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  * AK currently useless for 24 because the core ACPI code doesn't support S3.
10  *    and most of the infrastructure is missing.
11  */
12 
13 #include <linux/config.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/types.h>
18 #include <linux/spinlock.h>
19 #include <linux/poll.h>
20 #include <linux/delay.h>
21 #include <linux/sysrq.h>
22 #include <linux/proc_fs.h>
23 #include <linux/irq.h>
24 #include <linux/pm.h>
25 #include <asm/uaccess.h>
26 #include <asm/acpi.h>
27 #include <asm/io.h>
28 #include <asm/proto.h>
29 #include <asm/i387.h>
30 #include <asm/desc.h>
31 
32 void fix_processor_context(void);
33 
34 /* Image of the saved processor state. If you touch this, fix acpi_wakeup.S. */
35 struct saved_context {
36   	u16 ds, es, fs, gs, ss;
37 	unsigned long gs_base, gs_kernel_base, fs_base;
38 	unsigned long cr0, cr2, cr3, cr4;
39 	u16 gdt_pad;
40 	u16 gdt_limit;
41 	unsigned long gdt_base;
42 	u16 idt_pad;
43 	u16 idt_limit;
44 	unsigned long idt_base;
45 	u16 ldt;
46 	u16 tss;
47 	unsigned long tr;
48 	unsigned long safety;
49 	unsigned long return_address;
50 	unsigned long eflags;
51 } __attribute__((packed));
52 
53 struct saved_context saved_context;
54 
55 unsigned long saved_context_eax, saved_context_ebx, saved_context_ecx, saved_context_edx;
56 unsigned long saved_context_esp, saved_context_ebp, saved_context_esi, saved_context_edi;
57 unsigned long saved_context_r08, saved_context_r09, saved_context_r10, saved_context_r11;
58 unsigned long saved_context_r12, saved_context_r13, saved_context_r14, saved_context_r15;
59 unsigned long saved_context_eflags;
60 
save_processor_state(void)61 void save_processor_state (void)
62 {
63 	kernel_fpu_begin();
64 
65 	/*
66 	 * descriptor tables
67 	 */
68 	asm volatile ("sgdt %0" : "=m" (saved_context.gdt_limit));
69 	asm volatile ("sidt %0" : "=m" (saved_context.idt_limit));
70 	asm volatile ("sldt %0" : "=m" (saved_context.ldt));
71 	asm volatile ("str %0"  : "=m" (saved_context.tr));
72 
73 	/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
74 	/* EFER should be constant for kernel version, no need to handle it. */
75 	/*
76 	 * segment registers
77 	 */
78 	asm volatile ("movw %%ds, %0" : "=m" (saved_context.ds));
79 	asm volatile ("movw %%es, %0" : "=m" (saved_context.es));
80 	asm volatile ("movw %%fs, %0" : "=m" (saved_context.fs));
81 	asm volatile ("movw %%gs, %0" : "=m" (saved_context.gs));
82 	asm volatile ("movw %%ss, %0" : "=m" (saved_context.ss));
83 
84 	rdmsrl(MSR_FS_BASE, saved_context.fs_base);
85 	rdmsrl(MSR_GS_BASE, saved_context.gs_base);
86 	rdmsrl(MSR_KERNEL_GS_BASE, saved_context.gs_kernel_base);
87 
88 	/*
89 	 * control registers
90 	 */
91 	asm volatile ("movq %%cr0, %0" : "=r" (saved_context.cr0));
92 	asm volatile ("movq %%cr2, %0" : "=r" (saved_context.cr2));
93 	asm volatile ("movq %%cr3, %0" : "=r" (saved_context.cr3));
94 	asm volatile ("movq %%cr4, %0" : "=r" (saved_context.cr4));
95 }
96 
97 static void
do_fpu_end(void)98 do_fpu_end(void)
99 {
100         /* restore FPU regs if necessary */
101         kernel_fpu_end();
102 }
103 
restore_processor_state(void)104 void restore_processor_state(void)
105 {
106 	/*
107 	 * control registers
108 	 */
109 	asm volatile ("movq %0, %%cr4" :: "r" (saved_context.cr4));
110 	asm volatile ("movq %0, %%cr3" :: "r" (saved_context.cr3));
111 	asm volatile ("movq %0, %%cr2" :: "r" (saved_context.cr2));
112 	asm volatile ("movq %0, %%cr0" :: "r" (saved_context.cr0));
113 
114 	/*
115 	 * segment registers
116 	 */
117 	asm volatile ("movw %0, %%ds" :: "r" (saved_context.ds));
118 	asm volatile ("movw %0, %%es" :: "r" (saved_context.es));
119 	asm volatile ("movw %0, %%fs" :: "r" (saved_context.fs));
120 	load_gs_index(saved_context.gs);
121 	asm volatile ("movw %0, %%ss" :: "r" (saved_context.ss));
122 
123 	wrmsrl(MSR_FS_BASE, saved_context.fs_base);
124 	wrmsrl(MSR_GS_BASE, saved_context.gs_base);
125 	wrmsrl(MSR_KERNEL_GS_BASE, saved_context.gs_kernel_base);
126 
127 	/*
128 	 * now restore the descriptor tables to their proper values
129 	 * ltr is done i fix_processor_context().
130 	 */
131 	asm volatile ("lgdt %0" :: "m" (saved_context.gdt_limit));
132 	asm volatile ("lidt %0" :: "m" (saved_context.idt_limit));
133 	asm volatile ("lldt %0" :: "m" (saved_context.ldt));
134 
135 	fix_processor_context();
136 
137 	do_fpu_end();
138 }
139 
140 #define loaddebug(thread,register) \
141 		set_debug((thread)->debugreg[register], register)
142 
fix_processor_context(void)143 void fix_processor_context(void)
144 {
145 	int cpu = smp_processor_id();
146 	struct tss_struct * t = init_tss + cpu;
147 
148 	set_tss_desc(cpu,t);
149 
150 	/* clear busy TSS */
151 	gdt_cpu_table[cpu].tss.type = 9;
152 
153 	syscall_init();                      /* This sets MSR_*STAR and related */
154 	load_TR(cpu);				/* This does ltr */
155 	load_LDT(current->active_mm);		/* This does lldt */
156 
157 	/*
158 	 * Now maybe reload the debug registers
159 	 */
160 	if (current->thread.debugreg[7]){
161                 loaddebug(&current->thread, 0);
162                 loaddebug(&current->thread, 1);
163                 loaddebug(&current->thread, 2);
164                 loaddebug(&current->thread, 3);
165                 /* no 4 and 5 */
166                 loaddebug(&current->thread, 6);
167                 loaddebug(&current->thread, 7);
168 	}
169 
170 }
171 
172 
173