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-rw-r--r--arch/x86/power/cpu.c259
1 files changed, 259 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
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1/*
2 * Suspend support specific for i386/x86-64.
3 *
4 * Distribute under GPLv2
5 *
6 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
7 * Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
8 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
9 */
10
11#include <linux/suspend.h>
12#include <linux/smp.h>
13
14#include <asm/pgtable.h>
15#include <asm/proto.h>
16#include <asm/mtrr.h>
17#include <asm/page.h>
18#include <asm/mce.h>
19#include <asm/xcr.h>
20#include <asm/suspend.h>
21
22#ifdef CONFIG_X86_32
23static struct saved_context saved_context;
24
25unsigned long saved_context_ebx;
26unsigned long saved_context_esp, saved_context_ebp;
27unsigned long saved_context_esi, saved_context_edi;
28unsigned long saved_context_eflags;
29#else
30/* CONFIG_X86_64 */
31struct saved_context saved_context;
32#endif
33
34/**
35 * __save_processor_state - save CPU registers before creating a
36 * hibernation image and before restoring the memory state from it
37 * @ctxt - structure to store the registers contents in
38 *
39 * NOTE: If there is a CPU register the modification of which by the
40 * boot kernel (ie. the kernel used for loading the hibernation image)
41 * might affect the operations of the restored target kernel (ie. the one
42 * saved in the hibernation image), then its contents must be saved by this
43 * function. In other words, if kernel A is hibernated and different
44 * kernel B is used for loading the hibernation image into memory, the
45 * kernel A's __save_processor_state() function must save all registers
46 * needed by kernel A, so that it can operate correctly after the resume
47 * regardless of what kernel B does in the meantime.
48 */
49static void __save_processor_state(struct saved_context *ctxt)
50{
51#ifdef CONFIG_X86_32
52 mtrr_save_fixed_ranges(NULL);
53#endif
54 kernel_fpu_begin();
55
56 /*
57 * descriptor tables
58 */
59#ifdef CONFIG_X86_32
60 store_gdt(&ctxt->gdt);
61 store_idt(&ctxt->idt);
62#else
63/* CONFIG_X86_64 */
64 store_gdt((struct desc_ptr *)&ctxt->gdt_limit);
65 store_idt((struct desc_ptr *)&ctxt->idt_limit);
66#endif
67 store_tr(ctxt->tr);
68
69 /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
70 /*
71 * segment registers
72 */
73#ifdef CONFIG_X86_32
74 savesegment(es, ctxt->es);
75 savesegment(fs, ctxt->fs);
76 savesegment(gs, ctxt->gs);
77 savesegment(ss, ctxt->ss);
78#else
79/* CONFIG_X86_64 */
80 asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
81 asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
82 asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
83 asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs));
84 asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss));
85
86 rdmsrl(MSR_FS_BASE, ctxt->fs_base);
87 rdmsrl(MSR_GS_BASE, ctxt->gs_base);
88 rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
89 mtrr_save_fixed_ranges(NULL);
90
91 rdmsrl(MSR_EFER, ctxt->efer);
92#endif
93
94 /*
95 * control registers
96 */
97 ctxt->cr0 = read_cr0();
98 ctxt->cr2 = read_cr2();
99 ctxt->cr3 = read_cr3();
100#ifdef CONFIG_X86_32
101 ctxt->cr4 = read_cr4_safe();
102#else
103/* CONFIG_X86_64 */
104 ctxt->cr4 = read_cr4();
105 ctxt->cr8 = read_cr8();
106#endif
107}
108
109/* Needed by apm.c */
110void save_processor_state(void)
111{
112 __save_processor_state(&saved_context);
113}
114#ifdef CONFIG_X86_32
115EXPORT_SYMBOL(save_processor_state);
116#endif
117
118static void do_fpu_end(void)
119{
120 /*
121 * Restore FPU regs if necessary.
122 */
123 kernel_fpu_end();
124}
125
126static void fix_processor_context(void)
127{
128 int cpu = smp_processor_id();
129 struct tss_struct *t = &per_cpu(init_tss, cpu);
130
131 set_tss_desc(cpu, t); /*
132 * This just modifies memory; should not be
133 * necessary. But... This is necessary, because
134 * 386 hardware has concept of busy TSS or some
135 * similar stupidity.
136 */
137
138#ifdef CONFIG_X86_64
139 get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS].type = 9;
140
141 syscall_init(); /* This sets MSR_*STAR and related */
142#endif
143 load_TR_desc(); /* This does ltr */
144 load_LDT(&current->active_mm->context); /* This does lldt */
145
146 /*
147 * Now maybe reload the debug registers
148 */
149 if (current->thread.debugreg7) {
150#ifdef CONFIG_X86_32
151 set_debugreg(current->thread.debugreg0, 0);
152 set_debugreg(current->thread.debugreg1, 1);
153 set_debugreg(current->thread.debugreg2, 2);
154 set_debugreg(current->thread.debugreg3, 3);
155 /* no 4 and 5 */
156 set_debugreg(current->thread.debugreg6, 6);
157 set_debugreg(current->thread.debugreg7, 7);
158#else
159 /* CONFIG_X86_64 */
160 loaddebug(&current->thread, 0);
161 loaddebug(&current->thread, 1);
162 loaddebug(&current->thread, 2);
163 loaddebug(&current->thread, 3);
164 /* no 4 and 5 */
165 loaddebug(&current->thread, 6);
166 loaddebug(&current->thread, 7);
167#endif
168 }
169
170}
171
172/**
173 * __restore_processor_state - restore the contents of CPU registers saved
174 * by __save_processor_state()
175 * @ctxt - structure to load the registers contents from
176 */
177static void __restore_processor_state(struct saved_context *ctxt)
178{
179 /*
180 * control registers
181 */
182 /* cr4 was introduced in the Pentium CPU */
183#ifdef CONFIG_X86_32
184 if (ctxt->cr4)
185 write_cr4(ctxt->cr4);
186#else
187/* CONFIG X86_64 */
188 wrmsrl(MSR_EFER, ctxt->efer);
189 write_cr8(ctxt->cr8);
190 write_cr4(ctxt->cr4);
191#endif
192 write_cr3(ctxt->cr3);
193 write_cr2(ctxt->cr2);
194 write_cr0(ctxt->cr0);
195
196 /*
197 * now restore the descriptor tables to their proper values
198 * ltr is done i fix_processor_context().
199 */
200#ifdef CONFIG_X86_32
201 load_gdt(&ctxt->gdt);
202 load_idt(&ctxt->idt);
203#else
204/* CONFIG_X86_64 */
205 load_gdt((const struct desc_ptr *)&ctxt->gdt_limit);
206 load_idt((const struct desc_ptr *)&ctxt->idt_limit);
207#endif
208
209 /*
210 * segment registers
211 */
212#ifdef CONFIG_X86_32
213 loadsegment(es, ctxt->es);
214 loadsegment(fs, ctxt->fs);
215 loadsegment(gs, ctxt->gs);
216 loadsegment(ss, ctxt->ss);
217
218 /*
219 * sysenter MSRs
220 */
221 if (boot_cpu_has(X86_FEATURE_SEP))
222 enable_sep_cpu();
223#else
224/* CONFIG_X86_64 */
225 asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
226 asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
227 asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
228 load_gs_index(ctxt->gs);
229 asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));
230
231 wrmsrl(MSR_FS_BASE, ctxt->fs_base);
232 wrmsrl(MSR_GS_BASE, ctxt->gs_base);
233 wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
234#endif
235
236 /*
237 * restore XCR0 for xsave capable cpu's.
238 */
239 if (cpu_has_xsave)
240 xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
241
242 fix_processor_context();
243
244 do_fpu_end();
245 mtrr_ap_init();
246
247#ifdef CONFIG_X86_32
248 mcheck_init(&boot_cpu_data);
249#endif
250}
251
252/* Needed by apm.c */
253void restore_processor_state(void)
254{
255 __restore_processor_state(&saved_context);
256}
257#ifdef CONFIG_X86_32
258EXPORT_SYMBOL(restore_processor_state);
259#endif
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