/* Copyright 2004,2005 Pavel Machek <pavel@suse.cz>, Andi Kleen <ak@suse.de>, Rafael J. Wysocki <rjw@sisk.pl>
 *
 * Distribute under GPLv2.
 *
 * swsusp_arch_resume must not use any stack or any nonlocal variables while
 * copying pages:
 *
 * Its rewriting one kernel image with another. What is stack in "old"
 * image could very well be data page in "new" image, and overwriting
 * your own stack under you is bad idea.
 */
	
	.text
#include <linux/linkage.h>
#include <asm/segment.h>
#include <asm/page.h>
#include <asm/asm-offsets.h>

ENTRY(swsusp_arch_suspend)

	movq %rsp, saved_context_esp(%rip)
	movq %rax, saved_context_eax(%rip)
	movq %rbx, saved_context_ebx(%rip)
	movq %rcx, saved_context_ecx(%rip)
	movq %rdx, saved_context_edx(%rip)
	movq %rbp, saved_context_ebp(%rip)
	movq %rsi, saved_context_esi(%rip)
	movq %rdi, saved_context_edi(%rip)
	movq %r8,  saved_context_r08(%rip)
	movq %r9,  saved_context_r09(%rip)
	movq %r10, saved_context_r10(%rip)
	movq %r11, saved_context_r11(%rip)
	movq %r12, saved_context_r12(%rip)
	movq %r13, saved_context_r13(%rip)
	movq %r14, saved_context_r14(%rip)
	movq %r15, saved_context_r15(%rip)
	pushfq ; popq saved_context_eflags(%rip)

	/* save the address of restore_registers */
	movq	$restore_registers, %rax
	movq	%rax, restore_jump_address(%rip)
	/* save cr3 */
	movq	%cr3, %rax
	movq	%rax, restore_cr3(%rip)

	call swsusp_save
	ret

ENTRY(restore_image)
	/* switch to temporary page tables */
	movq	$__PAGE_OFFSET, %rdx
	movq	temp_level4_pgt(%rip), %rax
	subq	%rdx, %rax
	movq	%rax, %cr3
	/* Flush TLB */
	movq	mmu_cr4_features(%rip), %rax
	movq	%rax, %rdx
	andq	$~(1<<7), %rdx	# PGE
	movq	%rdx, %cr4;  # turn off PGE
	movq	%cr3, %rcx;  # flush TLB
	movq	%rcx, %cr3;
	movq	%rax, %cr4;  # turn PGE back on

	/* prepare to jump to the image kernel */
	movq	restore_jump_address(%rip), %rax
	movq	restore_cr3(%rip), %rbx

	/* prepare to copy image data to their original locations */
	movq	restore_pblist(%rip), %rdx
	movq	relocated_restore_code(%rip), %rcx
	jmpq	*%rcx

	/* code below has been relocated to a safe page */
ENTRY(core_restore_code)
loop:
	testq	%rdx, %rdx
	jz	done

	/* get addresses from the pbe and copy the page */
	movq	pbe_address(%rdx), %rsi
	movq	pbe_orig_address(%rdx), %rdi
	movq	$(PAGE_SIZE >> 3), %rcx
	rep
	movsq

	/* progress to the next pbe */
	movq	pbe_next(%rdx), %rdx
	jmp	loop
done:
	/* jump to the restore_registers address from the image header */
	jmpq	*%rax
	/*
	 * NOTE: This assumes that the boot kernel's text mapping covers the
	 * image kernel's page containing restore_registers and the address of
	 * this page is the same as in the image kernel's text mapping (it
	 * should always be true, because the text mapping is linear, starting
	 * from 0, and is supposed to cover the entire kernel text for every
	 * kernel).
	 *
	 * code below belongs to the image kernel
	 */

ENTRY(restore_registers)
	/* go back to the original page tables */
	movq    %rbx, %cr3

	/* Flush TLB, including "global" things (vmalloc) */
	movq	mmu_cr4_features(%rip), %rax
	movq	%rax, %rdx
	andq	$~(1<<7), %rdx;  # PGE
	movq	%rdx, %cr4;  # turn off PGE
	movq	%cr3, %rcx;  # flush TLB
	movq	%rcx, %cr3
	movq	%rax, %cr4;  # turn PGE back on

	movq saved_context_esp(%rip), %rsp
	movq saved_context_ebp(%rip), %rbp
	/* restore GPRs (we don't restore %rax, it must be 0 anyway) */
	movq saved_context_ebx(%rip), %rbx
	movq saved_context_ecx(%rip), %rcx
	movq saved_context_edx(%rip), %rdx
	movq saved_context_esi(%rip), %rsi
	movq saved_context_edi(%rip), %rdi
	movq saved_context_r08(%rip), %r8
	movq saved_context_r09(%rip), %r9
	movq saved_context_r10(%rip), %r10
	movq saved_context_r11(%rip), %r11
	movq saved_context_r12(%rip), %r12
	movq saved_context_r13(%rip), %r13
	movq saved_context_r14(%rip), %r14
	movq saved_context_r15(%rip), %r15
	pushq saved_context_eflags(%rip) ; popfq

	xorq	%rax, %rax

	/* tell the hibernation core that we've just restored the memory */
	movq	%rax, in_suspend(%rip)

	ret