xref: /openbmc/qemu/hw/ppc/ppce500_spin.c (revision d4b70fa4)
1 /*
2  * QEMU PowerPC e500v2 ePAPR spinning code
3  *
4  * Copyright (C) 2011 Freescale Semiconductor, Inc. All rights reserved.
5  *
6  * Author: Alexander Graf, <agraf@suse.de>
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  * This code is not really a device, but models an interface that usually
22  * firmware takes care of. It's used when QEMU plays the role of firmware.
23  *
24  * Specification:
25  *
26  * https://www.power.org/resources/downloads/Power_ePAPR_APPROVED_v1.1.pdf
27  *
28  */
29 
30 #include "qemu/osdep.h"
31 #include "qemu/module.h"
32 #include "qemu/units.h"
33 #include "hw/hw.h"
34 #include "hw/sysbus.h"
35 #include "sysemu/hw_accel.h"
36 #include "e500.h"
37 #include "qom/object.h"
38 
39 #define MAX_CPUS 32
40 
41 typedef struct spin_info {
42     uint64_t addr;
43     uint64_t r3;
44     uint32_t resv;
45     uint32_t pir;
46     uint64_t reserved;
47 } QEMU_PACKED SpinInfo;
48 
49 #define TYPE_E500_SPIN "e500-spin"
50 OBJECT_DECLARE_SIMPLE_TYPE(SpinState, E500_SPIN)
51 
52 struct SpinState {
53     SysBusDevice parent_obj;
54 
55     MemoryRegion iomem;
56     SpinInfo spin[MAX_CPUS];
57 };
58 
59 static void spin_reset(DeviceState *dev)
60 {
61     SpinState *s = E500_SPIN(dev);
62     int i;
63 
64     for (i = 0; i < MAX_CPUS; i++) {
65         SpinInfo *info = &s->spin[i];
66 
67         stl_p(&info->pir, i);
68         stq_p(&info->r3, i);
69         stq_p(&info->addr, 1);
70     }
71 }
72 
73 static void mmubooke_create_initial_mapping(CPUPPCState *env,
74                                      target_ulong va,
75                                      hwaddr pa,
76                                      hwaddr len)
77 {
78     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
79     hwaddr size;
80 
81     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
82     tlb->mas1 = MAS1_VALID | size;
83     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
84     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
85     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
86     env->tlb_dirty = true;
87 }
88 
89 static void spin_kick(CPUState *cs, run_on_cpu_data data)
90 {
91     PowerPCCPU *cpu = POWERPC_CPU(cs);
92     CPUPPCState *env = &cpu->env;
93     SpinInfo *curspin = data.host_ptr;
94     hwaddr map_size = 64 * MiB;
95     hwaddr map_start;
96 
97     cpu_synchronize_state(cs);
98     stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
99     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
100     env->gpr[3] = ldq_p(&curspin->r3);
101     env->gpr[4] = 0;
102     env->gpr[5] = 0;
103     env->gpr[6] = 0;
104     env->gpr[7] = map_size;
105     env->gpr[8] = 0;
106     env->gpr[9] = 0;
107 
108     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
109     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
110 
111     cs->halted = 0;
112     cs->exception_index = -1;
113     cs->stopped = false;
114     qemu_cpu_kick(cs);
115 }
116 
117 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
118                        unsigned len)
119 {
120     SpinState *s = opaque;
121     int env_idx = addr / sizeof(SpinInfo);
122     CPUState *cpu;
123     SpinInfo *curspin = &s->spin[env_idx];
124     uint8_t *curspin_p = (uint8_t*)curspin;
125 
126     cpu = qemu_get_cpu(env_idx);
127     if (cpu == NULL) {
128         /* Unknown CPU */
129         return;
130     }
131 
132     if (cpu->cpu_index == 0) {
133         /* primary CPU doesn't spin */
134         return;
135     }
136 
137     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
138     switch (len) {
139     case 1:
140         stb_p(curspin_p, value);
141         break;
142     case 2:
143         stw_p(curspin_p, value);
144         break;
145     case 4:
146         stl_p(curspin_p, value);
147         break;
148     }
149 
150     if (!(ldq_p(&curspin->addr) & 1)) {
151         /* run CPU */
152         run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
153     }
154 }
155 
156 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
157 {
158     SpinState *s = opaque;
159     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
160 
161     switch (len) {
162     case 1:
163         return ldub_p(spin_p);
164     case 2:
165         return lduw_p(spin_p);
166     case 4:
167         return ldl_p(spin_p);
168     default:
169         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
170     }
171 }
172 
173 static const MemoryRegionOps spin_rw_ops = {
174     .read = spin_read,
175     .write = spin_write,
176     .endianness = DEVICE_BIG_ENDIAN,
177 };
178 
179 static void ppce500_spin_initfn(Object *obj)
180 {
181     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
182     SpinState *s = E500_SPIN(dev);
183 
184     memory_region_init_io(&s->iomem, obj, &spin_rw_ops, s,
185                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
186     sysbus_init_mmio(dev, &s->iomem);
187 }
188 
189 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
190 {
191     DeviceClass *dc = DEVICE_CLASS(klass);
192 
193     dc->reset = spin_reset;
194 }
195 
196 static const TypeInfo ppce500_spin_info = {
197     .name          = TYPE_E500_SPIN,
198     .parent        = TYPE_SYS_BUS_DEVICE,
199     .instance_size = sizeof(SpinState),
200     .instance_init = ppce500_spin_initfn,
201     .class_init    = ppce500_spin_class_init,
202 };
203 
204 static void ppce500_spin_register_types(void)
205 {
206     type_register_static(&ppce500_spin_info);
207 }
208 
209 type_init(ppce500_spin_register_types)
210