David Howells wrote:
Nick Piggin <[email protected]> wrote:
I wonder if we can just start with the nice powerpc code that uses
atomic_add_return and cmpxchg (should use atomic_cmpxchg)
Because i386 (and x86_64) can do better by using XADDL/XADDQ.
I mean cmpxchg for the cmpxchg part. atomic_add_return already uses
xadd (for i386, or eg. a fetchadd on ia64).
and chuck out the "crappy" rwsem fallback implementation,
CMPXCHG is not available on all archs, and may not be implemented on all archs
through other atomic instructions.
atomic_cmpxchg is available on all architectures.
as well as all the arch specific code?
Using CMPXCHG is only optimal where that's the best available.
If this following patch is one or two cycles slower on some architectures
when everything is hot in cache and you're going down hill, then it is
still going to be faster overall due to being 22 icache lines smaller on
my SMP PIII kernel.
Also, the code sharing and complexity reduction IMO would be worth it
anyway even if it was slightly slower (unless that proved to be
significant on any real workload).
Anyway, this is my proposal for a generic rwsem. IMO this is a good place
to start from scratch, and if any arch really needs specific code, then we
can look at making a sane abstraction for them.
Comments?
--
SUSE Labs, Novell Inc.
include/asm-alpha/rwsem.h | 259 -------------------------
include/asm-i386/rwsem.h | 296 -----------------------------
include/asm-ia64/rwsem.h | 178 -----------------
include/asm-powerpc/rwsem.h | 152 --------------
include/asm-s390/rwsem.h | 387 -------------------------------------- include/asm-sh/rwsem.h | 159 ---------------
include/asm-sparc64/rwsem-const.h | 12 -
include/asm-sparc64/rwsem.h | 66 ------
include/asm-um/rwsem.h | 6
include/asm-xtensa/rwsem.h | 164 ----------------
lib/rwsem-spinlock.c | 316 -------------------------------
lib/rwsem.c | 257 -------------------------
linux-2.6/arch/alpha/Kconfig | 7
linux-2.6/arch/arm/Kconfig | 7
linux-2.6/arch/arm26/Kconfig | 7
linux-2.6/arch/cris/Kconfig | 7
linux-2.6/arch/frv/Kconfig | 7
linux-2.6/arch/h8300/Kconfig | 8
linux-2.6/arch/i386/Kconfig.cpu | 10
linux-2.6/arch/ia64/Kconfig | 4
linux-2.6/arch/m32r/Kconfig | 9
linux-2.6/arch/m68k/Kconfig | 7
linux-2.6/arch/m68knommu/Kconfig | 8
linux-2.6/arch/mips/Kconfig | 11 -
linux-2.6/arch/parisc/Kconfig | 6
linux-2.6/arch/powerpc/Kconfig | 7
linux-2.6/arch/ppc/Kconfig | 7
linux-2.6/arch/s390/Kconfig | 7
linux-2.6/arch/sh/Kconfig | 7
linux-2.6/arch/sh64/Kconfig | 7
linux-2.6/arch/sparc/Kconfig | 7
linux-2.6/arch/sparc64/Kconfig | 7
linux-2.6/arch/um/Kconfig.x86_64 | 4
linux-2.6/arch/v850/Kconfig | 6
linux-2.6/arch/x86_64/Kconfig | 7
linux-2.6/arch/xtensa/Kconfig | 4
linux-2.6/include/linux/rwsem.h | 76 ++++++-
linux-2.6/kernel/rwsem.c | 292 +++++++++++++++++++++++++++-
linux-2.6/lib/Makefile | 2
39 files changed, 351 insertions(+), 2439 deletions(-)
Index: linux-2.6/include/asm-powerpc/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-powerpc/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,152 +0,0 @@
-#ifndef _ASM_POWERPC_RWSEM_H
-#define _ASM_POWERPC_RWSEM_H
-
-#ifdef __KERNEL__
-
-/*
- * include/asm-powerpc/rwsem.h: R/W semaphores for PPC using the stuff
- * in lib/rwsem.c. Adapted largely from include/asm-i386/rwsem.h
- * by Paul Mackerras <[email protected]>.
- */
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- /* XXX this should be able to be an atomic_t -- paulus */
- signed int count;
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS (-0x00010000)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
- spinlock_t wait_lock;
- struct list_head wait_list;
-};
-
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
- LIST_HEAD_INIT((name).wait_list) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-static inline void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-/*
- * lock for reading
- */
-static inline void __down_read(struct rw_semaphore *sem)
-{
- if (unlikely(atomic_inc_return((atomic_t *)(&sem->count)) <= 0))
- rwsem_down_read_failed(sem);
-}
-
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- while ((tmp = sem->count) >= 0) {
- if (tmp == cmpxchg(&sem->count, tmp,
- tmp + RWSEM_ACTIVE_READ_BIAS)) {
- return 1;
- }
- }
- return 0;
-}
-
-/*
- * lock for writing
- */
-static inline void __down_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count));
- if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))
- rwsem_down_write_failed(sem);
-}
-
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- return tmp == RWSEM_UNLOCKED_VALUE;
-}
-
-/*
- * unlock after reading
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = atomic_dec_return((atomic_t *)(&sem->count));
- if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0))
- rwsem_wake(sem);
-}
-
-/*
- * unlock after writing
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
- if (unlikely(atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count)) < 0))
- rwsem_wake(sem);
-}
-
-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
-{
- atomic_add(delta, (atomic_t *)(&sem->count));
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count));
- if (tmp < 0)
- rwsem_downgrade_wake(sem);
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
-{
- return atomic_add_return(delta, (atomic_t *)(&sem->count));
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-#endif /* _ASM_POWERPC_RWSEM_H */
Index: linux-2.6/include/linux/rwsem.h
===================================================================
--- linux-2.6.orig/include/linux/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ linux-2.6/include/linux/rwsem.h 2006-09-14 03:46:18.000000000 +1000
@@ -1,7 +1,34 @@
-/* rwsem.h: R/W semaphores, public interface
+/*
+ * rwsem.h: R/W semaphores, public interface
*
* Written by David Howells ([email protected]).
* Derived from asm-i386/semaphore.h
+ *
+ * Also by Paul Mackerras <[email protected]>
+ * and Nick Piggin <[email protected]>
+ *
+ * The MSW of the count is the negated number of active writers and waiting
+ * lockers, and the LSW is the total number of active locks
+ *
+ * The lock count is initialized to 0 (no active and no waiting lockers).
+ *
+ * When a writer subtracts WRITE_BIAS, it'll get 0xffff0001 for the case of an
+ * uncontended lock. This can be determined because XADD returns the old value.
+ * Readers increment by 1 and see a positive value when uncontended, negative
+ * if there are writers (and maybe) readers waiting (in which case it goes to
+ * sleep).
+ *
+ * The value of WAITING_BIAS supports up to 32766 waiting processes. This can
+ * be extended to 65534 by manually checking the whole MSW rather than relying
+ * on the S flag.
+ *
+ * The value of ACTIVE_BIAS supports up to 65535 active processes.
+ *
+ * This should be totally fair - if anything is waiting, a process that wants a
+ * lock will go to the back of the queue. When the currently active lock is
+ * released, if there's a writer at the front of the queue, then that and only
+ * that will be woken up; if there's a bunch of consequtive readers at the
+ * front, then they'll all be woken up, but no other readers will be.
*/
#ifndef _LINUX_RWSEM_H
@@ -16,14 +43,53 @@
#include <asm/system.h>
#include <asm/atomic.h>
-struct rw_semaphore;
+/*
+ * the semaphore definition
+ */
+struct rw_semaphore {
+ atomic_t count;
+#define RWSEM_UNLOCKED_VALUE 0x00000000
+#define RWSEM_ACTIVE_BIAS 0x00000001
+#define RWSEM_ACTIVE_MASK 0x0000ffff
+#define RWSEM_WAITING_BIAS 0xffff0000
+#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
+#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
+ spinlock_t wait_lock;
+ struct list_head wait_list;
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ struct lockdep_map dep_map;
+#endif
+};
-#ifdef CONFIG_RWSEM_GENERIC_SPINLOCK
-#include <linux/rwsem-spinlock.h> /* use a generic implementation */
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+# define __RWSEM_DEP_MAP_INIT(lockname) .dep_map = { .name = #lockname }
#else
-#include <asm/rwsem.h> /* use an arch-specific implementation */
+# define __RWSEM_DEP_MAP_INIT(lockname)
#endif
+
+#define __RWSEM_INITIALIZER(name) \
+{ ATOMIC_INIT(RWSEM_UNLOCKED_VALUE), SPIN_LOCK_UNLOCKED, \
+ LIST_HEAD_INIT((name).wait_list), __RWSEM_DEP_MAP_INIT(name) }
+
+#define DECLARE_RWSEM(name) \
+ struct rw_semaphore name = __RWSEM_INITIALIZER(name)
+
+extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
+ struct lock_class_key *key);
+
+#define init_rwsem(sem) \
+do { \
+ static struct lock_class_key __key; \
+ \
+ __init_rwsem((sem), #sem, &__key); \
+} while (0)
+
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+ return (atomic_read(&sem->count) != 0);
+}
+
/*
* lock for reading
*/
Index: linux-2.6/lib/rwsem-spinlock.c
===================================================================
--- linux-2.6.orig/lib/rwsem-spinlock.c 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,316 +0,0 @@
-/* rwsem-spinlock.c: R/W semaphores: contention handling functions for
- * generic spinlock implementation
- *
- * Copyright (c) 2001 David Howells ([email protected]).
- * - Derived partially from idea by Andrea Arcangeli <[email protected]>
- * - Derived also from comments by Linus
- */
-#include <linux/rwsem.h>
-#include <linux/sched.h>
-#include <linux/module.h>
-
-struct rwsem_waiter {
- struct list_head list;
- struct task_struct *task;
- unsigned int flags;
-#define RWSEM_WAITING_FOR_READ 0x00000001
-#define RWSEM_WAITING_FOR_WRITE 0x00000002
-};
-
-/*
- * initialise the semaphore
- */
-void __init_rwsem(struct rw_semaphore *sem, const char *name,
- struct lock_class_key *key)
-{
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- /*
- * Make sure we are not reinitializing a held semaphore:
- */
- debug_check_no_locks_freed((void *)sem, sizeof(*sem));
- lockdep_init_map(&sem->dep_map, name, key);
-#endif
- sem->activity = 0;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-/*
- * handle the lock release when processes blocked on it that can now run
- * - if we come here, then:
- * - the 'active count' _reached_ zero
- * - the 'waiting count' is non-zero
- * - the spinlock must be held by the caller
- * - woken process blocks are discarded from the list after having task zeroed
- * - writers are only woken if wakewrite is non-zero
- */
-static inline struct rw_semaphore *
-__rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
-{
- struct rwsem_waiter *waiter;
- struct task_struct *tsk;
- int woken;
-
- waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
-
- if (!wakewrite) {
- if (waiter->flags & RWSEM_WAITING_FOR_WRITE)
- goto out;
- goto dont_wake_writers;
- }
-
- /* if we are allowed to wake writers try to grant a single write lock
- * if there's a writer at the front of the queue
- * - we leave the 'waiting count' incremented to signify potential
- * contention
- */
- if (waiter->flags & RWSEM_WAITING_FOR_WRITE) {
- sem->activity = -1;
- list_del(&waiter->list);
- tsk = waiter->task;
- /* Don't touch waiter after ->task has been NULLed */
- smp_mb();
- waiter->task = NULL;
- wake_up_process(tsk);
- put_task_struct(tsk);
- goto out;
- }
-
- /* grant an infinite number of read locks to the front of the queue */
- dont_wake_writers:
- woken = 0;
- while (waiter->flags & RWSEM_WAITING_FOR_READ) {
- struct list_head *next = waiter->list.next;
-
- list_del(&waiter->list);
- tsk = waiter->task;
- smp_mb();
- waiter->task = NULL;
- wake_up_process(tsk);
- put_task_struct(tsk);
- woken++;
- if (list_empty(&sem->wait_list))
- break;
- waiter = list_entry(next, struct rwsem_waiter, list);
- }
-
- sem->activity += woken;
-
- out:
- return sem;
-}
-
-/*
- * wake a single writer
- */
-static inline struct rw_semaphore *
-__rwsem_wake_one_writer(struct rw_semaphore *sem)
-{
- struct rwsem_waiter *waiter;
- struct task_struct *tsk;
-
- sem->activity = -1;
-
- waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
- list_del(&waiter->list);
-
- tsk = waiter->task;
- smp_mb();
- waiter->task = NULL;
- wake_up_process(tsk);
- put_task_struct(tsk);
- return sem;
-}
-
-/*
- * get a read lock on the semaphore
- */
-void fastcall __sched __down_read(struct rw_semaphore *sem)
-{
- struct rwsem_waiter waiter;
- struct task_struct *tsk;
-
- spin_lock_irq(&sem->wait_lock);
-
- if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
- /* granted */
- sem->activity++;
- spin_unlock_irq(&sem->wait_lock);
- goto out;
- }
-
- tsk = current;
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-
- /* set up my own style of waitqueue */
- waiter.task = tsk;
- waiter.flags = RWSEM_WAITING_FOR_READ;
- get_task_struct(tsk);
-
- list_add_tail(&waiter.list, &sem->wait_list);
-
- /* we don't need to touch the semaphore struct anymore */
- spin_unlock_irq(&sem->wait_lock);
-
- /* wait to be given the lock */
- for (;;) {
- if (!waiter.task)
- break;
- schedule();
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
- }
-
- tsk->state = TASK_RUNNING;
- out:
- ;
-}
-
-/*
- * trylock for reading -- returns 1 if successful, 0 if contention
- */
-int fastcall __down_read_trylock(struct rw_semaphore *sem)
-{
- unsigned long flags;
- int ret = 0;
-
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
- /* granted */
- sem->activity++;
- ret = 1;
- }
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- return ret;
-}
-
-/*
- * get a write lock on the semaphore
- * - we increment the waiting count anyway to indicate an exclusive lock
- */
-void fastcall __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
-{
- struct rwsem_waiter waiter;
- struct task_struct *tsk;
-
- spin_lock_irq(&sem->wait_lock);
-
- if (sem->activity == 0 && list_empty(&sem->wait_list)) {
- /* granted */
- sem->activity = -1;
- spin_unlock_irq(&sem->wait_lock);
- goto out;
- }
-
- tsk = current;
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-
- /* set up my own style of waitqueue */
- waiter.task = tsk;
- waiter.flags = RWSEM_WAITING_FOR_WRITE;
- get_task_struct(tsk);
-
- list_add_tail(&waiter.list, &sem->wait_list);
-
- /* we don't need to touch the semaphore struct anymore */
- spin_unlock_irq(&sem->wait_lock);
-
- /* wait to be given the lock */
- for (;;) {
- if (!waiter.task)
- break;
- schedule();
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
- }
-
- tsk->state = TASK_RUNNING;
- out:
- ;
-}
-
-void fastcall __sched __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-int fastcall __down_write_trylock(struct rw_semaphore *sem)
-{
- unsigned long flags;
- int ret = 0;
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- if (sem->activity == 0 && list_empty(&sem->wait_list)) {
- /* granted */
- sem->activity = -1;
- ret = 1;
- }
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- return ret;
-}
-
-/*
- * release a read lock on the semaphore
- */
-void fastcall __up_read(struct rw_semaphore *sem)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- if (--sem->activity == 0 && !list_empty(&sem->wait_list))
- sem = __rwsem_wake_one_writer(sem);
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-}
-
-/*
- * release a write lock on the semaphore
- */
-void fastcall __up_write(struct rw_semaphore *sem)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- sem->activity = 0;
- if (!list_empty(&sem->wait_list))
- sem = __rwsem_do_wake(sem, 1);
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-}
-
-/*
- * downgrade a write lock into a read lock
- * - just wake up any readers at the front of the queue
- */
-void fastcall __downgrade_write(struct rw_semaphore *sem)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- sem->activity = 1;
- if (!list_empty(&sem->wait_list))
- sem = __rwsem_do_wake(sem, 0);
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-}
-
-EXPORT_SYMBOL(__init_rwsem);
-EXPORT_SYMBOL(__down_read);
-EXPORT_SYMBOL(__down_read_trylock);
-EXPORT_SYMBOL(__down_write_nested);
-EXPORT_SYMBOL(__down_write);
-EXPORT_SYMBOL(__down_write_trylock);
-EXPORT_SYMBOL(__up_read);
-EXPORT_SYMBOL(__up_write);
-EXPORT_SYMBOL(__downgrade_write);
Index: linux-2.6/include/asm-alpha/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-alpha/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,259 +0,0 @@
-#ifndef _ALPHA_RWSEM_H
-#define _ALPHA_RWSEM_H
-
-/*
- * Written by Ivan Kokshaysky <[email protected]>, 2001.
- * Based on asm-alpha/semaphore.h and asm-i386/rwsem.h
- */
-
-#ifndef _LINUX_RWSEM_H
-#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
-#endif
-
-#ifdef __KERNEL__
-
-#include <linux/compiler.h>
-#include <linux/list.h>
-#include <linux/spinlock.h>
-
-struct rwsem_waiter;
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- long count;
-#define RWSEM_UNLOCKED_VALUE 0x0000000000000000L
-#define RWSEM_ACTIVE_BIAS 0x0000000000000001L
-#define RWSEM_ACTIVE_MASK 0x00000000ffffffffL
-#define RWSEM_WAITING_BIAS (-0x0000000100000000L)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
- spinlock_t wait_lock;
- struct list_head wait_list;
-};
-
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
- LIST_HEAD_INIT((name).wait_list) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-static inline void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-static inline void __down_read(struct rw_semaphore *sem)
-{
- long oldcount;
-#ifndef CONFIG_SMP
- oldcount = sem->count;
- sem->count += RWSEM_ACTIVE_READ_BIAS;
-#else
- long temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%3,%2\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- " mb\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp)
- :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory");
-#endif
- if (unlikely(oldcount < 0))
- rwsem_down_read_failed(sem);
-}
-
-/*
- * trylock for reading -- returns 1 if successful, 0 if contention
- */
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- long old, new, res;
-
- res = sem->count;
- do {
- new = res + RWSEM_ACTIVE_READ_BIAS;
- if (new <= 0)
- break;
- old = res;
- res = cmpxchg(&sem->count, old, new);
- } while (res != old);
- return res >= 0 ? 1 : 0;
-}
-
-static inline void __down_write(struct rw_semaphore *sem)
-{
- long oldcount;
-#ifndef CONFIG_SMP
- oldcount = sem->count;
- sem->count += RWSEM_ACTIVE_WRITE_BIAS;
-#else
- long temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%3,%2\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- " mb\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp)
- :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory");
-#endif
- if (unlikely(oldcount))
- rwsem_down_write_failed(sem);
-}
-
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- long ret = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- if (ret == RWSEM_UNLOCKED_VALUE)
- return 1;
- return 0;
-}
-
-static inline void __up_read(struct rw_semaphore *sem)
-{
- long oldcount;
-#ifndef CONFIG_SMP
- oldcount = sem->count;
- sem->count -= RWSEM_ACTIVE_READ_BIAS;
-#else
- long temp;
- __asm__ __volatile__(
- " mb\n"
- "1: ldq_l %0,%1\n"
- " subq %0,%3,%2\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp)
- :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory");
-#endif
- if (unlikely(oldcount < 0))
- if ((int)oldcount - RWSEM_ACTIVE_READ_BIAS == 0)
- rwsem_wake(sem);
-}
-
-static inline void __up_write(struct rw_semaphore *sem)
-{
- long count;
-#ifndef CONFIG_SMP
- sem->count -= RWSEM_ACTIVE_WRITE_BIAS;
- count = sem->count;
-#else
- long temp;
- __asm__ __volatile__(
- " mb\n"
- "1: ldq_l %0,%1\n"
- " subq %0,%3,%2\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- " subq %0,%3,%0\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (count), "=m" (sem->count), "=&r" (temp)
- :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory");
-#endif
- if (unlikely(count))
- if ((int)count == 0)
- rwsem_wake(sem);
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- long oldcount;
-#ifndef CONFIG_SMP
- oldcount = sem->count;
- sem->count -= RWSEM_WAITING_BIAS;
-#else
- long temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%3,%2\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- " mb\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp)
- :"Ir" (-RWSEM_WAITING_BIAS), "m" (sem->count) : "memory");
-#endif
- if (unlikely(oldcount < 0))
- rwsem_downgrade_wake(sem);
-}
-
-static inline void rwsem_atomic_add(long val, struct rw_semaphore *sem)
-{
-#ifndef CONFIG_SMP
- sem->count += val;
-#else
- long temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%2,%0\n"
- " stq_c %0,%1\n"
- " beq %0,2f\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (temp), "=m" (sem->count)
- :"Ir" (val), "m" (sem->count));
-#endif
-}
-
-static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem)
-{
-#ifndef CONFIG_SMP
- sem->count += val;
- return sem->count;
-#else
- long ret, temp;
- __asm__ __volatile__(
- "1: ldq_l %0,%1\n"
- " addq %0,%3,%2\n"
- " addq %0,%3,%0\n"
- " stq_c %2,%1\n"
- " beq %2,2f\n"
- ".subsection 2\n"
- "2: br 1b\n"
- ".previous"
- :"=&r" (ret), "=m" (sem->count), "=&r" (temp)
- :"Ir" (val), "m" (sem->count));
-
- return ret;
-#endif
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-#endif /* _ALPHA_RWSEM_H */
Index: linux-2.6/include/asm-i386/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-i386/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,296 +0,0 @@
-/* rwsem.h: R/W semaphores implemented using XADD/CMPXCHG for i486+
- *
- * Written by David Howells ([email protected]).
- *
- * Derived from asm-i386/semaphore.h
- *
- *
- * The MSW of the count is the negated number of active writers and waiting
- * lockers, and the LSW is the total number of active locks
- *
- * The lock count is initialized to 0 (no active and no waiting lockers).
- *
- * When a writer subtracts WRITE_BIAS, it'll get 0xffff0001 for the case of an
- * uncontended lock. This can be determined because XADD returns the old value.
- * Readers increment by 1 and see a positive value when uncontended, negative
- * if there are writers (and maybe) readers waiting (in which case it goes to
- * sleep).
- *
- * The value of WAITING_BIAS supports up to 32766 waiting processes. This can
- * be extended to 65534 by manually checking the whole MSW rather than relying
- * on the S flag.
- *
- * The value of ACTIVE_BIAS supports up to 65535 active processes.
- *
- * This should be totally fair - if anything is waiting, a process that wants a
- * lock will go to the back of the queue. When the currently active lock is
- * released, if there's a writer at the front of the queue, then that and only
- * that will be woken up; if there's a bunch of consequtive readers at the
- * front, then they'll all be woken up, but no other readers will be.
- */
-
-#ifndef _I386_RWSEM_H
-#define _I386_RWSEM_H
-
-#ifndef _LINUX_RWSEM_H
-#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
-#endif
-
-#ifdef __KERNEL__
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <linux/lockdep.h>
-
-struct rwsem_waiter;
-
-extern struct rw_semaphore *FASTCALL(rwsem_down_read_failed(struct rw_semaphore *sem));
-extern struct rw_semaphore *FASTCALL(rwsem_down_write_failed(struct rw_semaphore *sem));
-extern struct rw_semaphore *FASTCALL(rwsem_wake(struct rw_semaphore *));
-extern struct rw_semaphore *FASTCALL(rwsem_downgrade_wake(struct rw_semaphore *sem));
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- signed long count;
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS (-0x00010000)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
- spinlock_t wait_lock;
- struct list_head wait_list;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lockdep_map dep_map;
-#endif
-};
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
-#else
-# define __RWSEM_DEP_MAP_INIT(lockname)
-#endif
-
-
-#define __RWSEM_INITIALIZER(name) \
-{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \
- __RWSEM_DEP_MAP_INIT(name) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
- struct lock_class_key *key);
-
-#define init_rwsem(sem) \
-do { \
- static struct lock_class_key __key; \
- \
- __init_rwsem((sem), #sem, &__key); \
-} while (0)
-
-/*
- * lock for reading
- */
-static inline void __down_read(struct rw_semaphore *sem)
-{
- __asm__ __volatile__(
- "# beginning down_read\n\t"
-LOCK_PREFIX " incl (%%eax)\n\t" /* adds 0x00000001, returns the old value */
- " js 2f\n\t" /* jump if we weren't granted the lock */
- "1:\n\t"
- LOCK_SECTION_START("")
- "2:\n\t"
- " pushl %%ecx\n\t"
- " pushl %%edx\n\t"
- " call rwsem_down_read_failed\n\t"
- " popl %%edx\n\t"
- " popl %%ecx\n\t"
- " jmp 1b\n"
- LOCK_SECTION_END
- "# ending down_read\n\t"
- : "+m" (sem->count)
- : "a" (sem)
- : "memory", "cc");
-}
-
-/*
- * trylock for reading -- returns 1 if successful, 0 if contention
- */
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- __s32 result, tmp;
- __asm__ __volatile__(
- "# beginning __down_read_trylock\n\t"
- " movl %0,%1\n\t"
- "1:\n\t"
- " movl %1,%2\n\t"
- " addl %3,%2\n\t"
- " jle 2f\n\t"
-LOCK_PREFIX " cmpxchgl %2,%0\n\t"
- " jnz 1b\n\t"
- "2:\n\t"
- "# ending __down_read_trylock\n\t"
- : "+m" (sem->count), "=&a" (result), "=&r" (tmp)
- : "i" (RWSEM_ACTIVE_READ_BIAS)
- : "memory", "cc");
- return result>=0 ? 1 : 0;
-}
-
-/*
- * lock for writing
- */
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
-{
- int tmp;
-
- tmp = RWSEM_ACTIVE_WRITE_BIAS;
- __asm__ __volatile__(
- "# beginning down_write\n\t"
-LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtract 0x0000ffff, returns the old value */
- " testl %%edx,%%edx\n\t" /* was the count 0 before? */
- " jnz 2f\n\t" /* jump if we weren't granted the lock */
- "1:\n\t"
- LOCK_SECTION_START("")
- "2:\n\t"
- " pushl %%ecx\n\t"
- " call rwsem_down_write_failed\n\t"
- " popl %%ecx\n\t"
- " jmp 1b\n"
- LOCK_SECTION_END
- "# ending down_write"
- : "+m" (sem->count), "=d" (tmp)
- : "a" (sem), "1" (tmp)
- : "memory", "cc");
-}
-
-static inline void __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- signed long ret = cmpxchg(&sem->count,
- RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- if (ret == RWSEM_UNLOCKED_VALUE)
- return 1;
- return 0;
-}
-
-/*
- * unlock after reading
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
- __s32 tmp = -RWSEM_ACTIVE_READ_BIAS;
- __asm__ __volatile__(
- "# beginning __up_read\n\t"
-LOCK_PREFIX " xadd %%edx,(%%eax)\n\t" /* subtracts 1, returns the old value */
- " js 2f\n\t" /* jump if the lock is being waited upon */
- "1:\n\t"
- LOCK_SECTION_START("")
- "2:\n\t"
- " decw %%dx\n\t" /* do nothing if still outstanding active readers */
- " jnz 1b\n\t"
- " pushl %%ecx\n\t"
- " call rwsem_wake\n\t"
- " popl %%ecx\n\t"
- " jmp 1b\n"
- LOCK_SECTION_END
- "# ending __up_read\n"
- : "+m" (sem->count), "=d" (tmp)
- : "a" (sem), "1" (tmp)
- : "memory", "cc");
-}
-
-/*
- * unlock after writing
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
- __asm__ __volatile__(
- "# beginning __up_write\n\t"
- " movl %2,%%edx\n\t"
-LOCK_PREFIX " xaddl %%edx,(%%eax)\n\t" /* tries to transition 0xffff0001 -> 0x00000000 */
- " jnz 2f\n\t" /* jump if the lock is being waited upon */
- "1:\n\t"
- LOCK_SECTION_START("")
- "2:\n\t"
- " decw %%dx\n\t" /* did the active count reduce to 0? */
- " jnz 1b\n\t" /* jump back if not */
- " pushl %%ecx\n\t"
- " call rwsem_wake\n\t"
- " popl %%ecx\n\t"
- " jmp 1b\n"
- LOCK_SECTION_END
- "# ending __up_write\n"
- : "+m" (sem->count)
- : "a" (sem), "i" (-RWSEM_ACTIVE_WRITE_BIAS)
- : "memory", "cc", "edx");
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- __asm__ __volatile__(
- "# beginning __downgrade_write\n\t"
-LOCK_PREFIX " addl %2,(%%eax)\n\t" /* transitions 0xZZZZ0001 -> 0xYYYY0001 */
- " js 2f\n\t" /* jump if the lock is being waited upon */
- "1:\n\t"
- LOCK_SECTION_START("")
- "2:\n\t"
- " pushl %%ecx\n\t"
- " pushl %%edx\n\t"
- " call rwsem_downgrade_wake\n\t"
- " popl %%edx\n\t"
- " popl %%ecx\n\t"
- " jmp 1b\n"
- LOCK_SECTION_END
- "# ending __downgrade_write\n"
- : "+m" (sem->count)
- : "a" (sem), "i" (-RWSEM_WAITING_BIAS)
- : "memory", "cc");
-}
-
-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
-{
- __asm__ __volatile__(
-LOCK_PREFIX "addl %1,%0"
- : "+m" (sem->count)
- : "ir" (delta));
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
-{
- int tmp = delta;
-
- __asm__ __volatile__(
-LOCK_PREFIX "xadd %0,%1"
- : "+r" (tmp), "+m" (sem->count)
- : : "memory");
-
- return tmp+delta;
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-#endif /* _I386_RWSEM_H */
Index: linux-2.6/include/asm-ia64/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-ia64/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,178 +0,0 @@
-/*
- * asm-ia64/rwsem.h: R/W semaphores for ia64
- *
- * Copyright (C) 2003 Ken Chen <[email protected]>
- * Copyright (C) 2003 Asit Mallick <[email protected]>
- * Copyright (C) 2005 Christoph Lameter <[email protected]>
- *
- * Based on asm-i386/rwsem.h and other architecture implementation.
- *
- * The MSW of the count is the negated number of active writers and
- * waiting lockers, and the LSW is the total number of active locks.
- *
- * The lock count is initialized to 0 (no active and no waiting lockers).
- *
- * When a writer subtracts WRITE_BIAS, it'll get 0xffffffff00000001 for
- * the case of an uncontended lock. Readers increment by 1 and see a positive
- * value when uncontended, negative if there are writers (and maybe) readers
- * waiting (in which case it goes to sleep).
- */
-
-#ifndef _ASM_IA64_RWSEM_H
-#define _ASM_IA64_RWSEM_H
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-
-#include <asm/intrinsics.h>
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- signed long count;
- spinlock_t wait_lock;
- struct list_head wait_list;
-};
-
-#define RWSEM_UNLOCKED_VALUE __IA64_UL_CONST(0x0000000000000000)
-#define RWSEM_ACTIVE_BIAS __IA64_UL_CONST(0x0000000000000001)
-#define RWSEM_ACTIVE_MASK __IA64_UL_CONST(0x00000000ffffffff)
-#define RWSEM_WAITING_BIAS -__IA64_UL_CONST(0x0000000100000000)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
-
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
- LIST_HEAD_INIT((name).wait_list) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-static inline void
-init_rwsem (struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-/*
- * lock for reading
- */
-static inline void
-__down_read (struct rw_semaphore *sem)
-{
- long result = ia64_fetchadd8_acq((unsigned long *)&sem->count, 1);
-
- if (result < 0)
- rwsem_down_read_failed(sem);
-}
-
-/*
- * lock for writing
- */
-static inline void
-__down_write (struct rw_semaphore *sem)
-{
- long old, new;
-
- do {
- old = sem->count;
- new = old + RWSEM_ACTIVE_WRITE_BIAS;
- } while (cmpxchg_acq(&sem->count, old, new) != old);
-
- if (old != 0)
- rwsem_down_write_failed(sem);
-}
-
-/*
- * unlock after reading
- */
-static inline void
-__up_read (struct rw_semaphore *sem)
-{
- long result = ia64_fetchadd8_rel((unsigned long *)&sem->count, -1);
-
- if (result < 0 && (--result & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * unlock after writing
- */
-static inline void
-__up_write (struct rw_semaphore *sem)
-{
- long old, new;
-
- do {
- old = sem->count;
- new = old - RWSEM_ACTIVE_WRITE_BIAS;
- } while (cmpxchg_rel(&sem->count, old, new) != old);
-
- if (new < 0 && (new & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * trylock for reading -- returns 1 if successful, 0 if contention
- */
-static inline int
-__down_read_trylock (struct rw_semaphore *sem)
-{
- long tmp;
- while ((tmp = sem->count) >= 0) {
- if (tmp == cmpxchg_acq(&sem->count, tmp, tmp+1)) {
- return 1;
- }
- }
- return 0;
-}
-
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-static inline int
-__down_write_trylock (struct rw_semaphore *sem)
-{
- long tmp = cmpxchg_acq(&sem->count, RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- return tmp == RWSEM_UNLOCKED_VALUE;
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void
-__downgrade_write (struct rw_semaphore *sem)
-{
- long old, new;
-
- do {
- old = sem->count;
- new = old - RWSEM_WAITING_BIAS;
- } while (cmpxchg_rel(&sem->count, old, new) != old);
-
- if (old < 0)
- rwsem_downgrade_wake(sem);
-}
-
-/*
- * Implement atomic add functionality. These used to be "inline" functions, but GCC v3.1
- * doesn't quite optimize this stuff right and ends up with bad calls to fetchandadd.
- */
-#define rwsem_atomic_add(delta, sem) atomic64_add(delta, (atomic64_t *)(&(sem)->count))
-#define rwsem_atomic_update(delta, sem) atomic64_add_return(delta, (atomic64_t *)(&(sem)->count))
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* _ASM_IA64_RWSEM_H */
Index: linux-2.6/include/asm-s390/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-s390/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,387 +0,0 @@
-#ifndef _S390_RWSEM_H
-#define _S390_RWSEM_H
-
-/*
- * include/asm-s390/rwsem.h
- *
- * S390 version
- * Copyright (C) 2002 IBM Deutschland Entwicklung GmbH, IBM Corporation
- * Author(s): Martin Schwidefsky ([email protected])
- *
- * Based on asm-alpha/semaphore.h and asm-i386/rwsem.h
- */
-
-/*
- *
- * The MSW of the count is the negated number of active writers and waiting
- * lockers, and the LSW is the total number of active locks
- *
- * The lock count is initialized to 0 (no active and no waiting lockers).
- *
- * When a writer subtracts WRITE_BIAS, it'll get 0xffff0001 for the case of an
- * uncontended lock. This can be determined because XADD returns the old value.
- * Readers increment by 1 and see a positive value when uncontended, negative
- * if there are writers (and maybe) readers waiting (in which case it goes to
- * sleep).
- *
- * The value of WAITING_BIAS supports up to 32766 waiting processes. This can
- * be extended to 65534 by manually checking the whole MSW rather than relying
- * on the S flag.
- *
- * The value of ACTIVE_BIAS supports up to 65535 active processes.
- *
- * This should be totally fair - if anything is waiting, a process that wants a
- * lock will go to the back of the queue. When the currently active lock is
- * released, if there's a writer at the front of the queue, then that and only
- * that will be woken up; if there's a bunch of consequtive readers at the
- * front, then they'll all be woken up, but no other readers will be.
- */
-
-#ifndef _LINUX_RWSEM_H
-#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
-#endif
-
-#ifdef __KERNEL__
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-
-struct rwsem_waiter;
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *);
-extern struct rw_semaphore *rwsem_downgrade_write(struct rw_semaphore *);
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- signed long count;
- spinlock_t wait_lock;
- struct list_head wait_list;
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- struct lockdep_map dep_map;
-#endif
-};
-
-#ifndef __s390x__
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS (-0x00010000)
-#else /* __s390x__ */
-#define RWSEM_UNLOCKED_VALUE 0x0000000000000000L
-#define RWSEM_ACTIVE_BIAS 0x0000000000000001L
-#define RWSEM_ACTIVE_MASK 0x00000000ffffffffL
-#define RWSEM_WAITING_BIAS (-0x0000000100000000L)
-#endif /* __s390x__ */
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
-
-/*
- * initialisation
- */
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __RWSEM_DEP_MAP_INIT(lockname) , .dep_map = { .name = #lockname }
-#else
-# define __RWSEM_DEP_MAP_INIT(lockname)
-#endif
-
-#define __RWSEM_INITIALIZER(name) \
-{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \
- __RWSEM_DEP_MAP_INIT(name) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-static inline void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-extern void __init_rwsem(struct rw_semaphore *sem, const char *name,
- struct lock_class_key *key);
-
-#define init_rwsem(sem) \
-do { \
- static struct lock_class_key __key; \
- \
- __init_rwsem((sem), #sem, &__key); \
-} while (0)
-
-
-/*
- * lock for reading
- */
-static inline void __down_read(struct rw_semaphore *sem)
-{
- signed long old, new;
-
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " ahi %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " aghi %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count),
- "i" (RWSEM_ACTIVE_READ_BIAS) : "cc", "memory" );
- if (old < 0)
- rwsem_down_read_failed(sem);
-}
-
-/*
- * trylock for reading -- returns 1 if successful, 0 if contention
- */
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- signed long old, new;
-
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: ltr %1,%0\n"
- " jm 1f\n"
- " ahi %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b\n"
- "1:"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: ltgr %1,%0\n"
- " jm 1f\n"
- " aghi %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b\n"
- "1:"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count),
- "i" (RWSEM_ACTIVE_READ_BIAS) : "cc", "memory" );
- return old >= 0 ? 1 : 0;
-}
-
-/*
- * lock for writing
- */
-static inline void __down_write_nested(struct rw_semaphore *sem, int subclass)
-{
- signed long old, new, tmp;
-
- tmp = RWSEM_ACTIVE_WRITE_BIAS;
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " a %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " ag %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count), "m" (tmp)
- : "cc", "memory" );
- if (old != 0)
- rwsem_down_write_failed(sem);
-}
-
-static inline void __down_write(struct rw_semaphore *sem)
-{
- __down_write_nested(sem, 0);
-}
-
-/*
- * trylock for writing -- returns 1 if successful, 0 if contention
- */
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- signed long old;
-
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%2)\n"
- "0: ltr %0,%0\n"
- " jnz 1f\n"
- " cs %0,%4,0(%2)\n"
- " jl 0b\n"
-#else /* __s390x__ */
- " lg %0,0(%2)\n"
- "0: ltgr %0,%0\n"
- " jnz 1f\n"
- " csg %0,%4,0(%2)\n"
- " jl 0b\n"
-#endif /* __s390x__ */
- "1:"
- : "=&d" (old), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count),
- "d" (RWSEM_ACTIVE_WRITE_BIAS) : "cc", "memory" );
- return (old == RWSEM_UNLOCKED_VALUE) ? 1 : 0;
-}
-
-/*
- * unlock after reading
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
- signed long old, new;
-
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " ahi %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " aghi %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count),
- "i" (-RWSEM_ACTIVE_READ_BIAS)
- : "cc", "memory" );
- if (new < 0)
- if ((new & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * unlock after writing
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
- signed long old, new, tmp;
-
- tmp = -RWSEM_ACTIVE_WRITE_BIAS;
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " a %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " ag %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count), "m" (tmp)
- : "cc", "memory" );
- if (new < 0)
- if ((new & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- signed long old, new, tmp;
-
- tmp = -RWSEM_WAITING_BIAS;
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " a %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " ag %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count), "m" (tmp)
- : "cc", "memory" );
- if (new > 1)
- rwsem_downgrade_wake(sem);
-}
-
-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(long delta, struct rw_semaphore *sem)
-{
- signed long old, new;
-
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " ar %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " agr %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count), "d" (delta)
- : "cc", "memory" );
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
-{
- signed long old, new;
-
- __asm__ __volatile__(
-#ifndef __s390x__
- " l %0,0(%3)\n"
- "0: lr %1,%0\n"
- " ar %1,%5\n"
- " cs %0,%1,0(%3)\n"
- " jl 0b"
-#else /* __s390x__ */
- " lg %0,0(%3)\n"
- "0: lgr %1,%0\n"
- " agr %1,%5\n"
- " csg %0,%1,0(%3)\n"
- " jl 0b"
-#endif /* __s390x__ */
- : "=&d" (old), "=&d" (new), "=m" (sem->count)
- : "a" (&sem->count), "m" (sem->count), "d" (delta)
- : "cc", "memory" );
- return new;
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-#endif /* _S390_RWSEM_H */
Index: linux-2.6/include/asm-sh/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-sh/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,159 +0,0 @@
-/*
- * include/asm-ppc/rwsem.h: R/W semaphores for SH using the stuff
- * in lib/rwsem.c.
- */
-
-#ifndef _ASM_SH_RWSEM_H
-#define _ASM_SH_RWSEM_H
-
-#ifdef __KERNEL__
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- long count;
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS (-0x00010000)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
- spinlock_t wait_lock;
- struct list_head wait_list;
-};
-
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
- LIST_HEAD_INIT((name).wait_list) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-static inline void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-/*
- * lock for reading
- */
-static inline void __down_read(struct rw_semaphore *sem)
-{
- if (atomic_inc_return((atomic_t *)(&sem->count)) > 0)
- smp_wmb();
- else
- rwsem_down_read_failed(sem);
-}
-
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- while ((tmp = sem->count) >= 0) {
- if (tmp == cmpxchg(&sem->count, tmp,
- tmp + RWSEM_ACTIVE_READ_BIAS)) {
- smp_wmb();
- return 1;
- }
- }
- return 0;
-}
-
-/*
- * lock for writing
- */
-static inline void __down_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count));
- if (tmp == RWSEM_ACTIVE_WRITE_BIAS)
- smp_wmb();
- else
- rwsem_down_write_failed(sem);
-}
-
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- smp_wmb();
- return tmp == RWSEM_UNLOCKED_VALUE;
-}
-
-/*
- * unlock after reading
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
- int tmp;
-
- smp_wmb();
- tmp = atomic_dec_return((atomic_t *)(&sem->count));
- if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * unlock after writing
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
- smp_wmb();
- if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count)) < 0)
- rwsem_wake(sem);
-}
-
-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
-{
- atomic_add(delta, (atomic_t *)(&sem->count));
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- smp_wmb();
- tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count));
- if (tmp < 0)
- rwsem_downgrade_wake(sem);
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
-{
- smp_mb();
- return atomic_add_return(delta, (atomic_t *)(&sem->count));
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-#endif /* _ASM_SH_RWSEM_H */
Index: linux-2.6/include/asm-sparc64/rwsem-const.h
===================================================================
--- linux-2.6.orig/include/asm-sparc64/rwsem-const.h 2005-06-22 12:56:58.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,12 +0,0 @@
-/* rwsem-const.h: RW semaphore counter constants. */
-#ifndef _SPARC64_RWSEM_CONST_H
-#define _SPARC64_RWSEM_CONST_H
-
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS 0xffff0000
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
-
-#endif /* _SPARC64_RWSEM_CONST_H */
Index: linux-2.6/include/asm-sparc64/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-sparc64/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,66 +0,0 @@
-/* $Id: rwsem.h,v 1.5 2001/11/18 00:12:56 davem Exp $
- * rwsem.h: R/W semaphores implemented using CAS
- *
- * Written by David S. Miller ([email protected]), 2001.
- * Derived from asm-i386/rwsem.h
- */
-#ifndef _SPARC64_RWSEM_H
-#define _SPARC64_RWSEM_H
-
-#ifndef _LINUX_RWSEM_H
-#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead"
-#endif
-
-#ifdef __KERNEL__
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <asm/rwsem-const.h>
-
-struct rwsem_waiter;
-
-struct rw_semaphore {
- signed int count;
- spinlock_t wait_lock;
- struct list_head wait_list;
-};
-
-#define __RWSEM_INITIALIZER(name) \
-{ RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-static __inline__ void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-extern void __down_read(struct rw_semaphore *sem);
-extern int __down_read_trylock(struct rw_semaphore *sem);
-extern void __down_write(struct rw_semaphore *sem);
-extern int __down_write_trylock(struct rw_semaphore *sem);
-extern void __up_read(struct rw_semaphore *sem);
-extern void __up_write(struct rw_semaphore *sem);
-extern void __downgrade_write(struct rw_semaphore *sem);
-
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
-{
- return atomic_add_return(delta, (atomic_t *)(&sem->count));
-}
-
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
-{
- atomic_add(delta, (atomic_t *)(&sem->count));
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* __KERNEL__ */
-
-#endif /* _SPARC64_RWSEM_H */
Index: linux-2.6/include/asm-um/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-um/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,6 +0,0 @@
-#ifndef __UM_RWSEM_H__
-#define __UM_RWSEM_H__
-
-#include "asm/arch/rwsem.h"
-
-#endif
Index: linux-2.6/include/asm-xtensa/rwsem.h
===================================================================
--- linux-2.6.orig/include/asm-xtensa/rwsem.h 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,164 +0,0 @@
-/*
- * include/asm-xtensa/rwsem.h
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file "COPYING" in the main directory of this archive
- * for more details.
- *
- * Largely copied from include/asm-ppc/rwsem.h
- *
- * Copyright (C) 2001 - 2005 Tensilica Inc.
- */
-
-#ifndef _XTENSA_RWSEM_H
-#define _XTENSA_RWSEM_H
-
-#include <linux/list.h>
-#include <linux/spinlock.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-
-/*
- * the semaphore definition
- */
-struct rw_semaphore {
- signed long count;
-#define RWSEM_UNLOCKED_VALUE 0x00000000
-#define RWSEM_ACTIVE_BIAS 0x00000001
-#define RWSEM_ACTIVE_MASK 0x0000ffff
-#define RWSEM_WAITING_BIAS (-0x00010000)
-#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS
-#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
- spinlock_t wait_lock;
- struct list_head wait_list;
-};
-
-#define __RWSEM_INITIALIZER(name) \
- { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, \
- LIST_HEAD_INIT((name).wait_list) }
-
-#define DECLARE_RWSEM(name) \
- struct rw_semaphore name = __RWSEM_INITIALIZER(name)
-
-extern struct rw_semaphore *rwsem_down_read_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_down_write_failed(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem);
-extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem);
-
-static inline void init_rwsem(struct rw_semaphore *sem)
-{
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-/*
- * lock for reading
- */
-static inline void __down_read(struct rw_semaphore *sem)
-{
- if (atomic_add_return(1,(atomic_t *)(&sem->count)) > 0)
- smp_wmb();
- else
- rwsem_down_read_failed(sem);
-}
-
-static inline int __down_read_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- while ((tmp = sem->count) >= 0) {
- if (tmp == cmpxchg(&sem->count, tmp,
- tmp + RWSEM_ACTIVE_READ_BIAS)) {
- smp_wmb();
- return 1;
- }
- }
- return 0;
-}
-
-/*
- * lock for writing
- */
-static inline void __down_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count));
- if (tmp == RWSEM_ACTIVE_WRITE_BIAS)
- smp_wmb();
- else
- rwsem_down_write_failed(sem);
-}
-
-static inline int __down_write_trylock(struct rw_semaphore *sem)
-{
- int tmp;
-
- tmp = cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
- RWSEM_ACTIVE_WRITE_BIAS);
- smp_wmb();
- return tmp == RWSEM_UNLOCKED_VALUE;
-}
-
-/*
- * unlock after reading
- */
-static inline void __up_read(struct rw_semaphore *sem)
-{
- int tmp;
-
- smp_wmb();
- tmp = atomic_sub_return(1,(atomic_t *)(&sem->count));
- if (tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)
- rwsem_wake(sem);
-}
-
-/*
- * unlock after writing
- */
-static inline void __up_write(struct rw_semaphore *sem)
-{
- smp_wmb();
- if (atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
- (atomic_t *)(&sem->count)) < 0)
- rwsem_wake(sem);
-}
-
-/*
- * implement atomic add functionality
- */
-static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
-{
- atomic_add(delta, (atomic_t *)(&sem->count));
-}
-
-/*
- * downgrade write lock to read lock
- */
-static inline void __downgrade_write(struct rw_semaphore *sem)
-{
- int tmp;
-
- smp_wmb();
- tmp = atomic_add_return(-RWSEM_WAITING_BIAS, (atomic_t *)(&sem->count));
- if (tmp < 0)
- rwsem_downgrade_wake(sem);
-}
-
-/*
- * implement exchange and add functionality
- */
-static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
-{
- smp_mb();
- return atomic_add_return(delta, (atomic_t *)(&sem->count));
-}
-
-static inline int rwsem_is_locked(struct rw_semaphore *sem)
-{
- return (sem->count != 0);
-}
-
-#endif /* _XTENSA_RWSEM_H */
Index: linux-2.6/kernel/rwsem.c
===================================================================
--- linux-2.6.orig/kernel/rwsem.c 2006-08-05 18:38:48.000000000 +1000
+++ linux-2.6/kernel/rwsem.c 2006-09-14 03:47:06.000000000 +1000
@@ -13,6 +13,249 @@
#include <asm/atomic.h>
/*
+ * Initialize an rwsem:
+ */
+void __init_rwsem(struct rw_semaphore *sem, const char *name,
+ struct lock_class_key *key)
+{
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ /*
+ * Make sure we are not reinitializing a held semaphore:
+ */
+ debug_check_no_locks_freed((void *)sem, sizeof(*sem));
+ lockdep_init_map(&sem->dep_map, name, key);
+#endif
+ atomic_set(&sem->count, RWSEM_UNLOCKED_VALUE);
+ spin_lock_init(&sem->wait_lock);
+ INIT_LIST_HEAD(&sem->wait_list);
+}
+
+EXPORT_SYMBOL(__init_rwsem);
+
+struct rwsem_waiter {
+ struct list_head list;
+ struct task_struct *task;
+ unsigned int flags;
+#define RWSEM_WAITING_FOR_READ 0x00000001
+#define RWSEM_WAITING_FOR_WRITE 0x00000002
+};
+
+/*
+ * handle the lock release when processes blocked on it that can now run
+ * - if we come here from up_xxxx(), then:
+ * - the 'active part' of count (&0x0000ffff) reached 0 (but may have changed)
+ * - the 'waiting part' of count (&0xffff0000) is -ve (and will still be so)
+ * - there must be someone on the queue
+ * - the spinlock must be held by the caller
+ * - woken process blocks are discarded from the list after having task zeroed
+ * - writers are only woken if downgrading is false
+ */
+static struct rw_semaphore *__rwsem_do_wake(struct rw_semaphore *sem,
+ int downgrading)
+{
+ struct rwsem_waiter *waiter;
+ struct task_struct *tsk;
+ struct list_head *next;
+ signed long oldcount, woken, loop;
+
+ if (downgrading)
+ goto dont_wake_writers;
+
+ /* if we came through an up_xxxx() call, we only only wake someone up
+ * if we can transition the active part of the count from 0 -> 1
+ */
+ try_again:
+ oldcount = atomic_add_return(RWSEM_ACTIVE_BIAS, &sem->count)
+ - RWSEM_ACTIVE_BIAS;
+ if (oldcount & RWSEM_ACTIVE_MASK)
+ goto undo;
+
+ waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
+
+ /* try to grant a single write lock if there's a writer at the front
+ * of the queue - note we leave the 'active part' of the count
+ * incremented by 1 and the waiting part incremented by 0x00010000
+ */
+ if (!(waiter->flags & RWSEM_WAITING_FOR_WRITE))
+ goto readers_only;
+
+ /* We must be careful not to touch 'waiter' after we set ->task = NULL.
+ * It is an allocated on the waiter's stack and may become invalid at
+ * any time after that point (due to a wakeup from another source).
+ */
+ list_del(&waiter->list);
+ tsk = waiter->task;
+ smp_mb();
+ waiter->task = NULL;
+ wake_up_process(tsk);
+ put_task_struct(tsk);
+ goto out;
+
+ /* don't want to wake any writers */
+ dont_wake_writers:
+ waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
+ if (waiter->flags & RWSEM_WAITING_FOR_WRITE)
+ goto out;
+
+ /* grant an infinite number of read locks to the readers at the front
+ * of the queue
+ * - note we increment the 'active part' of the count by the number of
+ * readers before waking any processes up
+ */
+ readers_only:
+ woken = 0;
+ do {
+ woken++;
+
+ if (waiter->list.next == &sem->wait_list)
+ break;
+
+ waiter = list_entry(waiter->list.next,
+ struct rwsem_waiter, list);
+
+ } while (waiter->flags & RWSEM_WAITING_FOR_READ);
+
+ loop = woken;
+ woken *= RWSEM_ACTIVE_BIAS - RWSEM_WAITING_BIAS;
+ if (!downgrading)
+ /* we'd already done one increment earlier */
+ woken -= RWSEM_ACTIVE_BIAS;
+
+ atomic_add(woken, &sem->count);
+
+ next = sem->wait_list.next;
+ for (; loop > 0; loop--) {
+ waiter = list_entry(next, struct rwsem_waiter, list);
+ next = waiter->list.next;
+ tsk = waiter->task;
+ smp_mb();
+ waiter->task = NULL;
+ wake_up_process(tsk);
+ put_task_struct(tsk);
+ }
+
+ sem->wait_list.next = next;
+ next->prev = &sem->wait_list;
+
+ out:
+ return sem;
+
+ /* undo the change to count, but check for a transition 1->0 */
+ undo:
+ if (atomic_add_return(-RWSEM_ACTIVE_BIAS, &sem->count) != 0)
+ goto out;
+ goto try_again;
+}
+
+/*
+ * wait for a lock to be granted
+ */
+static struct rw_semaphore *rwsem_down_failed_common(struct rw_semaphore *sem,
+ struct rwsem_waiter *waiter, signed long adjustment)
+{
+ struct task_struct *tsk = current;
+ signed long count;
+
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+
+ /* set up my own style of waitqueue */
+ spin_lock_irq(&sem->wait_lock);
+ waiter->task = tsk;
+ get_task_struct(tsk);
+
+ list_add_tail(&waiter->list, &sem->wait_list);
+
+ /* we're now waiting on the lock, but no longer actively read-locking */
+ count = atomic_add_return(adjustment, &sem->count);
+
+ /* if there are no active locks, wake the front queued process(es) up */
+ if (!(count & RWSEM_ACTIVE_MASK))
+ sem = __rwsem_do_wake(sem, 0);
+
+ spin_unlock_irq(&sem->wait_lock);
+
+ /* wait to be given the lock */
+ for (;;) {
+ if (!waiter->task)
+ break;
+ schedule();
+ set_task_state(tsk, TASK_UNINTERRUPTIBLE);
+ }
+
+ tsk->state = TASK_RUNNING;
+
+ return sem;
+}
+
+/*
+ * wait for the read lock to be granted
+ */
+static struct rw_semaphore __sched *rwsem_down_read_failed(
+ struct rw_semaphore *sem)
+{
+ struct rwsem_waiter waiter;
+
+ waiter.flags = RWSEM_WAITING_FOR_READ;
+ rwsem_down_failed_common(sem, &waiter,
+ RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
+ return sem;
+}
+
+/*
+ * wait for the write lock to be granted
+ */
+static struct rw_semaphore __sched *rwsem_down_write_failed(
+ struct rw_semaphore *sem)
+{
+ struct rwsem_waiter waiter;
+
+ waiter.flags = RWSEM_WAITING_FOR_WRITE;
+ rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
+
+ return sem;
+}
+
+/*
+ * handle waking up a waiter on the semaphore
+ * - up_read/up_write has decremented the active part of count if we come here
+ */
+static struct rw_semaphore *rwsem_wake(struct rw_semaphore *sem)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sem->wait_lock, flags);
+
+ /* do nothing if list empty */
+ if (!list_empty(&sem->wait_list))
+ sem = __rwsem_do_wake(sem, 0);
+
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
+
+ return sem;
+}
+
+/*
+ * downgrade a write lock into a read lock
+ * - caller incremented waiting part of count and discovered it still negative
+ * - just wake up any readers at the front of the queue
+ */
+static struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&sem->wait_lock, flags);
+
+ /* do nothing if list empty */
+ if (!list_empty(&sem->wait_list))
+ sem = __rwsem_do_wake(sem, 1);
+
+ spin_unlock_irqrestore(&sem->wait_lock, flags);
+
+ return sem;
+}
+
+
+/*
* lock for reading
*/
void down_read(struct rw_semaphore *sem)
@@ -20,7 +263,8 @@ void down_read(struct rw_semaphore *sem)
might_sleep();
rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
- __down_read(sem);
+ if (unlikely(atomic_inc_return(&sem->count) <= 0))
+ rwsem_down_read_failed(sem);
}
EXPORT_SYMBOL(down_read);
@@ -30,11 +274,16 @@ EXPORT_SYMBOL(down_read);
*/
int down_read_trylock(struct rw_semaphore *sem)
{
- int ret = __down_read_trylock(sem);
+ int tmp;
- if (ret == 1)
- rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
- return ret;
+ while ((tmp = atomic_read(&sem->count)) >= 0) {
+ if (tmp == atomic_cmpxchg(&sem->count, tmp,
+ tmp + RWSEM_ACTIVE_READ_BIAS)) {
+ rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
+ return 1;
+ }
+ }
+ return 0;
}
EXPORT_SYMBOL(down_read_trylock);
@@ -44,10 +293,14 @@ EXPORT_SYMBOL(down_read_trylock);
*/
void down_write(struct rw_semaphore *sem)
{
+ int tmp;
+
might_sleep();
rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
- __down_write(sem);
+ tmp = atomic_add_return(RWSEM_ACTIVE_WRITE_BIAS, &sem->count);
+ if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS))
+ rwsem_down_write_failed(sem);
}
EXPORT_SYMBOL(down_write);
@@ -57,11 +310,15 @@ EXPORT_SYMBOL(down_write);
*/
int down_write_trylock(struct rw_semaphore *sem)
{
- int ret = __down_write_trylock(sem);
+ int tmp;
- if (ret == 1)
+ tmp = atomic_cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE,
+ RWSEM_ACTIVE_WRITE_BIAS);
+ if (tmp == RWSEM_UNLOCKED_VALUE) {
rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
- return ret;
+ return 1;
+ }
+ return 0;
}
EXPORT_SYMBOL(down_write_trylock);
@@ -71,9 +328,13 @@ EXPORT_SYMBOL(down_write_trylock);
*/
void up_read(struct rw_semaphore *sem)
{
+ int tmp;
+
rwsem_release(&sem->dep_map, 1, _RET_IP_);
- __up_read(sem);
+ tmp = atomic_dec_return(&sem->count);
+ if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0))
+ rwsem_wake(sem);
}
EXPORT_SYMBOL(up_read);
@@ -85,7 +346,9 @@ void up_write(struct rw_semaphore *sem)
{
rwsem_release(&sem->dep_map, 1, _RET_IP_);
- __up_write(sem);
+ if (unlikely(atomic_sub_return(RWSEM_ACTIVE_WRITE_BIAS,
+ &sem->count) < 0))
+ rwsem_wake(sem);
}
EXPORT_SYMBOL(up_write);
@@ -95,11 +358,16 @@ EXPORT_SYMBOL(up_write);
*/
void downgrade_write(struct rw_semaphore *sem)
{
+ int tmp;
+
/*
* lockdep: a downgraded write will live on as a write
* dependency.
*/
- __downgrade_write(sem);
+
+ tmp = atomic_add_return(-RWSEM_WAITING_BIAS, &sem->count);
+ if (tmp < 0)
+ rwsem_downgrade_wake(sem);
}
EXPORT_SYMBOL(downgrade_write);
Index: linux-2.6/lib/rwsem.c
===================================================================
--- linux-2.6.orig/lib/rwsem.c 2006-09-14 03:18:49.000000000 +1000
+++ /dev/null 1970-01-01 00:00:00.000000000 +0000
@@ -1,257 +0,0 @@
-/* rwsem.c: R/W semaphores: contention handling functions
- *
- * Written by David Howells ([email protected]).
- * Derived from arch/i386/kernel/semaphore.c
- */
-#include <linux/rwsem.h>
-#include <linux/sched.h>
-#include <linux/init.h>
-#include <linux/module.h>
-
-/*
- * Initialize an rwsem:
- */
-void __init_rwsem(struct rw_semaphore *sem, const char *name,
- struct lock_class_key *key)
-{
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
- /*
- * Make sure we are not reinitializing a held semaphore:
- */
- debug_check_no_locks_freed((void *)sem, sizeof(*sem));
- lockdep_init_map(&sem->dep_map, name, key);
-#endif
- sem->count = RWSEM_UNLOCKED_VALUE;
- spin_lock_init(&sem->wait_lock);
- INIT_LIST_HEAD(&sem->wait_list);
-}
-
-EXPORT_SYMBOL(__init_rwsem);
-
-struct rwsem_waiter {
- struct list_head list;
- struct task_struct *task;
- unsigned int flags;
-#define RWSEM_WAITING_FOR_READ 0x00000001
-#define RWSEM_WAITING_FOR_WRITE 0x00000002
-};
-
-/*
- * handle the lock release when processes blocked on it that can now run
- * - if we come here from up_xxxx(), then:
- * - the 'active part' of count (&0x0000ffff) reached 0 (but may have changed)
- * - the 'waiting part' of count (&0xffff0000) is -ve (and will still be so)
- * - there must be someone on the queue
- * - the spinlock must be held by the caller
- * - woken process blocks are discarded from the list after having task zeroed
- * - writers are only woken if downgrading is false
- */
-static inline struct rw_semaphore *
-__rwsem_do_wake(struct rw_semaphore *sem, int downgrading)
-{
- struct rwsem_waiter *waiter;
- struct task_struct *tsk;
- struct list_head *next;
- signed long oldcount, woken, loop;
-
- if (downgrading)
- goto dont_wake_writers;
-
- /* if we came through an up_xxxx() call, we only only wake someone up
- * if we can transition the active part of the count from 0 -> 1
- */
- try_again:
- oldcount = rwsem_atomic_update(RWSEM_ACTIVE_BIAS, sem)
- - RWSEM_ACTIVE_BIAS;
- if (oldcount & RWSEM_ACTIVE_MASK)
- goto undo;
-
- waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
-
- /* try to grant a single write lock if there's a writer at the front
- * of the queue - note we leave the 'active part' of the count
- * incremented by 1 and the waiting part incremented by 0x00010000
- */
- if (!(waiter->flags & RWSEM_WAITING_FOR_WRITE))
- goto readers_only;
-
- /* We must be careful not to touch 'waiter' after we set ->task = NULL.
- * It is an allocated on the waiter's stack and may become invalid at
- * any time after that point (due to a wakeup from another source).
- */
- list_del(&waiter->list);
- tsk = waiter->task;
- smp_mb();
- waiter->task = NULL;
- wake_up_process(tsk);
- put_task_struct(tsk);
- goto out;
-
- /* don't want to wake any writers */
- dont_wake_writers:
- waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
- if (waiter->flags & RWSEM_WAITING_FOR_WRITE)
- goto out;
-
- /* grant an infinite number of read locks to the readers at the front
- * of the queue
- * - note we increment the 'active part' of the count by the number of
- * readers before waking any processes up
- */
- readers_only:
- woken = 0;
- do {
- woken++;
-
- if (waiter->list.next == &sem->wait_list)
- break;
-
- waiter = list_entry(waiter->list.next,
- struct rwsem_waiter, list);
-
- } while (waiter->flags & RWSEM_WAITING_FOR_READ);
-
- loop = woken;
- woken *= RWSEM_ACTIVE_BIAS - RWSEM_WAITING_BIAS;
- if (!downgrading)
- /* we'd already done one increment earlier */
- woken -= RWSEM_ACTIVE_BIAS;
-
- rwsem_atomic_add(woken, sem);
-
- next = sem->wait_list.next;
- for (; loop > 0; loop--) {
- waiter = list_entry(next, struct rwsem_waiter, list);
- next = waiter->list.next;
- tsk = waiter->task;
- smp_mb();
- waiter->task = NULL;
- wake_up_process(tsk);
- put_task_struct(tsk);
- }
-
- sem->wait_list.next = next;
- next->prev = &sem->wait_list;
-
- out:
- return sem;
-
- /* undo the change to count, but check for a transition 1->0 */
- undo:
- if (rwsem_atomic_update(-RWSEM_ACTIVE_BIAS, sem) != 0)
- goto out;
- goto try_again;
-}
-
-/*
- * wait for a lock to be granted
- */
-static inline struct rw_semaphore *
-rwsem_down_failed_common(struct rw_semaphore *sem,
- struct rwsem_waiter *waiter, signed long adjustment)
-{
- struct task_struct *tsk = current;
- signed long count;
-
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
-
- /* set up my own style of waitqueue */
- spin_lock_irq(&sem->wait_lock);
- waiter->task = tsk;
- get_task_struct(tsk);
-
- list_add_tail(&waiter->list, &sem->wait_list);
-
- /* we're now waiting on the lock, but no longer actively read-locking */
- count = rwsem_atomic_update(adjustment, sem);
-
- /* if there are no active locks, wake the front queued process(es) up */
- if (!(count & RWSEM_ACTIVE_MASK))
- sem = __rwsem_do_wake(sem, 0);
-
- spin_unlock_irq(&sem->wait_lock);
-
- /* wait to be given the lock */
- for (;;) {
- if (!waiter->task)
- break;
- schedule();
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
- }
-
- tsk->state = TASK_RUNNING;
-
- return sem;
-}
-
-/*
- * wait for the read lock to be granted
- */
-struct rw_semaphore fastcall __sched *
-rwsem_down_read_failed(struct rw_semaphore *sem)
-{
- struct rwsem_waiter waiter;
-
- waiter.flags = RWSEM_WAITING_FOR_READ;
- rwsem_down_failed_common(sem, &waiter,
- RWSEM_WAITING_BIAS - RWSEM_ACTIVE_BIAS);
- return sem;
-}
-
-/*
- * wait for the write lock to be granted
- */
-struct rw_semaphore fastcall __sched *
-rwsem_down_write_failed(struct rw_semaphore *sem)
-{
- struct rwsem_waiter waiter;
-
- waiter.flags = RWSEM_WAITING_FOR_WRITE;
- rwsem_down_failed_common(sem, &waiter, -RWSEM_ACTIVE_BIAS);
-
- return sem;
-}
-
-/*
- * handle waking up a waiter on the semaphore
- * - up_read/up_write has decremented the active part of count if we come here
- */
-struct rw_semaphore fastcall *rwsem_wake(struct rw_semaphore *sem)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- /* do nothing if list empty */
- if (!list_empty(&sem->wait_list))
- sem = __rwsem_do_wake(sem, 0);
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- return sem;
-}
-
-/*
- * downgrade a write lock into a read lock
- * - caller incremented waiting part of count and discovered it still negative
- * - just wake up any readers at the front of the queue
- */
-struct rw_semaphore fastcall *rwsem_downgrade_wake(struct rw_semaphore *sem)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&sem->wait_lock, flags);
-
- /* do nothing if list empty */
- if (!list_empty(&sem->wait_list))
- sem = __rwsem_do_wake(sem, 1);
-
- spin_unlock_irqrestore(&sem->wait_lock, flags);
-
- return sem;
-}
-
-EXPORT_SYMBOL(rwsem_down_read_failed);
-EXPORT_SYMBOL(rwsem_down_write_failed);
-EXPORT_SYMBOL(rwsem_wake);
-EXPORT_SYMBOL(rwsem_downgrade_wake);
Index: linux-2.6/arch/alpha/Kconfig
===================================================================
--- linux-2.6.orig/arch/alpha/Kconfig 2006-06-28 02:35:47.000000000 +1000
+++ linux-2.6/arch/alpha/Kconfig 2006-09-14 03:39:45.000000000 +1000
@@ -18,13 +18,6 @@ config MMU
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/arm/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm/Kconfig 2006-08-05 18:36:24.000000000 +1000
+++ linux-2.6/arch/arm/Kconfig 2006-09-14 03:39:49.000000000 +1000
@@ -59,13 +59,6 @@ config GENERIC_IRQ_PROBE
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/arm26/Kconfig
===================================================================
--- linux-2.6.orig/arch/arm26/Kconfig 2006-08-05 18:36:30.000000000 +1000
+++ linux-2.6/arch/arm26/Kconfig 2006-09-14 03:39:52.000000000 +1000
@@ -34,13 +34,6 @@ config FORCE_MAX_ZONEORDER
int
default 9
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/cris/Kconfig
===================================================================
--- linux-2.6.orig/arch/cris/Kconfig 2006-08-05 18:36:30.000000000 +1000
+++ linux-2.6/arch/cris/Kconfig 2006-09-14 03:39:54.000000000 +1000
@@ -9,13 +9,6 @@ config MMU
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/frv/Kconfig
===================================================================
--- linux-2.6.orig/arch/frv/Kconfig 2006-04-15 20:19:19.000000000 +1000
+++ linux-2.6/arch/frv/Kconfig 2006-09-14 03:39:57.000000000 +1000
@@ -6,13 +6,6 @@ config FRV
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/h8300/Kconfig
===================================================================
--- linux-2.6.orig/arch/h8300/Kconfig 2006-04-15 20:19:19.000000000 +1000
+++ linux-2.6/arch/h8300/Kconfig 2006-09-14 03:40:03.000000000 +1000
@@ -21,14 +21,6 @@ config FPU
bool
default n
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default n
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/ia64/Kconfig
===================================================================
--- linux-2.6.orig/arch/ia64/Kconfig 2006-09-13 13:16:22.000000000 +1000
+++ linux-2.6/arch/ia64/Kconfig 2006-09-14 03:40:13.000000000 +1000
@@ -30,10 +30,6 @@ config SWIOTLB
bool
default y
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/m32r/Kconfig
===================================================================
--- linux-2.6.orig/arch/m32r/Kconfig 2006-04-20 18:54:51.000000000 +1000
+++ linux-2.6/arch/m32r/Kconfig 2006-09-14 03:40:19.000000000 +1000
@@ -205,15 +205,6 @@ config IRAM_SIZE
# Define implied options from the CPU selection here
#
-config RWSEM_GENERIC_SPINLOCK
- bool
- depends on M32R
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default n
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/m68k/Kconfig
===================================================================
--- linux-2.6.orig/arch/m68k/Kconfig 2006-04-15 20:19:20.000000000 +1000
+++ linux-2.6/arch/m68k/Kconfig 2006-09-14 03:40:22.000000000 +1000
@@ -10,13 +10,6 @@ config MMU
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/m68knommu/Kconfig
===================================================================
--- linux-2.6.orig/arch/m68knommu/Kconfig 2006-08-05 18:36:40.000000000 +1000
+++ linux-2.6/arch/m68knommu/Kconfig 2006-09-14 03:40:26.000000000 +1000
@@ -17,14 +17,6 @@ config FPU
bool
default n
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default n
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/mips/Kconfig
===================================================================
--- linux-2.6.orig/arch/mips/Kconfig 2006-08-05 18:36:40.000000000 +1000
+++ linux-2.6/arch/mips/Kconfig 2006-09-14 03:42:45.000000000 +1000
@@ -837,13 +837,6 @@ source "arch/mips/cobalt/Kconfig"
endmenu
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_FIND_NEXT_BIT
bool
default y
@@ -1845,10 +1838,6 @@ config MIPS_INSANE_LARGE
endmenu
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
source "init/Kconfig"
menu "Bus options (PCI, PCMCIA, EISA, ISA, TC)"
Index: linux-2.6/arch/parisc/Kconfig
===================================================================
--- linux-2.6.orig/arch/parisc/Kconfig 2006-08-05 18:36:47.000000000 +1000
+++ linux-2.6/arch/parisc/Kconfig 2006-09-14 03:40:33.000000000 +1000
@@ -19,12 +19,6 @@ config MMU
config STACK_GROWSUP
def_bool y
-config RWSEM_GENERIC_SPINLOCK
- def_bool y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/powerpc/Kconfig
===================================================================
--- linux-2.6.orig/arch/powerpc/Kconfig 2006-09-13 13:16:22.000000000 +1000
+++ linux-2.6/arch/powerpc/Kconfig 2006-09-14 03:40:36.000000000 +1000
@@ -34,13 +34,6 @@ config IRQ_PER_CPU
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/ppc/Kconfig
===================================================================
--- linux-2.6.orig/arch/ppc/Kconfig 2006-08-05 18:36:52.000000000 +1000
+++ linux-2.6/arch/ppc/Kconfig 2006-09-14 03:40:38.000000000 +1000
@@ -12,13 +12,6 @@ config GENERIC_HARDIRQS
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/s390/Kconfig
===================================================================
--- linux-2.6.orig/arch/s390/Kconfig 2006-08-05 18:36:54.000000000 +1000
+++ linux-2.6/arch/s390/Kconfig 2006-09-14 03:40:41.000000000 +1000
@@ -15,13 +15,6 @@ config STACKTRACE_SUPPORT
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/sh/Kconfig
===================================================================
--- linux-2.6.orig/arch/sh/Kconfig 2006-08-05 18:36:55.000000000 +1000
+++ linux-2.6/arch/sh/Kconfig 2006-09-14 03:40:44.000000000 +1000
@@ -14,13 +14,6 @@ config SUPERH
gaming console. The SuperH port has a home page at
<http://www.linux-sh.org/>.
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/sh64/Kconfig
===================================================================
--- linux-2.6.orig/arch/sh64/Kconfig 2006-04-15 20:19:22.000000000 +1000
+++ linux-2.6/arch/sh64/Kconfig 2006-09-14 03:43:10.000000000 +1000
@@ -17,10 +17,6 @@ config MMU
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
config GENERIC_FIND_NEXT_BIT
bool
default y
@@ -33,9 +29,6 @@ config GENERIC_CALIBRATE_DELAY
bool
default y
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_ISA_DMA
bool
Index: linux-2.6/arch/sparc/Kconfig
===================================================================
--- linux-2.6.orig/arch/sparc/Kconfig 2006-04-15 20:19:22.000000000 +1000
+++ linux-2.6/arch/sparc/Kconfig 2006-09-14 03:40:51.000000000 +1000
@@ -143,13 +143,6 @@ config SUN_IO
bool
default y
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/sparc64/Kconfig
===================================================================
--- linux-2.6.orig/arch/sparc64/Kconfig 2006-08-05 18:36:59.000000000 +1000
+++ linux-2.6/arch/sparc64/Kconfig 2006-09-14 03:40:56.000000000 +1000
@@ -159,13 +159,6 @@ config US2E_FREQ
If in doubt, say N.
# Global things across all Sun machines.
-config RWSEM_GENERIC_SPINLOCK
- bool
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/v850/Kconfig
===================================================================
--- linux-2.6.orig/arch/v850/Kconfig 2006-04-15 20:19:23.000000000 +1000
+++ linux-2.6/arch/v850/Kconfig 2006-09-14 03:41:02.000000000 +1000
@@ -10,12 +10,6 @@ mainmenu "uClinux/v850 (w/o MMU) Kernel
config MMU
bool
default n
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default n
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/x86_64/Kconfig
===================================================================
--- linux-2.6.orig/arch/x86_64/Kconfig 2006-08-05 18:37:01.000000000 +1000
+++ linux-2.6/arch/x86_64/Kconfig 2006-09-14 03:41:05.000000000 +1000
@@ -46,13 +46,6 @@ config ISA
config SBUS
bool
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
-
config GENERIC_HWEIGHT
bool
default y
Index: linux-2.6/arch/xtensa/Kconfig
===================================================================
--- linux-2.6.orig/arch/xtensa/Kconfig 2006-08-05 18:37:03.000000000 +1000
+++ linux-2.6/arch/xtensa/Kconfig 2006-09-14 03:41:08.000000000 +1000
@@ -18,10 +18,6 @@ config XTENSA
with reasonable minimum requirements. The Xtensa Linux project has
a home page at <http://xtensa.sourceforge.net/>.
-config RWSEM_XCHGADD_ALGORITHM
- bool
- default y
-
config GENERIC_FIND_NEXT_BIT
bool
default y
Index: linux-2.6/arch/i386/Kconfig.cpu
===================================================================
--- linux-2.6.orig/arch/i386/Kconfig.cpu 2006-08-05 18:36:33.000000000 +1000
+++ linux-2.6/arch/i386/Kconfig.cpu 2006-09-14 03:42:35.000000000 +1000
@@ -230,16 +230,6 @@ config X86_L1_CACHE_SHIFT
default "5" if MWINCHIP3D || MWINCHIP2 || MWINCHIPC6 || MCRUSOE || MEFFICEON || MCYRIXIII || MK6 || MPENTIUMIII || MPENTIUMII || M686 || M586MMX || M586TSC || M586 || MVIAC3_2 || MGEODE_LX
default "6" if MK7 || MK8 || MPENTIUMM
-config RWSEM_GENERIC_SPINLOCK
- bool
- depends on M386
- default y
-
-config RWSEM_XCHGADD_ALGORITHM
- bool
- depends on !M386
- default y
-
config GENERIC_CALIBRATE_DELAY
bool
default y
Index: linux-2.6/arch/um/Kconfig.x86_64
===================================================================
--- linux-2.6.orig/arch/um/Kconfig.x86_64 2006-04-15 20:19:22.000000000 +1000
+++ linux-2.6/arch/um/Kconfig.x86_64 2006-09-14 03:43:07.000000000 +1000
@@ -7,10 +7,6 @@ config 64BIT
default y
#XXX: this is so in the underlying arch, but it's wrong!!!
-config RWSEM_GENERIC_SPINLOCK
- bool
- default y
-
config SEMAPHORE_SLEEPERS
bool
default y
Index: linux-2.6/lib/Makefile
===================================================================
--- linux-2.6.orig/lib/Makefile 2006-08-05 18:38:48.000000000 +1000
+++ linux-2.6/lib/Makefile 2006-09-14 03:47:18.000000000 +1000
@@ -20,8 +20,6 @@ endif
obj-$(CONFIG_DEBUG_LOCKING_API_SELFTESTS) += locking-selftest.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
-lib-$(CONFIG_RWSEM_GENERIC_SPINLOCK) += rwsem-spinlock.o
-lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_SEMAPHORE_SLEEPERS) += semaphore-sleepers.o
lib-$(CONFIG_GENERIC_FIND_NEXT_BIT) += find_next_bit.o
lib-$(CONFIG_GENERIC_HWEIGHT) += hweight.o
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