xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision 35658f6e)
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 
35 #define TYPE_ARM_GICV2M "arm-gicv2m"
36 #define ARM_GICV2M(obj) OBJECT_CHECK(ARMGICv2mState, (obj), TYPE_ARM_GICV2M)
37 
38 #define GICV2M_NUM_SPI_MAX 128
39 
40 #define V2M_MSI_TYPER           0x008
41 #define V2M_MSI_SETSPI_NS       0x040
42 #define V2M_MSI_IIDR            0xFCC
43 #define V2M_IIDR0               0xFD0
44 #define V2M_IIDR11              0xFFC
45 
46 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
47 
48 typedef struct ARMGICv2mState {
49     SysBusDevice parent_obj;
50 
51     MemoryRegion iomem;
52     qemu_irq spi[GICV2M_NUM_SPI_MAX];
53 
54     uint32_t base_spi;
55     uint32_t num_spi;
56 } ARMGICv2mState;
57 
58 static void gicv2m_set_irq(void *opaque, int irq)
59 {
60     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
61 
62     qemu_irq_pulse(s->spi[irq]);
63 }
64 
65 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
66                             unsigned size)
67 {
68     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
69     uint32_t val;
70 
71     if (size != 4) {
72         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
73         return 0;
74     }
75 
76     switch (offset) {
77     case V2M_MSI_TYPER:
78         val = (s->base_spi + 32) << 16;
79         val |= s->num_spi;
80         return val;
81     case V2M_MSI_IIDR:
82         /* We don't have any valid implementor so we leave that field as zero
83          * and we return 0 in the arch revision as per the spec.
84          */
85         return (PRODUCT_ID_QEMU << 20);
86     case V2M_IIDR0 ... V2M_IIDR11:
87         /* We do not implement any optional identification registers and the
88          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
89          * implementation defined registers here.
90          */
91         return 0;
92     default:
93         qemu_log_mask(LOG_GUEST_ERROR,
94                       "gicv2m_read: Bad offset %x\n", (int)offset);
95         return 0;
96     }
97 }
98 
99 static void gicv2m_write(void *opaque, hwaddr offset,
100                         uint64_t value, unsigned size)
101 {
102     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
103 
104     if (size != 2 && size != 4) {
105         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
106         return;
107     }
108 
109     switch (offset) {
110     case V2M_MSI_SETSPI_NS: {
111         int spi;
112 
113         spi = (value & 0x3ff) - (s->base_spi + 32);
114         if (spi >= 0 && spi < s->num_spi) {
115             gicv2m_set_irq(s, spi);
116         }
117         return;
118     }
119     default:
120         qemu_log_mask(LOG_GUEST_ERROR,
121                       "gicv2m_write: Bad offset %x\n", (int)offset);
122     }
123 }
124 
125 static const MemoryRegionOps gicv2m_ops = {
126     .read = gicv2m_read,
127     .write = gicv2m_write,
128     .endianness = DEVICE_LITTLE_ENDIAN,
129 };
130 
131 static void gicv2m_realize(DeviceState *dev, Error **errp)
132 {
133     ARMGICv2mState *s = ARM_GICV2M(dev);
134     int i;
135 
136     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
137         error_setg(errp,
138                    "requested %u SPIs exceeds GICv2m frame maximum %d",
139                    s->num_spi, GICV2M_NUM_SPI_MAX);
140         return;
141     }
142 
143     if (s->base_spi + 32 > 1020 - s->num_spi) {
144         error_setg(errp,
145                    "requested base SPI %u+%u exceeds max. number 1020",
146                    s->base_spi + 32, s->num_spi);
147         return;
148     }
149 
150     for (i = 0; i < s->num_spi; i++) {
151         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
152     }
153 
154     msi_nonbroken = true;
155     kvm_gsi_direct_mapping = true;
156     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
157 }
158 
159 static void gicv2m_init(Object *obj)
160 {
161     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
162     ARMGICv2mState *s = ARM_GICV2M(obj);
163 
164     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
165                           "gicv2m", 0x1000);
166     sysbus_init_mmio(sbd, &s->iomem);
167 }
168 
169 static Property gicv2m_properties[] = {
170     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
171     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
172     DEFINE_PROP_END_OF_LIST(),
173 };
174 
175 static void gicv2m_class_init(ObjectClass *klass, void *data)
176 {
177     DeviceClass *dc = DEVICE_CLASS(klass);
178 
179     dc->props = gicv2m_properties;
180     dc->realize = gicv2m_realize;
181 }
182 
183 static const TypeInfo gicv2m_info = {
184     .name          = TYPE_ARM_GICV2M,
185     .parent        = TYPE_SYS_BUS_DEVICE,
186     .instance_size = sizeof(ARMGICv2mState),
187     .instance_init = gicv2m_init,
188     .class_init    = gicv2m_class_init,
189 };
190 
191 static void gicv2m_register_types(void)
192 {
193     type_register_static(&gicv2m_info);
194 }
195 
196 type_init(gicv2m_register_types)
197