| /* |
| * arch/s390/lib/spinlock.c |
| * Out of line spinlock code. |
| * |
| * Copyright (C) IBM Corp. 2004, 2006 |
| * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| #include <linux/init.h> |
| #include <asm/io.h> |
| |
| int spin_retry = 1000; |
| |
| /** |
| * spin_retry= parameter |
| */ |
| static int __init spin_retry_setup(char *str) |
| { |
| spin_retry = simple_strtoul(str, &str, 0); |
| return 1; |
| } |
| __setup("spin_retry=", spin_retry_setup); |
| |
| static inline void |
| _diag44(void) |
| { |
| #ifdef CONFIG_64BIT |
| if (MACHINE_HAS_DIAG44) |
| #endif |
| asm volatile("diag 0,0,0x44"); |
| } |
| |
| void |
| _raw_spin_lock_wait(raw_spinlock_t *lp, unsigned int pc) |
| { |
| int count = spin_retry; |
| |
| while (1) { |
| if (count-- <= 0) { |
| _diag44(); |
| count = spin_retry; |
| } |
| if (__raw_spin_is_locked(lp)) |
| continue; |
| if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0) |
| return; |
| } |
| } |
| EXPORT_SYMBOL(_raw_spin_lock_wait); |
| |
| int |
| _raw_spin_trylock_retry(raw_spinlock_t *lp, unsigned int pc) |
| { |
| int count = spin_retry; |
| |
| while (count-- > 0) { |
| if (__raw_spin_is_locked(lp)) |
| continue; |
| if (_raw_compare_and_swap(&lp->lock, 0, pc) == 0) |
| return 1; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL(_raw_spin_trylock_retry); |
| |
| void |
| _raw_read_lock_wait(raw_rwlock_t *rw) |
| { |
| unsigned int old; |
| int count = spin_retry; |
| |
| while (1) { |
| if (count-- <= 0) { |
| _diag44(); |
| count = spin_retry; |
| } |
| if (!__raw_read_can_lock(rw)) |
| continue; |
| old = rw->lock & 0x7fffffffU; |
| if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old) |
| return; |
| } |
| } |
| EXPORT_SYMBOL(_raw_read_lock_wait); |
| |
| int |
| _raw_read_trylock_retry(raw_rwlock_t *rw) |
| { |
| unsigned int old; |
| int count = spin_retry; |
| |
| while (count-- > 0) { |
| if (!__raw_read_can_lock(rw)) |
| continue; |
| old = rw->lock & 0x7fffffffU; |
| if (_raw_compare_and_swap(&rw->lock, old, old + 1) == old) |
| return 1; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL(_raw_read_trylock_retry); |
| |
| void |
| _raw_write_lock_wait(raw_rwlock_t *rw) |
| { |
| int count = spin_retry; |
| |
| while (1) { |
| if (count-- <= 0) { |
| _diag44(); |
| count = spin_retry; |
| } |
| if (!__raw_write_can_lock(rw)) |
| continue; |
| if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0) |
| return; |
| } |
| } |
| EXPORT_SYMBOL(_raw_write_lock_wait); |
| |
| int |
| _raw_write_trylock_retry(raw_rwlock_t *rw) |
| { |
| int count = spin_retry; |
| |
| while (count-- > 0) { |
| if (!__raw_write_can_lock(rw)) |
| continue; |
| if (_raw_compare_and_swap(&rw->lock, 0, 0x80000000) == 0) |
| return 1; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL(_raw_write_trylock_retry); |