[PATCH] i386: inline assembler: cleanup and encapsulate descriptor and task register...
[linux-2.6.git] / arch / i386 / power / cpu.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/config.h>
11 #include <linux/kernel.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/types.h>
15 #include <linux/spinlock.h>
16 #include <linux/poll.h>
17 #include <linux/delay.h>
18 #include <linux/sysrq.h>
19 #include <linux/proc_fs.h>
20 #include <linux/irq.h>
21 #include <linux/pm.h>
22 #include <linux/device.h>
23 #include <linux/suspend.h>
24 #include <linux/acpi.h>
25
26 #include <asm/uaccess.h>
27 #include <asm/acpi.h>
28 #include <asm/tlbflush.h>
29 #include <asm/processor.h>
30
31 static struct saved_context saved_context;
32
33 unsigned long saved_context_ebx;
34 unsigned long saved_context_esp, saved_context_ebp;
35 unsigned long saved_context_esi, saved_context_edi;
36 unsigned long saved_context_eflags;
37
38 void __save_processor_state(struct saved_context *ctxt)
39 {
40         kernel_fpu_begin();
41
42         /*
43          * descriptor tables
44          */
45         store_gdt(&ctxt->gdt_limit);
46         store_idt(&ctxt->idt_limit);
47         store_tr(ctxt->tr);
48
49         /*
50          * segment registers
51          */
52         savesegment(es, ctxt->es);
53         savesegment(fs, ctxt->fs);
54         savesegment(gs, ctxt->gs);
55         savesegment(ss, ctxt->ss);
56
57         /*
58          * control registers 
59          */
60         ctxt->cr0 = read_cr0();
61         ctxt->cr2 = read_cr2();
62         ctxt->cr3 = read_cr3();
63         ctxt->cr4 = read_cr4();
64 }
65
66 void save_processor_state(void)
67 {
68         __save_processor_state(&saved_context);
69 }
70
71 static void
72 do_fpu_end(void)
73 {
74         /* restore FPU regs if necessary */
75         /* Do it out of line so that gcc does not move cr0 load to some stupid place */
76         kernel_fpu_end();
77         mxcsr_feature_mask_init();
78 }
79
80
81 static void fix_processor_context(void)
82 {
83         int cpu = smp_processor_id();
84         struct tss_struct * t = &per_cpu(init_tss, cpu);
85
86         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. */
87         per_cpu(cpu_gdt_table, cpu)[GDT_ENTRY_TSS].b &= 0xfffffdff;
88
89         load_TR_desc();                         /* This does ltr */
90         load_LDT(&current->active_mm->context); /* This does lldt */
91
92         /*
93          * Now maybe reload the debug registers
94          */
95         if (current->thread.debugreg[7]){
96                 set_debugreg(current->thread.debugreg[0], 0);
97                 set_debugreg(current->thread.debugreg[1], 1);
98                 set_debugreg(current->thread.debugreg[2], 2);
99                 set_debugreg(current->thread.debugreg[3], 3);
100                 /* no 4 and 5 */
101                 set_debugreg(current->thread.debugreg[6], 6);
102                 set_debugreg(current->thread.debugreg[7], 7);
103         }
104
105 }
106
107 void __restore_processor_state(struct saved_context *ctxt)
108 {
109         /*
110          * control registers
111          */
112         write_cr4(ctxt->cr4);
113         write_cr3(ctxt->cr3);
114         write_cr2(ctxt->cr2);
115         write_cr2(ctxt->cr0);
116
117         /*
118          * now restore the descriptor tables to their proper values
119          * ltr is done i fix_processor_context().
120          */
121         load_gdt(&ctxt->gdt_limit);
122         load_idt(&ctxt->idt_limit);
123
124         /*
125          * segment registers
126          */
127         loadsegment(es, ctxt->es);
128         loadsegment(fs, ctxt->fs);
129         loadsegment(gs, ctxt->gs);
130         loadsegment(ss, ctxt->ss);
131
132         /*
133          * sysenter MSRs
134          */
135         if (boot_cpu_has(X86_FEATURE_SEP))
136                 enable_sep_cpu();
137
138         fix_processor_context();
139         do_fpu_end();
140         mtrr_ap_init();
141 }
142
143 void restore_processor_state(void)
144 {
145         __restore_processor_state(&saved_context);
146 }
147
148 /* Needed by apm.c */
149 EXPORT_SYMBOL(save_processor_state);
150 EXPORT_SYMBOL(restore_processor_state);