126 lines
2.7 KiB
C
Executable file
126 lines
2.7 KiB
C
Executable file
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#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
|
|
arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
|
|
{
|
|
unsigned long int flags;
|
|
int oldval, ret;
|
|
u32 tmp;
|
|
|
|
_futex_spin_lock_irqsave(uaddr, &flags);
|
|
pagefault_disable();
|
|
|
|
ret = -EFAULT;
|
|
if (unlikely(get_user(oldval, uaddr) != 0))
|
|
goto out_pagefault_enable;
|
|
|
|
ret = 0;
|
|
tmp = oldval;
|
|
|
|
switch (op) {
|
|
case FUTEX_OP_SET:
|
|
tmp = oparg;
|
|
break;
|
|
case FUTEX_OP_ADD:
|
|
tmp += oparg;
|
|
break;
|
|
case FUTEX_OP_OR:
|
|
tmp |= oparg;
|
|
break;
|
|
case FUTEX_OP_ANDN:
|
|
tmp &= ~oparg;
|
|
break;
|
|
case FUTEX_OP_XOR:
|
|
tmp ^= oparg;
|
|
break;
|
|
default:
|
|
ret = -ENOSYS;
|
|
}
|
|
|
|
if (ret == 0 && unlikely(put_user(tmp, uaddr) != 0))
|
|
ret = -EFAULT;
|
|
|
|
out_pagefault_enable:
|
|
pagefault_enable();
|
|
_futex_spin_unlock_irqrestore(uaddr, &flags);
|
|
|
|
if (!ret)
|
|
*oval = oldval;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline int
|
|
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
|
|
u32 oldval, u32 newval)
|
|
{
|
|
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 (uaccess_kernel() && !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);
|
|
if (unlikely(get_user(val, uaddr) != 0)) {
|
|
_futex_spin_unlock_irqrestore(uaddr, &flags);
|
|
return -EFAULT;
|
|
}
|
|
|
|
if (val == oldval && unlikely(put_user(newval, uaddr) != 0)) {
|
|
_futex_spin_unlock_irqrestore(uaddr, &flags);
|
|
return -EFAULT;
|
|
}
|
|
|
|
*uval = val;
|
|
_futex_spin_unlock_irqrestore(uaddr, &flags);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#endif /*__KERNEL__*/
|
|
#endif /*_ASM_PARISC_FUTEX_H*/
|