mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 09:36:45 +07:00
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!
170 lines
3.4 KiB
C
170 lines
3.4 KiB
C
#ifndef __ASM_SPINLOCK_H
|
|
#define __ASM_SPINLOCK_H
|
|
|
|
#if __LINUX_ARM_ARCH__ < 6
|
|
#error SMP not supported on pre-ARMv6 CPUs
|
|
#endif
|
|
|
|
/*
|
|
* ARMv6 Spin-locking.
|
|
*
|
|
* We (exclusively) read the old value, and decrement it. If it
|
|
* hits zero, we may have won the lock, so we try (exclusively)
|
|
* storing it.
|
|
*
|
|
* Unlocked value: 0
|
|
* Locked value: 1
|
|
*/
|
|
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) = SPIN_LOCK_UNLOCKED; } while (0)
|
|
#define spin_is_locked(x) ((x)->lock != 0)
|
|
#define spin_unlock_wait(x) do { barrier(); } while (spin_is_locked(x))
|
|
#define _raw_spin_lock_flags(lock, flags) _raw_spin_lock(lock)
|
|
|
|
static inline void _raw_spin_lock(spinlock_t *lock)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldrex %0, [%1]\n"
|
|
" teq %0, #0\n"
|
|
" strexeq %0, %2, [%1]\n"
|
|
" teqeq %0, #0\n"
|
|
" bne 1b"
|
|
: "=&r" (tmp)
|
|
: "r" (&lock->lock), "r" (1)
|
|
: "cc", "memory");
|
|
}
|
|
|
|
static inline int _raw_spin_trylock(spinlock_t *lock)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
__asm__ __volatile__(
|
|
" ldrex %0, [%1]\n"
|
|
" teq %0, #0\n"
|
|
" strexeq %0, %2, [%1]"
|
|
: "=&r" (tmp)
|
|
: "r" (&lock->lock), "r" (1)
|
|
: "cc", "memory");
|
|
|
|
return tmp == 0;
|
|
}
|
|
|
|
static inline void _raw_spin_unlock(spinlock_t *lock)
|
|
{
|
|
__asm__ __volatile__(
|
|
" str %1, [%0]"
|
|
:
|
|
: "r" (&lock->lock), "r" (0)
|
|
: "cc", "memory");
|
|
}
|
|
|
|
/*
|
|
* RWLOCKS
|
|
*/
|
|
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)
|
|
|
|
/*
|
|
* Write locks are easy - we just set bit 31. When unlocking, we can
|
|
* just write zero since the lock is exclusively held.
|
|
*/
|
|
static inline void _raw_write_lock(rwlock_t *rw)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldrex %0, [%1]\n"
|
|
" teq %0, #0\n"
|
|
" strexeq %0, %2, [%1]\n"
|
|
" teq %0, #0\n"
|
|
" bne 1b"
|
|
: "=&r" (tmp)
|
|
: "r" (&rw->lock), "r" (0x80000000)
|
|
: "cc", "memory");
|
|
}
|
|
|
|
static inline void _raw_write_unlock(rwlock_t *rw)
|
|
{
|
|
__asm__ __volatile__(
|
|
"str %1, [%0]"
|
|
:
|
|
: "r" (&rw->lock), "r" (0)
|
|
: "cc", "memory");
|
|
}
|
|
|
|
/*
|
|
* Read locks are a bit more hairy:
|
|
* - Exclusively load the lock value.
|
|
* - Increment it.
|
|
* - Store new lock value if positive, and we still own this location.
|
|
* If the value is negative, we've already failed.
|
|
* - If we failed to store the value, we want a negative result.
|
|
* - If we failed, try again.
|
|
* Unlocking is similarly hairy. We may have multiple read locks
|
|
* currently active. However, we know we won't have any write
|
|
* locks.
|
|
*/
|
|
static inline void _raw_read_lock(rwlock_t *rw)
|
|
{
|
|
unsigned long tmp, tmp2;
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldrex %0, [%2]\n"
|
|
" adds %0, %0, #1\n"
|
|
" strexpl %1, %0, [%2]\n"
|
|
" rsbpls %0, %1, #0\n"
|
|
" bmi 1b"
|
|
: "=&r" (tmp), "=&r" (tmp2)
|
|
: "r" (&rw->lock)
|
|
: "cc", "memory");
|
|
}
|
|
|
|
static inline void _raw_read_unlock(rwlock_t *rw)
|
|
{
|
|
__asm__ __volatile__(
|
|
"1: ldrex %0, [%2]\n"
|
|
" sub %0, %0, #1\n"
|
|
" strex %1, %0, [%2]\n"
|
|
" teq %1, #0\n"
|
|
" bne 1b"
|
|
: "=&r" (tmp), "=&r" (tmp2)
|
|
: "r" (&rw->lock)
|
|
: "cc", "memory");
|
|
}
|
|
|
|
#define _raw_read_trylock(lock) generic_raw_read_trylock(lock)
|
|
|
|
static inline int _raw_write_trylock(rwlock_t *rw)
|
|
{
|
|
unsigned long tmp;
|
|
|
|
__asm__ __volatile__(
|
|
"1: ldrex %0, [%1]\n"
|
|
" teq %0, #0\n"
|
|
" strexeq %0, %2, [%1]"
|
|
: "=&r" (tmp)
|
|
: "r" (&rw->lock), "r" (0x80000000)
|
|
: "cc", "memory");
|
|
|
|
return tmp == 0;
|
|
}
|
|
|
|
#endif /* __ASM_SPINLOCK_H */
|