aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86_64/kernel/suspend.c
blob: 02516823f514bd299dcf6c925d701367d2aa85ef (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
/*
 * Suspend support specific for i386.
 *
 * Distribute under GPLv2
 *
 * Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
 */

#include <linux/config.h>
#include <linux/smp.h>
#include <linux/suspend.h>
#include <asm/proto.h>
#include <asm/page.h>
#include <asm/pgtable.h>

struct saved_context saved_context;

unsigned long saved_context_eax, saved_context_ebx, saved_context_ecx, saved_context_edx;
unsigned long saved_context_esp, saved_context_ebp, saved_context_esi, saved_context_edi;
unsigned long saved_context_r08, saved_context_r09, saved_context_r10, saved_context_r11;
unsigned long saved_context_r12, saved_context_r13, saved_context_r14, saved_context_r15;
unsigned long saved_context_eflags;

void __save_processor_state(struct saved_context *ctxt)
{
	kernel_fpu_begin();

	/*
	 * descriptor tables
	 */
	asm volatile ("sgdt %0" : "=m" (ctxt->gdt_limit));
	asm volatile ("sidt %0" : "=m" (ctxt->idt_limit));
	asm volatile ("str %0"  : "=m" (ctxt->tr));

	/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
	/* EFER should be constant for kernel version, no need to handle it. */
	/*
	 * segment registers
	 */
	asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
	asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
	asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
	asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs));
	asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss));

	rdmsrl(MSR_FS_BASE, ctxt->fs_base);
	rdmsrl(MSR_GS_BASE, ctxt->gs_base);
	rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

	/*
	 * control registers 
	 */
	asm volatile ("movq %%cr0, %0" : "=r" (ctxt->cr0));
	asm volatile ("movq %%cr2, %0" : "=r" (ctxt->cr2));
	asm volatile ("movq %%cr3, %0" : "=r" (ctxt->cr3));
	asm volatile ("movq %%cr4, %0" : "=r" (ctxt->cr4));
	asm volatile ("movq %%cr8, %0" : "=r" (ctxt->cr8));
}

void save_processor_state(void)
{
	__save_processor_state(&saved_context);
}

static void do_fpu_end(void)
{
	/*
	 * Restore FPU regs if necessary
	 */
	kernel_fpu_end();
}

void __restore_processor_state(struct saved_context *ctxt)
{
	/*
	 * control registers
	 */
	asm volatile ("movq %0, %%cr8" :: "r" (ctxt->cr8));
	asm volatile ("movq %0, %%cr4" :: "r" (ctxt->cr4));
	asm volatile ("movq %0, %%cr3" :: "r" (ctxt->cr3));
	asm volatile ("movq %0, %%cr2" :: "r" (ctxt->cr2));
	asm volatile ("movq %0, %%cr0" :: "r" (ctxt->cr0));

	/*
	 * now restore the descriptor tables to their proper values
	 * ltr is done i fix_processor_context().
	 */
	asm volatile ("lgdt %0" :: "m" (ctxt->gdt_limit));
	asm volatile ("lidt %0" :: "m" (ctxt->idt_limit));

	/*
	 * segment registers
	 */
	asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
	asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
	asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
	load_gs_index(ctxt->gs);
	asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));

	wrmsrl(MSR_FS_BASE, ctxt->fs_base);
	wrmsrl(MSR_GS_BASE, ctxt->gs_base);
	wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);

	fix_processor_context();

	do_fpu_end();
	mtrr_ap_init();
}

void restore_processor_state(void)
{
	__restore_processor_state(&saved_context);
}

void fix_processor_context(void)
{
	int cpu = smp_processor_id();
	struct tss_struct *t = &per_cpu(init_tss, cpu);

	set_tss_desc(cpu,t);	/* This just modifies memory; should not be neccessary. But... This is neccessary, because 386 hardware has concept of busy TSS or some similar stupidity. */

	cpu_gdt_table[cpu][GDT_ENTRY_TSS].type = 9;

	syscall_init();                         /* This sets MSR_*STAR and related */
	load_TR_desc();				/* This does ltr */
	load_LDT(&current->active_mm->context);	/* This does lldt */

	/*
	 * Now maybe reload the debug registers
	 */
	if (current->thread.debugreg7){
                loaddebug(&current->thread, 0);
                loaddebug(&current->thread, 1);
                loaddebug(&current->thread, 2);
                loaddebug(&current->thread, 3);
                /* no 4 and 5 */
                loaddebug(&current->thread, 6);
                loaddebug(&current->thread, 7);
	}

}

#ifdef CONFIG_SOFTWARE_SUSPEND
/* Defined in arch/x86_64/kernel/suspend_asm.S */
extern int restore_image(void);

pgd_t *temp_level4_pgt;

static void **pages;

static inline void *__add_page(void)
{
	void **c;

	c = (void **)get_usable_page(GFP_ATOMIC);
	if (c) {
		*c = pages;
		pages = c;
	}
	return c;
}

static inline void *__next_page(void)
{
	void **c;

	c = pages;
	if (c) {
		pages = *c;
		*c = NULL;
	}
	return c;
}

/*
 * Try to allocate as many usable pages as needed and daisy chain them.
 * If one allocation fails, free the pages allocated so far
 */
static int alloc_usable_pages(unsigned long n)
{
	void *p;

	pages = NULL;
	do
		if (!__add_page())
			break;
	while (--n);
	if (n) {
		p = __next_page();
		while (p) {
			free_page((unsigned long)p);
			p = __next_page();
		}
		return -ENOMEM;
	}
	return 0;
}

static void res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
{
	long i, j;

	i = pud_index(address);
	pud = pud + i;
	for (; i < PTRS_PER_PUD; pud++, i++) {
		unsigned long paddr;
		pmd_t *pmd;

		paddr = address + i*PUD_SIZE;
		if (paddr >= end)
			break;

		pmd = (pmd_t *)__next_page();
		set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
		for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
			unsigned long pe;

			if (paddr >= end)
				break;
			pe = _PAGE_NX | _PAGE_PSE | _KERNPG_TABLE | paddr;
			pe &= __supported_pte_mask;
			set_pmd(pmd, __pmd(pe));
		}
	}
}

static void set_up_temporary_mappings(void)
{
	unsigned long start, end, next;

	temp_level4_pgt = (pgd_t *)__next_page();

	/* It is safe to reuse the original kernel mapping */
	set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
		init_level4_pgt[pgd_index(__START_KERNEL_map)]);

	/* Set up the direct mapping from scratch */
	start = (unsigned long)pfn_to_kaddr(0);
	end = (unsigned long)pfn_to_kaddr(end_pfn);

	for (; start < end; start = next) {
		pud_t *pud = (pud_t *)__next_page();
		next = start + PGDIR_SIZE;
		if (next > end)
			next = end;
		res_phys_pud_init(pud, __pa(start), __pa(next));
		set_pgd(temp_level4_pgt + pgd_index(start),
			mk_kernel_pgd(__pa(pud)));
	}
}

int swsusp_arch_resume(void)
{
	unsigned long n;

	n = ((end_pfn << PAGE_SHIFT) + PUD_SIZE - 1) >> PUD_SHIFT;
	n += (n + PTRS_PER_PUD - 1) / PTRS_PER_PUD + 1;
	pr_debug("swsusp_arch_resume(): pages needed = %lu\n", n);
	if (alloc_usable_pages(n)) {
		free_eaten_memory();
		return -ENOMEM;
	}
	/* We have got enough memory and from now on we cannot recover */
	set_up_temporary_mappings();
	restore_image();
	return 0;
}
#endif /* CONFIG_SOFTWARE_SUSPEND */