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 19ENTRY(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 36ENDPROC(swsusp_arch_suspend) 37 38ENTRY(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 49/* code below has been relocated to a safe page */ 50ENTRY(core_restore_code) 51 movl temp_pgt, %eax 52 movl %eax, %cr3 53 54 jecxz 1f # cr4 Pentium and higher, skip if zero 55 andl $~(X86_CR4_PGE), %ecx 56 movl %ecx, %cr4; # turn off PGE 57 movl %cr3, %eax; # flush TLB 58 movl %eax, %cr3 591: 60 movl restore_pblist, %edx 61 .p2align 4,,7 62 63copy_loop: 64 testl %edx, %edx 65 jz done 66 67 movl pbe_address(%edx), %esi 68 movl pbe_orig_address(%edx), %edi 69 70 movl $(PAGE_SIZE >> 2), %ecx 71 rep 72 movsl 73 74 movl pbe_next(%edx), %edx 75 jmp copy_loop 76 .p2align 4,,7 77 78done: 79 jmpl *%ebx 80 81 /* code below belongs to the image kernel */ 82 .align PAGE_SIZE 83ENTRY(restore_registers) 84 /* go back to the original page tables */ 85 movl %ebp, %cr3 86 movl mmu_cr4_features, %ecx 87 jecxz 1f # cr4 Pentium and higher, skip if zero 88 movl %ecx, %cr4; # turn PGE back on 891: 90 91 movl saved_context_esp, %esp 92 movl saved_context_ebp, %ebp 93 movl saved_context_ebx, %ebx 94 movl saved_context_esi, %esi 95 movl saved_context_edi, %edi 96 97 pushl saved_context_eflags 98 popfl 99 100 /* Saved in save_processor_state. */ 101 movl $saved_context, %eax 102 lgdt saved_context_gdt_desc(%eax) 103 104 xorl %eax, %eax 105 106 /* tell the hibernation core that we've just restored the memory */ 107 movl %eax, in_suspend 108 109 ret 110ENDPROC(restore_registers) 111