[deliverable/linux.git] / arch / arm / kvm / psci.c

/*
 * Copyright (C) 2012 - ARM Ltd
 * Author: Marc Zyngier <marc.zyngier@arm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/preempt.h>
#include <linux/kvm_host.h>
#include <linux/wait.h>

#include <asm/cputype.h>
#include <asm/kvm_emulate.h>
#include <asm/kvm_psci.h>
#include <asm/kvm_host.h>

/*
 * This is an implementation of the Power State Coordination Interface
 * as described in ARM document number ARM DEN 0022A.
 */

#define AFFINITY_MASK(level)	~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)

static unsigned long psci_affinity_mask(unsigned long affinity_level)
{
	if (affinity_level <= 3)
		return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);

	return 0;
}

static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
{
	/*
	 * NOTE: For simplicity, we make VCPU suspend emulation to be
	 * same-as WFI (Wait-for-interrupt) emulation.
	 *
	 * This means for KVM the wakeup events are interrupts and
	 * this is consistent with intended use of StateID as described
	 * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A).
	 *
	 * Further, we also treat power-down request to be same as
	 * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2
	 * specification (ARM DEN 0022A). This means all suspend states
	 * for KVM will preserve the register state.
	 */
	kvm_vcpu_block(vcpu);

	return PSCI_RET_SUCCESS;
}

static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
{
	vcpu->arch.pause = true;
}

static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
{
	struct kvm *kvm = source_vcpu->kvm;
	struct kvm_vcpu *vcpu = NULL;
	wait_queue_head_t *wq;
	unsigned long cpu_id;
	unsigned long context_id;
	phys_addr_t target_pc;

	cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
	if (vcpu_mode_is_32bit(source_vcpu))
		cpu_id &= ~((u32) 0);

	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);

	/*
	 * Make sure the caller requested a valid CPU and that the CPU is
	 * turned off.
	 */
	if (!vcpu)
		return PSCI_RET_INVALID_PARAMS;
	if (!vcpu->arch.pause) {
		if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
			return PSCI_RET_ALREADY_ON;
		else
			return PSCI_RET_INVALID_PARAMS;
	}

	target_pc = *vcpu_reg(source_vcpu, 2);
	context_id = *vcpu_reg(source_vcpu, 3);

	kvm_reset_vcpu(vcpu);

	/* Gracefully handle Thumb2 entry point */
	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
		target_pc &= ~((phys_addr_t) 1);
		vcpu_set_thumb(vcpu);
	}

	/* Propagate caller endianness */
	if (kvm_vcpu_is_be(source_vcpu))
		kvm_vcpu_set_be(vcpu);

	*vcpu_pc(vcpu) = target_pc;
	/*
	 * NOTE: We always update r0 (or x0) because for PSCI v0.1
	 * the general puspose registers are undefined upon CPU_ON.
	 */
	*vcpu_reg(vcpu, 0) = context_id;
	vcpu->arch.pause = false;
	smp_mb();		/* Make sure the above is visible */

	wq = kvm_arch_vcpu_wq(vcpu);
	wake_up_interruptible(wq);

	return PSCI_RET_SUCCESS;
}

static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
{
	int i;
	unsigned long mpidr;
	unsigned long target_affinity;
	unsigned long target_affinity_mask;
	unsigned long lowest_affinity_level;
	struct kvm *kvm = vcpu->kvm;
	struct kvm_vcpu *tmp;

	target_affinity = *vcpu_reg(vcpu, 1);
	lowest_affinity_level = *vcpu_reg(vcpu, 2);

	/* Determine target affinity mask */
	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
	if (!target_affinity_mask)
		return PSCI_RET_INVALID_PARAMS;

	/* Ignore other bits of target affinity */
	target_affinity &= target_affinity_mask;

	/*
	 * If one or more VCPU matching target affinity are running
	 * then ON else OFF
	 */
	kvm_for_each_vcpu(i, tmp, kvm) {
		mpidr = kvm_vcpu_get_mpidr_aff(tmp);
		if (((mpidr & target_affinity_mask) == target_affinity) &&
		    !tmp->arch.pause) {
			return PSCI_0_2_AFFINITY_LEVEL_ON;
		}
	}

	return PSCI_0_2_AFFINITY_LEVEL_OFF;
}

static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
{
	int i;
	struct kvm_vcpu *tmp;

	/*
	 * The KVM ABI specifies that a system event exit may call KVM_RUN
	 * again and may perform shutdown/reboot at a later time that when the
	 * actual request is made.  Since we are implementing PSCI and a
	 * caller of PSCI reboot and shutdown expects that the system shuts
	 * down or reboots immediately, let's make sure that VCPUs are not run
	 * after this call is handled and before the VCPUs have been
	 * re-initialized.
	 */
	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
		tmp->arch.pause = true;
		kvm_vcpu_kick(tmp);
	}

	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
	vcpu->run->system_event.type = type;
	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
}

static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
{
	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
}

static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
{
	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
}

int kvm_psci_version(struct kvm_vcpu *vcpu)
{
	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
		return KVM_ARM_PSCI_0_2;

	return KVM_ARM_PSCI_0_1;
}

static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
{
	int ret = 1;
	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	unsigned long val;

	switch (psci_fn) {
	case PSCI_0_2_FN_PSCI_VERSION:
		/*
		 * Bits[31:16] = Major Version = 0
		 * Bits[15:0] = Minor Version = 2
		 */
		val = 2;
		break;
	case PSCI_0_2_FN_CPU_SUSPEND:
	case PSCI_0_2_FN64_CPU_SUSPEND:
		val = kvm_psci_vcpu_suspend(vcpu);
		break;
	case PSCI_0_2_FN_CPU_OFF:
		kvm_psci_vcpu_off(vcpu);
		val = PSCI_RET_SUCCESS;
		break;
	case PSCI_0_2_FN_CPU_ON:
	case PSCI_0_2_FN64_CPU_ON:
		val = kvm_psci_vcpu_on(vcpu);
		break;
	case PSCI_0_2_FN_AFFINITY_INFO:
	case PSCI_0_2_FN64_AFFINITY_INFO:
		val = kvm_psci_vcpu_affinity_info(vcpu);
		break;
	case PSCI_0_2_FN_MIGRATE:
	case PSCI_0_2_FN64_MIGRATE:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
		/*
		 * Trusted OS is MP hence does not require migration
	         * or
		 * Trusted OS is not present
		 */
		val = PSCI_0_2_TOS_MP;
		break;
	case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
	case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	case PSCI_0_2_FN_SYSTEM_OFF:
		kvm_psci_system_off(vcpu);
		/*
		 * We should'nt be going back to guest VCPU after
		 * receiving SYSTEM_OFF request.
		 *
		 * If user space accidently/deliberately resumes
		 * guest VCPU after SYSTEM_OFF request then guest
		 * VCPU should see internal failure from PSCI return
		 * value. To achieve this, we preload r0 (or x0) with
		 * PSCI return value INTERNAL_FAILURE.
		 */
		val = PSCI_RET_INTERNAL_FAILURE;
		ret = 0;
		break;
	case PSCI_0_2_FN_SYSTEM_RESET:
		kvm_psci_system_reset(vcpu);
		/*
		 * Same reason as SYSTEM_OFF for preloading r0 (or x0)
		 * with PSCI return value INTERNAL_FAILURE.
		 */
		val = PSCI_RET_INTERNAL_FAILURE;
		ret = 0;
		break;
	default:
		return -EINVAL;
	}

	*vcpu_reg(vcpu, 0) = val;
	return ret;
}

static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
{
	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	unsigned long val;

	switch (psci_fn) {
	case KVM_PSCI_FN_CPU_OFF:
		kvm_psci_vcpu_off(vcpu);
		val = PSCI_RET_SUCCESS;
		break;
	case KVM_PSCI_FN_CPU_ON:
		val = kvm_psci_vcpu_on(vcpu);
		break;
	case KVM_PSCI_FN_CPU_SUSPEND:
	case KVM_PSCI_FN_MIGRATE:
		val = PSCI_RET_NOT_SUPPORTED;
		break;
	default:
		return -EINVAL;
	}

	*vcpu_reg(vcpu, 0) = val;
	return 1;
}

/**
 * kvm_psci_call - handle PSCI call if r0 value is in range
 * @vcpu: Pointer to the VCPU struct
 *
 * Handle PSCI calls from guests through traps from HVC instructions.
 * The calling convention is similar to SMC calls to the secure world
 * where the function number is placed in r0.
 *
 * This function returns: > 0 (success), 0 (success but exit to user
 * space), and < 0 (errors)
 *
 * Errors:
 * -EINVAL: Unrecognized PSCI function
 */
int kvm_psci_call(struct kvm_vcpu *vcpu)
{
	switch (kvm_psci_version(vcpu)) {
	case KVM_ARM_PSCI_0_2:
		return kvm_psci_0_2_call(vcpu);
	case KVM_ARM_PSCI_0_1:
		return kvm_psci_0_1_call(vcpu);
	default:
		return -EINVAL;
	};
}
Commit	Line	Data
aa024c2f MZ	1	/*
	2	* Copyright (C) 2012 - ARM Ltd
	3	* Author: Marc Zyngier <marc.zyngier@arm.com>
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License version 2 as
	7	* published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope that it will be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License
	15	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	16	*/
	17
cf5d3188	18	#include <linux/preempt.h>
aa024c2f MZ	19	#include <linux/kvm_host.h>
	20	#include <linux/wait.h>
	21
79c64880	22	#include <asm/cputype.h>
aa024c2f MZ	23	#include <asm/kvm_emulate.h>
aa024c2f MZ	24	#include <asm/kvm_psci.h>
4429fc64	25	#include <asm/kvm_host.h>
aa024c2f MZ	26
	27	/*
	28	* This is an implementation of the Power State Coordination Interface
	29	* as described in ARM document number ARM DEN 0022A.
	30	*/
	31
e6bc13c8 AP	32	#define AFFINITY_MASK(level) ~((0x1UL << ((level) * MPIDR_LEVEL_BITS)) - 1)
	33
	34	static unsigned long psci_affinity_mask(unsigned long affinity_level)
	35	{
	36	if (affinity_level <= 3)
	37	return MPIDR_HWID_BITMASK & AFFINITY_MASK(affinity_level);
	38
	39	return 0;
	40	}
	41
b376d02b AP	42	static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu)
	43	{
	44	/*
	45	* NOTE: For simplicity, we make VCPU suspend emulation to be
	46	* same-as WFI (Wait-for-interrupt) emulation.
	47	*
	48	* This means for KVM the wakeup events are interrupts and
	49	* this is consistent with intended use of StateID as described
	50	* in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A).
	51	*
	52	* Further, we also treat power-down request to be same as
	53	* stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2
	54	* specification (ARM DEN 0022A). This means all suspend states
	55	* for KVM will preserve the register state.
	56	*/
	57	kvm_vcpu_block(vcpu);
	58
	59	return PSCI_RET_SUCCESS;
	60	}
	61
aa024c2f MZ	62	static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
	63	{
	64	vcpu->arch.pause = true;
	65	}
	66
	67	static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
	68	{
	69	struct kvm *kvm = source_vcpu->kvm;
4429fc64	70	struct kvm_vcpu *vcpu = NULL;
aa024c2f MZ	71	wait_queue_head_t *wq;
aa024c2f MZ	72	unsigned long cpu_id;
aa8aeefe	73	unsigned long context_id;
aa024c2f MZ	74	phys_addr_t target_pc;
aa024c2f MZ	75
4429fc64	76	cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
aa024c2f MZ	77	if (vcpu_mode_is_32bit(source_vcpu))
	78	cpu_id &= ~((u32) 0);
	79
4429fc64	80	vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
79c64880	81
478a8237 CD	82	/*
	83	* Make sure the caller requested a valid CPU and that the CPU is
	84	* turned off.
	85	*/
aa8aeefe	86	if (!vcpu)
7d0f84aa	87	return PSCI_RET_INVALID_PARAMS;
aa8aeefe AP	88	if (!vcpu->arch.pause) {
	89	if (kvm_psci_version(source_vcpu) != KVM_ARM_PSCI_0_1)
	90	return PSCI_RET_ALREADY_ON;
	91	else
	92	return PSCI_RET_INVALID_PARAMS;
	93	}
aa024c2f MZ	94
aa024c2f MZ	95	target_pc = *vcpu_reg(source_vcpu, 2);
aa8aeefe	96	context_id = *vcpu_reg(source_vcpu, 3);
aa024c2f	97
aa024c2f MZ	98	kvm_reset_vcpu(vcpu);
	99
	100	/* Gracefully handle Thumb2 entry point */
	101	if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
	102	target_pc &= ~((phys_addr_t) 1);
	103	vcpu_set_thumb(vcpu);
	104	}
	105
ce94fe93 MZ	106	/* Propagate caller endianness */
	107	if (kvm_vcpu_is_be(source_vcpu))
	108	kvm_vcpu_set_be(vcpu);
	109
aa024c2f	110	*vcpu_pc(vcpu) = target_pc;
aa8aeefe AP	111	/*
	112	* NOTE: We always update r0 (or x0) because for PSCI v0.1
	113	* the general puspose registers are undefined upon CPU_ON.
	114	*/
	115	*vcpu_reg(vcpu, 0) = context_id;
aa024c2f MZ	116	vcpu->arch.pause = false;
	117	smp_mb(); /* Make sure the above is visible */
	118
478a8237	119	wq = kvm_arch_vcpu_wq(vcpu);
aa024c2f MZ	120	wake_up_interruptible(wq);
aa024c2f MZ	121
7d0f84aa	122	return PSCI_RET_SUCCESS;
aa024c2f MZ	123	}
aa024c2f MZ	124
e6bc13c8 AP	125	static unsigned long kvm_psci_vcpu_affinity_info(struct kvm_vcpu *vcpu)
	126	{
	127	int i;
	128	unsigned long mpidr;
	129	unsigned long target_affinity;
	130	unsigned long target_affinity_mask;
	131	unsigned long lowest_affinity_level;
	132	struct kvm *kvm = vcpu->kvm;
	133	struct kvm_vcpu *tmp;
	134
	135	target_affinity = *vcpu_reg(vcpu, 1);
	136	lowest_affinity_level = *vcpu_reg(vcpu, 2);
	137
	138	/* Determine target affinity mask */
	139	target_affinity_mask = psci_affinity_mask(lowest_affinity_level);
	140	if (!target_affinity_mask)
	141	return PSCI_RET_INVALID_PARAMS;
	142
	143	/* Ignore other bits of target affinity */
	144	target_affinity &= target_affinity_mask;
	145
	146	/*
	147	* If one or more VCPU matching target affinity are running
	148	* then ON else OFF
	149	*/
	150	kvm_for_each_vcpu(i, tmp, kvm) {
4429fc64	151	mpidr = kvm_vcpu_get_mpidr_aff(tmp);
e6bc13c8 AP	152	if (((mpidr & target_affinity_mask) == target_affinity) &&
	153	!tmp->arch.pause) {
	154	return PSCI_0_2_AFFINITY_LEVEL_ON;
	155	}
	156	}
	157
	158	return PSCI_0_2_AFFINITY_LEVEL_OFF;
	159	}
	160
4b123826 AP	161	static void kvm_prepare_system_event(struct kvm_vcpu *vcpu, u32 type)
4b123826 AP	162	{
cf5d3188 CD	163	int i;
	164	struct kvm_vcpu *tmp;
	165
	166	/*
	167	* The KVM ABI specifies that a system event exit may call KVM_RUN
	168	* again and may perform shutdown/reboot at a later time that when the
	169	* actual request is made. Since we are implementing PSCI and a
	170	* caller of PSCI reboot and shutdown expects that the system shuts
	171	* down or reboots immediately, let's make sure that VCPUs are not run
	172	* after this call is handled and before the VCPUs have been
	173	* re-initialized.
	174	*/
	175	kvm_for_each_vcpu(i, tmp, vcpu->kvm) {
	176	tmp->arch.pause = true;
	177	kvm_vcpu_kick(tmp);
	178	}
	179
4b123826 AP	180	memset(&vcpu->run->system_event, 0, sizeof(vcpu->run->system_event));
	181	vcpu->run->system_event.type = type;
	182	vcpu->run->exit_reason = KVM_EXIT_SYSTEM_EVENT;
	183	}
	184
	185	static void kvm_psci_system_off(struct kvm_vcpu *vcpu)
	186	{
	187	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_SHUTDOWN);
	188	}
	189
	190	static void kvm_psci_system_reset(struct kvm_vcpu *vcpu)
	191	{
	192	kvm_prepare_system_event(vcpu, KVM_SYSTEM_EVENT_RESET);
	193	}
	194
7d0f84aa AP	195	int kvm_psci_version(struct kvm_vcpu *vcpu)
	196	{
	197	if (test_bit(KVM_ARM_VCPU_PSCI_0_2, vcpu->arch.features))
	198	return KVM_ARM_PSCI_0_2;
	199
	200	return KVM_ARM_PSCI_0_1;
	201	}
	202
e8e7fcc5	203	static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu)
7d0f84aa	204	{
4b123826	205	int ret = 1;
7d0f84aa AP	206	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	207	unsigned long val;
	208
	209	switch (psci_fn) {
	210	case PSCI_0_2_FN_PSCI_VERSION:
	211	/*
	212	* Bits[31:16] = Major Version = 0
	213	* Bits[15:0] = Minor Version = 2
	214	*/
	215	val = 2;
	216	break;
b376d02b AP	217	case PSCI_0_2_FN_CPU_SUSPEND:
	218	case PSCI_0_2_FN64_CPU_SUSPEND:
	219	val = kvm_psci_vcpu_suspend(vcpu);
	220	break;
7d0f84aa AP	221	case PSCI_0_2_FN_CPU_OFF:
	222	kvm_psci_vcpu_off(vcpu);
	223	val = PSCI_RET_SUCCESS;
	224	break;
	225	case PSCI_0_2_FN_CPU_ON:
	226	case PSCI_0_2_FN64_CPU_ON:
	227	val = kvm_psci_vcpu_on(vcpu);
	228	break;
e6bc13c8 AP	229	case PSCI_0_2_FN_AFFINITY_INFO:
	230	case PSCI_0_2_FN64_AFFINITY_INFO:
	231	val = kvm_psci_vcpu_affinity_info(vcpu);
	232	break;
bab0b430 AP	233	case PSCI_0_2_FN_MIGRATE:
	234	case PSCI_0_2_FN64_MIGRATE:
	235	val = PSCI_RET_NOT_SUPPORTED;
	236	break;
	237	case PSCI_0_2_FN_MIGRATE_INFO_TYPE:
	238	/*
	239	* Trusted OS is MP hence does not require migration
	240	* or
	241	* Trusted OS is not present
	242	*/
	243	val = PSCI_0_2_TOS_MP;
	244	break;
	245	case PSCI_0_2_FN_MIGRATE_INFO_UP_CPU:
	246	case PSCI_0_2_FN64_MIGRATE_INFO_UP_CPU:
	247	val = PSCI_RET_NOT_SUPPORTED;
	248	break;
4b123826 AP	249	case PSCI_0_2_FN_SYSTEM_OFF:
	250	kvm_psci_system_off(vcpu);
	251	/*
	252	* We should'nt be going back to guest VCPU after
	253	* receiving SYSTEM_OFF request.
	254	*
	255	* If user space accidently/deliberately resumes
	256	* guest VCPU after SYSTEM_OFF request then guest
	257	* VCPU should see internal failure from PSCI return
	258	* value. To achieve this, we preload r0 (or x0) with
	259	* PSCI return value INTERNAL_FAILURE.
	260	*/
	261	val = PSCI_RET_INTERNAL_FAILURE;
	262	ret = 0;
	263	break;
	264	case PSCI_0_2_FN_SYSTEM_RESET:
	265	kvm_psci_system_reset(vcpu);
	266	/*
	267	* Same reason as SYSTEM_OFF for preloading r0 (or x0)
	268	* with PSCI return value INTERNAL_FAILURE.
	269	*/
	270	val = PSCI_RET_INTERNAL_FAILURE;
	271	ret = 0;
	272	break;
7d0f84aa	273	default:
e8e7fcc5	274	return -EINVAL;
7d0f84aa AP	275	}
	276
	277	*vcpu_reg(vcpu, 0) = val;
4b123826	278	return ret;
7d0f84aa AP	279	}
7d0f84aa AP	280
e8e7fcc5	281	static int kvm_psci_0_1_call(struct kvm_vcpu *vcpu)
aa024c2f MZ	282	{
	283	unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
	284	unsigned long val;
	285
	286	switch (psci_fn) {
	287	case KVM_PSCI_FN_CPU_OFF:
	288	kvm_psci_vcpu_off(vcpu);
7d0f84aa	289	val = PSCI_RET_SUCCESS;
aa024c2f MZ	290	break;
	291	case KVM_PSCI_FN_CPU_ON:
	292	val = kvm_psci_vcpu_on(vcpu);
	293	break;
	294	case KVM_PSCI_FN_CPU_SUSPEND:
	295	case KVM_PSCI_FN_MIGRATE:
7d0f84aa	296	val = PSCI_RET_NOT_SUPPORTED;
aa024c2f	297	break;
aa024c2f	298	default:
e8e7fcc5	299	return -EINVAL;
aa024c2f MZ	300	}
	301
	302	*vcpu_reg(vcpu, 0) = val;
e8e7fcc5	303	return 1;
aa024c2f	304	}
7d0f84aa AP	305
	306	/**
	307	* kvm_psci_call - handle PSCI call if r0 value is in range
	308	* @vcpu: Pointer to the VCPU struct
	309	*
	310	* Handle PSCI calls from guests through traps from HVC instructions.
e8e7fcc5 AP	311	* The calling convention is similar to SMC calls to the secure world
	312	* where the function number is placed in r0.
	313	*
	314	* This function returns: > 0 (success), 0 (success but exit to user
	315	* space), and < 0 (errors)
	316	*
	317	* Errors:
	318	* -EINVAL: Unrecognized PSCI function
7d0f84aa	319	*/
e8e7fcc5	320	int kvm_psci_call(struct kvm_vcpu *vcpu)
7d0f84aa AP	321	{
	322	switch (kvm_psci_version(vcpu)) {
	323	case KVM_ARM_PSCI_0_2:
	324	return kvm_psci_0_2_call(vcpu);
	325	case KVM_ARM_PSCI_0_1:
	326	return kvm_psci_0_1_call(vcpu);
	327	default:
e8e7fcc5	328	return -EINVAL;
7d0f84aa AP	329	};
7d0f84aa AP	330	}