xref: /openbmc/qemu/hw/misc/mips_cpc.c (revision 3d9569b8)
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 
27 #include "hw/misc/mips_cpc.h"
28 
29 static inline uint64_t cpc_vp_run_mask(MIPSCPCState *cpc)
30 {
31     return (1ULL << cpc->num_vp) - 1;
32 }
33 
34 static void mips_cpu_reset_async_work(CPUState *cs, run_on_cpu_data data)
35 {
36     MIPSCPCState *cpc = (MIPSCPCState *) data.host_ptr;
37 
38     cpu_reset(cs);
39     cpc->vp_running |= 1ULL << cs->cpu_index;
40 }
41 
42 static void cpc_run_vp(MIPSCPCState *cpc, uint64_t vp_run)
43 {
44     CPUState *cs = first_cpu;
45 
46     CPU_FOREACH(cs) {
47         uint64_t i = 1ULL << cs->cpu_index;
48         if (i & vp_run & ~cpc->vp_running) {
49             /*
50              * To avoid racing with a CPU we are just kicking off.
51              * We do the final bit of preparation for the work in
52              * the target CPUs context.
53              */
54             async_safe_run_on_cpu(cs, mips_cpu_reset_async_work,
55                                   RUN_ON_CPU_HOST_PTR(cpc));
56         }
57     }
58 }
59 
60 static void cpc_stop_vp(MIPSCPCState *cpc, uint64_t vp_stop)
61 {
62     CPUState *cs = first_cpu;
63 
64     CPU_FOREACH(cs) {
65         uint64_t i = 1ULL << cs->cpu_index;
66         if (i & vp_stop & cpc->vp_running) {
67             cpu_interrupt(cs, CPU_INTERRUPT_HALT);
68             cpc->vp_running &= ~i;
69         }
70     }
71 }
72 
73 static void cpc_write(void *opaque, hwaddr offset, uint64_t data,
74                       unsigned size)
75 {
76     MIPSCPCState *s = opaque;
77 
78     switch (offset) {
79     case CPC_CL_BASE_OFS + CPC_VP_RUN_OFS:
80     case CPC_CO_BASE_OFS + CPC_VP_RUN_OFS:
81         cpc_run_vp(s, data & cpc_vp_run_mask(s));
82         break;
83     case CPC_CL_BASE_OFS + CPC_VP_STOP_OFS:
84     case CPC_CO_BASE_OFS + CPC_VP_STOP_OFS:
85         cpc_stop_vp(s, data & cpc_vp_run_mask(s));
86         break;
87     default:
88         qemu_log_mask(LOG_UNIMP,
89                       "%s: Bad offset 0x%x\n",  __func__, (int)offset);
90         break;
91     }
92 
93     return;
94 }
95 
96 static uint64_t cpc_read(void *opaque, hwaddr offset, unsigned size)
97 {
98     MIPSCPCState *s = opaque;
99 
100     switch (offset) {
101     case CPC_CL_BASE_OFS + CPC_VP_RUNNING_OFS:
102     case CPC_CO_BASE_OFS + CPC_VP_RUNNING_OFS:
103         return s->vp_running;
104     default:
105         qemu_log_mask(LOG_UNIMP,
106                       "%s: Bad offset 0x%x\n",  __func__, (int)offset);
107         return 0;
108     }
109 }
110 
111 static const MemoryRegionOps cpc_ops = {
112     .read = cpc_read,
113     .write = cpc_write,
114     .endianness = DEVICE_NATIVE_ENDIAN,
115     .impl = {
116         .max_access_size = 8,
117     },
118 };
119 
120 static void mips_cpc_init(Object *obj)
121 {
122     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
123     MIPSCPCState *s = MIPS_CPC(obj);
124 
125     memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "mips-cpc",
126                           CPC_ADDRSPACE_SZ);
127     sysbus_init_mmio(sbd, &s->mr);
128 }
129 
130 static void mips_cpc_realize(DeviceState *dev, Error **errp)
131 {
132     MIPSCPCState *s = MIPS_CPC(dev);
133 
134     if (s->vp_start_running > cpc_vp_run_mask(s)) {
135         error_setg(errp,
136                    "incorrect vp_start_running 0x%" PRIx64 " for num_vp = %d",
137                    s->vp_running, s->num_vp);
138         return;
139     }
140 }
141 
142 static void mips_cpc_reset(DeviceState *dev)
143 {
144     MIPSCPCState *s = MIPS_CPC(dev);
145 
146     /* Reflect the fact that all VPs are halted on reset */
147     s->vp_running = 0;
148 
149     /* Put selected VPs into run state */
150     cpc_run_vp(s, s->vp_start_running);
151 }
152 
153 static const VMStateDescription vmstate_mips_cpc = {
154     .name = "mips-cpc",
155     .version_id = 0,
156     .minimum_version_id = 0,
157     .fields = (VMStateField[]) {
158         VMSTATE_UINT64(vp_running, MIPSCPCState),
159         VMSTATE_END_OF_LIST()
160     },
161 };
162 
163 static Property mips_cpc_properties[] = {
164     DEFINE_PROP_UINT32("num-vp", MIPSCPCState, num_vp, 0x1),
165     DEFINE_PROP_UINT64("vp-start-running", MIPSCPCState, vp_start_running, 0x1),
166     DEFINE_PROP_END_OF_LIST(),
167 };
168 
169 static void mips_cpc_class_init(ObjectClass *klass, void *data)
170 {
171     DeviceClass *dc = DEVICE_CLASS(klass);
172 
173     dc->realize = mips_cpc_realize;
174     dc->reset = mips_cpc_reset;
175     dc->vmsd = &vmstate_mips_cpc;
176     dc->props = mips_cpc_properties;
177 }
178 
179 static const TypeInfo mips_cpc_info = {
180     .name          = TYPE_MIPS_CPC,
181     .parent        = TYPE_SYS_BUS_DEVICE,
182     .instance_size = sizeof(MIPSCPCState),
183     .instance_init = mips_cpc_init,
184     .class_init    = mips_cpc_class_init,
185 };
186 
187 static void mips_cpc_register_types(void)
188 {
189     type_register_static(&mips_cpc_info);
190 }
191 
192 type_init(mips_cpc_register_types)
193