xref: /openbmc/linux/arch/x86/kernel/acpi/sleep.c (revision a1e58bbd)
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@suse.cz>
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/bootmem.h>
10 #include <linux/dmi.h>
11 #include <linux/cpumask.h>
12 
13 #include <asm/smp.h>
14 
15 /* address in low memory of the wakeup routine. */
16 unsigned long acpi_wakeup_address = 0;
17 unsigned long acpi_realmode_flags;
18 extern char wakeup_start, wakeup_end;
19 
20 extern unsigned long acpi_copy_wakeup_routine(unsigned long);
21 
22 /**
23  * acpi_save_state_mem - save kernel state
24  *
25  * Create an identity mapped page table and copy the wakeup routine to
26  * low memory.
27  */
28 int acpi_save_state_mem(void)
29 {
30 	if (!acpi_wakeup_address) {
31 		printk(KERN_ERR "Could not allocate memory during boot, S3 disabled\n");
32 		return -ENOMEM;
33 	}
34 	memcpy((void *)acpi_wakeup_address, &wakeup_start,
35 	       &wakeup_end - &wakeup_start);
36 	acpi_copy_wakeup_routine(acpi_wakeup_address);
37 
38 	return 0;
39 }
40 
41 /*
42  * acpi_restore_state - undo effects of acpi_save_state_mem
43  */
44 void acpi_restore_state_mem(void)
45 {
46 }
47 
48 
49 /**
50  * acpi_reserve_bootmem - do _very_ early ACPI initialisation
51  *
52  * We allocate a page from the first 1MB of memory for the wakeup
53  * routine for when we come back from a sleep state. The
54  * runtime allocator allows specification of <16MB pages, but not
55  * <1MB pages.
56  */
57 void __init acpi_reserve_bootmem(void)
58 {
59 	if ((&wakeup_end - &wakeup_start) > PAGE_SIZE*2) {
60 		printk(KERN_ERR
61 		       "ACPI: Wakeup code way too big, S3 disabled.\n");
62 		return;
63 	}
64 
65 	acpi_wakeup_address = (unsigned long)alloc_bootmem_low(PAGE_SIZE*2);
66 	if (!acpi_wakeup_address)
67 		printk(KERN_ERR "ACPI: Cannot allocate lowmem, S3 disabled.\n");
68 }
69 
70 
71 static int __init acpi_sleep_setup(char *str)
72 {
73 	while ((str != NULL) && (*str != '\0')) {
74 		if (strncmp(str, "s3_bios", 7) == 0)
75 			acpi_realmode_flags |= 1;
76 		if (strncmp(str, "s3_mode", 7) == 0)
77 			acpi_realmode_flags |= 2;
78 		if (strncmp(str, "s3_beep", 7) == 0)
79 			acpi_realmode_flags |= 4;
80 		str = strchr(str, ',');
81 		if (str != NULL)
82 			str += strspn(str, ", \t");
83 	}
84 	return 1;
85 }
86 
87 __setup("acpi_sleep=", acpi_sleep_setup);
88