x86/lib/msr-reg.S

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #include <linux/linkage.h>
0003 #include <linux/errno.h>
0004 #include <asm/asm.h>
0005 #include <asm/msr.h>
0006
0007 #ifdef CONFIG_X86_64
0008 /*
0009  * int {rdmsr,wrmsr}_safe_regs(u32 gprs[8]);
0010  *
0011  * reg layout: u32 gprs[eax, ecx, edx, ebx, esp, ebp, esi, edi]
0012  *
0013  */
0014 .macro op_safe_regs op
0015 SYM_FUNC_START(\op\()_safe_regs)
0016     pushq %rbx
0017     pushq %r12
0018     movq    %rdi, %r10  /* Save pointer */
0019     xorl    %r11d, %r11d    /* Return value */
0020     movl    (%rdi), %eax
0021     movl    4(%rdi), %ecx
0022     movl    8(%rdi), %edx
0023     movl    12(%rdi), %ebx
0024     movl    20(%rdi), %r12d
0025     movl    24(%rdi), %esi
0026     movl    28(%rdi), %edi
0027 1:  \op
0028 2:  movl    %eax, (%r10)
0029     movl    %r11d, %eax /* Return value */
0030     movl    %ecx, 4(%r10)
0031     movl    %edx, 8(%r10)
0032     movl    %ebx, 12(%r10)
0033     movl    %r12d, 20(%r10)
0034     movl    %esi, 24(%r10)
0035     movl    %edi, 28(%r10)
0036     popq %r12
0037     popq %rbx
0038     RET
0039 3:
0040     movl    $-EIO, %r11d
0041     jmp     2b
0042
0043     _ASM_EXTABLE(1b, 3b)
0044 SYM_FUNC_END(\op\()_safe_regs)
0045 .endm
0046
0047 #else /* X86_32 */
0048
0049 .macro op_safe_regs op
0050 SYM_FUNC_START(\op\()_safe_regs)
0051     pushl %ebx
0052     pushl %ebp
0053     pushl %esi
0054     pushl %edi
0055     pushl $0              /* Return value */
0056     pushl %eax
0057     movl    4(%eax), %ecx
0058     movl    8(%eax), %edx
0059     movl    12(%eax), %ebx
0060     movl    20(%eax), %ebp
0061     movl    24(%eax), %esi
0062     movl    28(%eax), %edi
0063     movl    (%eax), %eax
0064 1:  \op
0065 2:  pushl %eax
0066     movl    4(%esp), %eax
0067     popl (%eax)
0068     addl    $4, %esp
0069     movl    %ecx, 4(%eax)
0070     movl    %edx, 8(%eax)
0071     movl    %ebx, 12(%eax)
0072     movl    %ebp, 20(%eax)
0073     movl    %esi, 24(%eax)
0074     movl    %edi, 28(%eax)
0075     popl %eax
0076     popl %edi
0077     popl %esi
0078     popl %ebp
0079     popl %ebx
0080     RET
0081 3:
0082     movl    $-EIO, 4(%esp)
0083     jmp     2b
0084
0085     _ASM_EXTABLE(1b, 3b)
0086 SYM_FUNC_END(\op\()_safe_regs)
0087 .endm
0088
0089 #endif
0090
0091 op_safe_regs rdmsr
0092 op_safe_regs wrmsr
0093