xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision 9884abee)
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 "hw/sysbus.h"
30 #include "hw/pci/msi.h"
31 
32 #define TYPE_ARM_GICV2M "arm-gicv2m"
33 #define ARM_GICV2M(obj) OBJECT_CHECK(ARMGICv2mState, (obj), TYPE_ARM_GICV2M)
34 
35 #define GICV2M_NUM_SPI_MAX 128
36 
37 #define V2M_MSI_TYPER           0x008
38 #define V2M_MSI_SETSPI_NS       0x040
39 #define V2M_MSI_IIDR            0xFCC
40 #define V2M_IIDR0               0xFD0
41 #define V2M_IIDR11              0xFFC
42 
43 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
44 
45 typedef struct ARMGICv2mState {
46     SysBusDevice parent_obj;
47 
48     MemoryRegion iomem;
49     qemu_irq spi[GICV2M_NUM_SPI_MAX];
50 
51     uint32_t base_spi;
52     uint32_t num_spi;
53 } ARMGICv2mState;
54 
55 static void gicv2m_set_irq(void *opaque, int irq)
56 {
57     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
58 
59     qemu_irq_pulse(s->spi[irq]);
60 }
61 
62 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
63                             unsigned size)
64 {
65     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
66     uint32_t val;
67 
68     if (size != 4) {
69         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
70         return 0;
71     }
72 
73     switch (offset) {
74     case V2M_MSI_TYPER:
75         val = (s->base_spi + 32) << 16;
76         val |= s->num_spi;
77         return val;
78     case V2M_MSI_IIDR:
79         /* We don't have any valid implementor so we leave that field as zero
80          * and we return 0 in the arch revision as per the spec.
81          */
82         return (PRODUCT_ID_QEMU << 20);
83     case V2M_IIDR0 ... V2M_IIDR11:
84         /* We do not implement any optional identification registers and the
85          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
86          * implementation defined registers here.
87          */
88         return 0;
89     default:
90         qemu_log_mask(LOG_GUEST_ERROR,
91                       "gicv2m_read: Bad offset %x\n", (int)offset);
92         return 0;
93     }
94 }
95 
96 static void gicv2m_write(void *opaque, hwaddr offset,
97                         uint64_t value, unsigned size)
98 {
99     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
100 
101     if (size != 2 && size != 4) {
102         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
103         return;
104     }
105 
106     switch (offset) {
107     case V2M_MSI_SETSPI_NS: {
108         int spi;
109 
110         spi = (value & 0x3ff) - (s->base_spi + 32);
111         if (spi >= 0 && spi < s->num_spi) {
112             gicv2m_set_irq(s, spi);
113         }
114         return;
115     }
116     default:
117         qemu_log_mask(LOG_GUEST_ERROR,
118                       "gicv2m_write: Bad offset %x\n", (int)offset);
119     }
120 }
121 
122 static const MemoryRegionOps gicv2m_ops = {
123     .read = gicv2m_read,
124     .write = gicv2m_write,
125     .endianness = DEVICE_LITTLE_ENDIAN,
126 };
127 
128 static void gicv2m_realize(DeviceState *dev, Error **errp)
129 {
130     ARMGICv2mState *s = ARM_GICV2M(dev);
131     int i;
132 
133     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
134         error_setg(errp,
135                    "requested %u SPIs exceeds GICv2m frame maximum %d",
136                    s->num_spi, GICV2M_NUM_SPI_MAX);
137         return;
138     }
139 
140     if (s->base_spi + 32 > 1020 - s->num_spi) {
141         error_setg(errp,
142                    "requested base SPI %u+%u exceeds max. number 1020",
143                    s->base_spi + 32, s->num_spi);
144         return;
145     }
146 
147     for (i = 0; i < s->num_spi; i++) {
148         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
149     }
150 
151     msi_supported = true;
152     kvm_gsi_direct_mapping = true;
153     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
154 }
155 
156 static void gicv2m_init(Object *obj)
157 {
158     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
159     ARMGICv2mState *s = ARM_GICV2M(obj);
160 
161     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
162                           "gicv2m", 0x1000);
163     sysbus_init_mmio(sbd, &s->iomem);
164 }
165 
166 static Property gicv2m_properties[] = {
167     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
168     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
169     DEFINE_PROP_END_OF_LIST(),
170 };
171 
172 static void gicv2m_class_init(ObjectClass *klass, void *data)
173 {
174     DeviceClass *dc = DEVICE_CLASS(klass);
175 
176     dc->props = gicv2m_properties;
177     dc->realize = gicv2m_realize;
178 }
179 
180 static const TypeInfo gicv2m_info = {
181     .name          = TYPE_ARM_GICV2M,
182     .parent        = TYPE_SYS_BUS_DEVICE,
183     .instance_size = sizeof(ARMGICv2mState),
184     .instance_init = gicv2m_init,
185     .class_init    = gicv2m_class_init,
186 };
187 
188 static void gicv2m_register_types(void)
189 {
190     type_register_static(&gicv2m_info);
191 }
192 
193 type_init(gicv2m_register_types)
194