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kernel/linux-rt-4.4.41/arch/x86/platform/olpc/xo1-wakeup.S 2.11 KB
5113f6f70   김현기   kernel add
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  .text
  #include <linux/linkage.h>
  #include <asm/segment.h>
  #include <asm/page.h>
  #include <asm/pgtable_32.h>
  
  	.macro writepost,value
  		movb $0x34, %al
  		outb %al, $0x70
  		movb $\value, %al
  		outb %al, $0x71
  	.endm
  
  wakeup_start:
  	# OFW lands us here, running in protected mode, with a
  	# kernel-compatible GDT already setup.
  
  	# Clear any dangerous flags
  	pushl $0
  	popfl
  
  	writepost 0x31
  
  	# Set up %cr3
  	movl $initial_page_table - __PAGE_OFFSET, %eax
  	movl %eax, %cr3
  
  	movl saved_cr4, %eax
  	movl %eax, %cr4
  
  	movl saved_cr0, %eax
  	movl %eax, %cr0
  
  	# Control registers were modified, pipeline resync is needed
  	jmp 1f
  1:
  
  	movw    $__KERNEL_DS, %ax
  	movw    %ax, %ss
  	movw    %ax, %ds
  	movw    %ax, %es
  	movw    %ax, %fs
  	movw    %ax, %gs
  
  	lgdt    saved_gdt
  	lidt    saved_idt
  	lldt    saved_ldt
  	ljmp    $(__KERNEL_CS),$1f
  1:
  	movl    %cr3, %eax
  	movl    %eax, %cr3
  	wbinvd
  
  	# Go back to the return point
  	jmp ret_point
  
  save_registers:
  	sgdt  saved_gdt
  	sidt  saved_idt
  	sldt  saved_ldt
  
  	pushl %edx
  	movl %cr4, %edx
  	movl %edx, saved_cr4
  
  	movl %cr0, %edx
  	movl %edx, saved_cr0
  
  	popl %edx
  
  	movl %ebx, saved_context_ebx
  	movl %ebp, saved_context_ebp
  	movl %esi, saved_context_esi
  	movl %edi, saved_context_edi
  
  	pushfl
  	popl saved_context_eflags
  
  	ret
  
  restore_registers:
  	movl saved_context_ebp, %ebp
  	movl saved_context_ebx, %ebx
  	movl saved_context_esi, %esi
  	movl saved_context_edi, %edi
  
  	pushl saved_context_eflags
  	popfl
  
  	ret
  
  ENTRY(do_olpc_suspend_lowlevel)
  	call	save_processor_state
  	call	save_registers
  
  	# This is the stack context we want to remember
  	movl %esp, saved_context_esp
  
  	pushl	$3
  	call	xo1_do_sleep
  
  	jmp	wakeup_start
  	.p2align 4,,7
  ret_point:
  	movl    saved_context_esp, %esp
  
  	writepost 0x32
  
  	call	restore_registers
  	call	restore_processor_state
  	ret
  
  .data
  saved_gdt:             .long   0,0
  saved_idt:             .long   0,0
  saved_ldt:             .long   0
  saved_cr4:             .long   0
  saved_cr0:             .long   0
  saved_context_esp:     .long   0
  saved_context_edi:     .long   0
  saved_context_esi:     .long   0
  saved_context_ebx:     .long   0
  saved_context_ebp:     .long   0
  saved_context_eflags:  .long   0