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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 | ||
18 | #include <linux/kvm_host.h> | |
19 | #include <linux/wait.h> | |
20 | ||
21 | #include <asm/kvm_emulate.h> | |
22 | #include <asm/kvm_psci.h> | |
23 | ||
24 | /* | |
25 | * This is an implementation of the Power State Coordination Interface | |
26 | * as described in ARM document number ARM DEN 0022A. | |
27 | */ | |
28 | ||
29 | static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) | |
30 | { | |
31 | vcpu->arch.pause = true; | |
32 | } | |
33 | ||
34 | static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu) | |
35 | { | |
36 | struct kvm *kvm = source_vcpu->kvm; | |
37 | struct kvm_vcpu *vcpu; | |
38 | wait_queue_head_t *wq; | |
39 | unsigned long cpu_id; | |
40 | phys_addr_t target_pc; | |
41 | ||
42 | cpu_id = *vcpu_reg(source_vcpu, 1); | |
43 | if (vcpu_mode_is_32bit(source_vcpu)) | |
44 | cpu_id &= ~((u32) 0); | |
45 | ||
46 | if (cpu_id >= atomic_read(&kvm->online_vcpus)) | |
47 | return KVM_PSCI_RET_INVAL; | |
48 | ||
49 | target_pc = *vcpu_reg(source_vcpu, 2); | |
50 | ||
51 | vcpu = kvm_get_vcpu(kvm, cpu_id); | |
52 | ||
53 | wq = kvm_arch_vcpu_wq(vcpu); | |
54 | if (!waitqueue_active(wq)) | |
55 | return KVM_PSCI_RET_INVAL; | |
56 | ||
57 | kvm_reset_vcpu(vcpu); | |
58 | ||
59 | /* Gracefully handle Thumb2 entry point */ | |
60 | if (vcpu_mode_is_32bit(vcpu) && (target_pc & 1)) { | |
61 | target_pc &= ~((phys_addr_t) 1); | |
62 | vcpu_set_thumb(vcpu); | |
63 | } | |
64 | ||
65 | *vcpu_pc(vcpu) = target_pc; | |
66 | vcpu->arch.pause = false; | |
67 | smp_mb(); /* Make sure the above is visible */ | |
68 | ||
69 | wake_up_interruptible(wq); | |
70 | ||
71 | return KVM_PSCI_RET_SUCCESS; | |
72 | } | |
73 | ||
74 | /** | |
75 | * kvm_psci_call - handle PSCI call if r0 value is in range | |
76 | * @vcpu: Pointer to the VCPU struct | |
77 | * | |
24a7f675 | 78 | * Handle PSCI calls from guests through traps from HVC instructions. |
aa024c2f MZ |
79 | * The calling convention is similar to SMC calls to the secure world where |
80 | * the function number is placed in r0 and this function returns true if the | |
81 | * function number specified in r0 is withing the PSCI range, and false | |
82 | * otherwise. | |
83 | */ | |
84 | bool kvm_psci_call(struct kvm_vcpu *vcpu) | |
85 | { | |
86 | unsigned long psci_fn = *vcpu_reg(vcpu, 0) & ~((u32) 0); | |
87 | unsigned long val; | |
88 | ||
89 | switch (psci_fn) { | |
90 | case KVM_PSCI_FN_CPU_OFF: | |
91 | kvm_psci_vcpu_off(vcpu); | |
92 | val = KVM_PSCI_RET_SUCCESS; | |
93 | break; | |
94 | case KVM_PSCI_FN_CPU_ON: | |
95 | val = kvm_psci_vcpu_on(vcpu); | |
96 | break; | |
97 | case KVM_PSCI_FN_CPU_SUSPEND: | |
98 | case KVM_PSCI_FN_MIGRATE: | |
99 | val = KVM_PSCI_RET_NI; | |
100 | break; | |
101 | ||
102 | default: | |
103 | return false; | |
104 | } | |
105 | ||
106 | *vcpu_reg(vcpu, 0) = val; | |
107 | return true; | |
108 | } |