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Diffstat (limited to 'hw/riscv/sifive_plic.c')
-rw-r--r--hw/riscv/sifive_plic.c505
1 files changed, 505 insertions, 0 deletions
diff --git a/hw/riscv/sifive_plic.c b/hw/riscv/sifive_plic.c
new file mode 100644
index 0000000000..874de2ebaf
--- /dev/null
+++ b/hw/riscv/sifive_plic.c
@@ -0,0 +1,505 @@
+/*
+ * 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
+void sifive_plic_set_pending(SiFivePLICState *plic, int irq, bool pending)
+{
+ qemu_mutex_lock(&plic->lock);
+ uint32_t word = irq >> 5;
+ if (pending) {
+ plic->pending[word] |= (1 << (irq & 31));
+ } else {
+ plic->pending[word] &= ~(1 << (irq & 31));
+ }
+ qemu_mutex_unlock(&plic->lock);
+}
+
+static
+void sifive_plic_set_claimed(SiFivePLICState *plic, int irq, bool claimed)
+{
+ qemu_mutex_lock(&plic->lock);
+ uint32_t word = irq >> 5;
+ if (claimed) {
+ plic->claimed[word] |= (1 << (irq & 31));
+ } else {
+ plic->claimed[word] &= ~(1 << (irq & 31));
+ }
+ qemu_mutex_unlock(&plic->lock);
+}
+
+static
+int sifive_plic_num_irqs_pending(SiFivePLICState *plic, uint32_t addrid)
+{
+ int i, j, count = 0;
+ 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]) {
+ count++;
+ }
+ }
+ }
+ return count;
+}
+
+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_num_irqs_pending(plic, addrid) > 0;
+ switch (mode) {
+ case PLICMode_M:
+ riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_MEIP, level);
+ break;
+ case PLICMode_S:
+ riscv_set_local_interrupt(RISCV_CPU(cpu), MIP_SEIP, 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->priority_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);
+ int i;
+
+ memory_region_init_io(&plic->mmio, OBJECT(dev), &sifive_plic_ops, plic,
+ TYPE_SIFIVE_PLIC, plic->aperture_size);
+ parse_hart_config(plic);
+ qemu_mutex_init(&plic->lock);
+ 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);
+ plic->irqs = g_new0(qemu_irq, plic->num_sources + 1);
+ for (i = 0; i <= plic->num_sources; i++) {
+ plic->irqs[i] = qemu_allocate_irq(sifive_plic_irq_request, plic, i);
+ }
+}
+
+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;
+}
generated by cgit v1.2.3 (git 2.26.2) at 2024-12-22 16:40:24 +0000