xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision f343346b)
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 OBJECT_DECLARE_SIMPLE_TYPE(ARMGICv2mState, ARM_GICV2M)
41 
42 #define GICV2M_NUM_SPI_MAX 128
43 
44 #define V2M_MSI_TYPER           0x008
45 #define V2M_MSI_SETSPI_NS       0x040
46 #define V2M_MSI_IIDR            0xFCC
47 #define V2M_IIDR0               0xFD0
48 #define V2M_IIDR11              0xFFC
49 
50 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
51 
52 struct ARMGICv2mState {
53     SysBusDevice parent_obj;
54 
55     MemoryRegion iomem;
56     qemu_irq spi[GICV2M_NUM_SPI_MAX];
57 
58     uint32_t base_spi;
59     uint32_t num_spi;
60 };
61 
62 static void gicv2m_set_irq(void *opaque, int irq)
63 {
64     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
65 
66     qemu_irq_pulse(s->spi[irq]);
67 }
68 
69 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
70                             unsigned size)
71 {
72     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
73     uint32_t val;
74 
75     if (size != 4) {
76         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
77         return 0;
78     }
79 
80     switch (offset) {
81     case V2M_MSI_TYPER:
82         val = (s->base_spi + 32) << 16;
83         val |= s->num_spi;
84         return val;
85     case V2M_MSI_IIDR:
86         /* We don't have any valid implementor so we leave that field as zero
87          * and we return 0 in the arch revision as per the spec.
88          */
89         return (PRODUCT_ID_QEMU << 20);
90     case V2M_IIDR0 ... V2M_IIDR11:
91         /* We do not implement any optional identification registers and the
92          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
93          * implementation defined registers here.
94          */
95         return 0;
96     default:
97         qemu_log_mask(LOG_GUEST_ERROR,
98                       "gicv2m_read: Bad offset %x\n", (int)offset);
99         return 0;
100     }
101 }
102 
103 static void gicv2m_write(void *opaque, hwaddr offset,
104                         uint64_t value, unsigned size)
105 {
106     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
107 
108     if (size != 2 && size != 4) {
109         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
110         return;
111     }
112 
113     switch (offset) {
114     case V2M_MSI_SETSPI_NS: {
115         int spi;
116 
117         spi = (value & 0x3ff) - (s->base_spi + 32);
118         if (spi >= 0 && spi < s->num_spi) {
119             gicv2m_set_irq(s, spi);
120         }
121         return;
122     }
123     default:
124         qemu_log_mask(LOG_GUEST_ERROR,
125                       "gicv2m_write: Bad offset %x\n", (int)offset);
126     }
127 }
128 
129 static const MemoryRegionOps gicv2m_ops = {
130     .read = gicv2m_read,
131     .write = gicv2m_write,
132     .endianness = DEVICE_LITTLE_ENDIAN,
133 };
134 
135 static void gicv2m_realize(DeviceState *dev, Error **errp)
136 {
137     ARMGICv2mState *s = ARM_GICV2M(dev);
138     int i;
139 
140     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
141         error_setg(errp,
142                    "requested %u SPIs exceeds GICv2m frame maximum %d",
143                    s->num_spi, GICV2M_NUM_SPI_MAX);
144         return;
145     }
146 
147     if (s->base_spi + 32 > 1020 - s->num_spi) {
148         error_setg(errp,
149                    "requested base SPI %u+%u exceeds max. number 1020",
150                    s->base_spi + 32, s->num_spi);
151         return;
152     }
153 
154     for (i = 0; i < s->num_spi; i++) {
155         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
156     }
157 
158     msi_nonbroken = true;
159     kvm_gsi_direct_mapping = true;
160     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
161 }
162 
163 static void gicv2m_init(Object *obj)
164 {
165     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
166     ARMGICv2mState *s = ARM_GICV2M(obj);
167 
168     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
169                           "gicv2m", 0x1000);
170     sysbus_init_mmio(sbd, &s->iomem);
171 }
172 
173 static Property gicv2m_properties[] = {
174     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
175     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
176     DEFINE_PROP_END_OF_LIST(),
177 };
178 
179 static void gicv2m_class_init(ObjectClass *klass, void *data)
180 {
181     DeviceClass *dc = DEVICE_CLASS(klass);
182 
183     device_class_set_props(dc, gicv2m_properties);
184     dc->realize = gicv2m_realize;
185 }
186 
187 static const TypeInfo gicv2m_info = {
188     .name          = TYPE_ARM_GICV2M,
189     .parent        = TYPE_SYS_BUS_DEVICE,
190     .instance_size = sizeof(ARMGICv2mState),
191     .instance_init = gicv2m_init,
192     .class_init    = gicv2m_class_init,
193 };
194 
195 static void gicv2m_register_types(void)
196 {
197     type_register_static(&gicv2m_info);
198 }
199 
200 type_init(gicv2m_register_types)
201