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/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright IBM Corp. 1999, 2011
*
* Author(s): Martin Schwidefsky <[email protected]>,
*/
#ifndef __ASM_CMPXCHG_H
#define __ASM_CMPXCHG_H
#include <linux/mmdebug.h>
#include <linux/types.h>
#include <linux/bug.h>
void __xchg_called_with_bad_pointer(void);
static __always_inline unsigned long
__arch_xchg(unsigned long x, unsigned long address, int size)
{
unsigned long old;
int shift;
switch (size) {
case 1:
shift = (3 ^ (address & 3)) << 3;
address ^= address & 3;
asm volatile(
" l %0,%1\n"
"0: lr 0,%0\n"
" nr 0,%3\n"
" or 0,%2\n"
" cs %0,0,%1\n"
" jl 0b\n"
: "=&d" (old), "+Q" (*(int *) address)
: "d" ((x & 0xff) << shift), "d" (~(0xff << shift))
: "memory", "cc", "0");
return old >> shift;
case 2:
shift = (2 ^ (address & 2)) << 3;
address ^= address & 2;
asm volatile(
" l %0,%1\n"
"0: lr 0,%0\n"
" nr 0,%3\n"
" or 0,%2\n"
" cs %0,0,%1\n"
" jl 0b\n"
: "=&d" (old), "+Q" (*(int *) address)
: "d" ((x & 0xffff) << shift), "d" (~(0xffff << shift))
: "memory", "cc", "0");
return old >> shift;
case 4:
asm volatile(
" l %0,%1\n"
"0: cs %0,%2,%1\n"
" jl 0b\n"
: "=&d" (old), "+Q" (*(int *) address)
: "d" (x)
: "memory", "cc");
return old;
case 8:
asm volatile(
" lg %0,%1\n"
"0: csg %0,%2,%1\n"
" jl 0b\n"
: "=&d" (old), "+QS" (*(long *) address)
: "d" (x)
: "memory", "cc");
return old;
}
__xchg_called_with_bad_pointer();
return x;
}
#define arch_xchg(ptr, x) \
({ \
__typeof__(*(ptr)) __ret; \
\
__ret = (__typeof__(*(ptr))) \
__arch_xchg((unsigned long)(x), (unsigned long)(ptr), \
sizeof(*(ptr))); \
__ret; \
})
void __cmpxchg_called_with_bad_pointer(void);
static __always_inline unsigned long __cmpxchg(unsigned long address,
unsigned long old,
unsigned long new, int size)
{
switch (size) {
case 1: {
unsigned int prev, shift, mask;
shift = (3 ^ (address & 3)) << 3;
address ^= address & 3;
old = (old & 0xff) << shift;
new = (new & 0xff) << shift;
mask = ~(0xff << shift);
asm volatile(
" l %[prev],%[address]\n"
" nr %[prev],%[mask]\n"
" xilf %[mask],0xffffffff\n"
" or %[new],%[prev]\n"
" or %[prev],%[tmp]\n"
"0: lr %[tmp],%[prev]\n"
" cs %[prev],%[new],%[address]\n"
" jnl 1f\n"
" xr %[tmp],%[prev]\n"
" xr %[new],%[tmp]\n"
" nr %[tmp],%[mask]\n"
" jz 0b\n"
"1:"
: [prev] "=&d" (prev),
[address] "+Q" (*(int *)address),
[tmp] "+&d" (old),
[new] "+&d" (new),
[mask] "+&d" (mask)
:: "memory", "cc");
return prev >> shift;
}
case 2: {
unsigned int prev, shift, mask;
shift = (2 ^ (address & 2)) << 3;
address ^= address & 2;
old = (old & 0xffff) << shift;
new = (new & 0xffff) << shift;
mask = ~(0xffff << shift);
asm volatile(
" l %[prev],%[address]\n"
" nr %[prev],%[mask]\n"
" xilf %[mask],0xffffffff\n"
" or %[new],%[prev]\n"
" or %[prev],%[tmp]\n"
"0: lr %[tmp],%[prev]\n"
" cs %[prev],%[new],%[address]\n"
" jnl 1f\n"
" xr %[tmp],%[prev]\n"
" xr %[new],%[tmp]\n"
" nr %[tmp],%[mask]\n"
" jz 0b\n"
"1:"
: [prev] "=&d" (prev),
[address] "+Q" (*(int *)address),
[tmp] "+&d" (old),
[new] "+&d" (new),
[mask] "+&d" (mask)
:: "memory", "cc");
return prev >> shift;
}
case 4: {
unsigned int prev = old;
asm volatile(
" cs %[prev],%[new],%[address]\n"
: [prev] "+&d" (prev),
[address] "+Q" (*(int *)address)
: [new] "d" (new)
: "memory", "cc");
return prev;
}
case 8: {
unsigned long prev = old;
asm volatile(
" csg %[prev],%[new],%[address]\n"
: [prev] "+&d" (prev),
[address] "+QS" (*(long *)address)
: [new] "d" (new)
: "memory", "cc");
return prev;
}
}
__cmpxchg_called_with_bad_pointer();
return old;
}
#define arch_cmpxchg(ptr, o, n) \
({ \
__typeof__(*(ptr)) __ret; \
\
__ret = (__typeof__(*(ptr))) \
__cmpxchg((unsigned long)(ptr), (unsigned long)(o), \
(unsigned long)(n), sizeof(*(ptr))); \
__ret; \
})
#define arch_cmpxchg64 arch_cmpxchg
#define arch_cmpxchg_local arch_cmpxchg
#define arch_cmpxchg64_local arch_cmpxchg
#define system_has_cmpxchg128() 1
static __always_inline u128 arch_cmpxchg128(volatile u128 *ptr, u128 old, u128 new)
{
asm volatile(
" cdsg %[old],%[new],%[ptr]\n"
: [old] "+d" (old), [ptr] "+QS" (*ptr)
: [new] "d" (new)
: "memory", "cc");
return old;
}
#define arch_cmpxchg128 arch_cmpxchg128
#endif /* __ASM_CMPXCHG_H */
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