1 /*
2 * QEMU RS/6000 memory controller
3 *
4 * Copyright (c) 2017 Hervé Poussineau
5 *
6 * SPDX-License-Identifier: GPL-2.0-or-later
7 *
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation, either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program 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
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "qemu/osdep.h"
23 #include "qemu/units.h"
24 #include "hw/isa/isa.h"
25 #include "hw/qdev-properties.h"
26 #include "migration/vmstate.h"
27 #include "exec/address-spaces.h"
28 #include "qapi/error.h"
29 #include "trace.h"
30 #include "qom/object.h"
31
32 #define TYPE_RS6000MC "rs6000-mc"
33 OBJECT_DECLARE_SIMPLE_TYPE(RS6000MCState, RS6000MC)
34
35 struct RS6000MCState {
36 ISADevice parent_obj;
37 /* see US patent 5,684,979 for details (expired 2001-11-04) */
38 uint32_t ram_size;
39 bool autoconfigure;
40 MemoryRegion simm[6];
41 unsigned int simm_size[6];
42 uint32_t end_address[8];
43 uint8_t port0820_index;
44 PortioList portio;
45 };
46
47 /* P0RT 0803 -- SIMM ID Register (32/8 MB) (Read Only) */
48
rs6000mc_port0803_read(void * opaque,uint32_t addr)49 static uint32_t rs6000mc_port0803_read(void *opaque, uint32_t addr)
50 {
51 RS6000MCState *s = opaque;
52 uint32_t val = 0;
53 int socket;
54
55 /* (1 << socket) indicates 32 MB SIMM at given socket */
56 for (socket = 0; socket < 6; socket++) {
57 if (s->simm_size[socket] == 32) {
58 val |= (1 << socket);
59 }
60 }
61
62 trace_rs6000mc_id_read(addr, val);
63 return val;
64 }
65
66 /* PORT 0804 -- SIMM Presence Register (Read Only) */
67
rs6000mc_port0804_read(void * opaque,uint32_t addr)68 static uint32_t rs6000mc_port0804_read(void *opaque, uint32_t addr)
69 {
70 RS6000MCState *s = opaque;
71 uint32_t val = 0xff;
72 int socket;
73
74 /* (1 << socket) indicates SIMM absence at given socket */
75 for (socket = 0; socket < 6; socket++) {
76 if (s->simm_size[socket]) {
77 val &= ~(1 << socket);
78 }
79 }
80 s->port0820_index = 0;
81
82 trace_rs6000mc_presence_read(addr, val);
83 return val;
84 }
85
86 /* Memory Controller Size Programming Register */
87
rs6000mc_port0820_read(void * opaque,uint32_t addr)88 static uint32_t rs6000mc_port0820_read(void *opaque, uint32_t addr)
89 {
90 RS6000MCState *s = opaque;
91 uint32_t val = s->end_address[s->port0820_index] & 0x1f;
92 s->port0820_index = (s->port0820_index + 1) & 7;
93 trace_rs6000mc_size_read(addr, val);
94 return val;
95 }
96
rs6000mc_port0820_write(void * opaque,uint32_t addr,uint32_t val)97 static void rs6000mc_port0820_write(void *opaque, uint32_t addr, uint32_t val)
98 {
99 RS6000MCState *s = opaque;
100 uint8_t socket = val >> 5;
101 uint32_t end_address = val & 0x1f;
102
103 trace_rs6000mc_size_write(addr, val);
104 s->end_address[socket] = end_address;
105 if (socket > 0 && socket < 7) {
106 if (s->simm_size[socket - 1]) {
107 uint32_t size;
108 uint32_t start_address = 0;
109 if (socket > 1) {
110 start_address = s->end_address[socket - 1];
111 }
112
113 size = end_address - start_address;
114 memory_region_set_enabled(&s->simm[socket - 1], size != 0);
115 memory_region_set_address(&s->simm[socket - 1],
116 start_address * 8 * MiB);
117 }
118 }
119 }
120
121 /* Read Memory Parity Error */
122
123 enum {
124 PORT0841_NO_ERROR_DETECTED = 0x01,
125 };
126
rs6000mc_port0841_read(void * opaque,uint32_t addr)127 static uint32_t rs6000mc_port0841_read(void *opaque, uint32_t addr)
128 {
129 uint32_t val = PORT0841_NO_ERROR_DETECTED;
130 trace_rs6000mc_parity_read(addr, val);
131 return val;
132 }
133
134 static const MemoryRegionPortio rs6000mc_port_list[] = {
135 { 0x803, 1, 1, .read = rs6000mc_port0803_read },
136 { 0x804, 1, 1, .read = rs6000mc_port0804_read },
137 { 0x820, 1, 1, .read = rs6000mc_port0820_read,
138 .write = rs6000mc_port0820_write, },
139 { 0x841, 1, 1, .read = rs6000mc_port0841_read },
140 PORTIO_END_OF_LIST()
141 };
142
rs6000mc_realize(DeviceState * dev,Error ** errp)143 static void rs6000mc_realize(DeviceState *dev, Error **errp)
144 {
145 RS6000MCState *s = RS6000MC(dev);
146 int socket = 0;
147 unsigned int ram_size = s->ram_size / MiB;
148
149 while (socket < 6) {
150 if (ram_size >= 64) {
151 s->simm_size[socket] = 32;
152 s->simm_size[socket + 1] = 32;
153 ram_size -= 64;
154 } else if (ram_size >= 16) {
155 s->simm_size[socket] = 8;
156 s->simm_size[socket + 1] = 8;
157 ram_size -= 16;
158 } else {
159 /* Not enough memory */
160 break;
161 }
162 socket += 2;
163 }
164
165 for (socket = 0; socket < 6; socket++) {
166 if (s->simm_size[socket]) {
167 char name[] = "simm.?";
168 name[5] = socket + '0';
169 if (!memory_region_init_ram(&s->simm[socket], OBJECT(dev), name,
170 s->simm_size[socket] * MiB, errp)) {
171 return;
172 }
173 memory_region_add_subregion_overlap(get_system_memory(), 0,
174 &s->simm[socket], socket);
175 }
176 }
177 if (ram_size) {
178 /* unable to push all requested RAM in SIMMs */
179 error_setg(errp, "RAM size incompatible with this board. "
180 "Try again with something else, like %" PRId64 " MB",
181 s->ram_size / MiB - ram_size);
182 return;
183 }
184
185 if (s->autoconfigure) {
186 uint32_t start_address = 0;
187 for (socket = 0; socket < 6; socket++) {
188 if (s->simm_size[socket]) {
189 memory_region_set_enabled(&s->simm[socket], true);
190 memory_region_set_address(&s->simm[socket], start_address);
191 start_address += memory_region_size(&s->simm[socket]);
192 }
193 }
194 }
195
196 isa_register_portio_list(ISA_DEVICE(dev), &s->portio, 0x0,
197 rs6000mc_port_list, s, "rs6000mc");
198 }
199
200 static const VMStateDescription vmstate_rs6000mc = {
201 .name = "rs6000-mc",
202 .version_id = 1,
203 .minimum_version_id = 1,
204 .fields = (const VMStateField[]) {
205 VMSTATE_UINT8(port0820_index, RS6000MCState),
206 VMSTATE_END_OF_LIST()
207 },
208 };
209
210 static Property rs6000mc_properties[] = {
211 DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
212 DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
213 DEFINE_PROP_END_OF_LIST()
214 };
215
rs6000mc_class_initfn(ObjectClass * klass,void * data)216 static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
217 {
218 DeviceClass *dc = DEVICE_CLASS(klass);
219
220 dc->realize = rs6000mc_realize;
221 dc->vmsd = &vmstate_rs6000mc;
222 device_class_set_props(dc, rs6000mc_properties);
223 }
224
225 static const TypeInfo rs6000mc_info = {
226 .name = TYPE_RS6000MC,
227 .parent = TYPE_ISA_DEVICE,
228 .instance_size = sizeof(RS6000MCState),
229 .class_init = rs6000mc_class_initfn,
230 };
231
rs6000mc_types(void)232 static void rs6000mc_types(void)
233 {
234 type_register_static(&rs6000mc_info);
235 }
236
237 type_init(rs6000mc_types)
238