131 lines
2.7 KiB
C
131 lines
2.7 KiB
C
/*
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* Suspend support specific for i386.
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*
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* Distribute under GPLv2
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*
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* Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
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* Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
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*/
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#include <linux/config.h>
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#include <linux/module.h>
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#include <linux/suspend.h>
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static struct saved_context saved_context;
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unsigned long saved_context_ebx;
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unsigned long saved_context_esp, saved_context_ebp;
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unsigned long saved_context_esi, saved_context_edi;
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unsigned long saved_context_eflags;
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void __save_processor_state(struct saved_context *ctxt)
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{
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kernel_fpu_begin();
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/*
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* descriptor tables
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*/
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store_gdt(&ctxt->gdt_limit);
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store_idt(&ctxt->idt_limit);
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store_tr(ctxt->tr);
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/*
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* segment registers
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*/
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savesegment(es, ctxt->es);
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savesegment(fs, ctxt->fs);
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savesegment(gs, ctxt->gs);
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savesegment(ss, ctxt->ss);
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/*
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* control registers
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*/
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ctxt->cr0 = read_cr0();
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ctxt->cr2 = read_cr2();
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ctxt->cr3 = read_cr3();
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ctxt->cr4 = read_cr4();
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}
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void save_processor_state(void)
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{
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__save_processor_state(&saved_context);
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}
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static void do_fpu_end(void)
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{
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/*
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* Restore FPU regs if necessary.
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*/
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kernel_fpu_end();
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}
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static void fix_processor_context(void)
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{
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int cpu = smp_processor_id();
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struct tss_struct * t = &per_cpu(init_tss, cpu);
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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. */
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load_TR_desc(); /* This does ltr */
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load_LDT(¤t->active_mm->context); /* This does lldt */
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/*
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* Now maybe reload the debug registers
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*/
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if (current->thread.debugreg[7]){
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set_debugreg(current->thread.debugreg[0], 0);
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set_debugreg(current->thread.debugreg[1], 1);
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set_debugreg(current->thread.debugreg[2], 2);
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set_debugreg(current->thread.debugreg[3], 3);
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/* no 4 and 5 */
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set_debugreg(current->thread.debugreg[6], 6);
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set_debugreg(current->thread.debugreg[7], 7);
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}
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}
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void __restore_processor_state(struct saved_context *ctxt)
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{
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/*
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* control registers
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*/
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write_cr4(ctxt->cr4);
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write_cr3(ctxt->cr3);
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write_cr2(ctxt->cr2);
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write_cr2(ctxt->cr0);
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/*
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* now restore the descriptor tables to their proper values
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* ltr is done i fix_processor_context().
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*/
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load_gdt(&ctxt->gdt_limit);
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load_idt(&ctxt->idt_limit);
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/*
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* segment registers
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*/
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loadsegment(es, ctxt->es);
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loadsegment(fs, ctxt->fs);
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loadsegment(gs, ctxt->gs);
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loadsegment(ss, ctxt->ss);
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/*
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* sysenter MSRs
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*/
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if (boot_cpu_has(X86_FEATURE_SEP))
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enable_sep_cpu();
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fix_processor_context();
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do_fpu_end();
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mtrr_ap_init();
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}
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void restore_processor_state(void)
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{
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__restore_processor_state(&saved_context);
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}
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/* Needed by apm.c */
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EXPORT_SYMBOL(save_processor_state);
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EXPORT_SYMBOL(restore_processor_state);
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