7f9c6da04a4c143a01f9529125b775052cfb35d1
[sfrench/cifs-2.6.git] / arch / x86 / power / cpu_32.c
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 static 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(&current->active_mm->context); /* This does lldt */
73
74         /*
75          * Now maybe reload the debug registers
76          */
77         if (current->thread.debugreg7) {
78                 set_debugreg(current->thread.debugreg0, 0);
79                 set_debugreg(current->thread.debugreg1, 1);
80                 set_debugreg(current->thread.debugreg2, 2);
81                 set_debugreg(current->thread.debugreg3, 3);
82                 /* no 4 and 5 */
83                 set_debugreg(current->thread.debugreg6, 6);
84                 set_debugreg(current->thread.debugreg7, 7);
85         }
86
87 }
88
89 static 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);