xref: /linux/arch/loongarch/kvm/intc/dmsintc.c (revision 0fc8f6200d2313278fbf4539bbab74677c685531)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2025 Loongson Technology Corporation Limited
4  */
5 
6 #include <linux/kvm_host.h>
7 #include <asm/kvm_csr.h>
8 #include <asm/kvm_dmsintc.h>
9 #include <asm/kvm_vcpu.h>
10 
11 void dmsintc_inject_irq(struct kvm_vcpu *vcpu)
12 {
13 	unsigned int i;
14 	unsigned long vector[4], old;
15 	struct dmsintc_state *ds = &vcpu->arch.dmsintc_state;
16 
17 	if (!ds)
18 		return;
19 
20 	for (i = 0; i < 4; i++) {
21 		old = atomic64_read(&(ds->vector_map[i]));
22 		if (old)
23 			vector[i] = atomic64_xchg(&(ds->vector_map[i]), 0);
24 	}
25 
26 	if (vector[0]) {
27 		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR0);
28 		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR0, vector[0] | old);
29 	}
30 
31 	if (vector[1]) {
32 		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR1);
33 		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR1, vector[1] | old);
34 	}
35 
36 	if (vector[2]) {
37 		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR2);
38 		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR2, vector[2] | old);
39 	}
40 
41 	if (vector[3]) {
42 		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR3);
43 		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR3, vector[3] | old);
44 	}
45 }
46 
47 int dmsintc_deliver_msi_to_vcpu(struct kvm *kvm,
48 				struct kvm_vcpu *vcpu, u32 vector, int level)
49 {
50 	struct kvm_interrupt vcpu_irq;
51 	struct dmsintc_state *ds = &vcpu->arch.dmsintc_state;
52 
53 	if (!level)
54 		return 0;
55 	if (!vcpu || vector >= 256)
56 		return -EINVAL;
57 	if (!ds)
58 		return -ENODEV;
59 
60 	vcpu_irq.irq = INT_AVEC;
61 	set_bit(vector, (unsigned long *)&ds->vector_map);
62 	kvm_vcpu_ioctl_interrupt(vcpu, &vcpu_irq);
63 	kvm_vcpu_kick(vcpu);
64 
65 	return 0;
66 }
67 
68 int dmsintc_set_irq(struct kvm *kvm, u64 addr, int data, int level)
69 {
70 	unsigned int irq, cpu;
71 	struct kvm_vcpu *vcpu;
72 
73 	irq = (addr >> AVEC_IRQ_SHIFT) & AVEC_IRQ_MASK;
74 	cpu = (addr >> AVEC_CPU_SHIFT) & kvm->arch.dmsintc->cpu_mask;
75 	if (cpu >= KVM_MAX_VCPUS)
76 		return -EINVAL;
77 	vcpu = kvm_get_vcpu_by_cpuid(kvm, cpu);
78 	if (!vcpu)
79 		return -EINVAL;
80 
81 	return dmsintc_deliver_msi_to_vcpu(kvm, vcpu, irq, level);
82 }
83 
84 static int kvm_dmsintc_ctrl_access(struct kvm_device *dev,
85 				   struct kvm_device_attr *attr, bool is_write)
86 {
87 	int addr = attr->attr;
88 	unsigned long cpu_bit, val;
89 	void __user *data = (void __user *)attr->addr;
90 	struct loongarch_dmsintc *s = dev->kvm->arch.dmsintc;
91 
92 	switch (addr) {
93 	case KVM_DEV_LOONGARCH_DMSINTC_MSG_ADDR_BASE:
94 		if (is_write) {
95 			if (copy_from_user(&val, data, sizeof(s->msg_addr_base)))
96 				return -EFAULT;
97 			if (s->msg_addr_base)
98 				return -EFAULT; /* Duplicate setting are not allowed. */
99 			if ((val & (BIT(AVEC_CPU_SHIFT) - 1)) != 0)
100 				return -EINVAL;
101 			s->msg_addr_base = val;
102 			cpu_bit = find_first_bit((unsigned long *)&(s->msg_addr_base), 64) - AVEC_CPU_SHIFT;
103 			cpu_bit = min(cpu_bit, AVEC_CPU_BIT);
104 			s->cpu_mask = GENMASK(cpu_bit - 1, 0) & AVEC_CPU_MASK;
105 		}
106 		break;
107 	case KVM_DEV_LOONGARCH_DMSINTC_MSG_ADDR_SIZE:
108 		if (is_write) {
109 			if (copy_from_user(&val, data, sizeof(s->msg_addr_size)))
110 				return -EFAULT;
111 			if (s->msg_addr_size)
112 				return -EFAULT; /*Duplicate setting are not allowed. */
113 			s->msg_addr_size = val;
114 		}
115 		break;
116 	default:
117 		kvm_err("%s: unknown dmsintc register, addr = %d\n", __func__, addr);
118 		return -ENXIO;
119 	}
120 
121 	return 0;
122 }
123 
124 static int kvm_dmsintc_set_attr(struct kvm_device *dev,
125 				struct kvm_device_attr *attr)
126 {
127 	switch (attr->group) {
128 	case KVM_DEV_LOONGARCH_DMSINTC_GRP_CTRL:
129 		return kvm_dmsintc_ctrl_access(dev, attr, true);
130 	default:
131 		kvm_err("%s: unknown group (%d)\n", __func__, attr->group);
132 		return -EINVAL;
133 	}
134 }
135 
136 static int kvm_dmsintc_create(struct kvm_device *dev, u32 type)
137 {
138 	struct kvm *kvm;
139 	struct loongarch_dmsintc *s;
140 
141 	if (!dev) {
142 		kvm_err("%s: kvm_device ptr is invalid!\n", __func__);
143 		return -EINVAL;
144 	}
145 
146 	kvm = dev->kvm;
147 	if (kvm->arch.dmsintc) {
148 		kvm_err("%s: LoongArch DMSINTC has already been created!\n", __func__);
149 		return -EINVAL;
150 	}
151 
152 	s = kzalloc(sizeof(struct loongarch_dmsintc), GFP_KERNEL);
153 	if (!s)
154 		return -ENOMEM;
155 
156 	s->kvm = kvm;
157 	kvm->arch.dmsintc = s;
158 
159 	return 0;
160 }
161 
162 static void kvm_dmsintc_destroy(struct kvm_device *dev)
163 {
164 
165 	if (!dev || !dev->kvm || !dev->kvm->arch.dmsintc)
166 		return;
167 
168 	kfree(dev->kvm->arch.dmsintc);
169 	kfree(dev);
170 }
171 
172 static struct kvm_device_ops kvm_dmsintc_dev_ops = {
173 	.name = "kvm-loongarch-dmsintc",
174 	.create = kvm_dmsintc_create,
175 	.destroy = kvm_dmsintc_destroy,
176 	.set_attr = kvm_dmsintc_set_attr,
177 };
178 
179 int kvm_loongarch_register_dmsintc_device(void)
180 {
181 	return kvm_register_device_ops(&kvm_dmsintc_dev_ops, KVM_DEV_TYPE_LOONGARCH_DMSINTC);
182 }
183