#ifndef _ASM_PARISC_FUTEX_H
#define _ASM_PARISC_FUTEX_H

#ifdef __KERNEL__

#include <linux/futex.h>
#include <linux/uaccess.h>
#include <asm/atomic.h>
#include <asm/errno.h>

/* The following has to match the LWS code in syscall.S. We have
sixteen four-word locks. */

static inline void
_futex_spin_lock_irqsave(u32 __user *uaddr, unsigned long int *flags)
{
extern u32 lws_lock_start[];
long index = ((long)uaddr & 0xf0) >> 2;
arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
local_irq_save(*flags);
arch_spin_lock(s);
}

static inline void
_futex_spin_unlock_irqrestore(u32 __user *uaddr, unsigned long int *flags)
{
extern u32 lws_lock_start[];
long index = ((long)uaddr & 0xf0) >> 2;
arch_spinlock_t *s = (arch_spinlock_t *)&lws_lock_start[index];
arch_spin_unlock(s);
local_irq_restore(*flags);
}

static inline int
futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
{
unsigned long int flags;
u32 val;
int op = (encoded_op >> 28) & 7;
int cmp = (encoded_op >> 24) & 15;
int oparg = (encoded_op << 8) >> 20;
int cmparg = (encoded_op << 20) >> 20;
int oldval = 0, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;

if (!access_ok(VERIFY_WRITE, uaddr, sizeof(*uaddr)))
return -EFAULT;

pagefault_disable();

_futex_spin_lock_irqsave(uaddr, &flags);

switch (op) {
case FUTEX_OP_SET:
/* *(int *)UADDR2 = OPARG; */
ret = get_user(oldval, uaddr);
if (!ret)
ret = put_user(oparg, uaddr);
break;
case FUTEX_OP_ADD:
/* *(int *)UADDR2 += OPARG; */
ret = get_user(oldval, uaddr);
if (!ret) {
val = oldval + oparg;
ret = put_user(val, uaddr);
}
break;
case FUTEX_OP_OR:
/* *(int *)UADDR2 |= OPARG; */
ret = get_user(oldval, uaddr);
if (!ret) {
val = oldval | oparg;
ret = put_user(val, uaddr);
}
break;
case FUTEX_OP_ANDN:
/* *(int *)UADDR2 &= ~OPARG; */
ret = get_user(oldval, uaddr);
if (!ret) {
val = oldval & ~oparg;
ret = put_user(val, uaddr);
}
break;
case FUTEX_OP_XOR:
/* *(int *)UADDR2 ^= OPARG; */
ret = get_user(oldval, uaddr);
if (!ret) {
val = oldval ^ oparg;
ret = put_user(val, uaddr);
}
break;
default:
ret = -ENOSYS;
}

_futex_spin_unlock_irqrestore(uaddr, &flags);

pagefault_enable();

if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ: ret = (oldval == cmparg); break;
case FUTEX_OP_CMP_NE: ret = (oldval != cmparg); break;
case FUTEX_OP_CMP_LT: ret = (oldval < cmparg); break;
case FUTEX_OP_CMP_GE: ret = (oldval >= cmparg); break;
case FUTEX_OP_CMP_LE: ret = (oldval <= cmparg); break;
case FUTEX_OP_CMP_GT: ret = (oldval > cmparg); break;
default: ret = -ENOSYS;
}
}
return ret;
}

/* Non-atomic version */
static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
int ret;
u32 val;
unsigned long flags;

/* futex.c wants to do a cmpxchg_inatomic on kernel NULL, which is
* our gateway page, and causes no end of trouble...
*/
if (segment_eq(KERNEL_DS, get_fs()) && !uaddr)
return -EFAULT;

if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;

/* HPPA has no cmpxchg in hardware and therefore the
* best we can do here is use an array of locks. The
* lock selected is based on a hash of the userspace
* address. This should scale to a couple of CPUs.
*/

_futex_spin_lock_irqsave(uaddr, &flags);

ret = get_user(val, uaddr);

if (!ret && val == oldval)
ret = put_user(newval, uaddr);

*uval = val;

_futex_spin_unlock_irqrestore(uaddr, &flags);

return ret;
}

#endif /*__KERNEL__*/
#endif /*_ASM_PARISC_FUTEX_H*/