1 /* 2 * Suspend support specific for i386. 3 * 4 * Distribute under GPLv2 5 * 6 * Copyright (c) 2002 Pavel Machek <pavel@suse.cz> 7 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org> 8 */ 9 10 #include <linux/module.h> 11 #include <linux/suspend.h> 12 #include <asm/mtrr.h> 13 #include <asm/mce.h> 14 15 static struct saved_context saved_context; 16 17 unsigned long saved_context_ebx; 18 unsigned long saved_context_esp, saved_context_ebp; 19 unsigned long saved_context_esi, saved_context_edi; 20 unsigned long saved_context_eflags; 21 22 void __save_processor_state(struct saved_context *ctxt) 23 { 24 mtrr_save_fixed_ranges(NULL); 25 kernel_fpu_begin(); 26 27 /* 28 * descriptor tables 29 */ 30 store_gdt(&ctxt->gdt); 31 store_idt(&ctxt->idt); 32 store_tr(ctxt->tr); 33 34 /* 35 * segment registers 36 */ 37 savesegment(es, ctxt->es); 38 savesegment(fs, ctxt->fs); 39 savesegment(gs, ctxt->gs); 40 savesegment(ss, ctxt->ss); 41 42 /* 43 * control registers 44 */ 45 ctxt->cr0 = read_cr0(); 46 ctxt->cr2 = read_cr2(); 47 ctxt->cr3 = read_cr3(); 48 ctxt->cr4 = read_cr4(); 49 } 50 51 void save_processor_state(void) 52 { 53 __save_processor_state(&saved_context); 54 } 55 56 static void do_fpu_end(void) 57 { 58 /* 59 * Restore FPU regs if necessary. 60 */ 61 kernel_fpu_end(); 62 } 63 64 static void fix_processor_context(void) 65 { 66 int cpu = smp_processor_id(); 67 struct tss_struct * t = &per_cpu(init_tss, cpu); 68 69 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. */ 70 71 load_TR_desc(); /* This does ltr */ 72 load_LDT(¤t->active_mm->context); /* This does lldt */ 73 74 /* 75 * Now maybe reload the debug registers 76 */ 77 if (current->thread.debugreg[7]){ 78 set_debugreg(current->thread.debugreg[0], 0); 79 set_debugreg(current->thread.debugreg[1], 1); 80 set_debugreg(current->thread.debugreg[2], 2); 81 set_debugreg(current->thread.debugreg[3], 3); 82 /* no 4 and 5 */ 83 set_debugreg(current->thread.debugreg[6], 6); 84 set_debugreg(current->thread.debugreg[7], 7); 85 } 86 87 } 88 89 void __restore_processor_state(struct saved_context *ctxt) 90 { 91 /* 92 * control registers 93 */ 94 write_cr4(ctxt->cr4); 95 write_cr3(ctxt->cr3); 96 write_cr2(ctxt->cr2); 97 write_cr0(ctxt->cr0); 98 99 /* 100 * now restore the descriptor tables to their proper values 101 * ltr is done i fix_processor_context(). 102 */ 103 load_gdt(&ctxt->gdt); 104 load_idt(&ctxt->idt); 105 106 /* 107 * segment registers 108 */ 109 loadsegment(es, ctxt->es); 110 loadsegment(fs, ctxt->fs); 111 loadsegment(gs, ctxt->gs); 112 loadsegment(ss, ctxt->ss); 113 114 /* 115 * sysenter MSRs 116 */ 117 if (boot_cpu_has(X86_FEATURE_SEP)) 118 enable_sep_cpu(); 119 120 fix_processor_context(); 121 do_fpu_end(); 122 mtrr_ap_init(); 123 mcheck_init(&boot_cpu_data); 124 } 125 126 void restore_processor_state(void) 127 { 128 __restore_processor_state(&saved_context); 129 } 130 131 /* Needed by apm.c */ 132 EXPORT_SYMBOL(save_processor_state); 133 EXPORT_SYMBOL(restore_processor_state); 134