[linux-2.6-block.git] / drivers / firmware / efi / runtime-wrappers.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * runtime-wrappers.c - Runtime Services function call wrappers
 *
 * Implementation summary:
 * -----------------------
 * 1. When user/kernel thread requests to execute efi_runtime_service(),
 * enqueue work to efi_rts_wq.
 * 2. Caller thread waits for completion until the work is finished
 * because it's dependent on the return status and execution of
 * efi_runtime_service().
 * For instance, get_variable() and get_next_variable().
 *
 * 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
 */

#define pr_fmt(fmt)	"efi: " fmt

#include <linux/bug.h>
#include <linux/efi.h>
#include <linux/irqflags.h>
#include <linux/mutex.h>
#include <linux/semaphore.h>
#include <linux/stringify.h>
#include <linux/workqueue.h>
#include <linux/completion.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...)   \
	arch_efi_call_virt(efi.runtime, f, args)

union efi_rts_args {
	struct {
		efi_time_t 	*time;
		efi_time_cap_t	*capabilities;
	} GET_TIME;

	struct {
		efi_time_t	*time;
	} SET_TIME;

	struct {
		efi_bool_t	*enabled;
		efi_bool_t	*pending;
		efi_time_t	*time;
	} GET_WAKEUP_TIME;

	struct {
		efi_bool_t	enable;
		efi_time_t	*time;
	} SET_WAKEUP_TIME;

	struct {
		efi_char16_t	*name;
		efi_guid_t	*vendor;
		u32		*attr;
		unsigned long	*data_size;
		void		*data;
	} GET_VARIABLE;

	struct {
		unsigned long	*name_size;
		efi_char16_t	*name;
		efi_guid_t 	*vendor;
	} GET_NEXT_VARIABLE;

	struct {
		efi_char16_t	*name;
		efi_guid_t	*vendor;
		u32		attr;
		unsigned long	data_size;
		void		*data;
	} SET_VARIABLE;

	struct {
		u32		attr;
		u64		*storage_space;
		u64		*remaining_space;
		u64		*max_variable_size;
	} QUERY_VARIABLE_INFO;

	struct {
		u32		*high_count;
	} GET_NEXT_HIGH_MONO_COUNT;

	struct {
		efi_capsule_header_t **capsules;
		unsigned long	count;
		unsigned long	sg_list;
	} UPDATE_CAPSULE;

	struct {
		efi_capsule_header_t **capsules;
		unsigned long	count;
		u64		*max_size;
		int		*reset_type;
	} QUERY_CAPSULE_CAPS;

	struct {
		efi_status_t	(__efiapi *acpi_prm_handler)(u64, void *);
		u64		param_buffer_addr;
		void		*context;
	} ACPI_PRM_HANDLER;
};

struct efi_runtime_work efi_rts_work;

/*
 * efi_queue_work:	Queue EFI runtime service call and wait for completion
 * @_rts:		EFI runtime service function identifier
 * @_args:		Arguments to pass to the EFI runtime service
 *
 * Accesses to efi_runtime_services() are serialized by a binary
 * semaphore (efi_runtime_lock) and caller waits until the work is
 * finished, hence _only_ one work is queued at a time and the caller
 * thread waits for completion.
 */
#define efi_queue_work(_rts, _args...)					\
	__efi_queue_work(EFI_ ## _rts,					\
			 &(union efi_rts_args){ ._rts = { _args }})

#ifndef arch_efi_save_flags
#define arch_efi_save_flags(state_flags)	local_save_flags(state_flags)
#define arch_efi_restore_flags(state_flags)	local_irq_restore(state_flags)
#endif

unsigned long efi_call_virt_save_flags(void)
{
	unsigned long flags;

	arch_efi_save_flags(flags);
	return flags;
}

void efi_call_virt_check_flags(unsigned long flags, const void *caller)
{
	unsigned long cur_flags, mismatch;

	cur_flags = efi_call_virt_save_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 call from %pS\n",
			   flags, cur_flags, caller ?: __builtin_return_address(0));
	arch_efi_restore_flags(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 lock 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 lock to serialize all Runtime Services calls.
 */
static DEFINE_SEMAPHORE(efi_runtime_lock, 1);

/*
 * Expose the EFI runtime lock to the UV platform
 */
#ifdef CONFIG_X86_UV
extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock);
#endif

/*
 * Calls the appropriate efi_runtime_service() with the appropriate
 * arguments.
 */
static void __nocfi efi_call_rts(struct work_struct *work)
{
	const union efi_rts_args *args = efi_rts_work.args;
	efi_status_t status = EFI_NOT_FOUND;
	unsigned long flags;

	arch_efi_call_virt_setup();
	flags = efi_call_virt_save_flags();

	switch (efi_rts_work.efi_rts_id) {
	case EFI_GET_TIME:
		status = efi_call_virt(get_time,
				       args->GET_TIME.time,
				       args->GET_TIME.capabilities);
		break;
	case EFI_SET_TIME:
		status = efi_call_virt(set_time,
				       args->SET_TIME.time);
		break;
	case EFI_GET_WAKEUP_TIME:
		status = efi_call_virt(get_wakeup_time,
				       args->GET_WAKEUP_TIME.enabled,
				       args->GET_WAKEUP_TIME.pending,
				       args->GET_WAKEUP_TIME.time);
		break;
	case EFI_SET_WAKEUP_TIME:
		status = efi_call_virt(set_wakeup_time,
				       args->SET_WAKEUP_TIME.enable,
				       args->SET_WAKEUP_TIME.time);
		break;
	case EFI_GET_VARIABLE:
		status = efi_call_virt(get_variable,
				       args->GET_VARIABLE.name,
				       args->GET_VARIABLE.vendor,
				       args->GET_VARIABLE.attr,
				       args->GET_VARIABLE.data_size,
				       args->GET_VARIABLE.data);
		break;
	case EFI_GET_NEXT_VARIABLE:
		status = efi_call_virt(get_next_variable,
				       args->GET_NEXT_VARIABLE.name_size,
				       args->GET_NEXT_VARIABLE.name,
				       args->GET_NEXT_VARIABLE.vendor);
		break;
	case EFI_SET_VARIABLE:
		status = efi_call_virt(set_variable,
				       args->SET_VARIABLE.name,
				       args->SET_VARIABLE.vendor,
				       args->SET_VARIABLE.attr,
				       args->SET_VARIABLE.data_size,
				       args->SET_VARIABLE.data);
		break;
	case EFI_QUERY_VARIABLE_INFO:
		status = efi_call_virt(query_variable_info,
				       args->QUERY_VARIABLE_INFO.attr,
				       args->QUERY_VARIABLE_INFO.storage_space,
				       args->QUERY_VARIABLE_INFO.remaining_space,
				       args->QUERY_VARIABLE_INFO.max_variable_size);
		break;
	case EFI_GET_NEXT_HIGH_MONO_COUNT:
		status = efi_call_virt(get_next_high_mono_count,
				       args->GET_NEXT_HIGH_MONO_COUNT.high_count);
		break;
	case EFI_UPDATE_CAPSULE:
		status = efi_call_virt(update_capsule,
				       args->UPDATE_CAPSULE.capsules,
				       args->UPDATE_CAPSULE.count,
				       args->UPDATE_CAPSULE.sg_list);
		break;
	case EFI_QUERY_CAPSULE_CAPS:
		status = efi_call_virt(query_capsule_caps,
				       args->QUERY_CAPSULE_CAPS.capsules,
				       args->QUERY_CAPSULE_CAPS.count,
				       args->QUERY_CAPSULE_CAPS.max_size,
				       args->QUERY_CAPSULE_CAPS.reset_type);
		break;
	case EFI_ACPI_PRM_HANDLER:
#ifdef CONFIG_ACPI_PRMT
		status = arch_efi_call_virt(args, ACPI_PRM_HANDLER.acpi_prm_handler,
					    args->ACPI_PRM_HANDLER.param_buffer_addr,
					    args->ACPI_PRM_HANDLER.context);
		break;
#endif
	default:
		/*
		 * Ideally, we should never reach here because a caller of this
		 * function should have put the right efi_runtime_service()
		 * function identifier into efi_rts_work->efi_rts_id
		 */
		pr_err("Requested executing invalid EFI Runtime Service.\n");
	}

	efi_call_virt_check_flags(flags, efi_rts_work.caller);
	arch_efi_call_virt_teardown();

	efi_rts_work.status = status;
	complete(&efi_rts_work.efi_rts_comp);
}

static efi_status_t __efi_queue_work(enum efi_rts_ids id,
				     union efi_rts_args *args)
{
	efi_rts_work.efi_rts_id = id;
	efi_rts_work.args = args;
	efi_rts_work.caller = __builtin_return_address(0);
	efi_rts_work.status = EFI_ABORTED;

	if (!efi_enabled(EFI_RUNTIME_SERVICES)) {
		pr_warn_once("EFI Runtime Services are disabled!\n");
		efi_rts_work.status = EFI_DEVICE_ERROR;
		goto exit;
	}

	init_completion(&efi_rts_work.efi_rts_comp);
	INIT_WORK(&efi_rts_work.work, efi_call_rts);

	/*
	 * queue_work() returns 0 if work was already on queue,
	 * _ideally_ this should never happen.
	 */
	if (queue_work(efi_rts_wq, &efi_rts_work.work))
		wait_for_completion(&efi_rts_work.efi_rts_comp);
	else
		pr_err("Failed to queue work to efi_rts_wq.\n");

	WARN_ON_ONCE(efi_rts_work.status == EFI_ABORTED);
exit:
	efi_rts_work.efi_rts_id = EFI_NONE;
	return efi_rts_work.status;
}

static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
{
	efi_status_t status;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(GET_TIME, tm, tc);
	up(&efi_runtime_lock);
	return status;
}

static efi_status_t virt_efi_set_time(efi_time_t *tm)
{
	efi_status_t status;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(SET_TIME, tm);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(GET_WAKEUP_TIME, enabled, pending, tm);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(SET_WAKEUP_TIME, enabled, tm);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(GET_VARIABLE, name, vendor, attr, data_size,
				data);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(GET_NEXT_VARIABLE, name_size, name, vendor);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(SET_VARIABLE, name, vendor, attr, data_size,
				data);
	up(&efi_runtime_lock);
	return status;
}

static efi_status_t __nocfi
virt_efi_set_variable_nb(efi_char16_t *name, efi_guid_t *vendor, u32 attr,
			 unsigned long data_size, void *data)
{
	efi_status_t status;

	if (down_trylock(&efi_runtime_lock))
		return EFI_NOT_READY;

	status = efi_call_virt_pointer(efi.runtime, set_variable, name, vendor,
				       attr, data_size, data);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(QUERY_VARIABLE_INFO, attr, storage_space,
				remaining_space, max_variable_size);
	up(&efi_runtime_lock);
	return status;
}

static efi_status_t __nocfi
virt_efi_query_variable_info_nb(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 (down_trylock(&efi_runtime_lock))
		return EFI_NOT_READY;

	status = efi_call_virt_pointer(efi.runtime, query_variable_info, attr,
				       storage_space, remaining_space,
				       max_variable_size);
	up(&efi_runtime_lock);
	return status;
}

static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
{
	efi_status_t status;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(GET_NEXT_HIGH_MONO_COUNT, count);
	up(&efi_runtime_lock);
	return status;
}

static void __nocfi
virt_efi_reset_system(int reset_type, efi_status_t status,
		      unsigned long data_size, efi_char16_t *data)
{
	if (down_trylock(&efi_runtime_lock)) {
		pr_warn("failed to invoke the reset_system() runtime service:\n"
			"could not get exclusive access to the firmware\n");
		return;
	}

	arch_efi_call_virt_setup();
	efi_rts_work.efi_rts_id = EFI_RESET_SYSTEM;
	arch_efi_call_virt(efi.runtime, reset_system, reset_type, status,
			   data_size, data);
	arch_efi_call_virt_teardown();

	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(UPDATE_CAPSULE, capsules, count, sg_list);
	up(&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;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(QUERY_CAPSULE_CAPS, capsules, count,
				max_size, reset_type);
	up(&efi_runtime_lock);
	return status;
}

void __init 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_nb;
	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_nb;
	efi.update_capsule		    = virt_efi_update_capsule;
	efi.query_capsule_caps		    = virt_efi_query_capsule_caps;
}

#ifdef CONFIG_ACPI_PRMT

efi_status_t
efi_call_acpi_prm_handler(efi_status_t (__efiapi *handler_addr)(u64, void *),
			  u64 param_buffer_addr, void *context)
{
	efi_status_t status;

	if (down_interruptible(&efi_runtime_lock))
		return EFI_ABORTED;
	status = efi_queue_work(ACPI_PRM_HANDLER, handler_addr,
				param_buffer_addr, context);
	up(&efi_runtime_lock);
	return status;
}

#endif
Commit	Line	Data
55716d26	1	// SPDX-License-Identifier: GPL-2.0-only
022ee6c5 AB	2	/*
	3	* runtime-wrappers.c - Runtime Services function call wrappers
	4	*
3eb420e7 SP	5	* Implementation summary:
	6	* -----------------------
	7	* 1. When user/kernel thread requests to execute efi_runtime_service(),
	8	* enqueue work to efi_rts_wq.
	9	* 2. Caller thread waits for completion until the work is finished
	10	* because it's dependent on the return status and execution of
	11	* efi_runtime_service().
	12	* For instance, get_variable() and get_next_variable().
	13	*
022ee6c5 AB	14	* Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
	15	*
	16	* Split off from arch/x86/platform/efi/efi.c
	17	*
	18	* Copyright (C) 1999 VA Linux Systems
	19	* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
	20	* Copyright (C) 1999-2002 Hewlett-Packard Co.
	21	* Copyright (C) 2005-2008 Intel Co.
	22	* Copyright (C) 2013 SuSE Labs
022ee6c5 AB	23	*/
022ee6c5 AB	24
dce48e35 AB	25	#define pr_fmt(fmt) "efi: " fmt
dce48e35 AB	26
161485e8	27	#include <linux/bug.h>
022ee6c5	28	#include <linux/efi.h>
1d04ba17	29	#include <linux/irqflags.h>
161485e8	30	#include <linux/mutex.h>
dce48e35	31	#include <linux/semaphore.h>
1d04ba17	32	#include <linux/stringify.h>
3eb420e7 SP	33	#include <linux/workqueue.h>
	34	#include <linux/completion.h>
	35
022ee6c5 AB	36	#include <asm/efi.h>
022ee6c5 AB	37
80e75596 AT	38	/*
	39	* Wrap around the new efi_call_virt_generic() macros so that the
	40	* code doesn't get too cluttered:
	41	*/
	42	#define efi_call_virt(f, args...) \
3c17ae41	43	arch_efi_call_virt(efi.runtime, f, args)
80e75596	44
c7c7bce0 AB	45	union efi_rts_args {
	46	struct {
	47	efi_time_t *time;
	48	efi_time_cap_t *capabilities;
	49	} GET_TIME;
	50
	51	struct {
	52	efi_time_t *time;
	53	} SET_TIME;
	54
	55	struct {
	56	efi_bool_t *enabled;
	57	efi_bool_t *pending;
	58	efi_time_t *time;
	59	} GET_WAKEUP_TIME;
	60
	61	struct {
	62	efi_bool_t enable;
	63	efi_time_t *time;
	64	} SET_WAKEUP_TIME;
	65
	66	struct {
	67	efi_char16_t *name;
	68	efi_guid_t *vendor;
	69	u32 *attr;
	70	unsigned long *data_size;
	71	void *data;
	72	} GET_VARIABLE;
	73
	74	struct {
	75	unsigned long *name_size;
	76	efi_char16_t *name;
	77	efi_guid_t *vendor;
	78	} GET_NEXT_VARIABLE;
	79
	80	struct {
	81	efi_char16_t *name;
	82	efi_guid_t *vendor;
	83	u32 attr;
	84	unsigned long data_size;
	85	void *data;
	86	} SET_VARIABLE;
	87
	88	struct {
	89	u32 attr;
	90	u64 *storage_space;
	91	u64 *remaining_space;
	92	u64 *max_variable_size;
	93	} QUERY_VARIABLE_INFO;
	94
	95	struct {
	96	u32 *high_count;
	97	} GET_NEXT_HIGH_MONO_COUNT;
	98
	99	struct {
	100	efi_capsule_header_t **capsules;
	101	unsigned long count;
	102	unsigned long sg_list;
	103	} UPDATE_CAPSULE;
	104
	105	struct {
	106	efi_capsule_header_t **capsules;
	107	unsigned long count;
	108	u64 *max_size;
109	int *reset_type;
110	} QUERY_CAPSULE_CAPS;
5894cf57 AB	111
	112	struct {
	113	efi_status_t (__efiapi acpi_prm_handler)(u64, void );
	114	u64 param_buffer_addr;
	115	void *context;
	116	} ACPI_PRM_HANDLER;
c7c7bce0 AB	117	};
c7c7bce0 AB	118
9dbbedaa	119	struct efi_runtime_work efi_rts_work;
3eb420e7 SP	120
3eb420e7 SP	121	/*
c7c7bce0 AB	122	* efi_queue_work: Queue EFI runtime service call and wait for completion
	123	* @_rts: EFI runtime service function identifier
	124	* @_args: Arguments to pass to the EFI runtime service
3eb420e7 SP	125	*
	126	* Accesses to efi_runtime_services() are serialized by a binary
	127	* semaphore (efi_runtime_lock) and caller waits until the work is
	128	* finished, hence _only_ one work is queued at a time and the caller
	129	* thread waits for completion.
	130	*/
c7c7bce0	131	#define efi_queue_work(_rts, _args...) \
c99ba6e5 AB	132	__efi_queue_work(EFI_ ## _rts, \
c99ba6e5 AB	133	&(union efi_rts_args){ ._rts = { _args }})
3eb420e7	134
13b210dd JT	135	#ifndef arch_efi_save_flags
	136	#define arch_efi_save_flags(state_flags) local_save_flags(state_flags)
	137	#define arch_efi_restore_flags(state_flags) local_irq_restore(state_flags)
	138	#endif
	139
	140	unsigned long efi_call_virt_save_flags(void)
	141	{
	142	unsigned long flags;
	143
	144	arch_efi_save_flags(flags);
	145	return flags;
	146	}
	147
3c17ae41	148	void efi_call_virt_check_flags(unsigned long flags, const void *caller)
1d04ba17 MR	149	{
	150	unsigned long cur_flags, mismatch;
	151
13b210dd	152	cur_flags = efi_call_virt_save_flags();
1d04ba17 MR	153
	154	mismatch = flags ^ cur_flags;
	155	if (!WARN_ON_ONCE(mismatch & ARCH_EFI_IRQ_FLAGS_MASK))
	156	return;
	157
	158	add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_NOW_UNRELIABLE);
3c17ae41 AB	159	pr_err_ratelimited(FW_BUG "IRQ flags corrupted (0x%08lx=>0x%08lx) by EFI call from %pS\n",
3c17ae41 AB	160	flags, cur_flags, caller ?: __builtin_return_address(0));
13b210dd	161	arch_efi_restore_flags(flags);
1d04ba17	162	}
1d04ba17	163
161485e8 AB	164	/*
	165	* According to section 7.1 of the UEFI spec, Runtime Services are not fully
	166	* reentrant, and there are particular combinations of calls that need to be
	167	* serialized. (source: UEFI Specification v2.4A)
	168	*
	169	* Table 31. Rules for Reentry Into Runtime Services
	170	* +------------------------------------+-------------------------------+
	171	* \| If previous call is busy in \| Forbidden to call \|
	172	* +------------------------------------+-------------------------------+
	173	* \| Any \| SetVirtualAddressMap() \|
	174	* +------------------------------------+-------------------------------+
	175	* \| ConvertPointer() \| ConvertPointer() \|
	176	* +------------------------------------+-------------------------------+
	177	* \| SetVariable() \| ResetSystem() \|
	178	* \| UpdateCapsule() \| \|
	179	* \| SetTime() \| \|
	180	* \| SetWakeupTime() \| \|
	181	* \| GetNextHighMonotonicCount() \| \|
	182	* +------------------------------------+-------------------------------+
	183	* \| GetVariable() \| GetVariable() \|
	184	* \| GetNextVariableName() \| GetNextVariableName() \|
	185	* \| SetVariable() \| SetVariable() \|
	186	* \| QueryVariableInfo() \| QueryVariableInfo() \|
	187	* \| UpdateCapsule() \| UpdateCapsule() \|
	188	* \| QueryCapsuleCapabilities() \| QueryCapsuleCapabilities() \|
	189	* \| GetNextHighMonotonicCount() \| GetNextHighMonotonicCount() \|
	190	* +------------------------------------+-------------------------------+
	191	* \| GetTime() \| GetTime() \|
	192	* \| SetTime() \| SetTime() \|
	193	* \| GetWakeupTime() \| GetWakeupTime() \|
	194	* \| SetWakeupTime() \| SetWakeupTime() \|
	195	* +------------------------------------+-------------------------------+
	196	*
	197	* Due to the fact that the EFI pstore may write to the variable store in
dce48e35	198	* interrupt context, we need to use a lock for at least the groups that
161485e8 AB	199	* contain SetVariable() and QueryVariableInfo(). That leaves little else, as
161485e8 AB	200	* none of the remaining functions are actually ever called at runtime.
dce48e35	201	* So let's just use a single lock to serialize all Runtime Services calls.
161485e8	202	*/
48380368	203	static DEFINE_SEMAPHORE(efi_runtime_lock, 1);
161485e8	204
f331e766 HB	205	/*
	206	* Expose the EFI runtime lock to the UV platform
	207	*/
	208	#ifdef CONFIG_X86_UV
	209	extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock);
	210	#endif
	211
3eb420e7 SP	212	/*
	213	* Calls the appropriate efi_runtime_service() with the appropriate
	214	* arguments.
3eb420e7	215	*/
99280413	216	static void __nocfi efi_call_rts(struct work_struct *work)
3eb420e7	217	{
c7c7bce0	218	const union efi_rts_args *args = efi_rts_work.args;
3eb420e7	219	efi_status_t status = EFI_NOT_FOUND;
3c17ae41 AB	220	unsigned long flags;
	221
	222	arch_efi_call_virt_setup();
	223	flags = efi_call_virt_save_flags();
3eb420e7	224
9dbbedaa	225	switch (efi_rts_work.efi_rts_id) {
5c418dc7	226	case EFI_GET_TIME:
c7c7bce0 AB	227	status = efi_call_virt(get_time,
	228	args->GET_TIME.time,
	229	args->GET_TIME.capabilities);
3eb420e7	230	break;
5c418dc7	231	case EFI_SET_TIME:
c7c7bce0 AB	232	status = efi_call_virt(set_time,
c7c7bce0 AB	233	args->SET_TIME.time);
3eb420e7	234	break;
5c418dc7	235	case EFI_GET_WAKEUP_TIME:
c7c7bce0 AB	236	status = efi_call_virt(get_wakeup_time,
	237	args->GET_WAKEUP_TIME.enabled,
	238	args->GET_WAKEUP_TIME.pending,
	239	args->GET_WAKEUP_TIME.time);
3eb420e7	240	break;
5c418dc7	241	case EFI_SET_WAKEUP_TIME:
c7c7bce0 AB	242	status = efi_call_virt(set_wakeup_time,
	243	args->SET_WAKEUP_TIME.enable,
	244	args->SET_WAKEUP_TIME.time);
3eb420e7	245	break;
5c418dc7	246	case EFI_GET_VARIABLE:
c7c7bce0 AB	247	status = efi_call_virt(get_variable,
	248	args->GET_VARIABLE.name,
	249	args->GET_VARIABLE.vendor,
	250	args->GET_VARIABLE.attr,
	251	args->GET_VARIABLE.data_size,
	252	args->GET_VARIABLE.data);
3eb420e7	253	break;
5c418dc7	254	case EFI_GET_NEXT_VARIABLE:
c7c7bce0 AB	255	status = efi_call_virt(get_next_variable,
	256	args->GET_NEXT_VARIABLE.name_size,
	257	args->GET_NEXT_VARIABLE.name,
	258	args->GET_NEXT_VARIABLE.vendor);
3eb420e7	259	break;
5c418dc7	260	case EFI_SET_VARIABLE:
c7c7bce0 AB	261	status = efi_call_virt(set_variable,
	262	args->SET_VARIABLE.name,
	263	args->SET_VARIABLE.vendor,
	264	args->SET_VARIABLE.attr,
	265	args->SET_VARIABLE.data_size,
	266	args->SET_VARIABLE.data);
3eb420e7	267	break;
5c418dc7	268	case EFI_QUERY_VARIABLE_INFO:
c7c7bce0 AB	269	status = efi_call_virt(query_variable_info,
	270	args->QUERY_VARIABLE_INFO.attr,
	271	args->QUERY_VARIABLE_INFO.storage_space,
	272	args->QUERY_VARIABLE_INFO.remaining_space,
	273	args->QUERY_VARIABLE_INFO.max_variable_size);
3eb420e7	274	break;
5c418dc7	275	case EFI_GET_NEXT_HIGH_MONO_COUNT:
c7c7bce0 AB	276	status = efi_call_virt(get_next_high_mono_count,
c7c7bce0 AB	277	args->GET_NEXT_HIGH_MONO_COUNT.high_count);
3eb420e7	278	break;
5c418dc7	279	case EFI_UPDATE_CAPSULE:
3eb420e7	280	status = efi_call_virt(update_capsule,
c7c7bce0 AB	281	args->UPDATE_CAPSULE.capsules,
	282	args->UPDATE_CAPSULE.count,
	283	args->UPDATE_CAPSULE.sg_list);
3eb420e7	284	break;
5c418dc7	285	case EFI_QUERY_CAPSULE_CAPS:
3eb420e7	286	status = efi_call_virt(query_capsule_caps,
c7c7bce0 AB	287	args->QUERY_CAPSULE_CAPS.capsules,
	288	args->QUERY_CAPSULE_CAPS.count,
	289	args->QUERY_CAPSULE_CAPS.max_size,
	290	args->QUERY_CAPSULE_CAPS.reset_type);
3eb420e7	291	break;
5894cf57 AB	292	case EFI_ACPI_PRM_HANDLER:
	293	#ifdef CONFIG_ACPI_PRMT
	294	status = arch_efi_call_virt(args, ACPI_PRM_HANDLER.acpi_prm_handler,
	295	args->ACPI_PRM_HANDLER.param_buffer_addr,
	296	args->ACPI_PRM_HANDLER.context);
	297	break;
	298	#endif
3eb420e7 SP	299	default:
	300	/*
	301	* Ideally, we should never reach here because a caller of this
	302	* function should have put the right efi_runtime_service()
	303	* function identifier into efi_rts_work->efi_rts_id
	304	*/
	305	pr_err("Requested executing invalid EFI Runtime Service.\n");
	306	}
3c17ae41 AB	307
	308	efi_call_virt_check_flags(flags, efi_rts_work.caller);
	309	arch_efi_call_virt_teardown();
	310
9dbbedaa SP	311	efi_rts_work.status = status;
9dbbedaa SP	312	complete(&efi_rts_work.efi_rts_comp);
3eb420e7 SP	313	}
3eb420e7 SP	314
c99ba6e5 AB	315	static efi_status_t __efi_queue_work(enum efi_rts_ids id,
	316	union efi_rts_args *args)
	317	{
	318	efi_rts_work.efi_rts_id = id;
	319	efi_rts_work.args = args;
3c17ae41	320	efi_rts_work.caller = __builtin_return_address(0);
c99ba6e5 AB	321	efi_rts_work.status = EFI_ABORTED;
	322
	323	if (!efi_enabled(EFI_RUNTIME_SERVICES)) {
	324	pr_warn_once("EFI Runtime Services are disabled!\n");
	325	efi_rts_work.status = EFI_DEVICE_ERROR;
	326	goto exit;
	327	}
	328
	329	init_completion(&efi_rts_work.efi_rts_comp);
	330	INIT_WORK(&efi_rts_work.work, efi_call_rts);
	331
	332	/*
	333	* queue_work() returns 0 if work was already on queue,
	334	* _ideally_ this should never happen.
	335	*/
	336	if (queue_work(efi_rts_wq, &efi_rts_work.work))
	337	wait_for_completion(&efi_rts_work.efi_rts_comp);
	338	else
	339	pr_err("Failed to queue work to efi_rts_wq.\n");
	340
	341	WARN_ON_ONCE(efi_rts_work.status == EFI_ABORTED);
	342	exit:
	343	efi_rts_work.efi_rts_id = EFI_NONE;
	344	return efi_rts_work.status;
	345	}
	346
022ee6c5 AB	347	static efi_status_t virt_efi_get_time(efi_time_t tm, efi_time_cap_t tc)
022ee6c5 AB	348	{
022ee6c5 AB	349	efi_status_t status;
022ee6c5 AB	350
dce48e35 AB	351	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	352	return EFI_ABORTED;
c7c7bce0	353	status = efi_queue_work(GET_TIME, tm, tc);
dce48e35	354	up(&efi_runtime_lock);
022ee6c5 AB	355	return status;
	356	}
	357
	358	static efi_status_t virt_efi_set_time(efi_time_t *tm)
	359	{
022ee6c5 AB	360	efi_status_t status;
022ee6c5 AB	361
dce48e35 AB	362	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	363	return EFI_ABORTED;
c7c7bce0	364	status = efi_queue_work(SET_TIME, tm);
dce48e35	365	up(&efi_runtime_lock);
022ee6c5 AB	366	return status;
	367	}
	368
	369	static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
	370	efi_bool_t *pending,
	371	efi_time_t *tm)
	372	{
022ee6c5 AB	373	efi_status_t status;
022ee6c5 AB	374
dce48e35 AB	375	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	376	return EFI_ABORTED;
c7c7bce0	377	status = efi_queue_work(GET_WAKEUP_TIME, enabled, pending, tm);
dce48e35	378	up(&efi_runtime_lock);
022ee6c5 AB	379	return status;
	380	}
	381
	382	static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
	383	{
022ee6c5 AB	384	efi_status_t status;
022ee6c5 AB	385
dce48e35 AB	386	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	387	return EFI_ABORTED;
c7c7bce0	388	status = efi_queue_work(SET_WAKEUP_TIME, enabled, tm);
dce48e35	389	up(&efi_runtime_lock);
022ee6c5 AB	390	return status;
	391	}
	392
	393	static efi_status_t virt_efi_get_variable(efi_char16_t *name,
	394	efi_guid_t *vendor,
	395	u32 *attr,
	396	unsigned long *data_size,
	397	void *data)
	398	{
161485e8 AB	399	efi_status_t status;
161485e8 AB	400
dce48e35 AB	401	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	402	return EFI_ABORTED;
c7c7bce0	403	status = efi_queue_work(GET_VARIABLE, name, vendor, attr, data_size,
3eb420e7	404	data);
dce48e35	405	up(&efi_runtime_lock);
161485e8	406	return status;
022ee6c5 AB	407	}
	408
	409	static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
	410	efi_char16_t *name,
	411	efi_guid_t *vendor)
	412	{
161485e8 AB	413	efi_status_t status;
161485e8 AB	414
dce48e35 AB	415	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	416	return EFI_ABORTED;
c7c7bce0	417	status = efi_queue_work(GET_NEXT_VARIABLE, name_size, name, vendor);
dce48e35	418	up(&efi_runtime_lock);
161485e8	419	return status;
022ee6c5 AB	420	}
	421
	422	static efi_status_t virt_efi_set_variable(efi_char16_t *name,
	423	efi_guid_t *vendor,
	424	u32 attr,
	425	unsigned long data_size,
	426	void *data)
	427	{
161485e8	428	efi_status_t status;
161485e8	429
dce48e35 AB	430	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	431	return EFI_ABORTED;
c7c7bce0	432	status = efi_queue_work(SET_VARIABLE, name, vendor, attr, data_size,
3eb420e7	433	data);
dce48e35	434	up(&efi_runtime_lock);
161485e8	435	return status;
022ee6c5 AB	436	}
022ee6c5 AB	437
99280413	438	static efi_status_t __nocfi
a14198df AB	439	virt_efi_set_variable_nb(efi_char16_t name, efi_guid_t vendor, u32 attr,
a14198df AB	440	unsigned long data_size, void *data)
6d80dba1	441	{
6d80dba1 MF	442	efi_status_t status;
6d80dba1 MF	443
dce48e35	444	if (down_trylock(&efi_runtime_lock))
6d80dba1 MF	445	return EFI_NOT_READY;
6d80dba1 MF	446
3c17ae41 AB	447	status = efi_call_virt_pointer(efi.runtime, set_variable, name, vendor,
3c17ae41 AB	448	attr, data_size, data);
dce48e35	449	up(&efi_runtime_lock);
6d80dba1 MF	450	return status;
	451	}
	452
	453
022ee6c5 AB	454	static efi_status_t virt_efi_query_variable_info(u32 attr,
	455	u64 *storage_space,
	456	u64 *remaining_space,
	457	u64 *max_variable_size)
	458	{
161485e8	459	efi_status_t status;
161485e8	460
022ee6c5 AB	461	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	462	return EFI_UNSUPPORTED;
	463
dce48e35 AB	464	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	465	return EFI_ABORTED;
c7c7bce0 AB	466	status = efi_queue_work(QUERY_VARIABLE_INFO, attr, storage_space,
c7c7bce0 AB	467	remaining_space, max_variable_size);
dce48e35	468	up(&efi_runtime_lock);
161485e8	469	return status;
022ee6c5 AB	470	}
022ee6c5 AB	471
99280413	472	static efi_status_t __nocfi
a14198df AB	473	virt_efi_query_variable_info_nb(u32 attr, u64 *storage_space,
a14198df AB	474	u64 remaining_space, u64 max_variable_size)
d3cac1f8	475	{
d3cac1f8 AB	476	efi_status_t status;
	477
	478	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	479	return EFI_UNSUPPORTED;
	480
dce48e35	481	if (down_trylock(&efi_runtime_lock))
d3cac1f8 AB	482	return EFI_NOT_READY;
d3cac1f8 AB	483
3c17ae41 AB	484	status = efi_call_virt_pointer(efi.runtime, query_variable_info, attr,
	485	storage_space, remaining_space,
	486	max_variable_size);
dce48e35	487	up(&efi_runtime_lock);
d3cac1f8 AB	488	return status;
	489	}
	490
022ee6c5 AB	491	static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
022ee6c5 AB	492	{
161485e8 AB	493	efi_status_t status;
161485e8 AB	494
dce48e35 AB	495	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	496	return EFI_ABORTED;
c7c7bce0	497	status = efi_queue_work(GET_NEXT_HIGH_MONO_COUNT, count);
dce48e35	498	up(&efi_runtime_lock);
161485e8	499	return status;
022ee6c5 AB	500	}
022ee6c5 AB	501
99280413 AB	502	static void __nocfi
	503	virt_efi_reset_system(int reset_type, efi_status_t status,
	504	unsigned long data_size, efi_char16_t *data)
022ee6c5	505	{
38fa3206	506	if (down_trylock(&efi_runtime_lock)) {
dce48e35 AB	507	pr_warn("failed to invoke the reset_system() runtime service:\n"
	508	"could not get exclusive access to the firmware\n");
	509	return;
	510	}
e38abdab AB	511
e38abdab AB	512	arch_efi_call_virt_setup();
5c418dc7	513	efi_rts_work.efi_rts_id = EFI_RESET_SYSTEM;
e38abdab AB	514	arch_efi_call_virt(efi.runtime, reset_system, reset_type, status,
	515	data_size, data);
	516	arch_efi_call_virt_teardown();
	517
dce48e35	518	up(&efi_runtime_lock);
022ee6c5 AB	519	}
	520
	521	static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
	522	unsigned long count,
	523	unsigned long sg_list)
	524	{
161485e8 AB	525	efi_status_t status;
161485e8 AB	526
022ee6c5 AB	527	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	528	return EFI_UNSUPPORTED;
	529
dce48e35 AB	530	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	531	return EFI_ABORTED;
c7c7bce0	532	status = efi_queue_work(UPDATE_CAPSULE, capsules, count, sg_list);
dce48e35	533	up(&efi_runtime_lock);
161485e8	534	return status;
022ee6c5 AB	535	}
	536
	537	static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
	538	unsigned long count,
	539	u64 *max_size,
	540	int *reset_type)
	541	{
161485e8 AB	542	efi_status_t status;
161485e8 AB	543
022ee6c5 AB	544	if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION)
	545	return EFI_UNSUPPORTED;
	546
dce48e35 AB	547	if (down_interruptible(&efi_runtime_lock))
dce48e35 AB	548	return EFI_ABORTED;
c7c7bce0 AB	549	status = efi_queue_work(QUERY_CAPSULE_CAPS, capsules, count,
c7c7bce0 AB	550	max_size, reset_type);
dce48e35	551	up(&efi_runtime_lock);
161485e8	552	return status;
022ee6c5 AB	553	}
022ee6c5 AB	554
a14198df	555	void __init efi_native_runtime_setup(void)
022ee6c5	556	{
a14198df AB	557	efi.get_time = virt_efi_get_time;
	558	efi.set_time = virt_efi_set_time;
	559	efi.get_wakeup_time = virt_efi_get_wakeup_time;
	560	efi.set_wakeup_time = virt_efi_set_wakeup_time;
	561	efi.get_variable = virt_efi_get_variable;
	562	efi.get_next_variable = virt_efi_get_next_variable;
	563	efi.set_variable = virt_efi_set_variable;
	564	efi.set_variable_nonblocking = virt_efi_set_variable_nb;
	565	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
	566	efi.reset_system = virt_efi_reset_system;
	567	efi.query_variable_info = virt_efi_query_variable_info;
	568	efi.query_variable_info_nonblocking = virt_efi_query_variable_info_nb;
	569	efi.update_capsule = virt_efi_update_capsule;
	570	efi.query_capsule_caps = virt_efi_query_capsule_caps;
022ee6c5	571	}
5894cf57 AB	572
	573	#ifdef CONFIG_ACPI_PRMT
	574
	575	efi_status_t
	576	efi_call_acpi_prm_handler(efi_status_t (__efiapi handler_addr)(u64, void ),
	577	u64 param_buffer_addr, void *context)
	578	{
	579	efi_status_t status;
	580
	581	if (down_interruptible(&efi_runtime_lock))
	582	return EFI_ABORTED;
	583	status = efi_queue_work(ACPI_PRM_HANDLER, handler_addr,
	584	param_buffer_addr, context);
	585	up(&efi_runtime_lock);
	586	return status;
	587	}
	588
	589	#endif