Add RISC-V implementation of the Coherent Manager Global Control
Register (CMGCR) device. It is based on the existing MIPS CMGCR
implementation but adapted for RISC-V systems.
The CMGCR device provides global system control for multi-core
configurations 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 | 9 ++
hw/misc/meson.build | 2 +
hw/misc/riscv_cmgcr.c | 246 ++++++++++++++++++++++++++++++++++
include/hw/misc/riscv_cmgcr.h | 50 +++++++
4 files changed, 307 insertions(+)
create mode 100644 hw/misc/riscv_cmgcr.c
create mode 100644 include/hw/misc/riscv_cmgcr.h
diff --git a/hw/misc/Kconfig b/hw/misc/Kconfig
index 4e35657468..c72927c3ff 100644
--- a/hw/misc/Kconfig
+++ b/hw/misc/Kconfig
@@ -121,6 +121,15 @@ config MIPS_ITU
bool
depends on TCG
+config RISCV_CMGCR
+ bool
+
+config MIPS_BOSTON_AIA
+ bool
+ default y
+ depends on RISCV64
+ select RISCV_CMGCR
+
config MPS2_FPGAIO
bool
select LED
diff --git a/hw/misc/meson.build b/hw/misc/meson.build
index b1d8d8e5d2..ef891e465b 100644
--- a/hw/misc/meson.build
+++ b/hw/misc/meson.build
@@ -157,6 +157,8 @@ specific_ss.add(when: 'CONFIG_MAC_VIA', if_true: files('mac_via.c'))
specific_ss.add(when: 'CONFIG_MIPS_CPS', if_true: files('mips_cmgcr.c', 'mips_cpc.c'))
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'))
+
system_ss.add(when: 'CONFIG_SBSA_REF', if_true: files('sbsa_ec.c'))
# HPPA devices
diff --git a/hw/misc/riscv_cmgcr.c b/hw/misc/riscv_cmgcr.c
new file mode 100644
index 0000000000..cb8351a3bf
--- /dev/null
+++ b/hw/misc/riscv_cmgcr.c
@@ -0,0 +1,246 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
+ * Authors: Sanjay Lal <sanjayl@kymasys.com>
+ *
+ * Copyright (C) 2015 Imagination Technologies
+ *
+ * Copyright (C) 2025 MIPS
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+#include "qapi/error.h"
+#include "hw/sysbus.h"
+#include "migration/vmstate.h"
+#include "hw/misc/riscv_cmgcr.h"
+#include "hw/qdev-properties.h"
+
+#include "cpu.h"
+
+#define CM_RESET_VEC 0x1FC00000
+#define GCR_ADDRSPACE_SZ 0x8000
+
+/* Offsets to register blocks */
+#define RISCV_GCB_OFS 0x0000 /* Global Control Block */
+#define RISCV_CLCB_OFS 0x2000 /* Core Control Block */
+#define RISCV_CORE_REG_STRIDE 0x100 /* Stride between core-specific registers */
+
+/* Global Control Block Register Map */
+#define GCR_CONFIG_OFS 0x0000
+#define GCR_BASE_OFS 0x0008
+#define GCR_REV_OFS 0x0030
+#define GCR_CPC_STATUS_OFS 0x00F0
+#define GCR_L2_CONFIG_OFS 0x0130
+
+/* GCR_L2_CONFIG register fields */
+#define GCR_L2_CONFIG_BYPASS_SHF 20
+#define GCR_L2_CONFIG_BYPASS_MSK ((0x1ULL) << GCR_L2_CONFIG_BYPASS_SHF)
+
+/* GCR_BASE register fields */
+#define GCR_BASE_GCRBASE_MSK 0xffffffff8000ULL
+
+/* GCR_CPC_BASE register fields */
+#define GCR_CPC_BASE_CPCEN_MSK 1
+#define GCR_CPC_BASE_CPCBASE_MSK 0xFFFFFFFF8000ULL
+#define GCR_CPC_BASE_MSK (GCR_CPC_BASE_CPCEN_MSK | GCR_CPC_BASE_CPCBASE_MSK)
+
+/* GCR_CL_RESETBASE_OFS register fields */
+#define GCR_CL_RESET_BASE_RESETBASE_MSK 0xFFFFFFFFFFFFF000U
+#define GCR_CL_RESET_BASE_MSK GCR_CL_RESET_BASE_RESETBASE_MSK
+
+static inline bool is_cpc_connected(RISCVGCRState *s)
+{
+ return s->cpc_mr != NULL;
+}
+
+static inline void update_cpc_base(RISCVGCRState *gcr, uint64_t val)
+{
+ if (is_cpc_connected(gcr)) {
+ gcr->cpc_base = val & GCR_CPC_BASE_MSK;
+ memory_region_transaction_begin();
+ memory_region_set_address(gcr->cpc_mr,
+ gcr->cpc_base & GCR_CPC_BASE_CPCBASE_MSK);
+ memory_region_set_enabled(gcr->cpc_mr,
+ gcr->cpc_base & GCR_CPC_BASE_CPCEN_MSK);
+ memory_region_transaction_commit();
+ }
+}
+
+static inline void update_gcr_base(RISCVGCRState *gcr, uint64_t val)
+{
+ gcr->gcr_base = val & GCR_BASE_GCRBASE_MSK;
+ memory_region_set_address(&gcr->iomem, gcr->gcr_base);
+
+ /*
+ * For boston-aia, cpc_base is set to gcr_base + 0x8001 to enable
+ * cpc automatically.
+ */
+ update_cpc_base(gcr, val + 0x8001);
+}
+
+/* Read GCR registers */
+static uint64_t gcr_read(void *opaque, hwaddr addr, unsigned size)
+{
+ RISCVGCRState *gcr = (RISCVGCRState *) opaque;
+
+ switch (addr) {
+ /* Global Control Block Register */
+ case GCR_CONFIG_OFS:
+ /* Set PCORES to 0 */
+ return 0;
+ case GCR_BASE_OFS:
+ return gcr->gcr_base;
+ case GCR_REV_OFS:
+ return gcr->gcr_rev;
+ case GCR_CPC_STATUS_OFS:
+ return is_cpc_connected(gcr);
+ case GCR_L2_CONFIG_OFS:
+ /* L2 BYPASS */
+ return GCR_L2_CONFIG_BYPASS_MSK;
+ default:
+ qemu_log_mask(LOG_UNIMP, "Read %d bytes at GCR offset 0x%" HWADDR_PRIx
+ "\n", size, addr);
+ }
+ return 0;
+}
+
+static inline target_ulong get_exception_base(RISCVGCRVPState *vps)
+{
+ return vps->reset_base & GCR_CL_RESET_BASE_RESETBASE_MSK;
+}
+
+/* Write GCR registers */
+static void gcr_write(void *opaque, hwaddr addr, uint64_t data, unsigned size)
+{
+ RISCVGCRState *gcr = (RISCVGCRState *)opaque;
+ RISCVGCRVPState *current_vps;
+ int cpu_index, c, h;
+
+ for (c = 0; c < gcr->num_core; c++) {
+ for (h = 0; h < gcr->num_hart; h++) {
+ if (addr == RISCV_CLCB_OFS + c * RISCV_CORE_REG_STRIDE + h * 8) {
+ cpu_index = c * gcr->num_hart + h;
+ current_vps = &gcr->vps[cpu_index];
+ current_vps->reset_base = data & GCR_CL_RESET_BASE_MSK;
+ cpu_set_exception_base(cpu_index + gcr->cluster_id *
+ gcr->num_core * gcr->num_hart,
+ get_exception_base(current_vps));
+ return;
+ }
+ }
+ }
+
+ switch (addr) {
+ case GCR_BASE_OFS:
+ update_gcr_base(gcr, data);
+ break;
+ default:
+ qemu_log_mask(LOG_UNIMP, "Write %d bytes at GCR offset 0x%" HWADDR_PRIx
+ " 0x%" PRIx64 "\n", size, addr, data);
+ break;
+ }
+}
+
+static const MemoryRegionOps gcr_ops = {
+ .read = gcr_read,
+ .write = gcr_write,
+ .endianness = DEVICE_NATIVE_ENDIAN,
+ .impl = {
+ .max_access_size = 8,
+ },
+};
+
+static void riscv_gcr_init(Object *obj)
+{
+ SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+ RISCVGCRState *s = RISCV_GCR(obj);
+
+ memory_region_init_io(&s->iomem, OBJECT(s), &gcr_ops, s,
+ "riscv-gcr", GCR_ADDRSPACE_SZ);
+ sysbus_init_mmio(sbd, &s->iomem);
+}
+
+static void riscv_gcr_reset(DeviceState *dev)
+{
+ RISCVGCRState *s = RISCV_GCR(dev);
+ int i;
+
+ /* Update cpc_base to gcr_base + 0x8001 to enable cpc automatically. */
+ update_cpc_base(s, s->gcr_base + 0x8001);
+
+ for (i = 0; i < s->num_vps; i++) {
+ s->vps[i].reset_base = CM_RESET_VEC & GCR_CL_RESET_BASE_MSK;
+ cpu_set_exception_base(i, get_exception_base(&s->vps[i]));
+ }
+}
+
+static const VMStateDescription vmstate_riscv_gcr = {
+ .name = "riscv-gcr",
+ .version_id = 0,
+ .minimum_version_id = 0,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT64(cpc_base, RISCVGCRState),
+ VMSTATE_END_OF_LIST()
+ },
+};
+
+static const Property riscv_gcr_properties[] = {
+ DEFINE_PROP_UINT32("cluster-id", RISCVGCRState, cluster_id, 0),
+ DEFINE_PROP_UINT32("num-vp", RISCVGCRState, num_vps, 1),
+ DEFINE_PROP_UINT32("num-hart", RISCVGCRState, num_hart, 1),
+ DEFINE_PROP_UINT32("num-core", RISCVGCRState, num_core, 1),
+ DEFINE_PROP_INT32("gcr-rev", RISCVGCRState, gcr_rev, 0xa00),
+ DEFINE_PROP_UINT64("gcr-base", RISCVGCRState, gcr_base, GCR_BASE_ADDR),
+ DEFINE_PROP_LINK("cpc", RISCVGCRState, cpc_mr, TYPE_MEMORY_REGION,
+ MemoryRegion *),
+};
+
+static void riscv_gcr_realize(DeviceState *dev, Error **errp)
+{
+ RISCVGCRState *s = RISCV_GCR(dev);
+
+ /* Validate num_vps */
+ if (s->num_vps == 0) {
+ error_setg(errp, "num-vp must be at least 1");
+ return;
+ }
+ if (s->num_vps > GCR_MAX_VPS) {
+ error_setg(errp, "num-vp cannot exceed %d", GCR_MAX_VPS);
+ return;
+ }
+
+ /* Create local set of registers for each VP */
+ s->vps = g_new(RISCVGCRVPState, s->num_vps);
+}
+
+static void riscv_gcr_class_init(ObjectClass *klass, const void *data)
+{
+ DeviceClass *dc = DEVICE_CLASS(klass);
+ device_class_set_props(dc, riscv_gcr_properties);
+ dc->vmsd = &vmstate_riscv_gcr;
+ device_class_set_legacy_reset(dc, riscv_gcr_reset);
+ dc->realize = riscv_gcr_realize;
+}
+
+static const TypeInfo riscv_gcr_info = {
+ .name = TYPE_RISCV_GCR,
+ .parent = TYPE_SYS_BUS_DEVICE,
+ .instance_size = sizeof(RISCVGCRState),
+ .instance_init = riscv_gcr_init,
+ .class_init = riscv_gcr_class_init,
+};
+
+static void riscv_gcr_register_types(void)
+{
+ type_register_static(&riscv_gcr_info);
+}
+
+type_init(riscv_gcr_register_types)
diff --git a/include/hw/misc/riscv_cmgcr.h b/include/hw/misc/riscv_cmgcr.h
new file mode 100644
index 0000000000..c57d4ada1c
--- /dev/null
+++ b/include/hw/misc/riscv_cmgcr.h
@@ -0,0 +1,50 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2015 Imagination Technologies
+ *
+ * Copyright (C) 2025 MIPS
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ *
+ */
+
+#ifndef RISCV_CMGCR_H
+#define RISCV_CMGCR_H
+
+#include "hw/sysbus.h"
+#include "qom/object.h"
+
+#define TYPE_RISCV_GCR "riscv-gcr"
+OBJECT_DECLARE_SIMPLE_TYPE(RISCVGCRState, RISCV_GCR)
+
+#define GCR_BASE_ADDR 0x1fb80000ULL
+#define GCR_MAX_VPS 256
+
+typedef struct RISCVGCRVPState RISCVGCRVPState;
+struct RISCVGCRVPState {
+ uint64_t reset_base;
+};
+
+typedef struct RISCVGCRState RISCVGCRState;
+struct RISCVGCRState {
+ SysBusDevice parent_obj;
+
+ int32_t gcr_rev;
+ uint32_t cluster_id;
+ uint32_t num_vps;
+ uint32_t num_hart;
+ uint32_t num_core;
+ hwaddr gcr_base;
+ MemoryRegion iomem;
+ MemoryRegion *cpc_mr;
+
+ uint64_t cpc_base;
+
+ /* VP Local/Other Registers */
+ RISCVGCRVPState *vps;
+};
+
+#endif /* RISCV_CMGCR_H */
--
2.34.1© 2016 - 2025 Red Hat, Inc.