128 lines
2.6 KiB
C
128 lines
2.6 KiB
C
/*
|
|
* Atomic futex routines
|
|
*
|
|
* Based on the PowerPC implementataion
|
|
*
|
|
* 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.
|
|
*
|
|
* Copyright (C) 2013 TangoTec Ltd.
|
|
*
|
|
* Baruch Siach <baruch@tkos.co.il>
|
|
*/
|
|
|
|
#ifndef _ASM_XTENSA_FUTEX_H
|
|
#define _ASM_XTENSA_FUTEX_H
|
|
|
|
#ifdef __KERNEL__
|
|
|
|
#include <linux/futex.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/errno.h>
|
|
|
|
#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
|
|
__asm__ __volatile( \
|
|
"1: l32i %0, %2, 0\n" \
|
|
insn "\n" \
|
|
" wsr %0, scompare1\n" \
|
|
"2: s32c1i %1, %2, 0\n" \
|
|
" bne %1, %0, 1b\n" \
|
|
" movi %1, 0\n" \
|
|
"3:\n" \
|
|
" .section .fixup,\"ax\"\n" \
|
|
" .align 4\n" \
|
|
"4: .long 3b\n" \
|
|
"5: l32r %0, 4b\n" \
|
|
" movi %1, %3\n" \
|
|
" jx %0\n" \
|
|
" .previous\n" \
|
|
" .section __ex_table,\"a\"\n" \
|
|
" .long 1b,5b,2b,5b\n" \
|
|
" .previous\n" \
|
|
: "=&r" (oldval), "=&r" (ret) \
|
|
: "r" (uaddr), "I" (-EFAULT), "r" (oparg) \
|
|
: "memory")
|
|
|
|
static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
|
|
u32 __user *uaddr)
|
|
{
|
|
int oldval = 0, ret;
|
|
|
|
#if !XCHAL_HAVE_S32C1I
|
|
return -ENOSYS;
|
|
#endif
|
|
|
|
pagefault_disable();
|
|
|
|
switch (op) {
|
|
case FUTEX_OP_SET:
|
|
__futex_atomic_op("mov %1, %4", ret, oldval, uaddr, oparg);
|
|
break;
|
|
case FUTEX_OP_ADD:
|
|
__futex_atomic_op("add %1, %0, %4", ret, oldval, uaddr,
|
|
oparg);
|
|
break;
|
|
case FUTEX_OP_OR:
|
|
__futex_atomic_op("or %1, %0, %4", ret, oldval, uaddr,
|
|
oparg);
|
|
break;
|
|
case FUTEX_OP_ANDN:
|
|
__futex_atomic_op("and %1, %0, %4", ret, oldval, uaddr,
|
|
~oparg);
|
|
break;
|
|
case FUTEX_OP_XOR:
|
|
__futex_atomic_op("xor %1, %0, %4", ret, oldval, uaddr,
|
|
oparg);
|
|
break;
|
|
default:
|
|
ret = -ENOSYS;
|
|
}
|
|
|
|
pagefault_enable();
|
|
|
|
if (!ret)
|
|
*oval = oldval;
|
|
|
|
return ret;
|
|
}
|
|
|
|
static inline int
|
|
futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
|
|
u32 oldval, u32 newval)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (!access_ok(uaddr, sizeof(u32)))
|
|
return -EFAULT;
|
|
|
|
#if !XCHAL_HAVE_S32C1I
|
|
return -ENOSYS;
|
|
#endif
|
|
|
|
__asm__ __volatile__ (
|
|
" # futex_atomic_cmpxchg_inatomic\n"
|
|
" wsr %5, scompare1\n"
|
|
"1: s32c1i %1, %4, 0\n"
|
|
" s32i %1, %6, 0\n"
|
|
"2:\n"
|
|
" .section .fixup,\"ax\"\n"
|
|
" .align 4\n"
|
|
"3: .long 2b\n"
|
|
"4: l32r %1, 3b\n"
|
|
" movi %0, %7\n"
|
|
" jx %1\n"
|
|
" .previous\n"
|
|
" .section __ex_table,\"a\"\n"
|
|
" .long 1b,4b\n"
|
|
" .previous\n"
|
|
: "+r" (ret), "+r" (newval), "+m" (*uaddr), "+m" (*uval)
|
|
: "r" (uaddr), "r" (oldval), "r" (uval), "I" (-EFAULT)
|
|
: "memory");
|
|
|
|
return ret;
|
|
}
|
|
|
|
#endif /* __KERNEL__ */
|
|
#endif /* _ASM_XTENSA_FUTEX_H */
|