2 * Copyright (C) 2012 - ARM Ltd
3 * Author: Marc Zyngier <marc.zyngier@arm.com>
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.
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.
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/>.
18 #include <linux/kvm_host.h>
19 #include <linux/wait.h>
21 #include <asm/cputype.h>
22 #include <asm/kvm_emulate.h>
23 #include <asm/kvm_psci.h>
26 * This is an implementation of the Power State Coordination Interface
27 * as described in ARM document number ARM DEN 0022A.
30 static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
32 vcpu->arch.pause = true;
35 static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
37 struct kvm *kvm = source_vcpu->kvm;
38 struct kvm_vcpu *vcpu = NULL, *tmp;
39 wait_queue_head_t *wq;
42 phys_addr_t target_pc;
45 cpu_id = *vcpu_reg(source_vcpu, 1);
46 if (vcpu_mode_is_32bit(source_vcpu))
49 kvm_for_each_vcpu(i, tmp, kvm) {
50 mpidr = kvm_vcpu_get_mpidr(tmp);
51 if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {
58 return KVM_PSCI_RET_INVAL;
60 target_pc = *vcpu_reg(source_vcpu, 2);
62 wq = kvm_arch_vcpu_wq(vcpu);
63 if (!waitqueue_active(wq))
64 return KVM_PSCI_RET_INVAL;
68 /* Gracefully handle Thumb2 entry point */
69 if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) {
70 target_pc &= ~((phys_addr_t) 1);
74 /* Propagate caller endianness */
75 if (kvm_vcpu_is_be(source_vcpu))
76 kvm_vcpu_set_be(vcpu);
78 *vcpu_pc(vcpu) = target_pc;
79 vcpu->arch.pause = false;
80 smp_mb(); /* Make sure the above is visible */
82 wake_up_interruptible(wq);
84 return KVM_PSCI_RET_SUCCESS;
88 * kvm_psci_call - handle PSCI call if r0 value is in range
89 * @vcpu: Pointer to the VCPU struct
91 * Handle PSCI calls from guests through traps from HVC instructions.
92 * The calling convention is similar to SMC calls to the secure world where
93 * the function number is placed in r0 and this function returns true if the
94 * function number specified in r0 is withing the PSCI range, and false
97 bool kvm_psci_call(struct kvm_vcpu *vcpu)
99 unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0);
103 case KVM_PSCI_FN_CPU_OFF:
104 kvm_psci_vcpu_off(vcpu);
105 val = KVM_PSCI_RET_SUCCESS;
107 case KVM_PSCI_FN_CPU_ON:
108 val = kvm_psci_vcpu_on(vcpu);
110 case KVM_PSCI_FN_CPU_SUSPEND:
111 case KVM_PSCI_FN_MIGRATE:
112 val = KVM_PSCI_RET_NI;
119 *vcpu_reg(vcpu, 0) = val;