blob: 41958774cde301e5e1d1d5f3eef7be6e1eea0b59 [file] [log] [blame]
/*
* runtime-wrappers.c - Runtime Services function call wrappers
*
* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
*
* Split off from arch/x86/platform/efi/efi.c
*
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
* Copyright (C) 1999-2002 Hewlett-Packard Co.
* Copyright (C) 2005-2008 Intel Co.
* Copyright (C) 2013 SuSE Labs
*
* This file is released under the GPLv2.
*/
#include <linux/bug.h>
#include <linux/efi.h>
#include <linux/irqflags.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/stringify.h>
#include <asm/efi.h>
/*
* Wrap around the new efi_call_virt_generic() macros so that the
* code doesn't get too cluttered:
*/
#define efi_call_virt(f, args...) \
efi_call_virt_pointer(efi.systab->runtime, f, args)
#define __efi_call_virt(f, args...) \
__efi_call_virt_pointer(efi.systab->runtime, f, args)
void efi_call_virt_check_flags(unsigned long flags, const char *call)
{
unsigned long cur_flags, mismatch;
local_save_flags(cur_flags);
mismatch = flags ^ cur_flags;
if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK))
return;
add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_NOW_UNRELIABLE);
pr_err_ratelimited(FW_BUG "IRQ flags corrupted (0x%08lx=>0x%08lx) by EFI %s\n",
flags, cur_flags, call);
local_irq_restore(flags);
}
/*
* According to section 7.1 of the UEFI spec, Runtime Services are not fully
* reentrant, and there are particular combinations of calls that need to be
* serialized. (source: UEFI Specification v2.4A)
*
* Table 31. Rules for Reentry Into Runtime Services
* +------------------------------------+-------------------------------+
* | If previous call is busy in | Forbidden to call |
* +------------------------------------+-------------------------------+
* | Any | SetVirtualAddressMap() |
* +------------------------------------+-------------------------------+
* | ConvertPointer() | ConvertPointer() |
* +------------------------------------+-------------------------------+
* | SetVariable() | ResetSystem() |
* | UpdateCapsule() | |
* | SetTime() | |
* | SetWakeupTime() | |
* | GetNextHighMonotonicCount() | |
* +------------------------------------+-------------------------------+
* | GetVariable() | GetVariable() |
* | GetNextVariableName() | GetNextVariableName() |
* | SetVariable() | SetVariable() |
* | QueryVariableInfo() | QueryVariableInfo() |
* | UpdateCapsule() | UpdateCapsule() |
* | QueryCapsuleCapabilities() | QueryCapsuleCapabilities() |
* | GetNextHighMonotonicCount() | GetNextHighMonotonicCount() |
* +------------------------------------+-------------------------------+
* | GetTime() | GetTime() |
* | SetTime() | SetTime() |
* | GetWakeupTime() | GetWakeupTime() |
* | SetWakeupTime() | SetWakeupTime() |
* +------------------------------------+-------------------------------+
*
* Due to the fact that the EFI pstore may write to the variable store in
* interrupt context, we need to use a spinlock for at least the groups that
* contain SetVariable() and QueryVariableInfo(). That leaves little else, as
* none of the remaining functions are actually ever called at runtime.
* So let's just use a single spinlock to serialize all Runtime Services calls.
*/
static DEFINE_SPINLOCK(efi_runtime_lock);
static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(get_time, tm, tc);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_set_time(efi_time_t *tm)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(set_time, tm);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
efi_bool_t *pending,
efi_time_t *tm)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(get_wakeup_time, enabled, pending, tm);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(set_wakeup_time, enabled, tm);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_get_variable(efi_char16_t *name,
efi_guid_t *vendor,
u32 *attr,
unsigned long *data_size,
void *data)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(get_variable, name, vendor, attr, data_size,
data);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
efi_char16_t *name,
efi_guid_t *vendor)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(get_next_variable, name_size, name, vendor);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_set_variable(efi_char16_t *name,
efi_guid_t *vendor,
u32 attr,
unsigned long data_size,
void *data)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(set_variable, name, vendor, attr, data_size,
data);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t
virt_efi_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor,
u32 attr, unsigned long data_size,
void *data)
{
efi_status_t status;
if (!spin_trylock(&efi_runtime_lock))
return EFI_NOT_READY;
status = efi_call_virt(set_variable, name, vendor, attr, data_size,
data);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_query_variable_info(u32 attr,
u64 *storage_space,
u64 *remaining_space,
u64 *max_variable_size)
{
efi_status_t status;
if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
return EFI_UNSUPPORTED;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(query_variable_info, attr, storage_space,
remaining_space, max_variable_size);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t
virt_efi_query_variable_info_nonblocking(u32 attr,
u64 *storage_space,
u64 *remaining_space,
u64 *max_variable_size)
{
efi_status_t status;
if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
return EFI_UNSUPPORTED;
if (!spin_trylock(&efi_runtime_lock))
return EFI_NOT_READY;
status = efi_call_virt(query_variable_info, attr, storage_space,
remaining_space, max_variable_size);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
{
efi_status_t status;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(get_next_high_mono_count, count);
spin_unlock(&efi_runtime_lock);
return status;
}
static void virt_efi_reset_system(int reset_type,
efi_status_t status,
unsigned long data_size,
efi_char16_t *data)
{
spin_lock(&efi_runtime_lock);
__efi_call_virt(reset_system, reset_type, status, data_size, data);
spin_unlock(&efi_runtime_lock);
}
static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
unsigned long count,
unsigned long sg_list)
{
efi_status_t status;
if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
return EFI_UNSUPPORTED;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(update_capsule, capsules, count, sg_list);
spin_unlock(&efi_runtime_lock);
return status;
}
static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
unsigned long count,
u64 *max_size,
int *reset_type)
{
efi_status_t status;
if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
return EFI_UNSUPPORTED;
spin_lock(&efi_runtime_lock);
status = efi_call_virt(query_capsule_caps, capsules, count, max_size,
reset_type);
spin_unlock(&efi_runtime_lock);
return status;
}
void efi_native_runtime_setup(void)
{
efi.get_time = virt_efi_get_time;
efi.set_time = virt_efi_set_time;
efi.get_wakeup_time = virt_efi_get_wakeup_time;
efi.set_wakeup_time = virt_efi_set_wakeup_time;
efi.get_variable = virt_efi_get_variable;
efi.get_next_variable = virt_efi_get_next_variable;
efi.set_variable = virt_efi_set_variable;
efi.set_variable_nonblocking = virt_efi_set_variable_nonblocking;
efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
efi.reset_system = virt_efi_reset_system;
efi.query_variable_info = virt_efi_query_variable_info;
efi.query_variable_info_nonblocking = virt_efi_query_variable_info_nonblocking;
efi.update_capsule = virt_efi_update_capsule;
efi.query_capsule_caps = virt_efi_query_capsule_caps;
}