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linux/arch/i386/power/cpu.c
Linus Torvalds 1da177e4c3 Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!
2005-04-16 15:20:36 -07:00

153 lines
3.9 KiB
C

/*
* 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/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/spinlock.h>
#include <linux/poll.h>
#include <linux/delay.h>
#include <linux/sysrq.h>
#include <linux/proc_fs.h>
#include <linux/irq.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/suspend.h>
#include <linux/acpi.h>
#include <asm/uaccess.h>
#include <asm/acpi.h>
#include <asm/tlbflush.h>
static struct saved_context saved_context;
unsigned long saved_context_ebx;
unsigned long saved_context_esp, saved_context_ebp;
unsigned long saved_context_esi, saved_context_edi;
unsigned long saved_context_eflags;
extern void enable_sep_cpu(void *);
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 ("sldt %0" : "=m" (ctxt->ldt));
asm volatile ("str %0" : "=m" (ctxt->tr));
/*
* segment registers
*/
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));
/*
* control registers
*/
asm volatile ("movl %%cr0, %0" : "=r" (ctxt->cr0));
asm volatile ("movl %%cr2, %0" : "=r" (ctxt->cr2));
asm volatile ("movl %%cr3, %0" : "=r" (ctxt->cr3));
asm volatile ("movl %%cr4, %0" : "=r" (ctxt->cr4));
}
void save_processor_state(void)
{
__save_processor_state(&saved_context);
}
static void
do_fpu_end(void)
{
/* restore FPU regs if necessary */
/* Do it out of line so that gcc does not move cr0 load to some stupid place */
kernel_fpu_end();
mxcsr_feature_mask_init();
}
static 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 necessary. But... This is necessary, because 386 hardware has concept of busy TSS or some similar stupidity. */
per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TSS].b &= 0xfffffdff;
load_TR_desc(); /* This does ltr */
load_LDT(&current->active_mm->context); /* This does lldt */
/*
* Now maybe reload the debug registers
*/
if (current->thread.debugreg[7]){
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);
}
}
void __restore_processor_state(struct saved_context *ctxt)
{
/*
* control registers
*/
asm volatile ("movl %0, %%cr4" :: "r" (ctxt->cr4));
asm volatile ("movl %0, %%cr3" :: "r" (ctxt->cr3));
asm volatile ("movl %0, %%cr2" :: "r" (ctxt->cr2));
asm volatile ("movl %0, %%cr0" :: "r" (ctxt->cr0));
/*
* segment registers
*/
asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
asm volatile ("movw %0, %%gs" :: "r" (ctxt->gs));
asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));
/*
* 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));
asm volatile ("lldt %0" :: "m" (ctxt->ldt));
/*
* sysenter MSRs
*/
if (boot_cpu_has(X86_FEATURE_SEP))
enable_sep_cpu(NULL);
fix_processor_context();
do_fpu_end();
}
void restore_processor_state(void)
{
__restore_processor_state(&saved_context);
}
/* Needed by apm.c */
EXPORT_SYMBOL(save_processor_state);
EXPORT_SYMBOL(restore_processor_state);