xref: /openbmc/qemu/hw/ppc/ppce500_spin.c (revision 397d30e9)
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 "hw/hw.h"
32 #include "sysemu/sysemu.h"
33 #include "hw/sysbus.h"
34 #include "sysemu/kvm.h"
35 #include "e500.h"
36 
37 #define MAX_CPUS 32
38 
39 typedef struct spin_info {
40     uint64_t addr;
41     uint64_t r3;
42     uint32_t resv;
43     uint32_t pir;
44     uint64_t reserved;
45 } QEMU_PACKED SpinInfo;
46 
47 #define TYPE_E500_SPIN "e500-spin"
48 #define E500_SPIN(obj) OBJECT_CHECK(SpinState, (obj), TYPE_E500_SPIN)
49 
50 typedef struct SpinState {
51     SysBusDevice parent_obj;
52 
53     MemoryRegion iomem;
54     SpinInfo spin[MAX_CPUS];
55 } SpinState;
56 
57 static void spin_reset(void *opaque)
58 {
59     SpinState *s = opaque;
60     int i;
61 
62     for (i = 0; i < MAX_CPUS; i++) {
63         SpinInfo *info = &s->spin[i];
64 
65         stl_p(&info->pir, i);
66         stq_p(&info->r3, i);
67         stq_p(&info->addr, 1);
68     }
69 }
70 
71 static void mmubooke_create_initial_mapping(CPUPPCState *env,
72                                      target_ulong va,
73                                      hwaddr pa,
74                                      hwaddr len)
75 {
76     ppcmas_tlb_t *tlb = booke206_get_tlbm(env, 1, 0, 1);
77     hwaddr size;
78 
79     size = (booke206_page_size_to_tlb(len) << MAS1_TSIZE_SHIFT);
80     tlb->mas1 = MAS1_VALID | size;
81     tlb->mas2 = (va & TARGET_PAGE_MASK) | MAS2_M;
82     tlb->mas7_3 = pa & TARGET_PAGE_MASK;
83     tlb->mas7_3 |= MAS3_UR | MAS3_UW | MAS3_UX | MAS3_SR | MAS3_SW | MAS3_SX;
84     env->tlb_dirty = true;
85 }
86 
87 static void spin_kick(CPUState *cs, run_on_cpu_data data)
88 {
89     PowerPCCPU *cpu = POWERPC_CPU(cs);
90     CPUPPCState *env = &cpu->env;
91     SpinInfo *curspin = data.host_ptr;
92     hwaddr map_size = 64 * 1024 * 1024;
93     hwaddr map_start;
94 
95     cpu_synchronize_state(cs);
96     stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
97     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
98     env->gpr[3] = ldq_p(&curspin->r3);
99     env->gpr[4] = 0;
100     env->gpr[5] = 0;
101     env->gpr[6] = 0;
102     env->gpr[7] = map_size;
103     env->gpr[8] = 0;
104     env->gpr[9] = 0;
105 
106     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
107     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
108 
109     cs->halted = 0;
110     cs->exception_index = -1;
111     cs->stopped = false;
112     qemu_cpu_kick(cs);
113 }
114 
115 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
116                        unsigned len)
117 {
118     SpinState *s = opaque;
119     int env_idx = addr / sizeof(SpinInfo);
120     CPUState *cpu;
121     SpinInfo *curspin = &s->spin[env_idx];
122     uint8_t *curspin_p = (uint8_t*)curspin;
123 
124     cpu = qemu_get_cpu(env_idx);
125     if (cpu == NULL) {
126         /* Unknown CPU */
127         return;
128     }
129 
130     if (cpu->cpu_index == 0) {
131         /* primary CPU doesn't spin */
132         return;
133     }
134 
135     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
136     switch (len) {
137     case 1:
138         stb_p(curspin_p, value);
139         break;
140     case 2:
141         stw_p(curspin_p, value);
142         break;
143     case 4:
144         stl_p(curspin_p, value);
145         break;
146     }
147 
148     if (!(ldq_p(&curspin->addr) & 1)) {
149         /* run CPU */
150         run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
151     }
152 }
153 
154 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
155 {
156     SpinState *s = opaque;
157     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
158 
159     switch (len) {
160     case 1:
161         return ldub_p(spin_p);
162     case 2:
163         return lduw_p(spin_p);
164     case 4:
165         return ldl_p(spin_p);
166     default:
167         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
168     }
169 }
170 
171 static const MemoryRegionOps spin_rw_ops = {
172     .read = spin_read,
173     .write = spin_write,
174     .endianness = DEVICE_BIG_ENDIAN,
175 };
176 
177 static int ppce500_spin_initfn(SysBusDevice *dev)
178 {
179     SpinState *s = E500_SPIN(dev);
180 
181     memory_region_init_io(&s->iomem, OBJECT(s), &spin_rw_ops, s,
182                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
183     sysbus_init_mmio(dev, &s->iomem);
184 
185     qemu_register_reset(spin_reset, s);
186 
187     return 0;
188 }
189 
190 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
191 {
192     SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
193 
194     k->init = ppce500_spin_initfn;
195 }
196 
197 static const TypeInfo ppce500_spin_info = {
198     .name          = TYPE_E500_SPIN,
199     .parent        = TYPE_SYS_BUS_DEVICE,
200     .instance_size = sizeof(SpinState),
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