xref: /openbmc/qemu/hw/intc/arm_gicv2m.c (revision 77ac58ddc6be324abc3451ae78a1799efa7cc3b7)
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 
34 #define TYPE_ARM_GICV2M "arm-gicv2m"
35 #define ARM_GICV2M(obj) OBJECT_CHECK(ARMGICv2mState, (obj), TYPE_ARM_GICV2M)
36 
37 #define GICV2M_NUM_SPI_MAX 128
38 
39 #define V2M_MSI_TYPER           0x008
40 #define V2M_MSI_SETSPI_NS       0x040
41 #define V2M_MSI_IIDR            0xFCC
42 #define V2M_IIDR0               0xFD0
43 #define V2M_IIDR11              0xFFC
44 
45 #define PRODUCT_ID_QEMU         0x51 /* ASCII code Q */
46 
47 typedef struct ARMGICv2mState {
48     SysBusDevice parent_obj;
49 
50     MemoryRegion iomem;
51     qemu_irq spi[GICV2M_NUM_SPI_MAX];
52 
53     uint32_t base_spi;
54     uint32_t num_spi;
55 } ARMGICv2mState;
56 
57 static void gicv2m_set_irq(void *opaque, int irq)
58 {
59     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
60 
61     qemu_irq_pulse(s->spi[irq]);
62 }
63 
64 static uint64_t gicv2m_read(void *opaque, hwaddr offset,
65                             unsigned size)
66 {
67     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
68     uint32_t val;
69 
70     if (size != 4) {
71         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_read: bad size %u\n", size);
72         return 0;
73     }
74 
75     switch (offset) {
76     case V2M_MSI_TYPER:
77         val = (s->base_spi + 32) << 16;
78         val |= s->num_spi;
79         return val;
80     case V2M_MSI_IIDR:
81         /* We don't have any valid implementor so we leave that field as zero
82          * and we return 0 in the arch revision as per the spec.
83          */
84         return (PRODUCT_ID_QEMU << 20);
85     case V2M_IIDR0 ... V2M_IIDR11:
86         /* We do not implement any optional identification registers and the
87          * mandatory MSI_PIDR2 register reads as 0x0, so we capture all
88          * implementation defined registers here.
89          */
90         return 0;
91     default:
92         qemu_log_mask(LOG_GUEST_ERROR,
93                       "gicv2m_read: Bad offset %x\n", (int)offset);
94         return 0;
95     }
96 }
97 
98 static void gicv2m_write(void *opaque, hwaddr offset,
99                         uint64_t value, unsigned size)
100 {
101     ARMGICv2mState *s = (ARMGICv2mState *)opaque;
102 
103     if (size != 2 && size != 4) {
104         qemu_log_mask(LOG_GUEST_ERROR, "gicv2m_write: bad size %u\n", size);
105         return;
106     }
107 
108     switch (offset) {
109     case V2M_MSI_SETSPI_NS: {
110         int spi;
111 
112         spi = (value & 0x3ff) - (s->base_spi + 32);
113         if (spi >= 0 && spi < s->num_spi) {
114             gicv2m_set_irq(s, spi);
115         }
116         return;
117     }
118     default:
119         qemu_log_mask(LOG_GUEST_ERROR,
120                       "gicv2m_write: Bad offset %x\n", (int)offset);
121     }
122 }
123 
124 static const MemoryRegionOps gicv2m_ops = {
125     .read = gicv2m_read,
126     .write = gicv2m_write,
127     .endianness = DEVICE_LITTLE_ENDIAN,
128 };
129 
130 static void gicv2m_realize(DeviceState *dev, Error **errp)
131 {
132     ARMGICv2mState *s = ARM_GICV2M(dev);
133     int i;
134 
135     if (s->num_spi > GICV2M_NUM_SPI_MAX) {
136         error_setg(errp,
137                    "requested %u SPIs exceeds GICv2m frame maximum %d",
138                    s->num_spi, GICV2M_NUM_SPI_MAX);
139         return;
140     }
141 
142     if (s->base_spi + 32 > 1020 - s->num_spi) {
143         error_setg(errp,
144                    "requested base SPI %u+%u exceeds max. number 1020",
145                    s->base_spi + 32, s->num_spi);
146         return;
147     }
148 
149     for (i = 0; i < s->num_spi; i++) {
150         sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->spi[i]);
151     }
152 
153     msi_nonbroken = true;
154     kvm_gsi_direct_mapping = true;
155     kvm_msi_via_irqfd_allowed = kvm_irqfds_enabled();
156 }
157 
158 static void gicv2m_init(Object *obj)
159 {
160     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
161     ARMGICv2mState *s = ARM_GICV2M(obj);
162 
163     memory_region_init_io(&s->iomem, OBJECT(s), &gicv2m_ops, s,
164                           "gicv2m", 0x1000);
165     sysbus_init_mmio(sbd, &s->iomem);
166 }
167 
168 static Property gicv2m_properties[] = {
169     DEFINE_PROP_UINT32("base-spi", ARMGICv2mState, base_spi, 0),
170     DEFINE_PROP_UINT32("num-spi", ARMGICv2mState, num_spi, 64),
171     DEFINE_PROP_END_OF_LIST(),
172 };
173 
174 static void gicv2m_class_init(ObjectClass *klass, void *data)
175 {
176     DeviceClass *dc = DEVICE_CLASS(klass);
177 
178     dc->props = gicv2m_properties;
179     dc->realize = gicv2m_realize;
180 }
181 
182 static const TypeInfo gicv2m_info = {
183     .name          = TYPE_ARM_GICV2M,
184     .parent        = TYPE_SYS_BUS_DEVICE,
185     .instance_size = sizeof(ARMGICv2mState),
186     .instance_init = gicv2m_init,
187     .class_init    = gicv2m_class_init,
188 };
189 
190 static void gicv2m_register_types(void)
191 {
192     type_register_static(&gicv2m_info);
193 }
194 
195 type_init(gicv2m_register_types)
196