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