xref: /openbmc/qemu/hw/ppc/ppce500_spin.c (revision d36f7de8)
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/units.h"
32 #include "hw/hw.h"
33 #include "hw/sysbus.h"
34 #include "sysemu/hw_accel.h"
35 #include "sysemu/sysemu.h"
36 #include "e500.h"
37 
38 #define MAX_CPUS 32
39 
40 typedef struct spin_info {
41     uint64_t addr;
42     uint64_t r3;
43     uint32_t resv;
44     uint32_t pir;
45     uint64_t reserved;
46 } QEMU_PACKED SpinInfo;
47 
48 #define TYPE_E500_SPIN "e500-spin"
49 #define E500_SPIN(obj) OBJECT_CHECK(SpinState, (obj), TYPE_E500_SPIN)
50 
51 typedef struct SpinState {
52     SysBusDevice parent_obj;
53 
54     MemoryRegion iomem;
55     SpinInfo spin[MAX_CPUS];
56 } SpinState;
57 
58 static void spin_reset(DeviceState *dev)
59 {
60     SpinState *s = E500_SPIN(dev);
61     int i;
62 
63     for (i = 0; i < MAX_CPUS; i++) {
64         SpinInfo *info = &s->spin[i];
65 
66         stl_p(&info->pir, i);
67         stq_p(&info->r3, i);
68         stq_p(&info->addr, 1);
69     }
70 }
71 
72 static void mmubooke_create_initial_mapping(CPUPPCState *env,
73                                      target_ulong va,
74                                      hwaddr pa,
75                                      hwaddr len)
76 {
77     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
78     hwaddr size;
79 
80     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
81     tlb->mas1 = MAS1_VALID | size;
82     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
83     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
84     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
85     env->tlb_dirty = true;
86 }
87 
88 static void spin_kick(CPUState *cs, run_on_cpu_data data)
89 {
90     PowerPCCPU *cpu = POWERPC_CPU(cs);
91     CPUPPCState *env = &cpu->env;
92     SpinInfo *curspin = data.host_ptr;
93     hwaddr map_size = 64 * MiB;
94     hwaddr map_start;
95 
96     cpu_synchronize_state(cs);
97     stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
98     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
99     env->gpr[3] = ldq_p(&curspin->r3);
100     env->gpr[4] = 0;
101     env->gpr[5] = 0;
102     env->gpr[6] = 0;
103     env->gpr[7] = map_size;
104     env->gpr[8] = 0;
105     env->gpr[9] = 0;
106 
107     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
108     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
109 
110     cs->halted = 0;
111     cs->exception_index = -1;
112     cs->stopped = false;
113     qemu_cpu_kick(cs);
114 }
115 
116 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
117                        unsigned len)
118 {
119     SpinState *s = opaque;
120     int env_idx = addr / sizeof(SpinInfo);
121     CPUState *cpu;
122     SpinInfo *curspin = &s->spin[env_idx];
123     uint8_t *curspin_p = (uint8_t*)curspin;
124 
125     cpu = qemu_get_cpu(env_idx);
126     if (cpu == NULL) {
127         /* Unknown CPU */
128         return;
129     }
130 
131     if (cpu->cpu_index == 0) {
132         /* primary CPU doesn't spin */
133         return;
134     }
135 
136     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
137     switch (len) {
138     case 1:
139         stb_p(curspin_p, value);
140         break;
141     case 2:
142         stw_p(curspin_p, value);
143         break;
144     case 4:
145         stl_p(curspin_p, value);
146         break;
147     }
148 
149     if (!(ldq_p(&curspin->addr) & 1)) {
150         /* run CPU */
151         run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
152     }
153 }
154 
155 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
156 {
157     SpinState *s = opaque;
158     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
159 
160     switch (len) {
161     case 1:
162         return ldub_p(spin_p);
163     case 2:
164         return lduw_p(spin_p);
165     case 4:
166         return ldl_p(spin_p);
167     default:
168         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
169     }
170 }
171 
172 static const MemoryRegionOps spin_rw_ops = {
173     .read = spin_read,
174     .write = spin_write,
175     .endianness = DEVICE_BIG_ENDIAN,
176 };
177 
178 static void ppce500_spin_initfn(Object *obj)
179 {
180     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
181     SpinState *s = E500_SPIN(dev);
182 
183     memory_region_init_io(&s->iomem, obj, &spin_rw_ops, s,
184                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
185     sysbus_init_mmio(dev, &s->iomem);
186 }
187 
188 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
189 {
190     DeviceClass *dc = DEVICE_CLASS(klass);
191 
192     dc->reset = spin_reset;
193 }
194 
195 static const TypeInfo ppce500_spin_info = {
196     .name          = TYPE_E500_SPIN,
197     .parent        = TYPE_SYS_BUS_DEVICE,
198     .instance_size = sizeof(SpinState),
199     .instance_init = ppce500_spin_initfn,
200     .class_init    = ppce500_spin_class_init,
201 };
202 
203 static void ppce500_spin_register_types(void)
204 {
205     type_register_static(&ppce500_spin_info);
206 }
207 
208 type_init(ppce500_spin_register_types)
209