xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision f363d039)
1 /*
2  *  GICv2m extension for MSI/MSI-x support with a GICv2-based system
3  *
4  * Copyright (C) 2015 Linaro, All rights reserved.
5  *
6  * Author: Christoffer Dall <christoffer.dall@linaro.org>
7  *
8  * This library is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2 of the License, or (at your option) any later version.
12  *
13  * This library is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 /* This file implements an emulated GICv2m widget as described in the ARM
23  * Server Base System Architecture (SBSA) specification Version 2.2
24  * (ARM-DEN-0029 v2.2) pages 35-39 without any optional implementation defined
25  * identification registers and with a single non-secure MSI register frame.
26  */
27 
28 #include "qemu/osdep.h"
29 #include "qapi/error.h"
30 #include "hw/sysbus.h"
31 #include "hw/irq.h"
32 #include "hw/pci/msi.h"
33 #include "hw/qdev-properties.h"
34 #include "sysemu/kvm.h"
35 #include "qemu/log.h"
36 #include "qemu/module.h"
37 
38 #define TYPE_ARM_GICV2M "arm-gicv2m"
39 #define ARM_GICV2M(obj) OBJECT_CHECK(ARMGICv2mState, (obj), TYPE_ARM_GICV2M)
40 
41 #define GICV2M_NUM_SPI_MAX 128
42 
43 #define V2M_MSI_TYPER           0x008
44 #define V2M_MSI_SETSPI_NS       0x040
45 #define V2M_MSI_IIDR            0xFCC
46 #define V2M_IIDR0               0xFD0
47 #define V2M_IIDR11              0xFFC
48 
49 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
50 
51 typedef struct ARMGICv2mState {
52     SysBusDevice parent_obj;
53 
54     MemoryRegion iomem;
55     qemu_irq spi[GICV2M_NUM_SPI_MAX];
56 
57     uint32_t base_spi;
58     uint32_t num_spi;
59 } ARMGICv2mState;
60 
61 static void gicv2m_set_irq(void *opaque, int irq)
62 {
63     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
64 
65     qemu_irq_pulse(s->spi[irq]);
66 }
67 
68 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
69                             unsigned size)
70 {
71     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
72     uint32_t val;
73 
74     if (size != 4) {
75         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
76         return 0;
77     }
78 
79     switch (offset) {
80     case V2M_MSI_TYPER:
81         val = (s->base_spi + 32) << 16;
82         val |= s->num_spi;
83         return val;
84     case V2M_MSI_IIDR:
85         /* We don't have any valid implementor so we leave that field as zero
86          * and we return 0 in the arch revision as per the spec.
87          */
88         return (PRODUCT_ID_QEMU << 20);
89     case V2M_IIDR0 ... V2M_IIDR11:
90         /* We do not implement any optional identification registers and the
91          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
92          * implementation defined registers here.
93          */
94         return 0;
95     default:
96         qemu_log_mask(LOG_GUEST_ERROR,
97                       "gicv2m_read: Bad offset %x\n", (int)offset);
98         return 0;
99     }
100 }
101 
102 static void gicv2m_write(void *opaque, hwaddr offset,
103                         uint64_t value, unsigned size)
104 {
105     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
106 
107     if (size != 2 && size != 4) {
108         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
109         return;
110     }
111 
112     switch (offset) {
113     case V2M_MSI_SETSPI_NS: {
114         int spi;
115 
116         spi = (value & 0x3ff) - (s->base_spi + 32);
117         if (spi >= 0 && spi < s->num_spi) {
118             gicv2m_set_irq(s, spi);
119         }
120         return;
121     }
122     default:
123         qemu_log_mask(LOG_GUEST_ERROR,
124                       "gicv2m_write: Bad offset %x\n", (int)offset);
125     }
126 }
127 
128 static const MemoryRegionOps gicv2m_ops = {
129     .read = gicv2m_read,
130     .write = gicv2m_write,
131     .endianness = DEVICE_LITTLE_ENDIAN,
132 };
133 
134 static void gicv2m_realize(DeviceState *dev, Error **errp)
135 {
136     ARMGICv2mState *s = ARM_GICV2M(dev);
137     int i;
138 
139     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
140         error_setg(errp,
141                    "requested %u SPIs exceeds GICv2m frame maximum %d",
142                    s->num_spi, GICV2M_NUM_SPI_MAX);
143         return;
144     }
145 
146     if (s->base_spi + 32 > 1020 - s->num_spi) {
147         error_setg(errp,
148                    "requested base SPI %u+%u exceeds max. number 1020",
149                    s->base_spi + 32, s->num_spi);
150         return;
151     }
152 
153     for (i = 0; i < s->num_spi; i++) {
154         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
155     }
156 
157     msi_nonbroken = true;
158     kvm_gsi_direct_mapping = true;
159     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
160 }
161 
162 static void gicv2m_init(Object *obj)
163 {
164     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
165     ARMGICv2mState *s = ARM_GICV2M(obj);
166 
167     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
168                           "gicv2m", 0x1000);
169     sysbus_init_mmio(sbd, &s->iomem);
170 }
171 
172 static Property gicv2m_properties[] = {
173     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
174     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
175     DEFINE_PROP_END_OF_LIST(),
176 };
177 
178 static void gicv2m_class_init(ObjectClass *klass, void *data)
179 {
180     DeviceClass *dc = DEVICE_CLASS(klass);
181 
182     dc->props = gicv2m_properties;
183     dc->realize = gicv2m_realize;
184 }
185 
186 static const TypeInfo gicv2m_info = {
187     .name          = TYPE_ARM_GICV2M,
188     .parent        = TYPE_SYS_BUS_DEVICE,
189     .instance_size = sizeof(ARMGICv2mState),
190     .instance_init = gicv2m_init,
191     .class_init    = gicv2m_class_init,
192 };
193 
194 static void gicv2m_register_types(void)
195 {
196     type_register_static(&gicv2m_info);
197 }
198 
199 type_init(gicv2m_register_types)
200