/*
* linux/arch/unicore32/include/asm/futex.h
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __UNICORE_FUTEX_H__
#define __UNICORE_FUTEX_H__
#ifdef __KERNEL__
#include <linux/futex.h>
#include <linux/preempt.h>
#include <linux/uaccess.h>
#include <linux/errno.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
__asm__ __volatile__( \
"1: ldw.u %1, [%2]\n" \
" " insn "\n" \
"2: stw.u %0, [%2]\n" \
" mov %0, #0\n" \
"3:\n" \
" .pushsection __ex_table,\"a\"\n" \
" .align 3\n" \
" .long 1b, 4f, 2b, 4f\n" \
" .popsection\n" \
" .pushsection .fixup,\"ax\"\n" \
"4: mov %0, %4\n" \
" b 3b\n" \
" .popsection" \
: "=&r" (ret), "=&r" (oldval) \
: "r" (uaddr), "r" (oparg), "Ir" (-EFAULT) \
: "cc", "memory")
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 oldval = 0, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable(); /* implies preempt_disable() */
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("mov %0, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("add %0, %1, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("or %0, %1, %3", ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("and %0, %1, %3",
ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("xor %0, %1, %3", ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
pagefault_enable(); /* subsumes preempt_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;
}
static inline int
futex_atomic_cmpxchg_inatomic(int __user *uaddr, int oldval, int newval)
{
int val;
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
pagefault_disable(); /* implies preempt_disable() */
__asm__ __volatile__("@futex_atomic_cmpxchg_inatomic\n"
"1: ldw.u %0, [%3]\n"
" cmpxor.a %0, %1\n"
" bne 3f\n"
"2: stw.u %2, [%3]\n"
"3:\n"
" .pushsection __ex_table,\"a\"\n"
" .align 3\n"
" .long 1b, 4f, 2b, 4f\n"
" .popsection\n"
" .pushsection .fixup,\"ax\"\n"
"4: mov %0, %4\n"
" b 3b\n"
" .popsection"
: "=&r" (val)
: "r" (oldval), "r" (newval), "r" (uaddr), "Ir" (-EFAULT)
: "cc", "memory");
pagefault_enable(); /* subsumes preempt_enable() */
return val;
}
#endif /* __KERNEL__ */
#endif /* __UNICORE_FUTEX_H__ */
