1/* SPDX-License-Identifier: GPL-2.0-only */
 2
 3#include <linux/export.h>
 4#include <linux/linkage.h>
 5#include <asm/percpu.h>
 6#include <asm/processor-flags.h>
 7
 8.text
 9
10#ifndef CONFIG_X86_CMPXCHG64
11
12/*
13 * Emulate 'cmpxchg8b (%esi)' on UP
14 *
15 * Inputs:
16 * %esi : memory location to compare
17 * %eax : low 32 bits of old value
18 * %edx : high 32 bits of old value
19 * %ebx : low 32 bits of new value
20 * %ecx : high 32 bits of new value
21 */
22SYM_FUNC_START(cmpxchg8b_emu)
23
 
 
 
 
 
24	pushfl
25	cli
26
27	cmpl	0(%esi), %eax
28	jne	.Lnot_same
29	cmpl	4(%esi), %edx
30	jne	.Lnot_same
31
32	movl	%ebx, 0(%esi)
33	movl	%ecx, 4(%esi)
34
35	orl	$X86_EFLAGS_ZF, (%esp)
 
36
37	popfl
38	RET
39
40.Lnot_same:
41	movl	0(%esi), %eax
42	movl	4(%esi), %edx
43
44	andl	$(~X86_EFLAGS_ZF), (%esp)
45
46	popfl
47	RET
48
49SYM_FUNC_END(cmpxchg8b_emu)
50EXPORT_SYMBOL(cmpxchg8b_emu)
51
52#endif
53
54#ifndef CONFIG_UML
55
56SYM_FUNC_START(this_cpu_cmpxchg8b_emu)
57
58	pushfl
59	cli
60
61	cmpl	PER_CPU_VAR(0(%esi)), %eax
62	jne	.Lnot_same2
63	cmpl	PER_CPU_VAR(4(%esi)), %edx
64	jne	.Lnot_same2
65
66	movl	%ebx, PER_CPU_VAR(0(%esi))
67	movl	%ecx, PER_CPU_VAR(4(%esi))
68
69	orl	$X86_EFLAGS_ZF, (%esp)
70
71	popfl
72	RET
73
74.Lnot_same2:
75	movl	PER_CPU_VAR(0(%esi)), %eax
76	movl	PER_CPU_VAR(4(%esi)), %edx
77
78	andl	$(~X86_EFLAGS_ZF), (%esp)
79
80	popfl
81	RET
82
83SYM_FUNC_END(this_cpu_cmpxchg8b_emu)
84
85#endif

 1/* SPDX-License-Identifier: GPL-2.0-only */
 2
 
 3#include <linux/linkage.h>
 4#include <asm/export.h>
 
 5
 6.text
 7
 
 
 8/*
 
 
 9 * Inputs:
10 * %esi : memory location to compare
11 * %eax : low 32 bits of old value
12 * %edx : high 32 bits of old value
13 * %ebx : low 32 bits of new value
14 * %ecx : high 32 bits of new value
15 */
16SYM_FUNC_START(cmpxchg8b_emu)
17
18#
19# Emulate 'cmpxchg8b (%esi)' on UP except we don't
20# set the whole ZF thing (caller will just compare
21# eax:edx with the expected value)
22#
23	pushfl
24	cli
25
26	cmpl  (%esi), %eax
27	jne .Lnot_same
28	cmpl 4(%esi), %edx
29	jne .Lhalf_same
 
 
 
30
31	movl %ebx,  (%esi)
32	movl %ecx, 4(%esi)
33
34	popfl
35	RET
36
37.Lnot_same:
38	movl  (%esi), %eax
39.Lhalf_same:
40	movl 4(%esi), %edx
 
41
42	popfl
43	RET
44
45SYM_FUNC_END(cmpxchg8b_emu)
46EXPORT_SYMBOL(cmpxchg8b_emu)