xref: /openbmc/linux/arch/x86/lib/msr-reg.S (revision 56b5b1c7)
1/* SPDX-License-Identifier: GPL-2.0 */
2#include <linux/linkage.h>
3#include <linux/errno.h>
4#include <asm/asm.h>
5#include <asm/msr.h>
6
7#ifdef CONFIG_X86_64
8/*
9 * int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
10 *
11 * reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
12 *
13 */
14.macro op_safe_regs op
15SYM_FUNC_START(\op\()_safe_regs)
16	pushq %rbx
17	pushq %r12
18	movq	%rdi, %r10	/* Save pointer */
19	xorl	%r11d, %r11d	/* Return value */
20	movl    (%rdi), %eax
21	movl    4(%rdi), %ecx
22	movl    8(%rdi), %edx
23	movl    12(%rdi), %ebx
24	movl    20(%rdi), %r12d
25	movl    24(%rdi), %esi
26	movl    28(%rdi), %edi
271:	\op
282:	movl    %eax, (%r10)
29	movl	%r11d, %eax	/* Return value */
30	movl    %ecx, 4(%r10)
31	movl    %edx, 8(%r10)
32	movl    %ebx, 12(%r10)
33	movl    %r12d, 20(%r10)
34	movl    %esi, 24(%r10)
35	movl    %edi, 28(%r10)
36	popq %r12
37	popq %rbx
38	RET
393:
40	movl    $-EIO, %r11d
41	jmp     2b
42
43	_ASM_EXTABLE(1b, 3b)
44SYM_FUNC_END(\op\()_safe_regs)
45.endm
46
47#else /* X86_32 */
48
49.macro op_safe_regs op
50SYM_FUNC_START(\op\()_safe_regs)
51	pushl %ebx
52	pushl %ebp
53	pushl %esi
54	pushl %edi
55	pushl $0              /* Return value */
56	pushl %eax
57	movl    4(%eax), %ecx
58	movl    8(%eax), %edx
59	movl    12(%eax), %ebx
60	movl    20(%eax), %ebp
61	movl    24(%eax), %esi
62	movl    28(%eax), %edi
63	movl    (%eax), %eax
641:	\op
652:	pushl %eax
66	movl    4(%esp), %eax
67	popl (%eax)
68	addl    $4, %esp
69	movl    %ecx, 4(%eax)
70	movl    %edx, 8(%eax)
71	movl    %ebx, 12(%eax)
72	movl    %ebp, 20(%eax)
73	movl    %esi, 24(%eax)
74	movl    %edi, 28(%eax)
75	popl %eax
76	popl %edi
77	popl %esi
78	popl %ebp
79	popl %ebx
80	RET
813:
82	movl    $-EIO, 4(%esp)
83	jmp     2b
84
85	_ASM_EXTABLE(1b, 3b)
86SYM_FUNC_END(\op\()_safe_regs)
87.endm
88
89#endif
90
91op_safe_regs rdmsr
92op_safe_regs wrmsr
93
94