| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | /* |
| 3 | * This may not use any stack, nor any variable that is not "NoSave": |
| 4 | * |
| 5 | * Its rewriting one kernel image with another. What is stack in "old" |
| 6 | * image could very well be data page in "new" image, and overwriting |
| 7 | * your own stack under you is bad idea. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/linkage.h> |
| 11 | #include <asm/segment.h> |
| 12 | #include <asm/page_types.h> |
| 13 | #include <asm/asm-offsets.h> |
| 14 | #include <asm/processor-flags.h> |
| 15 | #include <asm/frame.h> |
| 16 | |
| 17 | .text |
| 18 | |
| 19 | ENTRY(swsusp_arch_suspend) |
| 20 | movl %esp, saved_context_esp |
| 21 | movl %ebx, saved_context_ebx |
| 22 | movl %ebp, saved_context_ebp |
| 23 | movl %esi, saved_context_esi |
| 24 | movl %edi, saved_context_edi |
| 25 | pushfl |
| 26 | popl saved_context_eflags |
| 27 | |
| 28 | /* save cr3 */ |
| 29 | movl %cr3, %eax |
| 30 | movl %eax, restore_cr3 |
| 31 | |
| 32 | FRAME_BEGIN |
| 33 | call swsusp_save |
| 34 | FRAME_END |
| 35 | ret |
| 36 | ENDPROC(swsusp_arch_suspend) |
| 37 | |
| 38 | SYM_CODE_START(restore_image) |
| 39 | /* prepare to jump to the image kernel */ |
| 40 | movl restore_jump_address, %ebx |
| 41 | movl restore_cr3, %ebp |
| 42 | |
| 43 | movl mmu_cr4_features, %ecx |
| 44 | |
| 45 | /* jump to relocated restore code */ |
| 46 | movl relocated_restore_code, %eax |
| 47 | jmpl *%eax |
| 48 | SYM_CODE_END(restore_image) |
| 49 | |
| 50 | /* code below has been relocated to a safe page */ |
| 51 | SYM_CODE_START(core_restore_code) |
| 52 | movl temp_pgt, %eax |
| 53 | movl %eax, %cr3 |
| 54 | |
| 55 | jecxz 1f # cr4 Pentium and higher, skip if zero |
| 56 | andl $~(X86_CR4_PGE), %ecx |
| 57 | movl %ecx, %cr4; # turn off PGE |
| 58 | movl %cr3, %eax; # flush TLB |
| 59 | movl %eax, %cr3 |
| 60 | 1: |
| 61 | movl restore_pblist, %edx |
| 62 | .p2align 4,,7 |
| 63 | |
| 64 | copy_loop: |
| 65 | testl %edx, %edx |
| 66 | jz done |
| 67 | |
| 68 | movl pbe_address(%edx), %esi |
| 69 | movl pbe_orig_address(%edx), %edi |
| 70 | |
| 71 | movl $(PAGE_SIZE >> 2), %ecx |
| 72 | rep |
| 73 | movsl |
| 74 | |
| 75 | movl pbe_next(%edx), %edx |
| 76 | jmp copy_loop |
| 77 | .p2align 4,,7 |
| 78 | |
| 79 | done: |
| 80 | jmpl *%ebx |
| 81 | SYM_CODE_END(core_restore_code) |
| 82 | |
| 83 | /* code below belongs to the image kernel */ |
| 84 | .align PAGE_SIZE |
| 85 | ENTRY(restore_registers) |
| 86 | /* go back to the original page tables */ |
| 87 | movl %ebp, %cr3 |
| 88 | movl mmu_cr4_features, %ecx |
| 89 | jecxz 1f # cr4 Pentium and higher, skip if zero |
| 90 | movl %ecx, %cr4; # turn PGE back on |
| 91 | 1: |
| 92 | |
| 93 | movl saved_context_esp, %esp |
| 94 | movl saved_context_ebp, %ebp |
| 95 | movl saved_context_ebx, %ebx |
| 96 | movl saved_context_esi, %esi |
| 97 | movl saved_context_edi, %edi |
| 98 | |
| 99 | pushl saved_context_eflags |
| 100 | popfl |
| 101 | |
| 102 | /* Saved in save_processor_state. */ |
| 103 | movl $saved_context, %eax |
| 104 | lgdt saved_context_gdt_desc(%eax) |
| 105 | |
| 106 | xorl %eax, %eax |
| 107 | |
| 108 | /* tell the hibernation core that we've just restored the memory */ |
| 109 | movl %eax, in_suspend |
| 110 | |
| 111 | ret |
| 112 | ENDPROC(restore_registers) |