qemu-e2k/hw/riscv/sifive_plic.c

497 lines
17 KiB
C

/*
* SiFive PLIC (Platform Level Interrupt Controller)
*
* Copyright (c) 2017 SiFive, Inc.
*
* This provides a parameterizable interrupt controller based on SiFive's PLIC.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2 or later, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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/log.h"
#include "qemu/error-report.h"
#include "hw/sysbus.h"
#include "target/riscv/cpu.h"
#include "hw/riscv/sifive_plic.h"
#define RISCV_DEBUG_PLIC 0
static PLICMode char_to_mode(char c)
{
switch (c) {
case 'U': return PLICMode_U;
case 'S': return PLICMode_S;
case 'H': return PLICMode_H;
case 'M': return PLICMode_M;
default:
error_report("plic: invalid mode '%c'", c);
exit(1);
}
}
static char mode_to_char(PLICMode m)
{
switch (m) {
case PLICMode_U: return 'U';
case PLICMode_S: return 'S';
case PLICMode_H: return 'H';
case PLICMode_M: return 'M';
default: return '?';
}
}
static void sifive_plic_print_state(SiFivePLICState *plic)
{
int i;
int addrid;
/* pending */
qemu_log("pending : ");
for (i = plic->bitfield_words - 1; i >= 0; i--) {
qemu_log("%08x", plic->pending[i]);
}
qemu_log("\n");
/* pending */
qemu_log("claimed : ");
for (i = plic->bitfield_words - 1; i >= 0; i--) {
qemu_log("%08x", plic->claimed[i]);
}
qemu_log("\n");
for (addrid = 0; addrid < plic->num_addrs; addrid++) {
qemu_log("hart%d-%c enable: ",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode));
for (i = plic->bitfield_words - 1; i >= 0; i--) {
qemu_log("%08x", plic->enable[addrid * plic->bitfield_words + i]);
}
qemu_log("\n");
}
}
static uint32_t atomic_set_masked(uint32_t *a, uint32_t mask, uint32_t value)
{
uint32_t old, new, cmp = atomic_read(a);
do {
old = cmp;
new = (old & ~mask) | (value & mask);
cmp = atomic_cmpxchg(a, old, new);
} while (old != cmp);
return old;
}
static void sifive_plic_set_pending(SiFivePLICState *plic, int irq, bool level)
{
atomic_set_masked(&plic->pending[irq >> 5], 1 << (irq & 31), -!!level);
}
static void sifive_plic_set_claimed(SiFivePLICState *plic, int irq, bool level)
{
atomic_set_masked(&plic->claimed[irq >> 5], 1 << (irq & 31), -!!level);
}
static int sifive_plic_irqs_pending(SiFivePLICState *plic, uint32_t addrid)
{
int i, j;
for (i = 0; i < plic->bitfield_words; i++) {
uint32_t pending_enabled_not_claimed =
(plic->pending[i] & ~plic->claimed[i]) &
plic->enable[addrid * plic->bitfield_words + i];
if (!pending_enabled_not_claimed) {
continue;
}
for (j = 0; j < 32; j++) {
int irq = (i << 5) + j;
uint32_t prio = plic->source_priority[irq];
int enabled = pending_enabled_not_claimed & (1 << j);
if (enabled && prio > plic->target_priority[addrid]) {
return 1;
}
}
}
return 0;
}
static void sifive_plic_update(SiFivePLICState *plic)
{
int addrid;
/* raise irq on harts where this irq is enabled */
for (addrid = 0; addrid < plic->num_addrs; addrid++) {
uint32_t hartid = plic->addr_config[addrid].hartid;
PLICMode mode = plic->addr_config[addrid].mode;
CPUState *cpu = qemu_get_cpu(hartid);
CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
if (!env) {
continue;
}
int level = sifive_plic_irqs_pending(plic, addrid);
switch (mode) {
case PLICMode_M:
riscv_cpu_update_mip(RISCV_CPU(cpu), MIP_MEIP, BOOL_TO_MASK(level));
break;
case PLICMode_S:
riscv_cpu_update_mip(RISCV_CPU(cpu), MIP_SEIP, BOOL_TO_MASK(level));
break;
default:
break;
}
}
if (RISCV_DEBUG_PLIC) {
sifive_plic_print_state(plic);
}
}
void sifive_plic_raise_irq(SiFivePLICState *plic, uint32_t irq)
{
sifive_plic_set_pending(plic, irq, true);
sifive_plic_update(plic);
}
void sifive_plic_lower_irq(SiFivePLICState *plic, uint32_t irq)
{
sifive_plic_set_pending(plic, irq, false);
sifive_plic_update(plic);
}
static uint32_t sifive_plic_claim(SiFivePLICState *plic, uint32_t addrid)
{
int i, j;
for (i = 0; i < plic->bitfield_words; i++) {
uint32_t pending_enabled_not_claimed =
(plic->pending[i] & ~plic->claimed[i]) &
plic->enable[addrid * plic->bitfield_words + i];
if (!pending_enabled_not_claimed) {
continue;
}
for (j = 0; j < 32; j++) {
int irq = (i << 5) + j;
uint32_t prio = plic->source_priority[irq];
int enabled = pending_enabled_not_claimed & (1 << j);
if (enabled && prio > plic->target_priority[addrid]) {
sifive_plic_set_pending(plic, irq, false);
sifive_plic_set_claimed(plic, irq, true);
return irq;
}
}
}
return 0;
}
static uint64_t sifive_plic_read(void *opaque, hwaddr addr, unsigned size)
{
SiFivePLICState *plic = opaque;
/* writes must be 4 byte words */
if ((addr & 0x3) != 0) {
goto err;
}
if (addr >= plic->priority_base && /* 4 bytes per source */
addr < plic->priority_base + (plic->num_sources << 2))
{
uint32_t irq = (addr - plic->priority_base) >> 2;
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: read priority: irq=%d priority=%d\n",
irq, plic->source_priority[irq]);
}
return plic->source_priority[irq];
} else if (addr >= plic->pending_base && /* 1 bit per source */
addr < plic->pending_base + (plic->num_sources >> 3))
{
uint32_t word = (addr - plic->pending_base) >> 2;
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: read pending: word=%d value=%d\n",
word, plic->pending[word]);
}
return plic->pending[word];
} else if (addr >= plic->enable_base && /* 1 bit per source */
addr < plic->enable_base + plic->num_addrs * plic->enable_stride)
{
uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride;
uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2;
if (wordid < plic->bitfield_words) {
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: read enable: hart%d-%c word=%d value=%x\n",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode), wordid,
plic->enable[addrid * plic->bitfield_words + wordid]);
}
return plic->enable[addrid * plic->bitfield_words + wordid];
}
} else if (addr >= plic->context_base && /* 1 bit per source */
addr < plic->context_base + plic->num_addrs * plic->context_stride)
{
uint32_t addrid = (addr - plic->context_base) / plic->context_stride;
uint32_t contextid = (addr & (plic->context_stride - 1));
if (contextid == 0) {
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: read priority: hart%d-%c priority=%x\n",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode),
plic->target_priority[addrid]);
}
return plic->target_priority[addrid];
} else if (contextid == 4) {
uint32_t value = sifive_plic_claim(plic, addrid);
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: read claim: hart%d-%c irq=%x\n",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode),
value);
sifive_plic_print_state(plic);
}
return value;
}
}
err:
error_report("plic: invalid register read: %08x", (uint32_t)addr);
return 0;
}
static void sifive_plic_write(void *opaque, hwaddr addr, uint64_t value,
unsigned size)
{
SiFivePLICState *plic = opaque;
/* writes must be 4 byte words */
if ((addr & 0x3) != 0) {
goto err;
}
if (addr >= plic->priority_base && /* 4 bytes per source */
addr < plic->priority_base + (plic->num_sources << 2))
{
uint32_t irq = (addr - plic->priority_base) >> 2;
plic->source_priority[irq] = value & 7;
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: write priority: irq=%d priority=%d\n",
irq, plic->source_priority[irq]);
}
return;
} else if (addr >= plic->pending_base && /* 1 bit per source */
addr < plic->pending_base + (plic->num_sources >> 3))
{
error_report("plic: invalid pending write: %08x", (uint32_t)addr);
return;
} else if (addr >= plic->enable_base && /* 1 bit per source */
addr < plic->enable_base + plic->num_addrs * plic->enable_stride)
{
uint32_t addrid = (addr - plic->enable_base) / plic->enable_stride;
uint32_t wordid = (addr & (plic->enable_stride - 1)) >> 2;
if (wordid < plic->bitfield_words) {
plic->enable[addrid * plic->bitfield_words + wordid] = value;
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: write enable: hart%d-%c word=%d value=%x\n",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode), wordid,
plic->enable[addrid * plic->bitfield_words + wordid]);
}
return;
}
} else if (addr >= plic->context_base && /* 4 bytes per reg */
addr < plic->context_base + plic->num_addrs * plic->context_stride)
{
uint32_t addrid = (addr - plic->context_base) / plic->context_stride;
uint32_t contextid = (addr & (plic->context_stride - 1));
if (contextid == 0) {
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: write priority: hart%d-%c priority=%x\n",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode),
plic->target_priority[addrid]);
}
if (value <= plic->num_priorities) {
plic->target_priority[addrid] = value;
sifive_plic_update(plic);
}
return;
} else if (contextid == 4) {
if (RISCV_DEBUG_PLIC) {
qemu_log("plic: write claim: hart%d-%c irq=%x\n",
plic->addr_config[addrid].hartid,
mode_to_char(plic->addr_config[addrid].mode),
(uint32_t)value);
}
if (value < plic->num_sources) {
sifive_plic_set_claimed(plic, value, false);
sifive_plic_update(plic);
}
return;
}
}
err:
error_report("plic: invalid register write: %08x", (uint32_t)addr);
}
static const MemoryRegionOps sifive_plic_ops = {
.read = sifive_plic_read,
.write = sifive_plic_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4
}
};
static Property sifive_plic_properties[] = {
DEFINE_PROP_STRING("hart-config", SiFivePLICState, hart_config),
DEFINE_PROP_UINT32("num-sources", SiFivePLICState, num_sources, 0),
DEFINE_PROP_UINT32("num-priorities", SiFivePLICState, num_priorities, 0),
DEFINE_PROP_UINT32("priority-base", SiFivePLICState, priority_base, 0),
DEFINE_PROP_UINT32("pending-base", SiFivePLICState, pending_base, 0),
DEFINE_PROP_UINT32("enable-base", SiFivePLICState, enable_base, 0),
DEFINE_PROP_UINT32("enable-stride", SiFivePLICState, enable_stride, 0),
DEFINE_PROP_UINT32("context-base", SiFivePLICState, context_base, 0),
DEFINE_PROP_UINT32("context-stride", SiFivePLICState, context_stride, 0),
DEFINE_PROP_UINT32("aperture-size", SiFivePLICState, aperture_size, 0),
DEFINE_PROP_END_OF_LIST(),
};
/*
* parse PLIC hart/mode address offset config
*
* "M" 1 hart with M mode
* "MS,MS" 2 harts, 0-1 with M and S mode
* "M,MS,MS,MS,MS" 5 harts, 0 with M mode, 1-5 with M and S mode
*/
static void parse_hart_config(SiFivePLICState *plic)
{
int addrid, hartid, modes;
const char *p;
char c;
/* count and validate hart/mode combinations */
addrid = 0, hartid = 0, modes = 0;
p = plic->hart_config;
while ((c = *p++)) {
if (c == ',') {
addrid += __builtin_popcount(modes);
modes = 0;
hartid++;
} else {
int m = 1 << char_to_mode(c);
if (modes == (modes | m)) {
error_report("plic: duplicate mode '%c' in config: %s",
c, plic->hart_config);
exit(1);
}
modes |= m;
}
}
if (modes) {
addrid += __builtin_popcount(modes);
}
hartid++;
/* store hart/mode combinations */
plic->num_addrs = addrid;
plic->addr_config = g_new(PLICAddr, plic->num_addrs);
addrid = 0, hartid = 0;
p = plic->hart_config;
while ((c = *p++)) {
if (c == ',') {
hartid++;
} else {
plic->addr_config[addrid].addrid = addrid;
plic->addr_config[addrid].hartid = hartid;
plic->addr_config[addrid].mode = char_to_mode(c);
addrid++;
}
}
}
static void sifive_plic_irq_request(void *opaque, int irq, int level)
{
SiFivePLICState *plic = opaque;
if (RISCV_DEBUG_PLIC) {
qemu_log("sifive_plic_irq_request: irq=%d level=%d\n", irq, level);
}
sifive_plic_set_pending(plic, irq, level > 0);
sifive_plic_update(plic);
}
static void sifive_plic_realize(DeviceState *dev, Error **errp)
{
SiFivePLICState *plic = SIFIVE_PLIC(dev);
memory_region_init_io(&plic->mmio, OBJECT(dev), &sifive_plic_ops, plic,
TYPE_SIFIVE_PLIC, plic->aperture_size);
parse_hart_config(plic);
plic->bitfield_words = (plic->num_sources + 31) >> 5;
plic->source_priority = g_new0(uint32_t, plic->num_sources);
plic->target_priority = g_new(uint32_t, plic->num_addrs);
plic->pending = g_new0(uint32_t, plic->bitfield_words);
plic->claimed = g_new0(uint32_t, plic->bitfield_words);
plic->enable = g_new0(uint32_t, plic->bitfield_words * plic->num_addrs);
sysbus_init_mmio(SYS_BUS_DEVICE(dev), &plic->mmio);
qdev_init_gpio_in(dev, sifive_plic_irq_request, plic->num_sources);
}
static void sifive_plic_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->props = sifive_plic_properties;
dc->realize = sifive_plic_realize;
}
static const TypeInfo sifive_plic_info = {
.name = TYPE_SIFIVE_PLIC,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(SiFivePLICState),
.class_init = sifive_plic_class_init,
};
static void sifive_plic_register_types(void)
{
type_register_static(&sifive_plic_info);
}
type_init(sifive_plic_register_types)
/*
* Create PLIC device.
*/
DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
uint32_t num_sources, uint32_t num_priorities,
uint32_t priority_base, uint32_t pending_base,
uint32_t enable_base, uint32_t enable_stride,
uint32_t context_base, uint32_t context_stride,
uint32_t aperture_size)
{
DeviceState *dev = qdev_create(NULL, TYPE_SIFIVE_PLIC);
assert(enable_stride == (enable_stride & -enable_stride));
assert(context_stride == (context_stride & -context_stride));
qdev_prop_set_string(dev, "hart-config", hart_config);
qdev_prop_set_uint32(dev, "num-sources", num_sources);
qdev_prop_set_uint32(dev, "num-priorities", num_priorities);
qdev_prop_set_uint32(dev, "priority-base", priority_base);
qdev_prop_set_uint32(dev, "pending-base", pending_base);
qdev_prop_set_uint32(dev, "enable-base", enable_base);
qdev_prop_set_uint32(dev, "enable-stride", enable_stride);
qdev_prop_set_uint32(dev, "context-base", context_base);
qdev_prop_set_uint32(dev, "context-stride", context_stride);
qdev_prop_set_uint32(dev, "aperture-size", aperture_size);
qdev_init_nofail(dev);
sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
return dev;
}