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 SYM_FUNC_START(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 SYM_FUNC_END(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 SYM_FUNC_START(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 SYM_FUNC_END(restore_registers) 113