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/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*
* These routines make two important assumptions:
*
* 1. atomic_t is really an int and can be freely cast back and forth
* (validated in __init_atomic_per_cpu).
*
* 2. userspace uses sys_cmpxchg() for all atomic operations, thus using
* the same locking convention that all the kernel atomic routines use.
*/
#ifndef _ASM_TILE_FUTEX_H
#define _ASM_TILE_FUTEX_H
#ifndef __ASSEMBLY__
#include <linux/futex.h>
#include <linux/uaccess.h>
#include <linux/errno.h>
extern struct __get_user futex_set(int __user *v, int i);
extern struct __get_user futex_add(int __user *v, int n);
extern struct __get_user futex_or(int __user *v, int n);
extern struct __get_user futex_andn(int __user *v, int n);
extern struct __get_user futex_cmpxchg(int __user *v, int o, int n);
#ifndef __tilegx__
extern struct __get_user futex_xor(int __user *v, int n);
#else
static inline struct __get_user futex_xor(int __user *uaddr, int n)
{
struct __get_user asm_ret = __get_user_4(uaddr);
if (!asm_ret.err) {
int oldval, newval;
do {
oldval = asm_ret.val;
newval = oldval ^ n;
asm_ret = futex_cmpxchg(uaddr, oldval, newval);
} while (asm_ret.err == 0 && oldval != asm_ret.val);
}
return asm_ret;
}
#endif
static inline int futex_atomic_op_inuser(int encoded_op, int __user *uaddr)
{
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 ret;
struct __get_user asm_ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
asm_ret = futex_set(uaddr, oparg);
break;
case FUTEX_OP_ADD:
asm_ret = futex_add(uaddr, oparg);
break;
case FUTEX_OP_OR:
asm_ret = futex_or(uaddr, oparg);
break;
case FUTEX_OP_ANDN:
asm_ret = futex_andn(uaddr, oparg);
break;
case FUTEX_OP_XOR:
asm_ret = futex_xor(uaddr, oparg);
break;
default:
asm_ret.err = -ENOSYS;
}
pagefault_enable();
ret = asm_ret.err;
if (!ret) {
switch (cmp) {
case FUTEX_OP_CMP_EQ:
ret = (asm_ret.val == cmparg);
break;
case FUTEX_OP_CMP_NE:
ret = (asm_ret.val != cmparg);
break;
case FUTEX_OP_CMP_LT:
ret = (asm_ret.val < cmparg);
break;
case FUTEX_OP_CMP_GE:
ret = (asm_ret.val >= cmparg);
break;
case FUTEX_OP_CMP_LE:
ret = (asm_ret.val <= cmparg);
break;
case FUTEX_OP_CMP_GT:
ret = (asm_ret.val > cmparg);
break;
default:
ret = -ENOSYS;
}
}
return ret;
}
static inline int futex_atomic_cmpxchg_inatomic(int *uval, int __user *uaddr,
int oldval, int newval)
{
struct __get_user asm_ret;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
asm_ret = futex_cmpxchg(uaddr, oldval, newval);
*uval = asm_ret.val;
return asm_ret.err;
}
#ifndef __tilegx__
/* Return failure from the atomic wrappers. */
struct __get_user __atomic_bad_address(int __user *addr);
#endif
#endif /* !__ASSEMBLY__ */
#endif /* _ASM_TILE_FUTEX_H */
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