162306a36Sopenharmony_ci/* SPDX-License-Identifier: GPL-2.0 */ 262306a36Sopenharmony_ci/* 362306a36Sopenharmony_ci * This may not use any stack, nor any variable that is not "NoSave": 462306a36Sopenharmony_ci * 562306a36Sopenharmony_ci * Its rewriting one kernel image with another. What is stack in "old" 662306a36Sopenharmony_ci * image could very well be data page in "new" image, and overwriting 762306a36Sopenharmony_ci * your own stack under you is bad idea. 862306a36Sopenharmony_ci */ 962306a36Sopenharmony_ci 1062306a36Sopenharmony_ci#include <linux/linkage.h> 1162306a36Sopenharmony_ci#include <asm/segment.h> 1262306a36Sopenharmony_ci#include <asm/page_types.h> 1362306a36Sopenharmony_ci#include <asm/asm-offsets.h> 1462306a36Sopenharmony_ci#include <asm/processor-flags.h> 1562306a36Sopenharmony_ci#include <asm/frame.h> 1662306a36Sopenharmony_ci 1762306a36Sopenharmony_ci.text 1862306a36Sopenharmony_ci 1962306a36Sopenharmony_ciSYM_FUNC_START(swsusp_arch_suspend) 2062306a36Sopenharmony_ci movl %esp, saved_context_esp 2162306a36Sopenharmony_ci movl %ebx, saved_context_ebx 2262306a36Sopenharmony_ci movl %ebp, saved_context_ebp 2362306a36Sopenharmony_ci movl %esi, saved_context_esi 2462306a36Sopenharmony_ci movl %edi, saved_context_edi 2562306a36Sopenharmony_ci pushfl 2662306a36Sopenharmony_ci popl saved_context_eflags 2762306a36Sopenharmony_ci 2862306a36Sopenharmony_ci /* save cr3 */ 2962306a36Sopenharmony_ci movl %cr3, %eax 3062306a36Sopenharmony_ci movl %eax, restore_cr3 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci FRAME_BEGIN 3362306a36Sopenharmony_ci call swsusp_save 3462306a36Sopenharmony_ci FRAME_END 3562306a36Sopenharmony_ci RET 3662306a36Sopenharmony_ciSYM_FUNC_END(swsusp_arch_suspend) 3762306a36Sopenharmony_ci 3862306a36Sopenharmony_ciSYM_CODE_START(restore_image) 3962306a36Sopenharmony_ci /* prepare to jump to the image kernel */ 4062306a36Sopenharmony_ci movl restore_jump_address, %ebx 4162306a36Sopenharmony_ci movl restore_cr3, %ebp 4262306a36Sopenharmony_ci 4362306a36Sopenharmony_ci movl mmu_cr4_features, %ecx 4462306a36Sopenharmony_ci 4562306a36Sopenharmony_ci /* jump to relocated restore code */ 4662306a36Sopenharmony_ci movl relocated_restore_code, %eax 4762306a36Sopenharmony_ci jmpl *%eax 4862306a36Sopenharmony_ciSYM_CODE_END(restore_image) 4962306a36Sopenharmony_ci 5062306a36Sopenharmony_ci/* code below has been relocated to a safe page */ 5162306a36Sopenharmony_ciSYM_CODE_START(core_restore_code) 5262306a36Sopenharmony_ci movl temp_pgt, %eax 5362306a36Sopenharmony_ci movl %eax, %cr3 5462306a36Sopenharmony_ci 5562306a36Sopenharmony_ci jecxz 1f # cr4 Pentium and higher, skip if zero 5662306a36Sopenharmony_ci andl $~(X86_CR4_PGE), %ecx 5762306a36Sopenharmony_ci movl %ecx, %cr4; # turn off PGE 5862306a36Sopenharmony_ci movl %cr3, %eax; # flush TLB 5962306a36Sopenharmony_ci movl %eax, %cr3 6062306a36Sopenharmony_ci1: 6162306a36Sopenharmony_ci movl restore_pblist, %edx 6262306a36Sopenharmony_ci .p2align 4,,7 6362306a36Sopenharmony_ci 6462306a36Sopenharmony_cicopy_loop: 6562306a36Sopenharmony_ci testl %edx, %edx 6662306a36Sopenharmony_ci jz done 6762306a36Sopenharmony_ci 6862306a36Sopenharmony_ci movl pbe_address(%edx), %esi 6962306a36Sopenharmony_ci movl pbe_orig_address(%edx), %edi 7062306a36Sopenharmony_ci 7162306a36Sopenharmony_ci movl $(PAGE_SIZE >> 2), %ecx 7262306a36Sopenharmony_ci rep 7362306a36Sopenharmony_ci movsl 7462306a36Sopenharmony_ci 7562306a36Sopenharmony_ci movl pbe_next(%edx), %edx 7662306a36Sopenharmony_ci jmp copy_loop 7762306a36Sopenharmony_ci .p2align 4,,7 7862306a36Sopenharmony_ci 7962306a36Sopenharmony_cidone: 8062306a36Sopenharmony_ci jmpl *%ebx 8162306a36Sopenharmony_ciSYM_CODE_END(core_restore_code) 8262306a36Sopenharmony_ci 8362306a36Sopenharmony_ci /* code below belongs to the image kernel */ 8462306a36Sopenharmony_ci .align PAGE_SIZE 8562306a36Sopenharmony_ciSYM_FUNC_START(restore_registers) 8662306a36Sopenharmony_ci /* go back to the original page tables */ 8762306a36Sopenharmony_ci movl %ebp, %cr3 8862306a36Sopenharmony_ci movl mmu_cr4_features, %ecx 8962306a36Sopenharmony_ci jecxz 1f # cr4 Pentium and higher, skip if zero 9062306a36Sopenharmony_ci movl %ecx, %cr4; # turn PGE back on 9162306a36Sopenharmony_ci1: 9262306a36Sopenharmony_ci 9362306a36Sopenharmony_ci movl saved_context_esp, %esp 9462306a36Sopenharmony_ci movl saved_context_ebp, %ebp 9562306a36Sopenharmony_ci movl saved_context_ebx, %ebx 9662306a36Sopenharmony_ci movl saved_context_esi, %esi 9762306a36Sopenharmony_ci movl saved_context_edi, %edi 9862306a36Sopenharmony_ci 9962306a36Sopenharmony_ci pushl saved_context_eflags 10062306a36Sopenharmony_ci popfl 10162306a36Sopenharmony_ci 10262306a36Sopenharmony_ci /* Saved in save_processor_state. */ 10362306a36Sopenharmony_ci movl $saved_context, %eax 10462306a36Sopenharmony_ci lgdt saved_context_gdt_desc(%eax) 10562306a36Sopenharmony_ci 10662306a36Sopenharmony_ci xorl %eax, %eax 10762306a36Sopenharmony_ci 10862306a36Sopenharmony_ci /* tell the hibernation core that we've just restored the memory */ 10962306a36Sopenharmony_ci movl %eax, in_suspend 11062306a36Sopenharmony_ci 11162306a36Sopenharmony_ci RET 11262306a36Sopenharmony_ciSYM_FUNC_END(restore_registers) 113