Pull lameter-rwsem-limit into release branch (87dbaaab) · Commits · git / linux-net

include/asm-ia64/rwsem.h

+18 −17

Original line number	Diff line number	Diff line
		@@ -3,6 +3,7 @@
		*
		* Copyright (C) 2003 Ken Chen <kenneth.w.chen@intel.com>
		* Copyright (C) 2003 Asit Mallick <asit.k.mallick@intel.com>
		* Copyright (C) 2005 Christoph Lameter <clameter@sgi.com>
		*
		* Based on asm-i386/rwsem.h and other architecture implementation.
		*
		@@ -11,9 +12,9 @@
		*
		* 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. Readers increment by 1 and see a positive value
		* when uncontended, negative if there are writers (and maybe) readers
		* 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).
		*/

		@@ -29,7 +30,7 @@
		* the semaphore definition
		*/
		struct rw_semaphore {
		signed int count;
		signed long count;
		spinlock_t wait_lock;
		struct list_head wait_list;
		#if RWSEM_DEBUG
		@@ -37,10 +38,10 @@ struct rw_semaphore {
		#endif
		};

		#define RWSEM_UNLOCKED_VALUE 0x00000000
		#define RWSEM_ACTIVE_BIAS 0x00000001
		#define RWSEM_ACTIVE_MASK 0x0000ffff
		#define RWSEM_WAITING_BIAS (-0x00010000)
		#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)

		@@ -83,7 +84,7 @@ init_rwsem (struct rw_semaphore *sem)
		static inline void
		__down_read (struct rw_semaphore *sem)
		{
		int result = ia64_fetchadd4_acq((unsigned int *)&sem->count, 1);
		long result = ia64_fetchadd8_acq((unsigned long *)&sem->count, 1);

		if (result < 0)
		rwsem_down_read_failed(sem);
		@@ -95,7 +96,7 @@ __down_read (struct rw_semaphore *sem)
		static inline void
		__down_write (struct rw_semaphore *sem)
		{
		int old, new;
		long old, new;

		do {
		old = sem->count;
		@@ -112,7 +113,7 @@ __down_write (struct rw_semaphore *sem)
		static inline void
		__up_read (struct rw_semaphore *sem)
		{
		int result = ia64_fetchadd4_rel((unsigned int *)&sem->count, -1);
		long result = ia64_fetchadd8_rel((unsigned long *)&sem->count, -1);

		if (result < 0 && (--result & RWSEM_ACTIVE_MASK) == 0)
		rwsem_wake(sem);
		@@ -124,7 +125,7 @@ __up_read (struct rw_semaphore *sem)
		static inline void
		__up_write (struct rw_semaphore *sem)
		{
		int old, new;
		long old, new;

		do {
		old = sem->count;
		@@ -141,7 +142,7 @@ __up_write (struct rw_semaphore *sem)
		static inline int
		__down_read_trylock (struct rw_semaphore *sem)
		{
		int tmp;
		long tmp;
		while ((tmp = sem->count) >= 0) {
		if (tmp == cmpxchg_acq(&sem->count, tmp, tmp+1)) {
		return 1;
		@@ -156,7 +157,7 @@ __down_read_trylock (struct rw_semaphore *sem)
		static inline int
		__down_write_trylock (struct rw_semaphore *sem)
		{
		int tmp = cmpxchg_acq(&sem->count, RWSEM_UNLOCKED_VALUE,
		long tmp = cmpxchg_acq(&sem->count, RWSEM_UNLOCKED_VALUE,
		RWSEM_ACTIVE_WRITE_BIAS);
		return tmp == RWSEM_UNLOCKED_VALUE;
		}
		@@ -167,7 +168,7 @@ __down_write_trylock (struct rw_semaphore *sem)
		static inline void
		__downgrade_write (struct rw_semaphore *sem)
		{
		int old, new;
		long old, new;

		do {
		old = sem->count;
		@@ -182,7 +183,7 @@ __downgrade_write (struct rw_semaphore *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) atomic_add(delta, (atomic_t *)(&(sem)->count))
		#define rwsem_atomic_update(delta, sem) atomic_add_return(delta, (atomic_t *)(&(sem)->count))
		#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))

		#endif /* _ASM_IA64_RWSEM_H */