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
 15wakeup_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
 371:
 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
 501:
 51	movl    %cr3, %eax
 52	movl    %eax, %cr3
 53	wbinvd
 54
 55	# Go back to the return point
 56	jmp ret_point
 57
 58save_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
 82restore_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
 93SYM_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
105ret_point:
106	movl    saved_context_esp, %esp
107
108	writepost 0x32
109
110	call	restore_registers
111	call	restore_processor_state
112	RET
113SYM_CODE_END(do_olpc_suspend_lowlevel)
114
115.data
116saved_gdt:             .long   0,0
117saved_idt:             .long   0,0
118saved_ldt:             .long   0
119saved_cr4:             .long   0
120saved_cr0:             .long   0
121saved_context_esp:     .long   0
122saved_context_edi:     .long   0
123saved_context_esi:     .long   0
124saved_context_ebx:     .long   0
125saved_context_ebp:     .long   0
126saved_context_eflags:  .long   0