1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Loongson-3 Virtual IPI interrupt support.
  4 *
  5 * Copyright (C) 2019  Loongson Technologies, Inc.  All rights reserved.
  6 *
  7 * Authors: Chen Zhu <zhuchen@loongson.cn>
  8 * Authors: Huacai Chen <chenhc@lemote.com>
  9 */
 10
 11#include <linux/kvm_host.h>
 12
 13#define IPI_BASE            0x3ff01000ULL
 14
 15#define CORE0_STATUS_OFF       0x000
 16#define CORE0_EN_OFF           0x004
 17#define CORE0_SET_OFF          0x008
 18#define CORE0_CLEAR_OFF        0x00c
 19#define CORE0_BUF_20           0x020
 20#define CORE0_BUF_28           0x028
 21#define CORE0_BUF_30           0x030
 22#define CORE0_BUF_38           0x038
 23
 24#define CORE1_STATUS_OFF       0x100
 25#define CORE1_EN_OFF           0x104
 26#define CORE1_SET_OFF          0x108
 27#define CORE1_CLEAR_OFF        0x10c
 28#define CORE1_BUF_20           0x120
 29#define CORE1_BUF_28           0x128
 30#define CORE1_BUF_30           0x130
 31#define CORE1_BUF_38           0x138
 32
 33#define CORE2_STATUS_OFF       0x200
 34#define CORE2_EN_OFF           0x204
 35#define CORE2_SET_OFF          0x208
 36#define CORE2_CLEAR_OFF        0x20c
 37#define CORE2_BUF_20           0x220
 38#define CORE2_BUF_28           0x228
 39#define CORE2_BUF_30           0x230
 40#define CORE2_BUF_38           0x238
 41
 42#define CORE3_STATUS_OFF       0x300
 43#define CORE3_EN_OFF           0x304
 44#define CORE3_SET_OFF          0x308
 45#define CORE3_CLEAR_OFF        0x30c
 46#define CORE3_BUF_20           0x320
 47#define CORE3_BUF_28           0x328
 48#define CORE3_BUF_30           0x330
 49#define CORE3_BUF_38           0x338
 50
 51static int loongson_vipi_read(struct loongson_kvm_ipi *ipi,
 52				gpa_t addr, int len, void *val)
 53{
 54	uint32_t core = (addr >> 8) & 3;
 55	uint32_t node = (addr >> 44) & 3;
 56	uint32_t id = core + node * 4;
 57	uint64_t offset = addr & 0xff;
 58	void *pbuf;
 59	struct ipi_state *s = &(ipi->ipistate[id]);
 60
 61	BUG_ON(offset & (len - 1));
 62
 63	switch (offset) {
 64	case CORE0_STATUS_OFF:
 65		*(uint64_t *)val = s->status;
 66		break;
 67
 68	case CORE0_EN_OFF:
 69		*(uint64_t *)val = s->en;
 70		break;
 71
 72	case CORE0_SET_OFF:
 73		*(uint64_t *)val = 0;
 74		break;
 75
 76	case CORE0_CLEAR_OFF:
 77		*(uint64_t *)val = 0;
 78		break;
 79
 80	case CORE0_BUF_20 ... CORE0_BUF_38:
 81		pbuf = (void *)s->buf + (offset - 0x20);
 82		if (len == 8)
 83			*(uint64_t *)val = *(uint64_t *)pbuf;
 84		else /* Assume len == 4 */
 85			*(uint32_t *)val = *(uint32_t *)pbuf;
 86		break;
 87
 88	default:
 89		pr_notice("%s with unknown addr %llx\n", __func__, addr);
 90		break;
 91	}
 92
 93	return 0;
 94}
 95
 96static int loongson_vipi_write(struct loongson_kvm_ipi *ipi,
 97				gpa_t addr, int len, const void *val)
 98{
 99	uint32_t core = (addr >> 8) & 3;
100	uint32_t node = (addr >> 44) & 3;
101	uint32_t id = core + node * 4;
102	uint64_t data, offset = addr & 0xff;
103	void *pbuf;
104	struct kvm *kvm = ipi->kvm;
105	struct kvm_mips_interrupt irq;
106	struct ipi_state *s = &(ipi->ipistate[id]);
107
108	data = *(uint64_t *)val;
109	BUG_ON(offset & (len - 1));
110
111	switch (offset) {
112	case CORE0_STATUS_OFF:
113		break;
114
115	case CORE0_EN_OFF:
116		s->en = data;
117		break;
118
119	case CORE0_SET_OFF:
120		s->status |= data;
121		irq.cpu = id;
122		irq.irq = 6;
123		kvm_vcpu_ioctl_interrupt(kvm_get_vcpu(kvm, id), &irq);
124		break;
125
126	case CORE0_CLEAR_OFF:
127		s->status &= ~data;
128		if (!s->status) {
129			irq.cpu = id;
130			irq.irq = -6;
131			kvm_vcpu_ioctl_interrupt(kvm_get_vcpu(kvm, id), &irq);
132		}
133		break;
134
135	case CORE0_BUF_20 ... CORE0_BUF_38:
136		pbuf = (void *)s->buf + (offset - 0x20);
137		if (len == 8)
138			*(uint64_t *)pbuf = (uint64_t)data;
139		else /* Assume len == 4 */
140			*(uint32_t *)pbuf = (uint32_t)data;
141		break;
142
143	default:
144		pr_notice("%s with unknown addr %llx\n", __func__, addr);
145		break;
146	}
147
148	return 0;
149}
150
151static int kvm_ipi_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
152			gpa_t addr, int len, void *val)
153{
154	unsigned long flags;
155	struct loongson_kvm_ipi *ipi;
156	struct ipi_io_device *ipi_device;
157
158	ipi_device = container_of(dev, struct ipi_io_device, device);
159	ipi = ipi_device->ipi;
160
161	spin_lock_irqsave(&ipi->lock, flags);
162	loongson_vipi_read(ipi, addr, len, val);
163	spin_unlock_irqrestore(&ipi->lock, flags);
164
165	return 0;
166}
167
168static int kvm_ipi_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
169			gpa_t addr, int len, const void *val)
170{
171	unsigned long flags;
172	struct loongson_kvm_ipi *ipi;
173	struct ipi_io_device *ipi_device;
174
175	ipi_device = container_of(dev, struct ipi_io_device, device);
176	ipi = ipi_device->ipi;
177
178	spin_lock_irqsave(&ipi->lock, flags);
179	loongson_vipi_write(ipi, addr, len, val);
180	spin_unlock_irqrestore(&ipi->lock, flags);
181
182	return 0;
183}
184
185static const struct kvm_io_device_ops kvm_ipi_ops = {
186	.read     = kvm_ipi_read,
187	.write    = kvm_ipi_write,
188};
189
190void kvm_init_loongson_ipi(struct kvm *kvm)
191{
192	int i;
193	unsigned long addr;
194	struct loongson_kvm_ipi *s;
195	struct kvm_io_device *device;
196
197	s = &kvm->arch.ipi;
198	s->kvm = kvm;
199	spin_lock_init(&s->lock);
200
201	/*
202	 * Initialize IPI device
203	 */
204	for (i = 0; i < 4; i++) {
205		device = &s->dev_ipi[i].device;
206		kvm_iodevice_init(device, &kvm_ipi_ops);
207		addr = (((unsigned long)i) << 44) + IPI_BASE;
208		mutex_lock(&kvm->slots_lock);
209		kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, addr, 0x400, device);
210		mutex_unlock(&kvm->slots_lock);
211		s->dev_ipi[i].ipi = s;
212		s->dev_ipi[i].node_id = i;
213	}
214}