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#include "interrupt.h"
 14
 15#define IPI_BASE            0x3ff01000ULL
 16
 17#define CORE0_STATUS_OFF       0x000
 18#define CORE0_EN_OFF           0x004
 19#define CORE0_SET_OFF          0x008
 20#define CORE0_CLEAR_OFF        0x00c
 21#define CORE0_BUF_20           0x020
 22#define CORE0_BUF_28           0x028
 23#define CORE0_BUF_30           0x030
 24#define CORE0_BUF_38           0x038
 25
 26#define CORE1_STATUS_OFF       0x100
 27#define CORE1_EN_OFF           0x104
 28#define CORE1_SET_OFF          0x108
 29#define CORE1_CLEAR_OFF        0x10c
 30#define CORE1_BUF_20           0x120
 31#define CORE1_BUF_28           0x128
 32#define CORE1_BUF_30           0x130
 33#define CORE1_BUF_38           0x138
 34
 35#define CORE2_STATUS_OFF       0x200
 36#define CORE2_EN_OFF           0x204
 37#define CORE2_SET_OFF          0x208
 38#define CORE2_CLEAR_OFF        0x20c
 39#define CORE2_BUF_20           0x220
 40#define CORE2_BUF_28           0x228
 41#define CORE2_BUF_30           0x230
 42#define CORE2_BUF_38           0x238
 43
 44#define CORE3_STATUS_OFF       0x300
 45#define CORE3_EN_OFF           0x304
 46#define CORE3_SET_OFF          0x308
 47#define CORE3_CLEAR_OFF        0x30c
 48#define CORE3_BUF_20           0x320
 49#define CORE3_BUF_28           0x328
 50#define CORE3_BUF_30           0x330
 51#define CORE3_BUF_38           0x338
 52
 53static int loongson_vipi_read(struct loongson_kvm_ipi *ipi,
 54				gpa_t addr, int len, void *val)
 55{
 56	uint32_t core = (addr >> 8) & 3;
 57	uint32_t node = (addr >> 44) & 3;
 58	uint32_t id = core + node * 4;
 59	uint64_t offset = addr & 0xff;
 60	void *pbuf;
 61	struct ipi_state *s = &(ipi->ipistate[id]);
 62
 63	BUG_ON(offset & (len - 1));
 64
 65	switch (offset) {
 66	case CORE0_STATUS_OFF:
 67		*(uint64_t *)val = s->status;
 68		break;
 69
 70	case CORE0_EN_OFF:
 71		*(uint64_t *)val = s->en;
 72		break;
 73
 74	case CORE0_SET_OFF:
 75		*(uint64_t *)val = 0;
 76		break;
 77
 78	case CORE0_CLEAR_OFF:
 79		*(uint64_t *)val = 0;
 80		break;
 81
 82	case CORE0_BUF_20 ... CORE0_BUF_38:
 83		pbuf = (void *)s->buf + (offset - 0x20);
 84		if (len == 8)
 85			*(uint64_t *)val = *(uint64_t *)pbuf;
 86		else /* Assume len == 4 */
 87			*(uint32_t *)val = *(uint32_t *)pbuf;
 88		break;
 89
 90	default:
 91		pr_notice("%s with unknown addr %llx\n", __func__, addr);
 92		break;
 93	}
 94
 95	return 0;
 96}
 97
 98static int loongson_vipi_write(struct loongson_kvm_ipi *ipi,
 99				gpa_t addr, int len, const void *val)
100{
101	uint32_t core = (addr >> 8) & 3;
102	uint32_t node = (addr >> 44) & 3;
103	uint32_t id = core + node * 4;
104	uint64_t data, offset = addr & 0xff;
105	void *pbuf;
106	struct kvm *kvm = ipi->kvm;
107	struct kvm_mips_interrupt irq;
108	struct ipi_state *s = &(ipi->ipistate[id]);
109
110	data = *(uint64_t *)val;
111	BUG_ON(offset & (len - 1));
112
113	switch (offset) {
114	case CORE0_STATUS_OFF:
115		break;
116
117	case CORE0_EN_OFF:
118		s->en = data;
119		break;
120
121	case CORE0_SET_OFF:
122		s->status |= data;
123		irq.cpu = id;
124		irq.irq = 6;
125		kvm_vcpu_ioctl_interrupt(kvm_get_vcpu(kvm, id), &irq);
126		break;
127
128	case CORE0_CLEAR_OFF:
129		s->status &= ~data;
130		if (!s->status) {
131			irq.cpu = id;
132			irq.irq = -6;
133			kvm_vcpu_ioctl_interrupt(kvm_get_vcpu(kvm, id), &irq);
134		}
135		break;
136
137	case CORE0_BUF_20 ... CORE0_BUF_38:
138		pbuf = (void *)s->buf + (offset - 0x20);
139		if (len == 8)
140			*(uint64_t *)pbuf = (uint64_t)data;
141		else /* Assume len == 4 */
142			*(uint32_t *)pbuf = (uint32_t)data;
143		break;
144
145	default:
146		pr_notice("%s with unknown addr %llx\n", __func__, addr);
147		break;
148	}
149
150	return 0;
151}
152
153static int kvm_ipi_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
154			gpa_t addr, int len, void *val)
155{
156	unsigned long flags;
157	struct loongson_kvm_ipi *ipi;
158	struct ipi_io_device *ipi_device;
159
160	ipi_device = container_of(dev, struct ipi_io_device, device);
161	ipi = ipi_device->ipi;
162
163	spin_lock_irqsave(&ipi->lock, flags);
164	loongson_vipi_read(ipi, addr, len, val);
165	spin_unlock_irqrestore(&ipi->lock, flags);
166
167	return 0;
168}
169
170static int kvm_ipi_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
171			gpa_t addr, int len, const void *val)
172{
173	unsigned long flags;
174	struct loongson_kvm_ipi *ipi;
175	struct ipi_io_device *ipi_device;
176
177	ipi_device = container_of(dev, struct ipi_io_device, device);
178	ipi = ipi_device->ipi;
179
180	spin_lock_irqsave(&ipi->lock, flags);
181	loongson_vipi_write(ipi, addr, len, val);
182	spin_unlock_irqrestore(&ipi->lock, flags);
183
184	return 0;
185}
186
187static const struct kvm_io_device_ops kvm_ipi_ops = {
188	.read     = kvm_ipi_read,
189	.write    = kvm_ipi_write,
190};
191
192void kvm_init_loongson_ipi(struct kvm *kvm)
193{
194	int i;
195	unsigned long addr;
196	struct loongson_kvm_ipi *s;
197	struct kvm_io_device *device;
198
199	s = &kvm->arch.ipi;
200	s->kvm = kvm;
201	spin_lock_init(&s->lock);
202
203	/*
204	 * Initialize IPI device
205	 */
206	for (i = 0; i < 4; i++) {
207		device = &s->dev_ipi[i].device;
208		kvm_iodevice_init(device, &kvm_ipi_ops);
209		addr = (((unsigned long)i) << 44) + IPI_BASE;
210		mutex_lock(&kvm->slots_lock);
211		kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, addr, 0x400, device);
212		mutex_unlock(&kvm->slots_lock);
213		s->dev_ipi[i].ipi = s;
214		s->dev_ipi[i].node_id = i;
215	}
216}