arch/x86_64/kernel/suspend.c - linux - Git at Google

 /*
  * Suspend support specific for i386.
  *
  * Distribute under GPLv2
  *
  * Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
  * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
  */

 #include <linux/config.h>
 #include <linux/smp.h>
 #include <linux/suspend.h>
 #include <asm/proto.h>
 #include <asm/page.h>
 #include <asm/pgtable.h>

 struct saved_context saved_context;

 unsigned long saved_context_eax, saved_context_ebx, saved_context_ecx, saved_context_edx;
 unsigned long saved_context_esp, saved_context_ebp, saved_context_esi, saved_context_edi;
 unsigned long saved_context_r08, saved_context_r09, saved_context_r10, saved_context_r11;
 unsigned long saved_context_r12, saved_context_r13, saved_context_r14, saved_context_r15;
 unsigned long saved_context_eflags;

 void __save_processor_state(struct saved_context *ctxt)
 {
 	kernel_fpu_begin();

 	/*
 	 * descriptor tables
 	 */
 	asm volatile ("sgdt %0" : "=m" (ctxt->gdt_limit));
 	asm volatile ("sidt %0" : "=m" (ctxt->idt_limit));
 	asm volatile ("str %0"  : "=m" (ctxt->tr));

 	/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
 	/* EFER should be constant for kernel version, no need to handle it. */
 	/*
 	 * segment registers
 	 */
 	asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
 	asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
 	asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
 	asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs));
 	asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss));

 	rdmsrl(MSR_FS_BASE, ctxt->fs_base);
 	rdmsrl(MSR_GS_BASE, ctxt->gs_base);
 	rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

 	/*
 	 * control registers
 	 */
 	asm volatile ("movq %%cr0, %0" : "=r" (ctxt->cr0));
 	asm volatile ("movq %%cr2, %0" : "=r" (ctxt->cr2));
 	asm volatile ("movq %%cr3, %0" : "=r" (ctxt->cr3));
 	asm volatile ("movq %%cr4, %0" : "=r" (ctxt->cr4));
 	asm volatile ("movq %%cr8, %0" : "=r" (ctxt->cr8));
 }

 void save_processor_state(void)
 {
 	__save_processor_state(&saved_context);
 }

 static void do_fpu_end(void)
 {
 	/*
 	 * Restore FPU regs if necessary
 	 */
 	kernel_fpu_end();
 }

 void __restore_processor_state(struct saved_context *ctxt)
 {
 	/*
 	 * control registers
 	 */
 	asm volatile ("movq %0, %%cr8" :: "r" (ctxt->cr8));
 	asm volatile ("movq %0, %%cr4" :: "r" (ctxt->cr4));
 	asm volatile ("movq %0, %%cr3" :: "r" (ctxt->cr3));
 	asm volatile ("movq %0, %%cr2" :: "r" (ctxt->cr2));
 	asm volatile ("movq %0, %%cr0" :: "r" (ctxt->cr0));

 	/*
 	 * now restore the descriptor tables to their proper values
 	 * ltr is done i fix_processor_context().
 	 */
 	asm volatile ("lgdt %0" :: "m" (ctxt->gdt_limit));
 	asm volatile ("lidt %0" :: "m" (ctxt->idt_limit));

 	/*
 	 * segment registers
 	 */
 	asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
 	asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
 	asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
 	load_gs_index(ctxt->gs);
 	asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));

 	wrmsrl(MSR_FS_BASE, ctxt->fs_base);
 	wrmsrl(MSR_GS_BASE, ctxt->gs_base);
 	wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

 	fix_processor_context();

 	do_fpu_end();
 	mtrr_ap_init();
 }

 void restore_processor_state(void)
 {
 	__restore_processor_state(&saved_context);
 }

 void fix_processor_context(void)
 {
 	int cpu = smp_processor_id();
 	struct tss_struct *t = &per_cpu(init_tss, cpu);

 	set_tss_desc(cpu,t);	/* This just modifies memory; should not be neccessary. But... This is neccessary, because 386 hardware has concept of busy TSS or some similar stupidity. */

 	cpu_gdt_table[cpu][GDT_ENTRY_TSS].type = 9;

 	syscall_init();                         /* This sets MSR_*STAR and related */
 	load_TR_desc();				/* This does ltr */
 	load_LDT(&current->active_mm->context);	/* This does lldt */

 	/*
 	 * Now maybe reload the debug registers
 	 */
 	if (current->thread.debugreg7){
                 loaddebug(&current->thread, 0);
                 loaddebug(&current->thread, 1);
                 loaddebug(&current->thread, 2);
                 loaddebug(&current->thread, 3);
                 /* no 4 and 5 */
                 loaddebug(&current->thread, 6);
                 loaddebug(&current->thread, 7);
 	}

 }

 #ifdef CONFIG_SOFTWARE_SUSPEND
 /* Defined in arch/x86_64/kernel/suspend_asm.S */
 extern int restore_image(void);

 pgd_t *temp_level4_pgt;

 static void **pages;

 static inline void *__add_page(void)
 {
 	void **c;

 	c = (void **)get_usable_page(GFP_ATOMIC);
 	if (c) {
 		*c = pages;
 		pages = c;
 	}
 	return c;
 }

 static inline void *__next_page(void)
 {
 	void **c;

 	c = pages;
 	if (c) {
 		pages = *c;
 		*c = NULL;
 	}
 	return c;
 }

 /*
  * Try to allocate as many usable pages as needed and daisy chain them.
  * If one allocation fails, free the pages allocated so far
  */
 static int alloc_usable_pages(unsigned long n)
 {
 	void *p;

 	pages = NULL;
 	do
 		if (!__add_page())
 			break;
 	while (--n);
 	if (n) {
 		p = __next_page();
 		while (p) {
 			free_page((unsigned long)p);
 			p = __next_page();
 		}
 		return -ENOMEM;
 	}
 	return 0;
 }

 static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
 {
 	long i, j;

 	i = pud_index(address);
 	pud = pud + i;
 	for (; i < PTRS_PER_PUD; pud++, i++) {
 		unsigned long paddr;
 		pmd_t *pmd;

 		paddr = address + i*PUD_SIZE;
 		if (paddr >= end)
 			break;

 		pmd = (pmd_t *)__next_page();
 		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
 		for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
 			unsigned long pe;

 			if (paddr >= end)
 				break;
 			pe = _PAGE_NX | _PAGE_PSE | _KERNPG_TABLE | paddr;
 			pe &= __supported_pte_mask;
 			set_pmd(pmd, __pmd(pe));
 		}
 	}
 }

 static void set_up_temporary_mappings(void)
 {
 	unsigned long start, end, next;

 	temp_level4_pgt = (pgd_t *)__next_page();

 	/* It is safe to reuse the original kernel mapping */
 	set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
 		init_level4_pgt[pgd_index(__START_KERNEL_map)]);

 	/* Set up the direct mapping from scratch */
 	start = (unsigned long)pfn_to_kaddr(0);
 	end = (unsigned long)pfn_to_kaddr(end_pfn);

 	for (; start < end; start = next) {
 		pud_t *pud = (pud_t *)__next_page();
 		next = start + PGDIR_SIZE;
 		if (next > end)
 			next = end;
 		res_phys_pud_init(pud, __pa(start), __pa(next));
 		set_pgd(temp_level4_pgt + pgd_index(start),
 			mk_kernel_pgd(__pa(pud)));
 	}
 }

 int swsusp_arch_resume(void)
 {
 	unsigned long n;

 	n = ((end_pfn << PAGE_SHIFT) + PUD_SIZE - 1) >> PUD_SHIFT;
 	n += (n + PTRS_PER_PUD - 1) / PTRS_PER_PUD + 1;
 	pr_debug("swsusp_arch_resume(): pages needed = %lu\n", n);
 	if (alloc_usable_pages(n)) {
 		free_eaten_memory();
 		return -ENOMEM;
 	}
 	/* We have got enough memory and from now on we cannot recover */
 	set_up_temporary_mappings();
 	restore_image();
 	return 0;
 }
 #endif /* CONFIG_SOFTWARE_SUSPEND */
	/*
	* Suspend support specific for i386.
	*
	* Distribute under GPLv2
	*
	* Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
	* Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
	*/

	#include <linux/config.h>
	#include <linux/smp.h>
	#include <linux/suspend.h>
	#include <asm/proto.h>
	#include <asm/page.h>
	#include <asm/pgtable.h>

	struct saved_context saved_context;

	unsigned long saved_context_eax, saved_context_ebx, saved_context_ecx, saved_context_edx;
	unsigned long saved_context_esp, saved_context_ebp, saved_context_esi, saved_context_edi;
	unsigned long saved_context_r08, saved_context_r09, saved_context_r10, saved_context_r11;
	unsigned long saved_context_r12, saved_context_r13, saved_context_r14, saved_context_r15;
	unsigned long saved_context_eflags;

	void __save_processor_state(struct saved_context *ctxt)
	{
	kernel_fpu_begin();

	/*
	* descriptor tables
	*/
	asm volatile ("sgdt %0" : "=m" (ctxt->gdt_limit));
	asm volatile ("sidt %0" : "=m" (ctxt->idt_limit));
	asm volatile ("str %0" : "=m" (ctxt->tr));

	/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
	/* EFER should be constant for kernel version, no need to handle it. */
	/*
	* segment registers
	*/
	asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
	asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
	asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
	asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs));
	asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss));

	rdmsrl(MSR_FS_BASE, ctxt->fs_base);
	rdmsrl(MSR_GS_BASE, ctxt->gs_base);
	rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

	/*
	* control registers
	*/
	asm volatile ("movq %%cr0, %0" : "=r" (ctxt->cr0));
	asm volatile ("movq %%cr2, %0" : "=r" (ctxt->cr2));
	asm volatile ("movq %%cr3, %0" : "=r" (ctxt->cr3));
	asm volatile ("movq %%cr4, %0" : "=r" (ctxt->cr4));
	asm volatile ("movq %%cr8, %0" : "=r" (ctxt->cr8));
	}

	void save_processor_state(void)
	{
	__save_processor_state(&saved_context);
	}

	static void do_fpu_end(void)
	{
	/*
	* Restore FPU regs if necessary
	*/
	kernel_fpu_end();
	}

	void __restore_processor_state(struct saved_context *ctxt)
	{
	/*
	* control registers
	*/
	asm volatile ("movq %0, %%cr8" :: "r" (ctxt->cr8));
	asm volatile ("movq %0, %%cr4" :: "r" (ctxt->cr4));
	asm volatile ("movq %0, %%cr3" :: "r" (ctxt->cr3));
	asm volatile ("movq %0, %%cr2" :: "r" (ctxt->cr2));
	asm volatile ("movq %0, %%cr0" :: "r" (ctxt->cr0));

	/*
	* now restore the descriptor tables to their proper values
	* ltr is done i fix_processor_context().
	*/
	asm volatile ("lgdt %0" :: "m" (ctxt->gdt_limit));
	asm volatile ("lidt %0" :: "m" (ctxt->idt_limit));

	/*
	* segment registers
	*/
	asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
	asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
	asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
	load_gs_index(ctxt->gs);
	asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));

	wrmsrl(MSR_FS_BASE, ctxt->fs_base);
	wrmsrl(MSR_GS_BASE, ctxt->gs_base);
	wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

	fix_processor_context();

	do_fpu_end();
	mtrr_ap_init();
	}

	void restore_processor_state(void)
	{
	__restore_processor_state(&saved_context);
	}

	void fix_processor_context(void)
	{
	int cpu = smp_processor_id();
	struct tss_struct *t = &per_cpu(init_tss, cpu);

	set_tss_desc(cpu,t); /* This just modifies memory; should not be neccessary. But... This is neccessary, because 386 hardware has concept of busy TSS or some similar stupidity. */

	cpu_gdt_table[cpu][GDT_ENTRY_TSS].type = 9;

	syscall_init(); /* This sets MSR_STAR and related /
	load_TR_desc(); /* This does ltr */
	load_LDT(&current->active_mm->context); /* This does lldt */

	/*
	* Now maybe reload the debug registers
	*/
	if (current->thread.debugreg7){
	loaddebug(&current->thread, 0);
	loaddebug(&current->thread, 1);
	loaddebug(&current->thread, 2);
	loaddebug(&current->thread, 3);
	/* no 4 and 5 */
	loaddebug(&current->thread, 6);
	loaddebug(&current->thread, 7);
	}

	}

	#ifdef CONFIG_SOFTWARE_SUSPEND
	/* Defined in arch/x86_64/kernel/suspend_asm.S */
	extern int restore_image(void);

	pgd_t *temp_level4_pgt;

	static void **pages;

	static inline void *__add_page(void)
	{
	void **c;

	c = (void **)get_usable_page(GFP_ATOMIC);
	if (c) {
	*c = pages;
	pages = c;
	}
	return c;
	}

	static inline void *__next_page(void)
	{
	void **c;

	c = pages;
	if (c) {
	pages = *c;
	*c = NULL;
	}
	return c;
	}

	/*
	* Try to allocate as many usable pages as needed and daisy chain them.
	* If one allocation fails, free the pages allocated so far
	*/
	static int alloc_usable_pages(unsigned long n)
	{
	void *p;

	pages = NULL;
	do
	if (!__add_page())
	break;
	while (--n);
	if (n) {
	p = __next_page();
	while (p) {
	free_page((unsigned long)p);
	p = __next_page();
	}
	return -ENOMEM;
	}
	return 0;
	}

	static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
	{
	long i, j;

	i = pud_index(address);
	pud = pud + i;
	for (; i < PTRS_PER_PUD; pud++, i++) {
	unsigned long paddr;
	pmd_t *pmd;

	paddr = address + i*PUD_SIZE;
	if (paddr >= end)
	break;

	pmd = (pmd_t *)__next_page();
	set_pud(pud, __pud(__pa(pmd) \| _KERNPG_TABLE));
	for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
	unsigned long pe;

	if (paddr >= end)
	break;
	pe = _PAGE_NX \| _PAGE_PSE \| _KERNPG_TABLE \| paddr;
	pe &= __supported_pte_mask;
	set_pmd(pmd, __pmd(pe));
	}
	}
	}

	static void set_up_temporary_mappings(void)
	{
	unsigned long start, end, next;

	temp_level4_pgt = (pgd_t *)__next_page();

	/* It is safe to reuse the original kernel mapping */
	set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
	init_level4_pgt[pgd_index(__START_KERNEL_map)]);

	/* Set up the direct mapping from scratch */
	start = (unsigned long)pfn_to_kaddr(0);
	end = (unsigned long)pfn_to_kaddr(end_pfn);

	for (; start < end; start = next) {
	pud_t pud = (pud_t )__next_page();
	next = start + PGDIR_SIZE;
	if (next > end)
	next = end;
	res_phys_pud_init(pud, __pa(start), __pa(next));
	set_pgd(temp_level4_pgt + pgd_index(start),
	mk_kernel_pgd(__pa(pud)));
	}
	}

	int swsusp_arch_resume(void)
	{
	unsigned long n;

	n = ((end_pfn << PAGE_SHIFT) + PUD_SIZE - 1) >> PUD_SHIFT;
	n += (n + PTRS_PER_PUD - 1) / PTRS_PER_PUD + 1;
	pr_debug("swsusp_arch_resume(): pages needed = %lu\n", n);
	if (alloc_usable_pages(n)) {
	free_eaten_memory();
	return -ENOMEM;
	}
	/* We have got enough memory and from now on we cannot recover */
	set_up_temporary_mappings();
	restore_image();
	return 0;
	}
	#endif /* CONFIG_SOFTWARE_SUSPEND */