/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (c) 2006 Ralf Baechle ([email protected])
*/
#ifndef _ASM_FUTEX_H
#define _ASM_FUTEX_H

#ifdef __KERNEL__

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

#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
{ \
if (cpu_has_llsc && R10000_LLSC_WAR) { \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
" .set mips3 \n" \
"1: ll %1, %4 # __futex_atomic_op \n" \
" .set mips0 \n" \
" " insn " \n" \
" .set mips3 \n" \
"2: sc $1, %2 \n" \
" beqzl $1, 1b \n" \
__WEAK_LLSC_MB \
"3: \n" \
" .set pop \n" \
" .set mips0 \n" \
" .section .fixup,\"ax\" \n" \
"4: li %0, %6 \n" \
" j 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" "__UA_ADDR "\t1b, 4b \n" \
" "__UA_ADDR "\t2b, 4b \n" \
" .previous \n" \
: "=r" (ret), "=&r" (oldval), "=R" (*uaddr) \
: "0" (0), "R" (*uaddr), "Jr" (oparg), "i" (-EFAULT) \
: "memory"); \
} else if (cpu_has_llsc) { \
__asm__ __volatile__( \
" .set push \n" \
" .set noat \n" \
" .set mips3 \n" \
"1: ll %1, %4 # __futex_atomic_op \n" \
" .set mips0 \n" \
" " insn " \n" \
" .set mips3 \n" \
"2: sc $1, %2 \n" \
" beqz $1, 1b \n" \
__WEAK_LLSC_MB \
"3: \n" \
" .set pop \n" \
" .set mips0 \n" \
" .section .fixup,\"ax\" \n" \
"4: li %0, %6 \n" \
" j 3b \n" \
" .previous \n" \
" .section __ex_table,\"a\" \n" \
" "__UA_ADDR "\t1b, 4b \n" \
" "__UA_ADDR "\t2b, 4b \n" \
" .previous \n" \
: "=r" (ret), "=&r" (oldval), "=R" (*uaddr) \
: "0" (0), "R" (*uaddr), "Jr" (oparg), "i" (-EFAULT) \
: "memory"); \
} else \
ret = -ENOSYS; \
}

static inline int
futex_atomic_op_inuser(int encoded_op, u32 __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(u32)))
return -EFAULT;

pagefault_disable();

switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("move $1, %z5", ret, oldval, uaddr, oparg);
break;

case FUTEX_OP_ADD:
__futex_atomic_op("addu $1, %1, %z5",
ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("or $1, %1, %z5",
ret, oldval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("and $1, %1, %z5",
ret, oldval, uaddr, ~oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("xor $1, %1, %z5",
ret, oldval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}

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;
}

static inline int
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
u32 oldval, u32 newval)
{
int ret = 0;
u32 val;

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

if (cpu_has_llsc && R10000_LLSC_WAR) {
__asm__ __volatile__(
"# futex_atomic_cmpxchg_inatomic \n"
" .set push \n"
" .set noat \n"
" .set mips3 \n"
"1: ll %1, %3 \n"
" bne %1, %z4, 3f \n"
" .set mips0 \n"
" move $1, %z5 \n"
" .set mips3 \n"
"2: sc $1, %2 \n"
" beqzl $1, 1b \n"
__WEAK_LLSC_MB
"3: \n"
" .set pop \n"
" .section .fixup,\"ax\" \n"
"4: li %0, %6 \n"
" j 3b \n"
" .previous \n"
" .section __ex_table,\"a\" \n"
" "__UA_ADDR "\t1b, 4b \n"
" "__UA_ADDR "\t2b, 4b \n"
" .previous \n"
: "+r" (ret), "=&r" (val), "=R" (*uaddr)
: "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT)
: "memory");
} else if (cpu_has_llsc) {
__asm__ __volatile__(
"# futex_atomic_cmpxchg_inatomic \n"
" .set push \n"
" .set noat \n"
" .set mips3 \n"
"1: ll %1, %3 \n"
" bne %1, %z4, 3f \n"
" .set mips0 \n"
" move $1, %z5 \n"
" .set mips3 \n"
"2: sc $1, %2 \n"
" beqz $1, 1b \n"
__WEAK_LLSC_MB
"3: \n"
" .set pop \n"
" .section .fixup,\"ax\" \n"
"4: li %0, %6 \n"
" j 3b \n"
" .previous \n"
" .section __ex_table,\"a\" \n"
" "__UA_ADDR "\t1b, 4b \n"
" "__UA_ADDR "\t2b, 4b \n"
" .previous \n"
: "+r" (ret), "=&r" (val), "=R" (*uaddr)
: "R" (*uaddr), "Jr" (oldval), "Jr" (newval), "i" (-EFAULT)
: "memory");
} else
return -ENOSYS;

*uval = val;
return ret;
}

#endif
#endif /* _ASM_FUTEX_H */