xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision 81d67439)
1 /*
2  * sleep.c - x86-specific ACPI sleep support.
3  *
4  *  Copyright (C) 2001-2003 Patrick Mochel
5  *  Copyright (C) 2001-2003 Pavel Machek <pavel@ucw.cz>
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/bootmem.h>
10 #include <linux/memblock.h>
11 #include <linux/dmi.h>
12 #include <linux/cpumask.h>
13 #include <asm/segment.h>
14 #include <asm/desc.h>
15 #include <asm/pgtable.h>
16 #include <asm/cacheflush.h>
17 
18 #include "realmode/wakeup.h"
19 #include "sleep.h"
20 
21 unsigned long acpi_realmode_flags;
22 
23 #if defined(CONFIG_SMP) && defined(CONFIG_64BIT)
24 static char temp_stack[4096];
25 #endif
26 
27 /**
28  * acpi_suspend_lowlevel - save kernel state
29  *
30  * Create an identity mapped page table and copy the wakeup routine to
31  * low memory.
32  */
33 int acpi_suspend_lowlevel(void)
34 {
35 	struct wakeup_header *header;
36 	/* address in low memory of the wakeup routine. */
37 	char *acpi_realmode;
38 
39 	acpi_realmode = TRAMPOLINE_SYM(acpi_wakeup_code);
40 
41 	header = (struct wakeup_header *)(acpi_realmode + WAKEUP_HEADER_OFFSET);
42 	if (header->signature != WAKEUP_HEADER_SIGNATURE) {
43 		printk(KERN_ERR "wakeup header does not match\n");
44 		return -EINVAL;
45 	}
46 
47 	header->video_mode = saved_video_mode;
48 
49 	header->wakeup_jmp_seg = acpi_wakeup_address >> 4;
50 
51 	/*
52 	 * Set up the wakeup GDT.  We set these up as Big Real Mode,
53 	 * that is, with limits set to 4 GB.  At least the Lenovo
54 	 * Thinkpad X61 is known to need this for the video BIOS
55 	 * initialization quirk to work; this is likely to also
56 	 * be the case for other laptops or integrated video devices.
57 	 */
58 
59 	/* GDT[0]: GDT self-pointer */
60 	header->wakeup_gdt[0] =
61 		(u64)(sizeof(header->wakeup_gdt) - 1) +
62 		((u64)__pa(&header->wakeup_gdt) << 16);
63 	/* GDT[1]: big real mode-like code segment */
64 	header->wakeup_gdt[1] =
65 		GDT_ENTRY(0x809b, acpi_wakeup_address, 0xfffff);
66 	/* GDT[2]: big real mode-like data segment */
67 	header->wakeup_gdt[2] =
68 		GDT_ENTRY(0x8093, acpi_wakeup_address, 0xfffff);
69 
70 #ifndef CONFIG_64BIT
71 	store_gdt((struct desc_ptr *)&header->pmode_gdt);
72 
73 	if (rdmsr_safe(MSR_EFER, &header->pmode_efer_low,
74 		       &header->pmode_efer_high))
75 		header->pmode_efer_low = header->pmode_efer_high = 0;
76 #endif /* !CONFIG_64BIT */
77 
78 	header->pmode_cr0 = read_cr0();
79 	header->pmode_cr4 = read_cr4_safe();
80 	header->pmode_behavior = 0;
81 	if (!rdmsr_safe(MSR_IA32_MISC_ENABLE,
82 			&header->pmode_misc_en_low,
83 			&header->pmode_misc_en_high))
84 		header->pmode_behavior |=
85 			(1 << WAKEUP_BEHAVIOR_RESTORE_MISC_ENABLE);
86 	header->realmode_flags = acpi_realmode_flags;
87 	header->real_magic = 0x12345678;
88 
89 #ifndef CONFIG_64BIT
90 	header->pmode_entry = (u32)&wakeup_pmode_return;
91 	header->pmode_cr3 = (u32)__pa(&initial_page_table);
92 	saved_magic = 0x12345678;
93 #else /* CONFIG_64BIT */
94 	header->trampoline_segment = trampoline_address() >> 4;
95 #ifdef CONFIG_SMP
96 	stack_start = (unsigned long)temp_stack + sizeof(temp_stack);
97 	early_gdt_descr.address =
98 			(unsigned long)get_cpu_gdt_table(smp_processor_id());
99 	initial_gs = per_cpu_offset(smp_processor_id());
100 #endif
101 	initial_code = (unsigned long)wakeup_long64;
102        saved_magic = 0x123456789abcdef0L;
103 #endif /* CONFIG_64BIT */
104 
105 	do_suspend_lowlevel();
106 	return 0;
107 }
108 
109 static int __init acpi_sleep_setup(char *str)
110 {
111 	while ((str != NULL) && (*str != '\0')) {
112 		if (strncmp(str, "s3_bios", 7) == 0)
113 			acpi_realmode_flags |= 1;
114 		if (strncmp(str, "s3_mode", 7) == 0)
115 			acpi_realmode_flags |= 2;
116 		if (strncmp(str, "s3_beep", 7) == 0)
117 			acpi_realmode_flags |= 4;
118 #ifdef CONFIG_HIBERNATION
119 		if (strncmp(str, "s4_nohwsig", 10) == 0)
120 			acpi_no_s4_hw_signature();
121 #endif
122 		if (strncmp(str, "nonvs", 5) == 0)
123 			acpi_nvs_nosave();
124 		if (strncmp(str, "old_ordering", 12) == 0)
125 			acpi_old_suspend_ordering();
126 		str = strchr(str, ',');
127 		if (str != NULL)
128 			str += strspn(str, ", \t");
129 	}
130 	return 1;
131 }
132 
133 __setup("acpi_sleep=", acpi_sleep_setup);
134