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
15 SYM_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
27 1: \op
28 2: 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
39 3:
40 movl $-EIO, %r11d
41 jmp 2b
42
43 _ASM_EXTABLE(1b, 3b)
44 SYM_FUNC_END(\op\()_safe_regs)
45 .endm
46
47 #else /* X86_32 */
48
49 .macro op_safe_regs op
50 SYM_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
64 1: \op
65 2: 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
81 3:
82 movl $-EIO, 4(%esp)
83 jmp 2b
84
85 _ASM_EXTABLE(1b, 3b)
86 SYM_FUNC_END(\op\()_safe_regs)
87 .endm
88
89 #endif
90
91 op_safe_regs rdmsr
92 op_safe_regs wrmsr
93
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