1 /*
2 * QEMU RS/6000 memory controller
3 *
4 * Copyright (c) 2017 Hervé Poussineau
5 *
6 * This program is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 2 of the License, or
9 * (at your option) version 3 or any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 */
19
20 #include "qemu/osdep.h"
21 #include "qemu/units.h"
22 #include "hw/isa/isa.h"
23 #include "hw/qdev-properties.h"
24 #include "migration/vmstate.h"
25 #include "exec/address-spaces.h"
26 #include "qapi/error.h"
27 #include "trace.h"
28 #include "qom/object.h"
29
30 #define TYPE_RS6000MC "rs6000-mc"
31 OBJECT_DECLARE_SIMPLE_TYPE(RS6000MCState, RS6000MC)
32
33 struct RS6000MCState {
34 ISADevice parent_obj;
35 /* see US patent 5,684,979 for details (expired 2001-11-04) */
36 uint32_t ram_size;
37 bool autoconfigure;
38 MemoryRegion simm[6];
39 unsigned int simm_size[6];
40 uint32_t end_address[8];
41 uint8_t port0820_index;
42 PortioList portio;
43 };
44
45 /* P0RT 0803 -- SIMM ID Register (32/8 MB) (Read Only) */
46
rs6000mc_port0803_read(void * opaque,uint32_t addr)47 static uint32_t rs6000mc_port0803_read(void *opaque, uint32_t addr)
48 {
49 RS6000MCState *s = opaque;
50 uint32_t val = 0;
51 int socket;
52
53 /* (1 << socket) indicates 32 MB SIMM at given socket */
54 for (socket = 0; socket < 6; socket++) {
55 if (s->simm_size[socket] == 32) {
56 val |= (1 << socket);
57 }
58 }
59
60 trace_rs6000mc_id_read(addr, val);
61 return val;
62 }
63
64 /* PORT 0804 -- SIMM Presence Register (Read Only) */
65
rs6000mc_port0804_read(void * opaque,uint32_t addr)66 static uint32_t rs6000mc_port0804_read(void *opaque, uint32_t addr)
67 {
68 RS6000MCState *s = opaque;
69 uint32_t val = 0xff;
70 int socket;
71
72 /* (1 << socket) indicates SIMM absence at given socket */
73 for (socket = 0; socket < 6; socket++) {
74 if (s->simm_size[socket]) {
75 val &= ~(1 << socket);
76 }
77 }
78 s->port0820_index = 0;
79
80 trace_rs6000mc_presence_read(addr, val);
81 return val;
82 }
83
84 /* Memory Controller Size Programming Register */
85
rs6000mc_port0820_read(void * opaque,uint32_t addr)86 static uint32_t rs6000mc_port0820_read(void *opaque, uint32_t addr)
87 {
88 RS6000MCState *s = opaque;
89 uint32_t val = s->end_address[s->port0820_index] & 0x1f;
90 s->port0820_index = (s->port0820_index + 1) & 7;
91 trace_rs6000mc_size_read(addr, val);
92 return val;
93 }
94
rs6000mc_port0820_write(void * opaque,uint32_t addr,uint32_t val)95 static void rs6000mc_port0820_write(void *opaque, uint32_t addr, uint32_t val)
96 {
97 RS6000MCState *s = opaque;
98 uint8_t socket = val >> 5;
99 uint32_t end_address = val & 0x1f;
100
101 trace_rs6000mc_size_write(addr, val);
102 s->end_address[socket] = end_address;
103 if (socket > 0 && socket < 7) {
104 if (s->simm_size[socket - 1]) {
105 uint32_t size;
106 uint32_t start_address = 0;
107 if (socket > 1) {
108 start_address = s->end_address[socket - 1];
109 }
110
111 size = end_address - start_address;
112 memory_region_set_enabled(&s->simm[socket - 1], size != 0);
113 memory_region_set_address(&s->simm[socket - 1],
114 start_address * 8 * MiB);
115 }
116 }
117 }
118
119 /* Read Memory Parity Error */
120
121 enum {
122 PORT0841_NO_ERROR_DETECTED = 0x01,
123 };
124
rs6000mc_port0841_read(void * opaque,uint32_t addr)125 static uint32_t rs6000mc_port0841_read(void *opaque, uint32_t addr)
126 {
127 uint32_t val = PORT0841_NO_ERROR_DETECTED;
128 trace_rs6000mc_parity_read(addr, val);
129 return val;
130 }
131
132 static const MemoryRegionPortio rs6000mc_port_list[] = {
133 { 0x803, 1, 1, .read = rs6000mc_port0803_read },
134 { 0x804, 1, 1, .read = rs6000mc_port0804_read },
135 { 0x820, 1, 1, .read = rs6000mc_port0820_read,
136 .write = rs6000mc_port0820_write, },
137 { 0x841, 1, 1, .read = rs6000mc_port0841_read },
138 PORTIO_END_OF_LIST()
139 };
140
rs6000mc_realize(DeviceState * dev,Error ** errp)141 static void rs6000mc_realize(DeviceState *dev, Error **errp)
142 {
143 RS6000MCState *s = RS6000MC(dev);
144 int socket = 0;
145 unsigned int ram_size = s->ram_size / MiB;
146
147 while (socket < 6) {
148 if (ram_size >= 64) {
149 s->simm_size[socket] = 32;
150 s->simm_size[socket + 1] = 32;
151 ram_size -= 64;
152 } else if (ram_size >= 16) {
153 s->simm_size[socket] = 8;
154 s->simm_size[socket + 1] = 8;
155 ram_size -= 16;
156 } else {
157 /* Not enough memory */
158 break;
159 }
160 socket += 2;
161 }
162
163 for (socket = 0; socket < 6; socket++) {
164 if (s->simm_size[socket]) {
165 char name[] = "simm.?";
166 name[5] = socket + '0';
167 if (!memory_region_init_ram(&s->simm[socket], OBJECT(dev), name,
168 s->simm_size[socket] * MiB, errp)) {
169 return;
170 }
171 memory_region_add_subregion_overlap(get_system_memory(), 0,
172 &s->simm[socket], socket);
173 }
174 }
175 if (ram_size) {
176 /* unable to push all requested RAM in SIMMs */
177 error_setg(errp, "RAM size incompatible with this board. "
178 "Try again with something else, like %" PRId64 " MB",
179 s->ram_size / MiB - ram_size);
180 return;
181 }
182
183 if (s->autoconfigure) {
184 uint32_t start_address = 0;
185 for (socket = 0; socket < 6; socket++) {
186 if (s->simm_size[socket]) {
187 memory_region_set_enabled(&s->simm[socket], true);
188 memory_region_set_address(&s->simm[socket], start_address);
189 start_address += memory_region_size(&s->simm[socket]);
190 }
191 }
192 }
193
194 isa_register_portio_list(ISA_DEVICE(dev), &s->portio, 0x0,
195 rs6000mc_port_list, s, "rs6000mc");
196 }
197
198 static const VMStateDescription vmstate_rs6000mc = {
199 .name = "rs6000-mc",
200 .version_id = 1,
201 .minimum_version_id = 1,
202 .fields = (const VMStateField[]) {
203 VMSTATE_UINT8(port0820_index, RS6000MCState),
204 VMSTATE_END_OF_LIST()
205 },
206 };
207
208 static Property rs6000mc_properties[] = {
209 DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
210 DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
211 DEFINE_PROP_END_OF_LIST()
212 };
213
rs6000mc_class_initfn(ObjectClass * klass,void * data)214 static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
215 {
216 DeviceClass *dc = DEVICE_CLASS(klass);
217
218 dc->realize = rs6000mc_realize;
219 dc->vmsd = &vmstate_rs6000mc;
220 device_class_set_props(dc, rs6000mc_properties);
221 }
222
223 static const TypeInfo rs6000mc_info = {
224 .name = TYPE_RS6000MC,
225 .parent = TYPE_ISA_DEVICE,
226 .instance_size = sizeof(RS6000MCState),
227 .class_init = rs6000mc_class_initfn,
228 };
229
rs6000mc_types(void)230 static void rs6000mc_types(void)
231 {
232 type_register_static(&rs6000mc_info);
233 }
234
235 type_init(rs6000mc_types)
236