forked from Minki/linux
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
300 lines
6.6 KiB
C
300 lines
6.6 KiB
C
/*
|
|
* 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.
|
|
*
|
|
* Copyright (C) 1999, 2000 by Ralf Baechle
|
|
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
|
|
*/
|
|
#ifndef _ASM_SPINLOCK_H
|
|
#define _ASM_SPINLOCK_H
|
|
|
|
#include <linux/config.h>
|
|
#include <asm/war.h>
|
|
|
|
/*
|
|
* Your basic SMP spinlocks, allowing only a single CPU anywhere
|
|
*/
|
|
|
|
typedef struct {
|
|
volatile unsigned int lock;
|
|
#ifdef CONFIG_PREEMPT
|
|
unsigned int break_lock;
|
|
#endif
|
|
} spinlock_t;
|
|
|
|
#define SPIN_LOCK_UNLOCKED (spinlock_t) { 0 }
|
|
|
|
#define spin_lock_init(x) do { (x)->lock = 0; } while(0)
|
|
|
|
#define spin_is_locked(x) ((x)->lock != 0)
|
|
#define spin_unlock_wait(x) do { barrier(); } while ((x)->lock)
|
|
#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
|
|
|
|
/*
|
|
* Simple spin lock operations. There are two variants, one clears IRQ's
|
|
* on the local processor, one does not.
|
|
*
|
|
* We make no fairness assumptions. They have a cost.
|
|
*/
|
|
|
|
static inline void _raw_spin_lock(spinlock_t *lock)
|
|
{
|
|
unsigned int tmp;
|
|
|
|
if (R10000_LLSC_WAR) {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_spin_lock \n"
|
|
"1: ll %1, %2 \n"
|
|
" bnez %1, 1b \n"
|
|
" li %1, 1 \n"
|
|
" sc %1, %0 \n"
|
|
" beqzl %1, 1b \n"
|
|
" nop \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (lock->lock), "=&r" (tmp)
|
|
: "m" (lock->lock)
|
|
: "memory");
|
|
} else {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_spin_lock \n"
|
|
"1: ll %1, %2 \n"
|
|
" bnez %1, 1b \n"
|
|
" li %1, 1 \n"
|
|
" sc %1, %0 \n"
|
|
" beqz %1, 1b \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (lock->lock), "=&r" (tmp)
|
|
: "m" (lock->lock)
|
|
: "memory");
|
|
}
|
|
}
|
|
|
|
static inline void _raw_spin_unlock(spinlock_t *lock)
|
|
{
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_spin_unlock \n"
|
|
" sync \n"
|
|
" sw $0, %0 \n"
|
|
" .set\treorder \n"
|
|
: "=m" (lock->lock)
|
|
: "m" (lock->lock)
|
|
: "memory");
|
|
}
|
|
|
|
static inline unsigned int _raw_spin_trylock(spinlock_t *lock)
|
|
{
|
|
unsigned int temp, res;
|
|
|
|
if (R10000_LLSC_WAR) {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_spin_trylock \n"
|
|
"1: ll %0, %3 \n"
|
|
" ori %2, %0, 1 \n"
|
|
" sc %2, %1 \n"
|
|
" beqzl %2, 1b \n"
|
|
" nop \n"
|
|
" andi %2, %0, 1 \n"
|
|
" sync \n"
|
|
" .set reorder"
|
|
: "=&r" (temp), "=m" (lock->lock), "=&r" (res)
|
|
: "m" (lock->lock)
|
|
: "memory");
|
|
} else {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_spin_trylock \n"
|
|
"1: ll %0, %3 \n"
|
|
" ori %2, %0, 1 \n"
|
|
" sc %2, %1 \n"
|
|
" beqz %2, 1b \n"
|
|
" andi %2, %0, 1 \n"
|
|
" sync \n"
|
|
" .set reorder"
|
|
: "=&r" (temp), "=m" (lock->lock), "=&r" (res)
|
|
: "m" (lock->lock)
|
|
: "memory");
|
|
}
|
|
|
|
return res == 0;
|
|
}
|
|
|
|
/*
|
|
* Read-write spinlocks, allowing multiple readers but only one writer.
|
|
*
|
|
* NOTE! it is quite common to have readers in interrupts but no interrupt
|
|
* writers. For those circumstances we can "mix" irq-safe locks - any writer
|
|
* needs to get a irq-safe write-lock, but readers can get non-irqsafe
|
|
* read-locks.
|
|
*/
|
|
|
|
typedef struct {
|
|
volatile unsigned int lock;
|
|
#ifdef CONFIG_PREEMPT
|
|
unsigned int break_lock;
|
|
#endif
|
|
} rwlock_t;
|
|
|
|
#define RW_LOCK_UNLOCKED (rwlock_t) { 0 }
|
|
|
|
#define rwlock_init(x) do { *(x) = RW_LOCK_UNLOCKED; } while(0)
|
|
|
|
static inline void _raw_read_lock(rwlock_t *rw)
|
|
{
|
|
unsigned int tmp;
|
|
|
|
if (R10000_LLSC_WAR) {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_read_lock \n"
|
|
"1: ll %1, %2 \n"
|
|
" bltz %1, 1b \n"
|
|
" addu %1, 1 \n"
|
|
" sc %1, %0 \n"
|
|
" beqzl %1, 1b \n"
|
|
" nop \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (rw->lock), "=&r" (tmp)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
} else {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_read_lock \n"
|
|
"1: ll %1, %2 \n"
|
|
" bltz %1, 1b \n"
|
|
" addu %1, 1 \n"
|
|
" sc %1, %0 \n"
|
|
" beqz %1, 1b \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (rw->lock), "=&r" (tmp)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
}
|
|
}
|
|
|
|
/* Note the use of sub, not subu which will make the kernel die with an
|
|
overflow exception if we ever try to unlock an rwlock that is already
|
|
unlocked or is being held by a writer. */
|
|
static inline void _raw_read_unlock(rwlock_t *rw)
|
|
{
|
|
unsigned int tmp;
|
|
|
|
if (R10000_LLSC_WAR) {
|
|
__asm__ __volatile__(
|
|
"1: ll %1, %2 # _raw_read_unlock \n"
|
|
" sub %1, 1 \n"
|
|
" sc %1, %0 \n"
|
|
" beqzl %1, 1b \n"
|
|
" sync \n"
|
|
: "=m" (rw->lock), "=&r" (tmp)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
} else {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_read_unlock \n"
|
|
"1: ll %1, %2 \n"
|
|
" sub %1, 1 \n"
|
|
" sc %1, %0 \n"
|
|
" beqz %1, 1b \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (rw->lock), "=&r" (tmp)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
}
|
|
}
|
|
|
|
static inline void _raw_write_lock(rwlock_t *rw)
|
|
{
|
|
unsigned int tmp;
|
|
|
|
if (R10000_LLSC_WAR) {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_write_lock \n"
|
|
"1: ll %1, %2 \n"
|
|
" bnez %1, 1b \n"
|
|
" lui %1, 0x8000 \n"
|
|
" sc %1, %0 \n"
|
|
" beqzl %1, 1b \n"
|
|
" nop \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (rw->lock), "=&r" (tmp)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
} else {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_write_lock \n"
|
|
"1: ll %1, %2 \n"
|
|
" bnez %1, 1b \n"
|
|
" lui %1, 0x8000 \n"
|
|
" sc %1, %0 \n"
|
|
" beqz %1, 1b \n"
|
|
" nop \n"
|
|
" sync \n"
|
|
" .set reorder \n"
|
|
: "=m" (rw->lock), "=&r" (tmp)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
}
|
|
}
|
|
|
|
static inline void _raw_write_unlock(rwlock_t *rw)
|
|
{
|
|
__asm__ __volatile__(
|
|
" sync # _raw_write_unlock \n"
|
|
" sw $0, %0 \n"
|
|
: "=m" (rw->lock)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
}
|
|
|
|
#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
|
|
|
|
static inline int _raw_write_trylock(rwlock_t *rw)
|
|
{
|
|
unsigned int tmp;
|
|
int ret;
|
|
|
|
if (R10000_LLSC_WAR) {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_write_trylock \n"
|
|
" li %2, 0 \n"
|
|
"1: ll %1, %3 \n"
|
|
" bnez %1, 2f \n"
|
|
" lui %1, 0x8000 \n"
|
|
" sc %1, %0 \n"
|
|
" beqzl %1, 1b \n"
|
|
" nop \n"
|
|
" sync \n"
|
|
" li %2, 1 \n"
|
|
" .set reorder \n"
|
|
"2: \n"
|
|
: "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
} else {
|
|
__asm__ __volatile__(
|
|
" .set noreorder # _raw_write_trylock \n"
|
|
" li %2, 0 \n"
|
|
"1: ll %1, %3 \n"
|
|
" bnez %1, 2f \n"
|
|
" lui %1, 0x8000 \n"
|
|
" sc %1, %0 \n"
|
|
" beqz %1, 1b \n"
|
|
" sync \n"
|
|
" li %2, 1 \n"
|
|
" .set reorder \n"
|
|
"2: \n"
|
|
: "=m" (rw->lock), "=&r" (tmp), "=&r" (ret)
|
|
: "m" (rw->lock)
|
|
: "memory");
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#endif /* _ASM_SPINLOCK_H */
|