xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision a68694cd)
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 #include "qom/object.h"
38 
39 #define TYPE_ARM_GICV2M "arm-gicv2m"
40 typedef struct ARMGICv2mState ARMGICv2mState;
41 DECLARE_INSTANCE_CHECKER(ARMGICv2mState, ARM_GICV2M,
42                          TYPE_ARM_GICV2M)
43 
44 #define GICV2M_NUM_SPI_MAX 128
45 
46 #define V2M_MSI_TYPER           0x008
47 #define V2M_MSI_SETSPI_NS       0x040
48 #define V2M_MSI_IIDR            0xFCC
49 #define V2M_IIDR0               0xFD0
50 #define V2M_IIDR11              0xFFC
51 
52 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
53 
54 struct ARMGICv2mState {
55     SysBusDevice parent_obj;
56 
57     MemoryRegion iomem;
58     qemu_irq spi[GICV2M_NUM_SPI_MAX];
59 
60     uint32_t base_spi;
61     uint32_t num_spi;
62 };
63 
64 static void gicv2m_set_irq(void *opaque, int irq)
65 {
66     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
67 
68     qemu_irq_pulse(s->spi[irq]);
69 }
70 
71 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
72                             unsigned size)
73 {
74     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
75     uint32_t val;
76 
77     if (size != 4) {
78         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
79         return 0;
80     }
81 
82     switch (offset) {
83     case V2M_MSI_TYPER:
84         val = (s->base_spi + 32) << 16;
85         val |= s->num_spi;
86         return val;
87     case V2M_MSI_IIDR:
88         /* We don't have any valid implementor so we leave that field as zero
89          * and we return 0 in the arch revision as per the spec.
90          */
91         return (PRODUCT_ID_QEMU << 20);
92     case V2M_IIDR0 ... V2M_IIDR11:
93         /* We do not implement any optional identification registers and the
94          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
95          * implementation defined registers here.
96          */
97         return 0;
98     default:
99         qemu_log_mask(LOG_GUEST_ERROR,
100                       "gicv2m_read: Bad offset %x\n", (int)offset);
101         return 0;
102     }
103 }
104 
105 static void gicv2m_write(void *opaque, hwaddr offset,
106                         uint64_t value, unsigned size)
107 {
108     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
109 
110     if (size != 2 && size != 4) {
111         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
112         return;
113     }
114 
115     switch (offset) {
116     case V2M_MSI_SETSPI_NS: {
117         int spi;
118 
119         spi = (value & 0x3ff) - (s->base_spi + 32);
120         if (spi >= 0 && spi < s->num_spi) {
121             gicv2m_set_irq(s, spi);
122         }
123         return;
124     }
125     default:
126         qemu_log_mask(LOG_GUEST_ERROR,
127                       "gicv2m_write: Bad offset %x\n", (int)offset);
128     }
129 }
130 
131 static const MemoryRegionOps gicv2m_ops = {
132     .read = gicv2m_read,
133     .write = gicv2m_write,
134     .endianness = DEVICE_LITTLE_ENDIAN,
135 };
136 
137 static void gicv2m_realize(DeviceState *dev, Error **errp)
138 {
139     ARMGICv2mState *s = ARM_GICV2M(dev);
140     int i;
141 
142     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
143         error_setg(errp,
144                    "requested %u SPIs exceeds GICv2m frame maximum %d",
145                    s->num_spi, GICV2M_NUM_SPI_MAX);
146         return;
147     }
148 
149     if (s->base_spi + 32 > 1020 - s->num_spi) {
150         error_setg(errp,
151                    "requested base SPI %u+%u exceeds max. number 1020",
152                    s->base_spi + 32, s->num_spi);
153         return;
154     }
155 
156     for (i = 0; i < s->num_spi; i++) {
157         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
158     }
159 
160     msi_nonbroken = true;
161     kvm_gsi_direct_mapping = true;
162     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
163 }
164 
165 static void gicv2m_init(Object *obj)
166 {
167     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
168     ARMGICv2mState *s = ARM_GICV2M(obj);
169 
170     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
171                           "gicv2m", 0x1000);
172     sysbus_init_mmio(sbd, &s->iomem);
173 }
174 
175 static Property gicv2m_properties[] = {
176     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
177     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
178     DEFINE_PROP_END_OF_LIST(),
179 };
180 
181 static void gicv2m_class_init(ObjectClass *klass, void *data)
182 {
183     DeviceClass *dc = DEVICE_CLASS(klass);
184 
185     device_class_set_props(dc, gicv2m_properties);
186     dc->realize = gicv2m_realize;
187 }
188 
189 static const TypeInfo gicv2m_info = {
190     .name          = TYPE_ARM_GICV2M,
191     .parent        = TYPE_SYS_BUS_DEVICE,
192     .instance_size = sizeof(ARMGICv2mState),
193     .instance_init = gicv2m_init,
194     .class_init    = gicv2m_class_init,
195 };
196 
197 static void gicv2m_register_types(void)
198 {
199     type_register_static(&gicv2m_info);
200 }
201 
202 type_init(gicv2m_register_types)
203