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
15static struct saved_context saved_context;
16
17unsigned long saved_context_ebx;
18unsigned long saved_context_esp, saved_context_ebp;
19unsigned long saved_context_esi, saved_context_edi;
20unsigned long saved_context_eflags;
21
22void __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
51void save_processor_state(void)
52{
53	__save_processor_state(&saved_context);
54}
55
56static void do_fpu_end(void)
57{
58	/*
59	 * Restore FPU regs if necessary.
60	 */
61	kernel_fpu_end();
62}
63
64static 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(&current->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
89void __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
126void restore_processor_state(void)
127{
128	__restore_processor_state(&saved_context);
129}
130
131/* Needed by apm.c */
132EXPORT_SYMBOL(save_processor_state);
133EXPORT_SYMBOL(restore_processor_state);
134