Add RISC-V implementation of the Cluster Power Controller (CPC) device.
It is based on the existing MIPS CPC implementations but adapted for
RISC-V systems.
The CPC device manages power control for CPU clusters in RISC-V
systems.
This is needed for the MIPS BOSTON AIA board.
Signed-off-by: Chao-ying Fu <cfu@mips.com>
Signed-off-by: Djordje Todorovic <djordje.todorovic@htecgroup.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
---
hw/misc/Kconfig | 4 +
hw/misc/meson.build | 1 +
hw/misc/riscv_cpc.c | 271 ++++++++++++++++++++++++++++++++++++
include/hw/misc/riscv_cpc.h | 75 ++++++++++
4 files changed, 351 insertions(+)
create mode 100644 hw/misc/riscv_cpc.c
create mode 100644 include/hw/misc/riscv_cpc.h
diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
index c72927c3ff..1e35bcd443 100644
--- a/hw/misc/Kconfig
+++ b/hw/misc/Kconfig
@@ -124,11 +124,15 @@ config MIPS_ITU
config RISCV_CMGCR
bool
+config RISCV_CPC
+ bool
+
config MIPS_BOSTON_AIA
bool
default y
depends on RISCV64
select RISCV_CMGCR
+ select RISCV_CPC
config MPS2_FPGAIO
bool
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index ef891e465b..1f9945755f 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -158,6 +158,7 @@ specific_ss.add(when: 'CONFIG_MIPS_CPS', if_true: files('mips_cmgcr.c', 'mips_cp
specific_ss.add(when: 'CONFIG_MIPS_ITU', if_true: files('mips_itu.c'))
specific_ss.add(when: 'CONFIG_RISCV_CMGCR', if_true: files('riscv_cmgcr.c'))
+specific_ss.add(when: 'CONFIG_RISCV_CPC', if_true: files('riscv_cpc.c'))
system_ss.add(when: 'CONFIG_SBSA_REF', if_true: files('sbsa_ec.c'))
diff --git a/hw/misc/riscv_cpc.c b/hw/misc/riscv_cpc.c
new file mode 100644
index 0000000000..6a6cf72d45
--- /dev/null
+++ b/hw/misc/riscv_cpc.c
@@ -0,0 +1,271 @@
+/*
+ * Cluster Power Controller emulation
+ *
+ * Copyright (c) 2016 Imagination Technologies
+ *
+ * Copyright (c) 2025 MIPS
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qapi/error.h"
+#include "cpu.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qemu/timer.h"
+#include "qemu/bitops.h"
+#include "hw/sysbus.h"
+#include "migration/vmstate.h"
+
+#include "hw/misc/riscv_cpc.h"
+#include "hw/qdev-properties.h"
+#include "hw/intc/riscv_aclint.h"
+#include "hw/resettable.h"
+
+static inline uint64_t cpc_vp_run_mask(RISCVCPCState *cpc)
+{
+ return MAKE_64BIT_MASK(0, cpc->num_vp);
+}
+
+static void riscv_cpu_reset_async_work(CPUState *cs, run_on_cpu_data data)
+{
+ RISCVCPCState *cpc = (RISCVCPCState *) data.host_ptr;
+ int i;
+
+ cpu_reset(cs);
+ cs->halted = 0;
+
+ /* Find this CPU's index in the CPC's CPU array */
+ for (i = 0; i < cpc->num_vp; i++) {
+ if (cpc->cpus[i] == cs) {
+ cpc->vps_running_mask |= BIT_ULL(i);
+ break;
+ }
+ }
+}
+
+static void cpc_run_vp(RISCVCPCState *cpc, uint64_t vps_run_mask)
+{
+ int vp;
+
+ for (vp = 0; vp < cpc->num_vp; vp++) {
+ CPUState *cs = cpc->cpus[vp];
+
+ if (!extract64(vps_run_mask, vp, 1)) {
+ continue;
+ }
+
+ if (extract64(cpc->vps_running_mask, vp, 1)) {
+ continue;
+ }
+
+ /*
+ * To avoid racing with a CPU we are just kicking off.
+ * We do the final bit of preparation for the work in
+ * the target CPUs context.
+ */
+ async_safe_run_on_cpu(cs, riscv_cpu_reset_async_work,
+ RUN_ON_CPU_HOST_PTR(cpc));
+ }
+}
+
+static void cpc_stop_vp(RISCVCPCState *cpc, uint64_t vps_stop_mask)
+{
+ int vp;
+
+ for (vp = 0; vp < cpc->num_vp; vp++) {
+ CPUState *cs = cpc->cpus[vp];
+
+ if (!extract64(vps_stop_mask, vp, 1)) {
+ continue;
+ }
+
+ if (!extract64(cpc->vps_running_mask, vp, 1)) {
+ continue;
+ }
+
+ cpu_interrupt(cs, CPU_INTERRUPT_HALT);
+ cpc->vps_running_mask &= ~BIT_ULL(vp);
+ }
+}
+
+static void cpc_write(void *opaque, hwaddr offset, uint64_t data,
+ unsigned size)
+{
+ RISCVCPCState *s = opaque;
+ int cpu_index, c;
+
+ for (c = 0; c < s->num_core; c++) {
+ cpu_index = c * s->num_hart +
+ s->cluster_id * s->num_core * s->num_hart;
+ if (offset == CPC_CL_BASE_OFS + CPC_VP_RUN_OFS + c * CPC_CORE_REG_STRIDE) {
+ cpc_run_vp(s, (data << cpu_index) & cpc_vp_run_mask(s));
+ return;
+ }
+ if (offset == CPC_CL_BASE_OFS + CPC_VP_STOP_OFS + c * CPC_CORE_REG_STRIDE) {
+ cpc_stop_vp(s, (data << cpu_index) & cpc_vp_run_mask(s));
+ return;
+ }
+ }
+
+ switch (offset) {
+ default:
+ qemu_log_mask(LOG_UNIMP,
+ "%s: Bad offset 0x%x\n", __func__, (int)offset);
+ break;
+ }
+
+ return;
+}
+
+static uint64_t cpc_read(void *opaque, hwaddr offset, unsigned size)
+{
+ RISCVCPCState *s = opaque;
+ int c;
+
+ for (c = 0; c < s->num_core; c++) {
+ if (offset == CPC_CL_BASE_OFS + CPC_STAT_CONF_OFS + c * CPC_CORE_REG_STRIDE) {
+ /* Return the state as U6. */
+ return CPC_Cx_STAT_CONF_SEQ_STATE_U6;
+ }
+ }
+
+ switch (offset) {
+ case CPC_CM_STAT_CONF_OFS:
+ return CPC_Cx_STAT_CONF_SEQ_STATE_U5;
+ case CPC_MTIME_REG_OFS:
+ return muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL),
+ RISCV_ACLINT_DEFAULT_TIMEBASE_FREQ,
+ NANOSECONDS_PER_SECOND);
+ return 0;
+ default:
+ qemu_log_mask(LOG_UNIMP,
+ "%s: Bad offset 0x%x\n", __func__, (int)offset);
+ return 0;
+ }
+}
+
+static const MemoryRegionOps cpc_ops = {
+ .read = cpc_read,
+ .write = cpc_write,
+ .endianness = DEVICE_LITTLE_ENDIAN,
+ .impl = {
+ .min_access_size = 8,
+ },
+};
+
+static void riscv_cpc_init(Object *obj)
+{
+ SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+ RISCVCPCState *s = RISCV_CPC(obj);
+ int i;
+
+ memory_region_init_io(&s->mr, OBJECT(s), &cpc_ops, s, "xmips-cpc",
+ CPC_ADDRSPACE_SZ);
+ sysbus_init_mmio(sbd, &s->mr);
+
+ /* Allocate CPU array */
+ s->cpus = g_new0(CPUState *, CPC_MAX_VPS);
+
+ /* Create link properties for each possible CPU slot */
+ for (i = 0; i < CPC_MAX_VPS; i++) {
+ char *propname = g_strdup_printf("cpu[%d]", i);
+ object_property_add_link(obj, propname, TYPE_CPU,
+ (Object **)&s->cpus[i],
+ qdev_prop_allow_set_link_before_realize,
+ OBJ_PROP_LINK_STRONG);
+ g_free(propname);
+ }
+}
+
+static void riscv_cpc_realize(DeviceState *dev, Error **errp)
+{
+ RISCVCPCState *s = RISCV_CPC(dev);
+ int i;
+
+ if (s->vps_start_running_mask & ~cpc_vp_run_mask(s)) {
+ error_setg(errp,
+ "incorrect vps-start-running-mask 0x%" PRIx64 " for num_vp = %d",
+ s->vps_start_running_mask, s->num_vp);
+ return;
+ }
+
+ /* Verify that required CPUs have been linked */
+ for (i = 0; i < s->num_vp; i++) {
+ if (!s->cpus[i]) {
+ error_setg(errp, "CPU %d has not been linked", i);
+ return;
+ }
+ }
+}
+
+static void riscv_cpc_reset_hold(Object *obj, ResetType type)
+{
+ RISCVCPCState *s = RISCV_CPC(obj);
+
+ /* Reflect the fact that all VPs are halted on reset */
+ s->vps_running_mask = 0;
+
+ /* Put selected VPs into run state */
+ cpc_run_vp(s, s->vps_start_running_mask);
+}
+
+static const VMStateDescription vmstate_riscv_cpc = {
+ .name = "xmips-cpc",
+ .version_id = 0,
+ .minimum_version_id = 0,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(vps_running_mask, RISCVCPCState),
+ VMSTATE_END_OF_LIST()
+ },
+};
+
+static const Property riscv_cpc_properties[] = {
+ DEFINE_PROP_UINT32("cluster-id", RISCVCPCState, cluster_id, 0x0),
+ DEFINE_PROP_UINT32("num-vp", RISCVCPCState, num_vp, 0x1),
+ DEFINE_PROP_UINT32("num-hart", RISCVCPCState, num_hart, 0x1),
+ DEFINE_PROP_UINT32("num-core", RISCVCPCState, num_core, 0x1),
+ DEFINE_PROP_UINT64("vps-start-running-mask", RISCVCPCState, vps_start_running_mask, 0x1),
+};
+
+static void riscv_cpc_class_init(ObjectClass *klass, const void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ ResettableClass *rc = RESETTABLE_CLASS(klass);
+
+ dc->realize = riscv_cpc_realize;
+ rc->phases.hold = riscv_cpc_reset_hold;
+ dc->vmsd = &vmstate_riscv_cpc;
+ device_class_set_props(dc, riscv_cpc_properties);
+ dc->user_creatable = false;
+}
+
+static const TypeInfo riscv_cpc_info = {
+ .name = TYPE_RISCV_CPC,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(RISCVCPCState),
+ .instance_init = riscv_cpc_init,
+ .class_init = riscv_cpc_class_init,
+};
+
+static void riscv_cpc_register_types(void)
+{
+ type_register_static(&riscv_cpc_info);
+}
+
+type_init(riscv_cpc_register_types)
diff --git a/include/hw/misc/riscv_cpc.h b/include/hw/misc/riscv_cpc.h
new file mode 100644
index 0000000000..3e908f4f44
--- /dev/null
+++ b/include/hw/misc/riscv_cpc.h
@@ -0,0 +1,75 @@
+/*
+ * Cluster Power Controller emulation
+ *
+ * Copyright (c) 2016 Imagination Technologies
+ *
+ * Copyright (c) 2025 MIPS
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ *
+ */
+
+#ifndef RISCV_CPC_H
+#define RISCV_CPC_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define CPC_ADDRSPACE_SZ 0x6000
+
+/* CPC global register offsets relative to base address */
+#define CPC_MTIME_REG_OFS 0x50
+
+#define CPC_CM_STAT_CONF_OFS 0x1008
+
+/* CPC blocks offsets relative to base address */
+#define CPC_CL_BASE_OFS 0x2000
+#define CPC_CORE_REG_STRIDE 0x100 /* Stride between core-specific registers */
+
+/* CPC register offsets relative to block offsets */
+#define CPC_STAT_CONF_OFS 0x08
+#define CPC_VP_STOP_OFS 0x20
+#define CPC_VP_RUN_OFS 0x28
+#define CPC_VP_RUNNING_OFS 0x30
+
+#define SEQ_STATE_BIT 19
+#define SEQ_STATE_U5 0x6
+#define SEQ_STATE_U6 0x7
+#define CPC_Cx_STAT_CONF_SEQ_STATE_U5 (SEQ_STATE_U5 << SEQ_STATE_BIT)
+#define CPC_Cx_STAT_CONF_SEQ_STATE_U6 (SEQ_STATE_U6 << SEQ_STATE_BIT)
+
+#define TYPE_RISCV_CPC "xmips-cpc"
+OBJECT_DECLARE_SIMPLE_TYPE(RISCVCPCState, RISCV_CPC)
+
+typedef struct RISCVCPCState {
+ SysBusDevice parent_obj;
+
+ uint32_t cluster_id;
+ uint32_t num_vp;
+ uint32_t num_hart;
+ uint32_t num_core;
+ uint64_t vps_start_running_mask; /* VPs running from restart mask */
+
+ MemoryRegion mr;
+ uint64_t vps_running_mask; /* Indicates which VPs are in the run state mask */
+
+ /* Array of CPUs managed by this CPC */
+ CPUState **cpus;
+} RISCVCPCState;
+
+#define CPC_MAX_VPS 64 /* Maximum number of VPs supported */
+
+#endif /* RISCV_CPC_H */
--
2.34.1On Mon, Sep 01, 2025 at 10:29:05AM +0000, Djordje Todorovic wrote:
> Add RISC-V implementation of the Cluster Power Controller (CPC) device.
> It is based on the existing MIPS CPC implementations but adapted for
> RISC-V systems.
>
> The CPC device manages power control for CPU clusters in RISC-V
> systems.
>
> This is needed for the MIPS BOSTON AIA board.
>
> Signed-off-by: Chao-ying Fu <cfu@mips.com>
> Signed-off-by: Djordje Todorovic <djordje.todorovic@htecgroup.com>
> Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
> ---
> hw/misc/Kconfig | 4 +
> hw/misc/meson.build | 1 +
> hw/misc/riscv_cpc.c | 271 ++++++++++++++++++++++++++++++++++++
> include/hw/misc/riscv_cpc.h | 75 ++++++++++
> 4 files changed, 351 insertions(+)
> create mode 100644 hw/misc/riscv_cpc.c
> create mode 100644 include/hw/misc/riscv_cpc.h
>
> diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
> index c72927c3ff..1e35bcd443 100644
> --- a/hw/misc/Kconfig
> +++ b/hw/misc/Kconfig
> @@ -124,11 +124,15 @@ config MIPS_ITU
> config RISCV_CMGCR
> bool
>
> +config RISCV_CPC
> + bool
> +
> config MIPS_BOSTON_AIA
> bool
> default y
> depends on RISCV64
> select RISCV_CMGCR
> + select RISCV_CPC
>
> config MPS2_FPGAIO
> bool
> diff --git a/hw/misc/meson.build b/hw/misc/meson.build
> index ef891e465b..1f9945755f 100644
> --- a/hw/misc/meson.build
> +++ b/hw/misc/meson.build
> @@ -158,6 +158,7 @@ specific_ss.add(when: 'CONFIG_MIPS_CPS', if_true: files('mips_cmgcr.c', 'mips_cp
> specific_ss.add(when: 'CONFIG_MIPS_ITU', if_true: files('mips_itu.c'))
>
> specific_ss.add(when: 'CONFIG_RISCV_CMGCR', if_true: files('riscv_cmgcr.c'))
> +specific_ss.add(when: 'CONFIG_RISCV_CPC', if_true: files('riscv_cpc.c'))
>
> system_ss.add(when: 'CONFIG_SBSA_REF', if_true: files('sbsa_ec.c'))
>
> diff --git a/hw/misc/riscv_cpc.c b/hw/misc/riscv_cpc.c
> new file mode 100644
> index 0000000000..6a6cf72d45
> --- /dev/null
> +++ b/hw/misc/riscv_cpc.c
> @@ -0,0 +1,271 @@
> +/*
> + * Cluster Power Controller emulation
> + *
> + * Copyright (c) 2016 Imagination Technologies
> + *
> + * Copyright (c) 2025 MIPS
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library 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
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + *
> + * SPDX-License-Identifier: LGPL-2.1-or-later
As this was copied from an existing file, just leave the original GPL
header here unchanged, don't add a SPDX tag to pre-existing code, only
to newly authored files.
> diff --git a/include/hw/misc/riscv_cpc.h b/include/hw/misc/riscv_cpc.h
> new file mode 100644
> index 0000000000..3e908f4f44
> --- /dev/null
> +++ b/include/hw/misc/riscv_cpc.h
> @@ -0,0 +1,75 @@
> +/*
> + * Cluster Power Controller emulation
> + *
> + * Copyright (c) 2016 Imagination Technologies
> + *
> + * Copyright (c) 2025 MIPS
> + *
> + * This library is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU Lesser General Public
> + * License as published by the Free Software Foundation; either
> + * version 2.1 of the License, or (at your option) any later version.
> + *
> + * This library 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
> + * Lesser General Public License for more details.
> + *
> + * You should have received a copy of the GNU Lesser General Public
> + * License along with this library; if not, see <http://www.gnu.org/licenses/>.
> + *
> + * SPDX-License-Identifier: LGPL-2.1-or-later
> + *
> + */
Same points as above.
With regards,
Daniel
--
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