/*
* QEMU RS/6000 memory controller
*
* Copyright (c) 2017 Hervé Poussineau
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) version 3 or any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "qemu/osdep.h"
#include "qemu/units.h"
#include "hw/isa/isa.h"
#include "hw/qdev-properties.h"
#include "migration/vmstate.h"
#include "exec/address-spaces.h"
#include "hw/boards.h"
#include "qapi/error.h"
#include "trace.h"
#include "qom/object.h"
#define TYPE_RS6000MC "rs6000-mc"
OBJECT_DECLARE_SIMPLE_TYPE(RS6000MCState, RS6000MC)
struct RS6000MCState {
ISADevice parent_obj;
/* see US patent 5,684,979 for details (expired 2001-11-04) */
uint32_t ram_size;
bool autoconfigure;
MemoryRegion simm[6];
unsigned int simm_size[6];
uint32_t end_address[8];
uint8_t port0820_index;
PortioList portio;
};
/* P0RT 0803 -- SIMM ID Register (32/8 MB) (Read Only) */
static uint32_t rs6000mc_port0803_read(void *opaque, uint32_t addr)
{
RS6000MCState *s = opaque;
uint32_t val = 0;
int socket;
/* (1 << socket) indicates 32 MB SIMM at given socket */
for (socket = 0; socket < 6; socket++) {
if (s->simm_size[socket] == 32) {
val |= (1 << socket);
}
}
trace_rs6000mc_id_read(addr, val);
return val;
}
/* PORT 0804 -- SIMM Presence Register (Read Only) */
static uint32_t rs6000mc_port0804_read(void *opaque, uint32_t addr)
{
RS6000MCState *s = opaque;
uint32_t val = 0xff;
int socket;
/* (1 << socket) indicates SIMM absence at given socket */
for (socket = 0; socket < 6; socket++) {
if (s->simm_size[socket]) {
val &= ~(1 << socket);
}
}
s->port0820_index = 0;
trace_rs6000mc_presence_read(addr, val);
return val;
}
/* Memory Controller Size Programming Register */
static uint32_t rs6000mc_port0820_read(void *opaque, uint32_t addr)
{
RS6000MCState *s = opaque;
uint32_t val = s->end_address[s->port0820_index] & 0x1f;
s->port0820_index = (s->port0820_index + 1) & 7;
trace_rs6000mc_size_read(addr, val);
return val;
}
static void rs6000mc_port0820_write(void *opaque, uint32_t addr, uint32_t val)
{
RS6000MCState *s = opaque;
uint8_t socket = val >> 5;
uint32_t end_address = val & 0x1f;
trace_rs6000mc_size_write(addr, val);
s->end_address[socket] = end_address;
if (socket > 0 && socket < 7) {
if (s->simm_size[socket - 1]) {
uint32_t size;
uint32_t start_address = 0;
if (socket > 1) {
start_address = s->end_address[socket - 1];
}
size = end_address - start_address;
memory_region_set_enabled(&s->simm[socket - 1], size != 0);
memory_region_set_address(&s->simm[socket - 1],
start_address * 8 * MiB);
}
}
}
/* Read Memory Parity Error */
enum {
PORT0841_NO_ERROR_DETECTED = 0x01,
};
static uint32_t rs6000mc_port0841_read(void *opaque, uint32_t addr)
{
uint32_t val = PORT0841_NO_ERROR_DETECTED;
trace_rs6000mc_parity_read(addr, val);
return val;
}
static const MemoryRegionPortio rs6000mc_port_list[] = {
{ 0x803, 1, 1, .read = rs6000mc_port0803_read },
{ 0x804, 1, 1, .read = rs6000mc_port0804_read },
{ 0x820, 1, 1, .read = rs6000mc_port0820_read,
.write = rs6000mc_port0820_write, },
{ 0x841, 1, 1, .read = rs6000mc_port0841_read },
PORTIO_END_OF_LIST()
};
static void rs6000mc_realize(DeviceState *dev, Error **errp)
{
RS6000MCState *s = RS6000MC(dev);
int socket = 0;
unsigned int ram_size = s->ram_size / MiB;
Error *local_err = NULL;
while (socket < 6) {
if (ram_size >= 64) {
s->simm_size[socket] = 32;
s->simm_size[socket + 1] = 32;
ram_size -= 64;
} else if (ram_size >= 16) {
s->simm_size[socket] = 8;
s->simm_size[socket + 1] = 8;
ram_size -= 16;
} else {
/* Not enough memory */
break;
}
socket += 2;
}
for (socket = 0; socket < 6; socket++) {
if (s->simm_size[socket]) {
char name[] = "simm.?";
name[5] = socket + '0';
memory_region_init_ram(&s->simm[socket], OBJECT(dev), name,
s->simm_size[socket] * MiB, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return;
}
memory_region_add_subregion_overlap(get_system_memory(), 0,
&s->simm[socket], socket);
}
}
if (ram_size) {
/* unable to push all requested RAM in SIMMs */
error_setg(errp, "RAM size incompatible with this board. "
"Try again with something else, like %" PRId64 " MB",
s->ram_size / MiB - ram_size);
return;
}
if (s->autoconfigure) {
uint32_t start_address = 0;
for (socket = 0; socket < 6; socket++) {
if (s->simm_size[socket]) {
memory_region_set_enabled(&s->simm[socket], true);
memory_region_set_address(&s->simm[socket], start_address);
start_address += memory_region_size(&s->simm[socket]);
}
}
}
isa_register_portio_list(ISA_DEVICE(dev), &s->portio, 0x0,
rs6000mc_port_list, s, "rs6000mc");
}
static const VMStateDescription vmstate_rs6000mc = {
.name = "rs6000-mc",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(port0820_index, RS6000MCState),
VMSTATE_END_OF_LIST()
},
};
static Property rs6000mc_properties[] = {
DEFINE_PROP_UINT32("ram-size", RS6000MCState, ram_size, 0),
DEFINE_PROP_BOOL("auto-configure", RS6000MCState, autoconfigure, true),
DEFINE_PROP_END_OF_LIST()
};
static void rs6000mc_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = rs6000mc_realize;
dc->vmsd = &vmstate_rs6000mc;
device_class_set_props(dc, rs6000mc_properties);
}
static const TypeInfo rs6000mc_info = {
.name = TYPE_RS6000MC,
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(RS6000MCState),
.class_init = rs6000mc_class_initfn,
};
static void rs6000mc_types(void)
{
type_register_static(&rs6000mc_info);
}
type_init(rs6000mc_types)
