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[PATCH] s390: futex atomic operations

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Add support for atomic futex operations.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Martin Schwidefsky 2006-04-27 18:40:12 -07:00 committed by Linus Torvalds
parent 40ac6b204c
commit 3363fbdd6f
1 changed files with 119 additions and 4 deletions
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123
include/asm-s390/futex.h
View file

@ -1,6 +1,121 @@
#ifndef _ASM_FUTEX_H #ifndef _ASM_S390_FUTEX_H
#define _ASM_FUTEX_H #define _ASM_S390_FUTEX_H
#include <asm-generic/futex.h> #ifdef __KERNEL__
#endif #include <linux/futex.h>
#include <asm/errno.h>
#include <asm/uaccess.h>
#ifndef __s390x__
#define __futex_atomic_fixup \
".section __ex_table,\"a\"\n" \
" .align 4\n" \
" .long 0b,2b,1b,2b\n" \
".previous"
#else /* __s390x__ */
#define __futex_atomic_fixup \
".section __ex_table,\"a\"\n" \
" .align 8\n" \
" .quad 0b,2b,1b,2b\n" \
".previous"
#endif /* __s390x__ */
#define __futex_atomic_op(insn, ret, oldval, newval, uaddr, oparg) \
asm volatile(" l %1,0(%6)\n" \
"0: " insn \
" cs %1,%2,0(%6)\n" \
"1: jl 0b\n" \
" lhi %0,0\n" \
"2:\n" \
__futex_atomic_fixup \
: "=d" (ret), "=&d" (oldval), "=&d" (newval), \
"=m" (*uaddr) \
: "0" (-EFAULT), "d" (oparg), "a" (uaddr), \
"m" (*uaddr) : "cc" );
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, newval, ret;
if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
oparg = 1 << oparg;
if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
inc_preempt_count();
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("lr %2,%5\n",
ret, oldval, newval, uaddr, oparg);
break;
case FUTEX_OP_ADD:
__futex_atomic_op("lr %2,%1\nar %2,%5\n",
ret, oldval, newval, uaddr, oparg);
break;
case FUTEX_OP_OR:
__futex_atomic_op("lr %2,%1\nor %2,%5\n",
ret, oldval, newval, uaddr, oparg);
break;
case FUTEX_OP_ANDN:
__futex_atomic_op("lr %2,%1\nnr %2,%5\n",
ret, oldval, newval, uaddr, oparg);
break;
case FUTEX_OP_XOR:
__futex_atomic_op("lr %2,%1\nxr %2,%5\n",
ret, oldval, newval, uaddr, oparg);
break;
default:
ret = -ENOSYS;
}
dec_preempt_count();
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 ret;
if (! access_ok (VERIFY_WRITE, uaddr, sizeof(int)))
return -EFAULT;
asm volatile(" cs %1,%4,0(%5)\n"
"0: lr %0,%1\n"
"1:\n"
#ifndef __s390x__
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 0b,1b\n"
".previous"
#else /* __s390x__ */
".section __ex_table,\"a\"\n"
" .align 8\n"
" .quad 0b,1b\n"
".previous"
#endif /* __s390x__ */
: "=d" (ret), "+d" (oldval), "=m" (*uaddr)
: "0" (-EFAULT), "d" (newval), "a" (uaddr), "m" (*uaddr)
: "cc", "memory" );
return oldval;
}
#endif /* __KERNEL__ */
#endif /* _ASM_S390_FUTEX_H */