[deliverable/linux.git] / drivers / firmware / efi / runtime-wrappers.c

/*
 * 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;
}
Commit	Line	Data
022ee6c5 AB	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
161485e8	17	#include <linux/bug.h>
022ee6c5	18	#include <linux/efi.h>
1d04ba17	19	#include <linux/irqflags.h>
161485e8 AB	20	#include <linux/mutex.h>
161485e8 AB	21	#include <linux/spinlock.h>
1d04ba17	22	#include <linux/stringify.h>
022ee6c5 AB	23	#include <asm/efi.h>
022ee6c5 AB	24
80e75596 AT	25	/*
	26	* Wrap around the new efi_call_virt_generic() macros so that the
	27	* code doesn't get too cluttered:
	28	*/
	29	#define efi_call_virt(f, args...) \
	30	efi_call_virt_pointer(efi.systab->runtime, f, args)
	31	#define __efi_call_virt(f, args...) \
	32	__efi_call_virt_pointer(efi.systab->runtime, f, args)
	33
	34	void efi_call_virt_check_flags(unsigned long flags, const char *call)
1d04ba17 MR	35	{
	36	unsigned long cur_flags, mismatch;
	37
	38	local_save_flags(cur_flags);
	39
	40	mismatch = flags ^ cur_flags;
	41	if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK))
	42	return;
	43
	44	add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_NOW_UNRELIABLE);
	45	pr_err_ratelimited(FW_BUG "IRQ flags corrupted (0x%08lx=>0x%08lx) by EFI %s\n",
	46	flags, cur_flags, call);
	47	local_irq_restore(flags);
	48	}
1d04ba17	49
161485e8 AB	50	/*
	51	* According to section 7.1 of the UEFI spec, Runtime Services are not fully
	52	* reentrant, and there are particular combinations of calls that need to be
	53	* serialized. (source: UEFI Specification v2.4A)
	54	*
	55	* Table 31. Rules for Reentry Into Runtime Services
	56	* +------------------------------------+-------------------------------+
	57	* \| If previous call is busy in \| Forbidden to call \|
	58	* +------------------------------------+-------------------------------+
	59	* \| Any \| SetVirtualAddressMap() \|
	60	* +------------------------------------+-------------------------------+
	61	* \| ConvertPointer() \| ConvertPointer() \|
	62	* +------------------------------------+-------------------------------+
	63	* \| SetVariable() \| ResetSystem() \|
	64	* \| UpdateCapsule() \| \|
	65	* \| SetTime() \| \|
	66	* \| SetWakeupTime() \| \|
	67	* \| GetNextHighMonotonicCount() \| \|
	68	* +------------------------------------+-------------------------------+
	69	* \| GetVariable() \| GetVariable() \|
	70	* \| GetNextVariableName() \| GetNextVariableName() \|
	71	* \| SetVariable() \| SetVariable() \|
	72	* \| QueryVariableInfo() \| QueryVariableInfo() \|
	73	* \| UpdateCapsule() \| UpdateCapsule() \|
	74	* \| QueryCapsuleCapabilities() \| QueryCapsuleCapabilities() \|
	75	* \| GetNextHighMonotonicCount() \| GetNextHighMonotonicCount() \|
	76	* +------------------------------------+-------------------------------+
	77	* \| GetTime() \| GetTime() \|
	78	* \| SetTime() \| SetTime() \|
	79	* \| GetWakeupTime() \| GetWakeupTime() \|
	80	* \| SetWakeupTime() \| SetWakeupTime() \|
	81	* +------------------------------------+-------------------------------+
	82	*
	83	* Due to the fact that the EFI pstore may write to the variable store in
	84	* interrupt context, we need to use a spinlock for at least the groups that
	85	* contain SetVariable() and QueryVariableInfo(). That leaves little else, as
	86	* none of the remaining functions are actually ever called at runtime.
	87	* So let's just use a single spinlock to serialize all Runtime Services calls.
	88	*/
	89	static DEFINE_SPINLOCK(efi_runtime_lock);
	90
022ee6c5 AB	91	static efi_status_t virt_efi_get_time(efi_time_t tm, efi_time_cap_t tc)
022ee6c5 AB	92	{
022ee6c5 AB	93	efi_status_t status;
022ee6c5 AB	94
fe324494	95	spin_lock(&efi_runtime_lock);
022ee6c5	96	status = efi_call_virt(get_time, tm, tc);
fe324494	97	spin_unlock(&efi_runtime_lock);
022ee6c5 AB	98	return status;
	99	}
	100
	101	static efi_status_t virt_efi_set_time(efi_time_t *tm)
	102	{
022ee6c5 AB	103	efi_status_t status;
022ee6c5 AB	104
fe324494	105	spin_lock(&efi_runtime_lock);
022ee6c5	106	status = efi_call_virt(set_time, tm);
fe324494	107	spin_unlock(&efi_runtime_lock);
022ee6c5 AB	108	return status;
	109	}
	110
	111	static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
	112	efi_bool_t *pending,
	113	efi_time_t *tm)
	114	{
022ee6c5 AB	115	efi_status_t status;
022ee6c5 AB	116
fe324494	117	spin_lock(&efi_runtime_lock);
022ee6c5	118	status = efi_call_virt(get_wakeup_time, enabled, pending, tm);
fe324494	119	spin_unlock(&efi_runtime_lock);
022ee6c5 AB	120	return status;
	121	}
	122
	123	static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
	124	{
022ee6c5 AB	125	efi_status_t status;
022ee6c5 AB	126
fe324494	127	spin_lock(&efi_runtime_lock);
022ee6c5	128	status = efi_call_virt(set_wakeup_time, enabled, tm);
fe324494	129	spin_unlock(&efi_runtime_lock);
022ee6c5 AB	130	return status;
	131	}
	132
	133	static efi_status_t virt_efi_get_variable(efi_char16_t *name,
	134	efi_guid_t *vendor,
	135	u32 *attr,
	136	unsigned long *data_size,
	137	void *data)
	138	{
161485e8 AB	139	efi_status_t status;
161485e8 AB	140
fe324494	141	spin_lock(&efi_runtime_lock);
161485e8 AB	142	status = efi_call_virt(get_variable, name, vendor, attr, data_size,
161485e8 AB	143	data);
fe324494	144	spin_unlock(&efi_runtime_lock);
161485e8	145	return status;
022ee6c5 AB	146	}
	147
	148	static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
	149	efi_char16_t *name,
	150	efi_guid_t *vendor)
	151	{
161485e8 AB	152	efi_status_t status;
161485e8 AB	153
fe324494	154	spin_lock(&efi_runtime_lock);
161485e8	155	status = efi_call_virt(get_next_variable, name_size, name, vendor);
fe324494	156	spin_unlock(&efi_runtime_lock);
161485e8	157	return status;
022ee6c5 AB	158	}
	159
	160	static efi_status_t virt_efi_set_variable(efi_char16_t *name,
	161	efi_guid_t *vendor,
	162	u32 attr,
	163	unsigned long data_size,
	164	void *data)
	165	{
161485e8	166	efi_status_t status;
161485e8	167
fe324494	168	spin_lock(&efi_runtime_lock);
161485e8 AB	169	status = efi_call_virt(set_variable, name, vendor, attr, data_size,
161485e8 AB	170	data);
fe324494	171	spin_unlock(&efi_runtime_lock);
161485e8	172	return status;
022ee6c5 AB	173	}
022ee6c5 AB	174
6d80dba1 MF	175	static efi_status_t
	176	virt_efi_set_variable_nonblocking(efi_char16_t name, efi_guid_t vendor,
	177	u32 attr, unsigned long data_size,
	178	void *data)
	179	{
6d80dba1 MF	180	efi_status_t status;
6d80dba1 MF	181
fe324494	182	if (!spin_trylock(&efi_runtime_lock))
6d80dba1 MF	183	return EFI_NOT_READY;
	184
	185	status = efi_call_virt(set_variable, name, vendor, attr, data_size,
	186	data);
fe324494	187	spin_unlock(&efi_runtime_lock);
6d80dba1 MF	188	return status;
	189	}
	190
	191
022ee6c5 AB	192	static efi_status_t virt_efi_query_variable_info(u32 attr,
	193	u64 *storage_space,
	194	u64 *remaining_space,
	195	u64 *max_variable_size)
	196	{
161485e8	197	efi_status_t status;
161485e8	198
022ee6c5 AB	199	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	200	return EFI_UNSUPPORTED;
	201
fe324494	202	spin_lock(&efi_runtime_lock);
161485e8 AB	203	status = efi_call_virt(query_variable_info, attr, storage_space,
161485e8 AB	204	remaining_space, max_variable_size);
fe324494	205	spin_unlock(&efi_runtime_lock);
161485e8	206	return status;
022ee6c5 AB	207	}
022ee6c5 AB	208
d3cac1f8 AB	209	static efi_status_t
	210	virt_efi_query_variable_info_nonblocking(u32 attr,
	211	u64 *storage_space,
	212	u64 *remaining_space,
	213	u64 *max_variable_size)
	214	{
d3cac1f8 AB	215	efi_status_t status;
	216
	217	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	218	return EFI_UNSUPPORTED;
	219
fe324494	220	if (!spin_trylock(&efi_runtime_lock))
d3cac1f8 AB	221	return EFI_NOT_READY;
	222
	223	status = efi_call_virt(query_variable_info, attr, storage_space,
	224	remaining_space, max_variable_size);
fe324494	225	spin_unlock(&efi_runtime_lock);
d3cac1f8 AB	226	return status;
	227	}
	228
022ee6c5 AB	229	static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
022ee6c5 AB	230	{
161485e8 AB	231	efi_status_t status;
161485e8 AB	232
fe324494	233	spin_lock(&efi_runtime_lock);
161485e8	234	status = efi_call_virt(get_next_high_mono_count, count);
fe324494	235	spin_unlock(&efi_runtime_lock);
161485e8	236	return status;
022ee6c5 AB	237	}
	238
	239	static void virt_efi_reset_system(int reset_type,
	240	efi_status_t status,
	241	unsigned long data_size,
	242	efi_char16_t *data)
	243	{
fe324494	244	spin_lock(&efi_runtime_lock);
022ee6c5	245	__efi_call_virt(reset_system, reset_type, status, data_size, data);
fe324494	246	spin_unlock(&efi_runtime_lock);
022ee6c5 AB	247	}
	248
	249	static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
	250	unsigned long count,
	251	unsigned long sg_list)
	252	{
161485e8 AB	253	efi_status_t status;
161485e8 AB	254
022ee6c5 AB	255	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	256	return EFI_UNSUPPORTED;
	257
fe324494	258	spin_lock(&efi_runtime_lock);
161485e8	259	status = efi_call_virt(update_capsule, capsules, count, sg_list);
fe324494	260	spin_unlock(&efi_runtime_lock);
161485e8	261	return status;
022ee6c5 AB	262	}
	263
	264	static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
	265	unsigned long count,
	266	u64 *max_size,
	267	int *reset_type)
	268	{
161485e8 AB	269	efi_status_t status;
161485e8 AB	270
022ee6c5 AB	271	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	272	return EFI_UNSUPPORTED;
	273
fe324494	274	spin_lock(&efi_runtime_lock);
161485e8 AB	275	status = efi_call_virt(query_capsule_caps, capsules, count, max_size,
161485e8 AB	276	reset_type);
fe324494	277	spin_unlock(&efi_runtime_lock);
161485e8	278	return status;
022ee6c5 AB	279	}
	280
	281	void efi_native_runtime_setup(void)
	282	{
	283	efi.get_time = virt_efi_get_time;
	284	efi.set_time = virt_efi_set_time;
	285	efi.get_wakeup_time = virt_efi_get_wakeup_time;
	286	efi.set_wakeup_time = virt_efi_set_wakeup_time;
	287	efi.get_variable = virt_efi_get_variable;
	288	efi.get_next_variable = virt_efi_get_next_variable;
	289	efi.set_variable = virt_efi_set_variable;
6d80dba1	290	efi.set_variable_nonblocking = virt_efi_set_variable_nonblocking;
022ee6c5 AB	291	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
	292	efi.reset_system = virt_efi_reset_system;
	293	efi.query_variable_info = virt_efi_query_variable_info;
d3cac1f8	294	efi.query_variable_info_nonblocking = virt_efi_query_variable_info_nonblocking;
022ee6c5 AB	295	efi.update_capsule = virt_efi_update_capsule;
	296	efi.query_capsule_caps = virt_efi_query_capsule_caps;
	297	}