore(flags); \ -} while(0) - -#define _raw_read_unlock(lock) \ -do { unsigned long flags; \ - local_irq_save(flags); \ - _do_read_unlock(lock, "read_unlock"); \ - local_irq_restore(flags); \ -} while(0) - -#define _raw_write_lock(lock) \ -do { unsigned long flags; \ - local_irq_save(flags); \ - _do_write_lock(lock, "write_lock"); \ - local_irq_restore(flags); \ -} while(0) - -#define _raw_write_unlock(lock) \ -do { unsigned long flags; \ - local_irq_save(flags); \ - _do_write_unlock(lock); \ - local_irq_restore(flags); \ -} while(0) - -#else /* !CONFIG_DEBUG_SPINLOCK */ - -typedef struct { - unsigned char lock; -#ifdef CONFIG_PREEMPT - unsigned int break_lock; -#endif -} spinlock_t; - -#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 } - -#define spin_lock_init(lock) (*((unsigned char *)(lock)) = 0) -#define spin_is_locked(lock) (*((volatile unsigned char *)(lock)) != 0) +#define __raw_spin_is_locked(lock) (*((volatile unsigned char *)(lock)) != 0) -#define spin_unlock_wait(lock) \ -do { \ - barrier(); \ -} while(*((volatile unsigned char *)lock)) +#define __raw_spin_unlock_wait(lock) \ + do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0) -extern __inline__ void _raw_spin_lock(spinlock_t *lock) +extern __inline__ void __raw_spin_lock(raw_spinlock_t *lock) { __asm__ __volatile__( "\n1:\n\t" @@ -121,7 +37,7 @@ extern __inline__ void _raw_spin_lock(spinlock_t *lock) : "g2", "memory", "cc"); } -extern __inline__ int _raw_spin_trylock(spinlock_t *lock) +extern __inline__ int __raw_spin_trylock(raw_spinlock_t *lock) { unsigned int result; __asm__ __volatile__("ldstub [%1], %0" @@ -131,7 +47,7 @@ extern __inline__ int _raw_spin_trylock(spinlock_t *lock) return (result == 0); } -extern __inline__ void _raw_spin_unlock(spinlock_t *lock) +extern __inline__ void __raw_spin_unlock(raw_spinlock_t *lock) { __asm__ __volatile__("stb %%g0, [%0]" : : "r" (lock) : "memory"); } @@ -147,23 +63,11 @@ extern __inline__ void _raw_spin_unlock(spinlock_t *lock) * * XXX This might create some problems with my dual spinlock * XXX scheme, deadlocks etc. -DaveM - */ -typedef struct { - volatile unsigned int lock; -#ifdef CONFIG_PREEMPT - unsigned int break_lock; -#endif -} rwlock_t; - -#define RW_LOCK_UNLOCKED (rwlock_t) { 0 } - -#define rwlock_init(lp) do { *(lp)= RW_LOCK_UNLOCKED; } while(0) - - -/* Sort of like atomic_t's on Sparc, but even more clever. + * + * Sort of like atomic_t's on Sparc, but even more clever. * * ------------------------------------ - * | 24-bit counter | wlock | rwlock_t + * | 24-bit counter | wlock | raw_rwlock_t * ------------------------------------ * 31 8 7 0 * @@ -174,9 +78,9 @@ typedef struct { * * Unfortunately this scheme limits us to ~16,000,000 cpus. */ -extern __inline__ void _read_lock(rwlock_t *rw) +extern __inline__ void __read_lock(raw_rwlock_t *rw) { - register rwlock_t *lp asm("g1"); + register raw_rwlock_t *lp asm("g1"); lp = rw; __asm__ __volatile__( "mov %%o7, %%g4\n\t" @@ -187,16 +91,16 @@ extern __inline__ void _read_lock(rwlock_t *rw) : "g2", "g4", "memory", "cc"); } -#define _raw_read_lock(lock) \ +#define __raw_read_lock(lock) \ do { unsigned long flags; \ local_irq_save(flags); \ - _read_lock(lock); \ + __raw_read_lock(lock); \ local_irq_restore(flags); \ } while(0) -extern __inline__ void _read_unlock(rwlock_t *rw) +extern __inline__ void __read_unlock(raw_rwlock_t *rw) { - register rwlock_t *lp asm("g1"); + register raw_rwlock_t *lp asm("g1"); lp = rw; __asm__ __volatile__( "mov %%o7, %%g4\n\t" @@ -207,16 +111,16 @@ extern __inline__ void _read_unlock(rwlock_t *rw) : "g2", "g4", "memory", "cc"); } -#define _raw_read_unlock(lock) \ +#define __raw_read_unlock(lock) \ do { unsigned long flags; \ local_irq_save(flags); \ - _read_unlock(lock); \ + __raw_read_unlock(lock); \ local_irq_restore(flags); \ } while(0) -extern __inline__ void _raw_write_lock(rwlock_t *rw) +extern __inline__ void __raw_write_lock(raw_rwlock_t *rw) { - register rwlock_t *lp asm("g1"); + register raw_rwlock_t *lp asm("g1"); lp = rw; __asm__ __volatile__( "mov %%o7, %%g4\n\t" @@ -227,11 +131,9 @@ extern __inline__ void _raw_write_lock(rwlock_t *rw) : "g2", "g4", "memory", "cc"); } -#define _raw_write_unlock(rw) do { (rw)->lock = 0; } while(0) - -#endif /* CONFIG_DEBUG_SPINLOCK */ +#define __raw_write_unlock(rw) do { (rw)->lock = 0; } while(0) -#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock) +#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock) #endif /* !(__ASSEMBLY__) */ diff --git a/include/asm-sparc/spinlock_types.h b/include/asm-sparc/spinlock_types.h new file mode 100644 index 00000000000..0a0fb116c4e --- /dev/null +++ b/include/asm-sparc/spinlock_types.h @@ -0,0 +1,20 @@ +#ifndef __SPARC_SPINLOCK_TYPES_H +#define __SPARC_SPINLOCK_TYPES_H + +#ifndef __LINUX_SPINLOCK_TYPES_H +# error "please don't include this file directly" +#endif + +typedef struct { + unsigned char lock; +} raw_spinlock_t; + +#define __RAW_SPIN_LOCK_UNLOCKED { 0 } + +typedef struct { + volatile unsigned int lock; +} raw_rwlock_t; + +#define __RAW_RW_LOCK_UNLOCKED { 0 } + +#endif -- cgit v1.2.3