drivers/firmware/efi/runtime-wrappers.c

   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 }