xref: /openbmc/qemu/hw/misc/mips_cpc.c (revision 135b03cb)
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 #include "hw/qdev-properties.h"
30 
31 static inline uint64_t cpc_vp_run_mask(MIPSCPCState *cpc)
32 {
33     return (1ULL << cpc->num_vp) - 1;
34 }
35 
36 static void mips_cpu_reset_async_work(CPUState *cs, run_on_cpu_data data)
37 {
38     MIPSCPCState *cpc = (MIPSCPCState *) data.host_ptr;
39 
40     cpu_reset(cs);
41     cpc->vp_running |= 1ULL << cs->cpu_index;
42 }
43 
44 static void cpc_run_vp(MIPSCPCState *cpc, uint64_t vp_run)
45 {
46     CPUState *cs = first_cpu;
47 
48     CPU_FOREACH(cs) {
49         uint64_t i = 1ULL << cs->cpu_index;
50         if (i & vp_run & ~cpc->vp_running) {
51             /*
52              * To avoid racing with a CPU we are just kicking off.
53              * We do the final bit of preparation for the work in
54              * the target CPUs context.
55              */
56             async_safe_run_on_cpu(cs, mips_cpu_reset_async_work,
57                                   RUN_ON_CPU_HOST_PTR(cpc));
58         }
59     }
60 }
61 
62 static void cpc_stop_vp(MIPSCPCState *cpc, uint64_t vp_stop)
63 {
64     CPUState *cs = first_cpu;
65 
66     CPU_FOREACH(cs) {
67         uint64_t i = 1ULL << cs->cpu_index;
68         if (i & vp_stop & cpc->vp_running) {
69             cpu_interrupt(cs, CPU_INTERRUPT_HALT);
70             cpc->vp_running &= ~i;
71         }
72     }
73 }
74 
75 static void cpc_write(void *opaque, hwaddr offset, uint64_t data,
76                       unsigned size)
77 {
78     MIPSCPCState *s = opaque;
79 
80     switch (offset) {
81     case CPC_CL_BASE_OFS + CPC_VP_RUN_OFS:
82     case CPC_CO_BASE_OFS + CPC_VP_RUN_OFS:
83         cpc_run_vp(s, data & cpc_vp_run_mask(s));
84         break;
85     case CPC_CL_BASE_OFS + CPC_VP_STOP_OFS:
86     case CPC_CO_BASE_OFS + CPC_VP_STOP_OFS:
87         cpc_stop_vp(s, data & cpc_vp_run_mask(s));
88         break;
89     default:
90         qemu_log_mask(LOG_UNIMP,
91                       "%s: Bad offset 0x%x\n",  __func__, (int)offset);
92         break;
93     }
94 
95     return;
96 }
97 
98 static uint64_t cpc_read(void *opaque, hwaddr offset, unsigned size)
99 {
100     MIPSCPCState *s = opaque;
101 
102     switch (offset) {
103     case CPC_CL_BASE_OFS + CPC_VP_RUNNING_OFS:
104     case CPC_CO_BASE_OFS + CPC_VP_RUNNING_OFS:
105         return s->vp_running;
106     default:
107         qemu_log_mask(LOG_UNIMP,
108                       "%s: Bad offset 0x%x\n",  __func__, (int)offset);
109         return 0;
110     }
111 }
112 
113 static const MemoryRegionOps cpc_ops = {
114     .read = cpc_read,
115     .write = cpc_write,
116     .endianness = DEVICE_NATIVE_ENDIAN,
117     .impl = {
118         .max_access_size = 8,
119     },
120 };
121 
122 static void mips_cpc_init(Object *obj)
123 {
124     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
125     MIPSCPCState *s = MIPS_CPC(obj);
126 
127     memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "mips-cpc",
128                           CPC_ADDRSPACE_SZ);
129     sysbus_init_mmio(sbd, &s->mr);
130 }
131 
132 static void mips_cpc_realize(DeviceState *dev, Error **errp)
133 {
134     MIPSCPCState *s = MIPS_CPC(dev);
135 
136     if (s->vp_start_running > cpc_vp_run_mask(s)) {
137         error_setg(errp,
138                    "incorrect vp_start_running 0x%" PRIx64 " for num_vp = %d",
139                    s->vp_running, s->num_vp);
140         return;
141     }
142 }
143 
144 static void mips_cpc_reset(DeviceState *dev)
145 {
146     MIPSCPCState *s = MIPS_CPC(dev);
147 
148     /* Reflect the fact that all VPs are halted on reset */
149     s->vp_running = 0;
150 
151     /* Put selected VPs into run state */
152     cpc_run_vp(s, s->vp_start_running);
153 }
154 
155 static const VMStateDescription vmstate_mips_cpc = {
156     .name = "mips-cpc",
157     .version_id = 0,
158     .minimum_version_id = 0,
159     .fields = (VMStateField[]) {
160         VMSTATE_UINT64(vp_running, MIPSCPCState),
161         VMSTATE_END_OF_LIST()
162     },
163 };
164 
165 static Property mips_cpc_properties[] = {
166     DEFINE_PROP_UINT32("num-vp", MIPSCPCState, num_vp, 0x1),
167     DEFINE_PROP_UINT64("vp-start-running", MIPSCPCState, vp_start_running, 0x1),
168     DEFINE_PROP_END_OF_LIST(),
169 };
170 
171 static void mips_cpc_class_init(ObjectClass *klass, void *data)
172 {
173     DeviceClass *dc = DEVICE_CLASS(klass);
174 
175     dc->realize = mips_cpc_realize;
176     dc->reset = mips_cpc_reset;
177     dc->vmsd = &vmstate_mips_cpc;
178     dc->props = mips_cpc_properties;
179 }
180 
181 static const TypeInfo mips_cpc_info = {
182     .name          = TYPE_MIPS_CPC,
183     .parent        = TYPE_SYS_BUS_DEVICE,
184     .instance_size = sizeof(MIPSCPCState),
185     .instance_init = mips_cpc_init,
186     .class_init    = mips_cpc_class_init,
187 };
188 
189 static void mips_cpc_register_types(void)
190 {
191     type_register_static(&mips_cpc_info);
192 }
193 
194 type_init(mips_cpc_register_types)
195