xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision 500eb6db)
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/pci/msi.h"
32 #include "sysemu/kvm.h"
33 #include "qemu/log.h"
34 #include "qemu/module.h"
35 
36 #define TYPE_ARM_GICV2M "arm-gicv2m"
37 #define ARM_GICV2M(obj) OBJECT_CHECK(ARMGICv2mState, (obj), TYPE_ARM_GICV2M)
38 
39 #define GICV2M_NUM_SPI_MAX 128
40 
41 #define V2M_MSI_TYPER           0x008
42 #define V2M_MSI_SETSPI_NS       0x040
43 #define V2M_MSI_IIDR            0xFCC
44 #define V2M_IIDR0               0xFD0
45 #define V2M_IIDR11              0xFFC
46 
47 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
48 
49 typedef struct ARMGICv2mState {
50     SysBusDevice parent_obj;
51 
52     MemoryRegion iomem;
53     qemu_irq spi[GICV2M_NUM_SPI_MAX];
54 
55     uint32_t base_spi;
56     uint32_t num_spi;
57 } ARMGICv2mState;
58 
59 static void gicv2m_set_irq(void *opaque, int irq)
60 {
61     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
62 
63     qemu_irq_pulse(s->spi[irq]);
64 }
65 
66 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
67                             unsigned size)
68 {
69     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
70     uint32_t val;
71 
72     if (size != 4) {
73         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
74         return 0;
75     }
76 
77     switch (offset) {
78     case V2M_MSI_TYPER:
79         val = (s->base_spi + 32) << 16;
80         val |= s->num_spi;
81         return val;
82     case V2M_MSI_IIDR:
83         /* We don't have any valid implementor so we leave that field as zero
84          * and we return 0 in the arch revision as per the spec.
85          */
86         return (PRODUCT_ID_QEMU << 20);
87     case V2M_IIDR0 ... V2M_IIDR11:
88         /* We do not implement any optional identification registers and the
89          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
90          * implementation defined registers here.
91          */
92         return 0;
93     default:
94         qemu_log_mask(LOG_GUEST_ERROR,
95                       "gicv2m_read: Bad offset %x\n", (int)offset);
96         return 0;
97     }
98 }
99 
100 static void gicv2m_write(void *opaque, hwaddr offset,
101                         uint64_t value, unsigned size)
102 {
103     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
104 
105     if (size != 2 && size != 4) {
106         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
107         return;
108     }
109 
110     switch (offset) {
111     case V2M_MSI_SETSPI_NS: {
112         int spi;
113 
114         spi = (value & 0x3ff) - (s->base_spi + 32);
115         if (spi >= 0 && spi < s->num_spi) {
116             gicv2m_set_irq(s, spi);
117         }
118         return;
119     }
120     default:
121         qemu_log_mask(LOG_GUEST_ERROR,
122                       "gicv2m_write: Bad offset %x\n", (int)offset);
123     }
124 }
125 
126 static const MemoryRegionOps gicv2m_ops = {
127     .read = gicv2m_read,
128     .write = gicv2m_write,
129     .endianness = DEVICE_LITTLE_ENDIAN,
130 };
131 
132 static void gicv2m_realize(DeviceState *dev, Error **errp)
133 {
134     ARMGICv2mState *s = ARM_GICV2M(dev);
135     int i;
136 
137     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
138         error_setg(errp,
139                    "requested %u SPIs exceeds GICv2m frame maximum %d",
140                    s->num_spi, GICV2M_NUM_SPI_MAX);
141         return;
142     }
143 
144     if (s->base_spi + 32 > 1020 - s->num_spi) {
145         error_setg(errp,
146                    "requested base SPI %u+%u exceeds max. number 1020",
147                    s->base_spi + 32, s->num_spi);
148         return;
149     }
150 
151     for (i = 0; i < s->num_spi; i++) {
152         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
153     }
154 
155     msi_nonbroken = true;
156     kvm_gsi_direct_mapping = true;
157     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
158 }
159 
160 static void gicv2m_init(Object *obj)
161 {
162     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
163     ARMGICv2mState *s = ARM_GICV2M(obj);
164 
165     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
166                           "gicv2m", 0x1000);
167     sysbus_init_mmio(sbd, &s->iomem);
168 }
169 
170 static Property gicv2m_properties[] = {
171     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
172     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
173     DEFINE_PROP_END_OF_LIST(),
174 };
175 
176 static void gicv2m_class_init(ObjectClass *klass, void *data)
177 {
178     DeviceClass *dc = DEVICE_CLASS(klass);
179 
180     dc->props = gicv2m_properties;
181     dc->realize = gicv2m_realize;
182 }
183 
184 static const TypeInfo gicv2m_info = {
185     .name          = TYPE_ARM_GICV2M,
186     .parent        = TYPE_SYS_BUS_DEVICE,
187     .instance_size = sizeof(ARMGICv2mState),
188     .instance_init = gicv2m_init,
189     .class_init    = gicv2m_class_init,
190 };
191 
192 static void gicv2m_register_types(void)
193 {
194     type_register_static(&gicv2m_info);
195 }
196 
197 type_init(gicv2m_register_types)
198