root/arch/x86/power/cpu_32.c

DEFINITIONS

1. __save_processor_state
2. save_processor_state
3. do_fpu_end
4. fix_processor_context
5. __restore_processor_state
6. restore_processor_state

/*
 * 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/module.h>
#include <linux/suspend.h>
#include <asm/mtrr.h>
#include <asm/mce.h>
#include <asm/xcr.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;

static void __save_processor_state(struct saved_context *ctxt)
{
        mtrr_save_fixed_ranges(NULL);
        kernel_fpu_begin();

        /*
         * descriptor tables
         */
        store_gdt(&ctxt->gdt);
        store_idt(&ctxt->idt);
        store_tr(ctxt->tr);

        /*
         * segment registers
         */
        savesegment(es, ctxt->es);
        savesegment(fs, ctxt->fs);
        savesegment(gs, ctxt->gs);
        savesegment(ss, ctxt->ss);

        /*
         * control registers
         */
        ctxt->cr0 = read_cr0();
        ctxt->cr2 = read_cr2();
        ctxt->cr3 = read_cr3();
        ctxt->cr4 = read_cr4_safe();
}

/* Needed by apm.c */
void save_processor_state(void)
{
        __save_processor_state(&saved_context);
}
EXPORT_SYMBOL(save_processor_state);

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

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.
                                 */

        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) {
                set_debugreg(current->thread.debugreg0, 0);
                set_debugreg(current->thread.debugreg1, 1);
                set_debugreg(current->thread.debugreg2, 2);
                set_debugreg(current->thread.debugreg3, 3);
                /* no 4 and 5 */
                set_debugreg(current->thread.debugreg6, 6);
                set_debugreg(current->thread.debugreg7, 7);
        }

}

static void __restore_processor_state(struct saved_context *ctxt)
{
        /*
         * control registers
         */
        /* cr4 was introduced in the Pentium CPU */
        if (ctxt->cr4)
                write_cr4(ctxt->cr4);
        write_cr3(ctxt->cr3);
        write_cr2(ctxt->cr2);
        write_cr0(ctxt->cr0);

        /*
         * now restore the descriptor tables to their proper values
         * ltr is done i fix_processor_context().
         */
        load_gdt(&ctxt->gdt);
        load_idt(&ctxt->idt);

        /*
         * segment registers
         */
        loadsegment(es, ctxt->es);
        loadsegment(fs, ctxt->fs);
        loadsegment(gs, ctxt->gs);
        loadsegment(ss, ctxt->ss);

        /*
         * sysenter MSRs
         */
        if (boot_cpu_has(X86_FEATURE_SEP))
                enable_sep_cpu();

        /*
         * restore XCR0 for xsave capable cpu's.
         */
        if (cpu_has_xsave)
                xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);

        fix_processor_context();
        do_fpu_end();
        mtrr_ap_init();
        mcheck_init(&boot_cpu_data);
}

/* Needed by apm.c */
void restore_processor_state(void)
{
        __restore_processor_state(&saved_context);
}
EXPORT_SYMBOL(restore_processor_state);