xref: /openbmc/qemu/hw/intc/ompic.c (revision c16de0d9)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Authors: Stafford Horne <shorne@gmail.com>
7  */
8 
9 #include "qemu/osdep.h"
10 #include "qemu/module.h"
11 #include "qapi/error.h"
12 #include "hw/irq.h"
13 #include "hw/qdev-properties.h"
14 #include "hw/sysbus.h"
15 #include "migration/vmstate.h"
16 #include "exec/memory.h"
17 #include "qom/object.h"
18 
19 #define TYPE_OR1K_OMPIC "or1k-ompic"
20 OBJECT_DECLARE_SIMPLE_TYPE(OR1KOMPICState, OR1K_OMPIC)
21 
22 #define OMPIC_CTRL_IRQ_ACK  (1 << 31)
23 #define OMPIC_CTRL_IRQ_GEN  (1 << 30)
24 #define OMPIC_CTRL_DST(cpu) (((cpu) >> 16) & 0x3fff)
25 
26 #define OMPIC_REG(addr)     (((addr) >> 2) & 0x1)
27 #define OMPIC_SRC_CPU(addr) (((addr) >> 3) & 0x4f)
28 #define OMPIC_DST_CPU(addr) (((addr) >> 3) & 0x4f)
29 
30 #define OMPIC_STATUS_IRQ_PENDING (1 << 30)
31 #define OMPIC_STATUS_SRC(cpu)    (((cpu) & 0x3fff) << 16)
32 #define OMPIC_STATUS_DATA(data)  ((data) & 0xffff)
33 
34 #define OMPIC_CONTROL 0
35 #define OMPIC_STATUS  1
36 
37 #define OMPIC_MAX_CPUS 4 /* Real max is much higher, but dont waste memory */
38 #define OMPIC_ADDRSPACE_SZ (OMPIC_MAX_CPUS * 2 * 4) /* 2 32-bit regs per cpu */
39 
40 typedef struct OR1KOMPICCPUState OR1KOMPICCPUState;
41 
42 struct OR1KOMPICCPUState {
43     qemu_irq irq;
44     uint32_t status;
45     uint32_t control;
46 };
47 
48 struct OR1KOMPICState {
49     SysBusDevice parent_obj;
50     MemoryRegion mr;
51 
52     OR1KOMPICCPUState cpus[OMPIC_MAX_CPUS];
53 
54     uint32_t num_cpus;
55 };
56 
57 static uint64_t ompic_read(void *opaque, hwaddr addr, unsigned size)
58 {
59     OR1KOMPICState *s = opaque;
60     int src_cpu = OMPIC_SRC_CPU(addr);
61 
62     /* We can only write to control control, write control + update status */
63     if (OMPIC_REG(addr) == OMPIC_CONTROL) {
64         return s->cpus[src_cpu].control;
65     } else {
66         return s->cpus[src_cpu].status;
67    }
68 
69 }
70 
71 static void ompic_write(void *opaque, hwaddr addr, uint64_t data, unsigned size)
72 {
73     OR1KOMPICState *s = opaque;
74     /* We can only write to control control, write control + update status */
75     if (OMPIC_REG(addr) == OMPIC_CONTROL) {
76         int src_cpu = OMPIC_SRC_CPU(addr);
77 
78         s->cpus[src_cpu].control = data;
79 
80         if (data & OMPIC_CTRL_IRQ_GEN) {
81             int dst_cpu = OMPIC_CTRL_DST(data);
82 
83             s->cpus[dst_cpu].status = OMPIC_STATUS_IRQ_PENDING |
84                 OMPIC_STATUS_SRC(src_cpu) |
85                 OMPIC_STATUS_DATA(data);
86 
87             qemu_irq_raise(s->cpus[dst_cpu].irq);
88         }
89         if (data & OMPIC_CTRL_IRQ_ACK) {
90             s->cpus[src_cpu].status &= ~OMPIC_STATUS_IRQ_PENDING;
91             qemu_irq_lower(s->cpus[src_cpu].irq);
92         }
93     }
94 }
95 
96 static const MemoryRegionOps ompic_ops = {
97     .read = ompic_read,
98     .write = ompic_write,
99     .endianness = DEVICE_NATIVE_ENDIAN,
100     .impl = {
101         .max_access_size = 8,
102     },
103 };
104 
105 static void or1k_ompic_init(Object *obj)
106 {
107     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
108     OR1KOMPICState *s = OR1K_OMPIC(obj);
109 
110     memory_region_init_io(&s->mr, OBJECT(s), &ompic_ops, s,
111                           "or1k-ompic", OMPIC_ADDRSPACE_SZ);
112     sysbus_init_mmio(sbd, &s->mr);
113 }
114 
115 static void or1k_ompic_realize(DeviceState *dev, Error **errp)
116 {
117     OR1KOMPICState *s = OR1K_OMPIC(dev);
118     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
119     int i;
120 
121     if (s->num_cpus > OMPIC_MAX_CPUS) {
122         error_setg(errp, "Exceeded maximum CPUs %d", s->num_cpus);
123         return;
124     }
125     /* Init IRQ sources for all CPUs */
126     for (i = 0; i < s->num_cpus; i++) {
127         sysbus_init_irq(sbd, &s->cpus[i].irq);
128     }
129 }
130 
131 static Property or1k_ompic_properties[] = {
132     DEFINE_PROP_UINT32("num-cpus", OR1KOMPICState, num_cpus, 1),
133     DEFINE_PROP_END_OF_LIST(),
134 };
135 
136 static const VMStateDescription vmstate_or1k_ompic_cpu = {
137     .name = "or1k_ompic_cpu",
138     .version_id = 1,
139     .minimum_version_id = 1,
140     .fields = (const VMStateField[]) {
141          VMSTATE_UINT32(status, OR1KOMPICCPUState),
142          VMSTATE_UINT32(control, OR1KOMPICCPUState),
143          VMSTATE_END_OF_LIST()
144     }
145 };
146 
147 static const VMStateDescription vmstate_or1k_ompic = {
148     .name = TYPE_OR1K_OMPIC,
149     .version_id = 1,
150     .minimum_version_id = 1,
151     .fields = (const VMStateField[]) {
152          VMSTATE_STRUCT_ARRAY(cpus, OR1KOMPICState, OMPIC_MAX_CPUS, 1,
153              vmstate_or1k_ompic_cpu, OR1KOMPICCPUState),
154          VMSTATE_UINT32(num_cpus, OR1KOMPICState),
155          VMSTATE_END_OF_LIST()
156     }
157 };
158 
159 static void or1k_ompic_class_init(ObjectClass *klass, void *data)
160 {
161     DeviceClass *dc = DEVICE_CLASS(klass);
162 
163     device_class_set_props(dc, or1k_ompic_properties);
164     dc->realize = or1k_ompic_realize;
165     dc->vmsd = &vmstate_or1k_ompic;
166 }
167 
168 static const TypeInfo or1k_ompic_info = {
169     .name          = TYPE_OR1K_OMPIC,
170     .parent        = TYPE_SYS_BUS_DEVICE,
171     .instance_size = sizeof(OR1KOMPICState),
172     .instance_init = or1k_ompic_init,
173     .class_init    = or1k_ompic_class_init,
174 };
175 
176 static void or1k_ompic_register_types(void)
177 {
178     type_register_static(&or1k_ompic_info);
179 }
180 
181 type_init(or1k_ompic_register_types)
182