xref: /openbmc/qemu/hw/ppc/ppce500_spin.c (revision a68694cd)
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 typedef struct SpinState SpinState;
51 DECLARE_INSTANCE_CHECKER(SpinState, E500_SPIN,
52                          TYPE_E500_SPIN)
53 
54 struct SpinState {
55     SysBusDevice parent_obj;
56 
57     MemoryRegion iomem;
58     SpinInfo spin[MAX_CPUS];
59 };
60 
61 static void spin_reset(DeviceState *dev)
62 {
63     SpinState *s = E500_SPIN(dev);
64     int i;
65 
66     for (i = 0; i < MAX_CPUS; i++) {
67         SpinInfo *info = &s->spin[i];
68 
69         stl_p(&info->pir, i);
70         stq_p(&info->r3, i);
71         stq_p(&info->addr, 1);
72     }
73 }
74 
75 static void mmubooke_create_initial_mapping(CPUPPCState *env,
76                                      target_ulong va,
77                                      hwaddr pa,
78                                      hwaddr len)
79 {
80     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
81     hwaddr size;
82 
83     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
84     tlb->mas1 = MAS1_VALID | size;
85     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
86     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
87     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
88     env->tlb_dirty = true;
89 }
90 
91 static void spin_kick(CPUState *cs, run_on_cpu_data data)
92 {
93     PowerPCCPU *cpu = POWERPC_CPU(cs);
94     CPUPPCState *env = &cpu->env;
95     SpinInfo *curspin = data.host_ptr;
96     hwaddr map_size = 64 * MiB;
97     hwaddr map_start;
98 
99     cpu_synchronize_state(cs);
100     stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
101     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
102     env->gpr[3] = ldq_p(&curspin->r3);
103     env->gpr[4] = 0;
104     env->gpr[5] = 0;
105     env->gpr[6] = 0;
106     env->gpr[7] = map_size;
107     env->gpr[8] = 0;
108     env->gpr[9] = 0;
109 
110     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
111     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
112 
113     cs->halted = 0;
114     cs->exception_index = -1;
115     cs->stopped = false;
116     qemu_cpu_kick(cs);
117 }
118 
119 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
120                        unsigned len)
121 {
122     SpinState *s = opaque;
123     int env_idx = addr / sizeof(SpinInfo);
124     CPUState *cpu;
125     SpinInfo *curspin = &s->spin[env_idx];
126     uint8_t *curspin_p = (uint8_t*)curspin;
127 
128     cpu = qemu_get_cpu(env_idx);
129     if (cpu == NULL) {
130         /* Unknown CPU */
131         return;
132     }
133 
134     if (cpu->cpu_index == 0) {
135         /* primary CPU doesn't spin */
136         return;
137     }
138 
139     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
140     switch (len) {
141     case 1:
142         stb_p(curspin_p, value);
143         break;
144     case 2:
145         stw_p(curspin_p, value);
146         break;
147     case 4:
148         stl_p(curspin_p, value);
149         break;
150     }
151 
152     if (!(ldq_p(&curspin->addr) & 1)) {
153         /* run CPU */
154         run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
155     }
156 }
157 
158 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
159 {
160     SpinState *s = opaque;
161     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
162 
163     switch (len) {
164     case 1:
165         return ldub_p(spin_p);
166     case 2:
167         return lduw_p(spin_p);
168     case 4:
169         return ldl_p(spin_p);
170     default:
171         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
172     }
173 }
174 
175 static const MemoryRegionOps spin_rw_ops = {
176     .read = spin_read,
177     .write = spin_write,
178     .endianness = DEVICE_BIG_ENDIAN,
179 };
180 
181 static void ppce500_spin_initfn(Object *obj)
182 {
183     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
184     SpinState *s = E500_SPIN(dev);
185 
186     memory_region_init_io(&s->iomem, obj, &spin_rw_ops, s,
187                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
188     sysbus_init_mmio(dev, &s->iomem);
189 }
190 
191 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
192 {
193     DeviceClass *dc = DEVICE_CLASS(klass);
194 
195     dc->reset = spin_reset;
196 }
197 
198 static const TypeInfo ppce500_spin_info = {
199     .name          = TYPE_E500_SPIN,
200     .parent        = TYPE_SYS_BUS_DEVICE,
201     .instance_size = sizeof(SpinState),
202     .instance_init = ppce500_spin_initfn,
203     .class_init    = ppce500_spin_class_init,
204 };
205 
206 static void ppce500_spin_register_types(void)
207 {
208     type_register_static(&ppce500_spin_info);
209 }
210 
211 type_init(ppce500_spin_register_types)
212