xref: /openbmc/qemu/hw/ppc/ppce500_spin.c (revision f2a4459d)
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 2.1 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 #ifdef CONFIG_KVM
87     env->tlb_dirty = true;
88 #endif
89 }
90 
91 static void spin_kick(CPUState *cs, run_on_cpu_data data)
92 {
93     CPUPPCState *env = cpu_env(cs);
94     SpinInfo *curspin = data.host_ptr;
95     hwaddr map_size = 64 * MiB;
96     hwaddr map_start;
97 
98     cpu_synchronize_state(cs);
99     stl_p(&curspin->pir, env->spr[SPR_BOOKE_PIR]);
100     env->nip = ldq_p(&curspin->addr) & (map_size - 1);
101     env->gpr[3] = ldq_p(&curspin->r3);
102     env->gpr[4] = 0;
103     env->gpr[5] = 0;
104     env->gpr[6] = 0;
105     env->gpr[7] = map_size;
106     env->gpr[8] = 0;
107     env->gpr[9] = 0;
108 
109     map_start = ldq_p(&curspin->addr) & ~(map_size - 1);
110     mmubooke_create_initial_mapping(env, 0, map_start, map_size);
111 
112     cs->halted = 0;
113     cs->exception_index = -1;
114     cs->stopped = false;
115     qemu_cpu_kick(cs);
116 }
117 
118 static void spin_write(void *opaque, hwaddr addr, uint64_t value,
119                        unsigned len)
120 {
121     SpinState *s = opaque;
122     int env_idx = addr / sizeof(SpinInfo);
123     CPUState *cpu;
124     SpinInfo *curspin = &s->spin[env_idx];
125     uint8_t *curspin_p = (uint8_t*)curspin;
126 
127     cpu = qemu_get_cpu(env_idx);
128     if (cpu == NULL) {
129         /* Unknown CPU */
130         return;
131     }
132 
133     if (cpu->cpu_index == 0) {
134         /* primary CPU doesn't spin */
135         return;
136     }
137 
138     curspin_p = &curspin_p[addr % sizeof(SpinInfo)];
139     switch (len) {
140     case 1:
141         stb_p(curspin_p, value);
142         break;
143     case 2:
144         stw_p(curspin_p, value);
145         break;
146     case 4:
147         stl_p(curspin_p, value);
148         break;
149     }
150 
151     if (!(ldq_p(&curspin->addr) & 1)) {
152         /* run CPU */
153         run_on_cpu(cpu, spin_kick, RUN_ON_CPU_HOST_PTR(curspin));
154     }
155 }
156 
157 static uint64_t spin_read(void *opaque, hwaddr addr, unsigned len)
158 {
159     SpinState *s = opaque;
160     uint8_t *spin_p = &((uint8_t*)s->spin)[addr];
161 
162     switch (len) {
163     case 1:
164         return ldub_p(spin_p);
165     case 2:
166         return lduw_p(spin_p);
167     case 4:
168         return ldl_p(spin_p);
169     default:
170         hw_error("ppce500: unexpected %s with len = %u", __func__, len);
171     }
172 }
173 
174 static const MemoryRegionOps spin_rw_ops = {
175     .read = spin_read,
176     .write = spin_write,
177     .endianness = DEVICE_BIG_ENDIAN,
178 };
179 
180 static void ppce500_spin_initfn(Object *obj)
181 {
182     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
183     SpinState *s = E500_SPIN(dev);
184 
185     memory_region_init_io(&s->iomem, obj, &spin_rw_ops, s,
186                           "e500 spin pv device", sizeof(SpinInfo) * MAX_CPUS);
187     sysbus_init_mmio(dev, &s->iomem);
188 }
189 
190 static void ppce500_spin_class_init(ObjectClass *klass, void *data)
191 {
192     DeviceClass *dc = DEVICE_CLASS(klass);
193 
194     dc->reset = spin_reset;
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     .instance_init = ppce500_spin_initfn,
202     .class_init    = ppce500_spin_class_init,
203 };
204 
205 static void ppce500_spin_register_types(void)
206 {
207     type_register_static(&ppce500_spin_info);
208 }
209 
210 type_init(ppce500_spin_register_types)
211