xref: /openbmc/qemu/hw/misc/mips_cpc.c (revision 650d103d)
1 /*
2  * Cluster Power Controller emulation
3  *
4  * Copyright (c) 2016 Imagination Technologies
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "qapi/error.h"
22 #include "cpu.h"
23 #include "qemu/log.h"
24 #include "qemu/module.h"
25 #include "hw/sysbus.h"
26 #include "migration/vmstate.h"
27 
28 #include "hw/misc/mips_cpc.h"
29 
30 static inline uint64_t cpc_vp_run_mask(MIPSCPCState *cpc)
31 {
32     return (1ULL << cpc->num_vp) - 1;
33 }
34 
35 static void mips_cpu_reset_async_work(CPUState *cs, run_on_cpu_data data)
36 {
37     MIPSCPCState *cpc = (MIPSCPCState *) data.host_ptr;
38 
39     cpu_reset(cs);
40     cpc->vp_running |= 1ULL << cs->cpu_index;
41 }
42 
43 static void cpc_run_vp(MIPSCPCState *cpc, uint64_t vp_run)
44 {
45     CPUState *cs = first_cpu;
46 
47     CPU_FOREACH(cs) {
48         uint64_t i = 1ULL << cs->cpu_index;
49         if (i & vp_run & ~cpc->vp_running) {
50             /*
51              * To avoid racing with a CPU we are just kicking off.
52              * We do the final bit of preparation for the work in
53              * the target CPUs context.
54              */
55             async_safe_run_on_cpu(cs, mips_cpu_reset_async_work,
56                                   RUN_ON_CPU_HOST_PTR(cpc));
57         }
58     }
59 }
60 
61 static void cpc_stop_vp(MIPSCPCState *cpc, uint64_t vp_stop)
62 {
63     CPUState *cs = first_cpu;
64 
65     CPU_FOREACH(cs) {
66         uint64_t i = 1ULL << cs->cpu_index;
67         if (i & vp_stop & cpc->vp_running) {
68             cpu_interrupt(cs, CPU_INTERRUPT_HALT);
69             cpc->vp_running &= ~i;
70         }
71     }
72 }
73 
74 static void cpc_write(void *opaque, hwaddr offset, uint64_t data,
75                       unsigned size)
76 {
77     MIPSCPCState *s = opaque;
78 
79     switch (offset) {
80     case CPC_CL_BASE_OFS + CPC_VP_RUN_OFS:
81     case CPC_CO_BASE_OFS + CPC_VP_RUN_OFS:
82         cpc_run_vp(s, data & cpc_vp_run_mask(s));
83         break;
84     case CPC_CL_BASE_OFS + CPC_VP_STOP_OFS:
85     case CPC_CO_BASE_OFS + CPC_VP_STOP_OFS:
86         cpc_stop_vp(s, data & cpc_vp_run_mask(s));
87         break;
88     default:
89         qemu_log_mask(LOG_UNIMP,
90                       "%s: Bad offset 0x%x\n",  __func__, (int)offset);
91         break;
92     }
93 
94     return;
95 }
96 
97 static uint64_t cpc_read(void *opaque, hwaddr offset, unsigned size)
98 {
99     MIPSCPCState *s = opaque;
100 
101     switch (offset) {
102     case CPC_CL_BASE_OFS + CPC_VP_RUNNING_OFS:
103     case CPC_CO_BASE_OFS + CPC_VP_RUNNING_OFS:
104         return s->vp_running;
105     default:
106         qemu_log_mask(LOG_UNIMP,
107                       "%s: Bad offset 0x%x\n",  __func__, (int)offset);
108         return 0;
109     }
110 }
111 
112 static const MemoryRegionOps cpc_ops = {
113     .read = cpc_read,
114     .write = cpc_write,
115     .endianness = DEVICE_NATIVE_ENDIAN,
116     .impl = {
117         .max_access_size = 8,
118     },
119 };
120 
121 static void mips_cpc_init(Object *obj)
122 {
123     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
124     MIPSCPCState *s = MIPS_CPC(obj);
125 
126     memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "mips-cpc",
127                           CPC_ADDRSPACE_SZ);
128     sysbus_init_mmio(sbd, &s->mr);
129 }
130 
131 static void mips_cpc_realize(DeviceState *dev, Error **errp)
132 {
133     MIPSCPCState *s = MIPS_CPC(dev);
134 
135     if (s->vp_start_running > cpc_vp_run_mask(s)) {
136         error_setg(errp,
137                    "incorrect vp_start_running 0x%" PRIx64 " for num_vp = %d",
138                    s->vp_running, s->num_vp);
139         return;
140     }
141 }
142 
143 static void mips_cpc_reset(DeviceState *dev)
144 {
145     MIPSCPCState *s = MIPS_CPC(dev);
146 
147     /* Reflect the fact that all VPs are halted on reset */
148     s->vp_running = 0;
149 
150     /* Put selected VPs into run state */
151     cpc_run_vp(s, s->vp_start_running);
152 }
153 
154 static const VMStateDescription vmstate_mips_cpc = {
155     .name = "mips-cpc",
156     .version_id = 0,
157     .minimum_version_id = 0,
158     .fields = (VMStateField[]) {
159         VMSTATE_UINT64(vp_running, MIPSCPCState),
160         VMSTATE_END_OF_LIST()
161     },
162 };
163 
164 static Property mips_cpc_properties[] = {
165     DEFINE_PROP_UINT32("num-vp", MIPSCPCState, num_vp, 0x1),
166     DEFINE_PROP_UINT64("vp-start-running", MIPSCPCState, vp_start_running, 0x1),
167     DEFINE_PROP_END_OF_LIST(),
168 };
169 
170 static void mips_cpc_class_init(ObjectClass *klass, void *data)
171 {
172     DeviceClass *dc = DEVICE_CLASS(klass);
173 
174     dc->realize = mips_cpc_realize;
175     dc->reset = mips_cpc_reset;
176     dc->vmsd = &vmstate_mips_cpc;
177     dc->props = mips_cpc_properties;
178 }
179 
180 static const TypeInfo mips_cpc_info = {
181     .name          = TYPE_MIPS_CPC,
182     .parent        = TYPE_SYS_BUS_DEVICE,
183     .instance_size = sizeof(MIPSCPCState),
184     .instance_init = mips_cpc_init,
185     .class_init    = mips_cpc_class_init,
186 };
187 
188 static void mips_cpc_register_types(void)
189 {
190     type_register_static(&mips_cpc_info);
191 }
192 
193 type_init(mips_cpc_register_types)
194