Merge branch 'for-2.6.30' of git://linux-nfs.org/~bfields/linux
[linux-2.6] / 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 #include <asm/xcr.h>
15 #include <asm/suspend.h>
16
17 static struct saved_context saved_context;
18
19 unsigned long saved_context_ebx;
20 unsigned long saved_context_esp, saved_context_ebp;
21 unsigned long saved_context_esi, saved_context_edi;
22 unsigned long saved_context_eflags;
23
24 static void __save_processor_state(struct saved_context *ctxt)
25 {
26         mtrr_save_fixed_ranges(NULL);
27         kernel_fpu_begin();
28
29         /*
30          * descriptor tables
31          */
32         store_gdt(&ctxt->gdt);
33         store_idt(&ctxt->idt);
34         store_tr(ctxt->tr);
35
36         /*
37          * segment registers
38          */
39         savesegment(es, ctxt->es);
40         savesegment(fs, ctxt->fs);
41         savesegment(gs, ctxt->gs);
42         savesegment(ss, ctxt->ss);
43
44         /*
45          * control registers
46          */
47         ctxt->cr0 = read_cr0();
48         ctxt->cr2 = read_cr2();
49         ctxt->cr3 = read_cr3();
50         ctxt->cr4 = read_cr4_safe();
51 }
52
53 /* Needed by apm.c */
54 void save_processor_state(void)
55 {
56         __save_processor_state(&saved_context);
57 }
58 EXPORT_SYMBOL(save_processor_state);
59
60 static void do_fpu_end(void)
61 {
62         /*
63          * Restore FPU regs if necessary.
64          */
65         kernel_fpu_end();
66 }
67
68 static void fix_processor_context(void)
69 {
70         int cpu = smp_processor_id();
71         struct tss_struct *t = &per_cpu(init_tss, cpu);
72
73         set_tss_desc(cpu, t);   /*
74                                  * This just modifies memory; should not be
75                                  * necessary. But... This is necessary, because
76                                  * 386 hardware has concept of busy TSS or some
77                                  * similar stupidity.
78                                  */
79
80         load_TR_desc();                         /* This does ltr */
81         load_LDT(&current->active_mm->context); /* This does lldt */
82
83         /*
84          * Now maybe reload the debug registers
85          */
86         if (current->thread.debugreg7) {
87                 set_debugreg(current->thread.debugreg0, 0);
88                 set_debugreg(current->thread.debugreg1, 1);
89                 set_debugreg(current->thread.debugreg2, 2);
90                 set_debugreg(current->thread.debugreg3, 3);
91                 /* no 4 and 5 */
92                 set_debugreg(current->thread.debugreg6, 6);
93                 set_debugreg(current->thread.debugreg7, 7);
94         }
95
96 }
97
98 static void __restore_processor_state(struct saved_context *ctxt)
99 {
100         /*
101          * control registers
102          */
103         /* cr4 was introduced in the Pentium CPU */
104         if (ctxt->cr4)
105                 write_cr4(ctxt->cr4);
106         write_cr3(ctxt->cr3);
107         write_cr2(ctxt->cr2);
108         write_cr0(ctxt->cr0);
109
110         /*
111          * now restore the descriptor tables to their proper values
112          * ltr is done i fix_processor_context().
113          */
114         load_gdt(&ctxt->gdt);
115         load_idt(&ctxt->idt);
116
117         /*
118          * segment registers
119          */
120         loadsegment(es, ctxt->es);
121         loadsegment(fs, ctxt->fs);
122         loadsegment(gs, ctxt->gs);
123         loadsegment(ss, ctxt->ss);
124
125         /*
126          * sysenter MSRs
127          */
128         if (boot_cpu_has(X86_FEATURE_SEP))
129                 enable_sep_cpu();
130
131         /*
132          * restore XCR0 for xsave capable cpu's.
133          */
134         if (cpu_has_xsave)
135                 xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
136
137         fix_processor_context();
138         do_fpu_end();
139         mtrr_ap_init();
140         mcheck_init(&boot_cpu_data);
141 }
142
143 /* Needed by apm.c */
144 void restore_processor_state(void)
145 {
146         __restore_processor_state(&saved_context);
147 }
148 EXPORT_SYMBOL(restore_processor_state);