1 /*
2  * runtime-wrappers.c - Runtime Services function call wrappers
3  *
4  * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
5  *
6  * Split off from arch/x86/platform/efi/efi.c
7  *
8  * Copyright (C) 1999 VA Linux Systems
9  * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
10  * Copyright (C) 1999-2002 Hewlett-Packard Co.
11  * Copyright (C) 2005-2008 Intel Co.
12  * Copyright (C) 2013 SuSE Labs
13  *
14  * This file is released under the GPLv2.
15  */
16 
17 #include <linux/efi.h>
18 #include <linux/spinlock.h>             /* spinlock_t */
19 #include <asm/efi.h>
20 
21 /*
22  * As per commit ef68c8f87ed1 ("x86: Serialize EFI time accesses on rtc_lock"),
23  * the EFI specification requires that callers of the time related runtime
24  * functions serialize with other CMOS accesses in the kernel, as the EFI time
25  * functions may choose to also use the legacy CMOS RTC.
26  */
27 __weak DEFINE_SPINLOCK(rtc_lock);
28 
29 static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
30 {
31 	unsigned long flags;
32 	efi_status_t status;
33 
34 	spin_lock_irqsave(&rtc_lock, flags);
35 	status = efi_call_virt(get_time, tm, tc);
36 	spin_unlock_irqrestore(&rtc_lock, flags);
37 	return status;
38 }
39 
40 static efi_status_t virt_efi_set_time(efi_time_t *tm)
41 {
42 	unsigned long flags;
43 	efi_status_t status;
44 
45 	spin_lock_irqsave(&rtc_lock, flags);
46 	status = efi_call_virt(set_time, tm);
47 	spin_unlock_irqrestore(&rtc_lock, flags);
48 	return status;
49 }
50 
51 static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
52 					     efi_bool_t *pending,
53 					     efi_time_t *tm)
54 {
55 	unsigned long flags;
56 	efi_status_t status;
57 
58 	spin_lock_irqsave(&rtc_lock, flags);
59 	status = efi_call_virt(get_wakeup_time, enabled, pending, tm);
60 	spin_unlock_irqrestore(&rtc_lock, flags);
61 	return status;
62 }
63 
64 static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
65 {
66 	unsigned long flags;
67 	efi_status_t status;
68 
69 	spin_lock_irqsave(&rtc_lock, flags);
70 	status = efi_call_virt(set_wakeup_time, enabled, tm);
71 	spin_unlock_irqrestore(&rtc_lock, flags);
72 	return status;
73 }
74 
75 static efi_status_t virt_efi_get_variable(efi_char16_t *name,
76 					  efi_guid_t *vendor,
77 					  u32 *attr,
78 					  unsigned long *data_size,
79 					  void *data)
80 {
81 	return efi_call_virt(get_variable, name, vendor, attr, data_size, data);
82 }
83 
84 static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
85 					       efi_char16_t *name,
86 					       efi_guid_t *vendor)
87 {
88 	return efi_call_virt(get_next_variable, name_size, name, vendor);
89 }
90 
91 static efi_status_t virt_efi_set_variable(efi_char16_t *name,
92 					  efi_guid_t *vendor,
93 					  u32 attr,
94 					  unsigned long data_size,
95 					  void *data)
96 {
97 	return efi_call_virt(set_variable, name, vendor, attr, data_size, data);
98 }
99 
100 static efi_status_t virt_efi_query_variable_info(u32 attr,
101 						 u64 *storage_space,
102 						 u64 *remaining_space,
103 						 u64 *max_variable_size)
104 {
105 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
106 		return EFI_UNSUPPORTED;
107 
108 	return efi_call_virt(query_variable_info, attr, storage_space,
109 			     remaining_space, max_variable_size);
110 }
111 
112 static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
113 {
114 	return efi_call_virt(get_next_high_mono_count, count);
115 }
116 
117 static void virt_efi_reset_system(int reset_type,
118 				  efi_status_t status,
119 				  unsigned long data_size,
120 				  efi_char16_t *data)
121 {
122 	__efi_call_virt(reset_system, reset_type, status, data_size, data);
123 }
124 
125 static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
126 					    unsigned long count,
127 					    unsigned long sg_list)
128 {
129 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
130 		return EFI_UNSUPPORTED;
131 
132 	return efi_call_virt(update_capsule, capsules, count, sg_list);
133 }
134 
135 static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
136 						unsigned long count,
137 						u64 *max_size,
138 						int *reset_type)
139 {
140 	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
141 		return EFI_UNSUPPORTED;
142 
143 	return efi_call_virt(query_capsule_caps, capsules, count, max_size,
144 			     reset_type);
145 }
146 
147 void efi_native_runtime_setup(void)
148 {
149 	efi.get_time = virt_efi_get_time;
150 	efi.set_time = virt_efi_set_time;
151 	efi.get_wakeup_time = virt_efi_get_wakeup_time;
152 	efi.set_wakeup_time = virt_efi_set_wakeup_time;
153 	efi.get_variable = virt_efi_get_variable;
154 	efi.get_next_variable = virt_efi_get_next_variable;
155 	efi.set_variable = virt_efi_set_variable;
156 	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
157 	efi.reset_system = virt_efi_reset_system;
158 	efi.query_variable_info = virt_efi_query_variable_info;
159 	efi.update_capsule = virt_efi_update_capsule;
160 	efi.query_capsule_caps = virt_efi_query_capsule_caps;
161 }
162