1 /* SPDX-License-Identifier: GPL-2.0 */ 2 .text 3 #include <linux/linkage.h> 4 #include <asm/segment.h> 5 #include <asm/page.h> 6 #include <asm/pgtable_32.h> 7 8 .macro writepost,value 9 movb $0x34, %al 10 outb %al, $0x70 11 movb $\value, %al 12 outb %al, $0x71 13 .endm 14 15 wakeup_start: 16 # OFW lands us here, running in protected mode, with a 17 # kernel-compatible GDT already setup. 18 19 # Clear any dangerous flags 20 pushl $0 21 popfl 22 23 writepost 0x31 24 25 # Set up %cr3 26 movl $initial_page_table - __PAGE_OFFSET, %eax 27 movl %eax, %cr3 28 29 movl saved_cr4, %eax 30 movl %eax, %cr4 31 32 movl saved_cr0, %eax 33 movl %eax, %cr0 34 35 # Control registers were modified, pipeline resync is needed 36 jmp 1f 37 1: 38 39 movw $__KERNEL_DS, %ax 40 movw %ax, %ss 41 movw %ax, %ds 42 movw %ax, %es 43 movw %ax, %fs 44 movw %ax, %gs 45 46 lgdt saved_gdt 47 lidt saved_idt 48 lldt saved_ldt 49 ljmp $(__KERNEL_CS),$1f 50 1: 51 movl %cr3, %eax 52 movl %eax, %cr3 53 wbinvd 54 55 # Go back to the return point 56 jmp ret_point 57 58 save_registers: 59 sgdt saved_gdt 60 sidt saved_idt 61 sldt saved_ldt 62 63 pushl %edx 64 movl %cr4, %edx 65 movl %edx, saved_cr4 66 67 movl %cr0, %edx 68 movl %edx, saved_cr0 69 70 popl %edx 71 72 movl %ebx, saved_context_ebx 73 movl %ebp, saved_context_ebp 74 movl %esi, saved_context_esi 75 movl %edi, saved_context_edi 76 77 pushfl 78 popl saved_context_eflags 79 80 RET 81 82 restore_registers: 83 movl saved_context_ebp, %ebp 84 movl saved_context_ebx, %ebx 85 movl saved_context_esi, %esi 86 movl saved_context_edi, %edi 87 88 pushl saved_context_eflags 89 popfl 90 91 RET 92 93 SYM_CODE_START(do_olpc_suspend_lowlevel) 94 call save_processor_state 95 call save_registers 96 97 # This is the stack context we want to remember 98 movl %esp, saved_context_esp 99 100 pushl $3 101 call xo1_do_sleep 102 103 jmp wakeup_start 104 .p2align 4,,7 105 ret_point: 106 movl saved_context_esp, %esp 107 108 writepost 0x32 109 110 call restore_registers 111 call restore_processor_state 112 RET 113 SYM_CODE_END(do_olpc_suspend_lowlevel) 114 115 .data 116 saved_gdt: .long 0,0 117 saved_idt: .long 0,0 118 saved_ldt: .long 0 119 saved_cr4: .long 0 120 saved_cr0: .long 0 121 saved_context_esp: .long 0 122 saved_context_edi: .long 0 123 saved_context_esi: .long 0 124 saved_context_ebx: .long 0 125 saved_context_ebp: .long 0 126 saved_context_eflags: .long 0 127