hw/riscv: add riscv-iommu-sys platform device

This device models the RISC-V IOMMU as a sysbus device. The same design
decisions taken in the riscv-iommu-pci device were kept, namely the
existence of 4 vectors are available for each interrupt cause.

The WSIs are emitted using the input of the s->notify() callback as a
index to an IRQ list. The IRQ list starts at 'base_irq' and goes until
base_irq + 3. This means that boards must have 4 contiguous IRQ lines
available, starting from 'base_irq'.

Signed-off-by: Tomasz Jeznach <tjeznach@rivosinc.com>
Signed-off-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-ID: <20241106133407.604587-4-dbarboza@ventanamicro.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

hw/riscv/meson.build

@@ -10,6 +10,6 @@ riscv_ss.add(when: 'CONFIG_SIFIVE_U', if_true: files('sifive_u.c'))
 riscv_ss.add(when: 'CONFIG_SPIKE', if_true: files('spike.c'))
 riscv_ss.add(when: 'CONFIG_MICROCHIP_PFSOC', if_true: files('microchip_pfsoc.c'))
 riscv_ss.add(when: 'CONFIG_ACPI', if_true: files('virt-acpi-build.c'))
-riscv_ss.add(when: 'CONFIG_RISCV_IOMMU', if_true: files('riscv-iommu.c', 'riscv-iommu-pci.c'))
+riscv_ss.add(when: 'CONFIG_RISCV_IOMMU', if_true: files('riscv-iommu.c', 'riscv-iommu-pci.c', 'riscv-iommu-sys.c'))
 
 hw_arch += {'riscv': riscv_ss}

hw/riscv/riscv-iommu-sys.c

@@ -0,0 +1,128 @@
+/*
+ * QEMU emulation of an RISC-V IOMMU Platform Device
+ *
+ * Copyright (C) 2022-2023 Rivos Inc.
+ *
+ * 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 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 "hw/irq.h"
+#include "hw/pci/pci_bus.h"
+#include "hw/qdev-properties.h"
+#include "hw/sysbus.h"
+#include "qapi/error.h"
+#include "qemu/error-report.h"
+#include "qemu/host-utils.h"
+#include "qemu/module.h"
+#include "qom/object.h"
+
+#include "riscv-iommu.h"
+
+#define RISCV_IOMMU_SYSDEV_ICVEC_VECTORS 0x3333
+
+/* RISC-V IOMMU System Platform Device Emulation */
+
+struct RISCVIOMMUStateSys {
+    SysBusDevice     parent;
+    uint64_t         addr;
+    uint32_t         base_irq;
+    DeviceState      *irqchip;
+    RISCVIOMMUState  iommu;
+    qemu_irq         irqs[RISCV_IOMMU_INTR_COUNT];
+};
+
+static void riscv_iommu_sysdev_notify(RISCVIOMMUState *iommu,
+                                      unsigned vector)
+{
+    RISCVIOMMUStateSys *s = container_of(iommu, RISCVIOMMUStateSys, iommu);
+    uint32_t fctl =  riscv_iommu_reg_get32(iommu, RISCV_IOMMU_REG_FCTL);
+
+    /* We do not support MSIs yet */
+    if (!(fctl & RISCV_IOMMU_FCTL_WSI)) {
+        return;
+    }
+
+    qemu_irq_pulse(s->irqs[vector]);
+}
+
+static void riscv_iommu_sys_realize(DeviceState *dev, Error **errp)
+{
+    RISCVIOMMUStateSys *s = RISCV_IOMMU_SYS(dev);
+    SysBusDevice *sysdev = SYS_BUS_DEVICE(s);
+    PCIBus *pci_bus;
+    qemu_irq irq;
+
+    qdev_realize(DEVICE(&s->iommu), NULL, errp);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iommu.regs_mr);
+    if (s->addr) {
+        sysbus_mmio_map(SYS_BUS_DEVICE(s), 0, s->addr);
+    }
+
+    pci_bus = (PCIBus *) object_resolve_path_type("", TYPE_PCI_BUS, NULL);
+    if (pci_bus) {
+        riscv_iommu_pci_setup_iommu(&s->iommu, pci_bus, errp);
+    }
+
+    s->iommu.notify = riscv_iommu_sysdev_notify;
+
+    /* 4 IRQs are defined starting from s->base_irq */
+    for (int i = 0; i < RISCV_IOMMU_INTR_COUNT; i++) {
+        sysbus_init_irq(sysdev, &s->irqs[i]);
+        irq = qdev_get_gpio_in(s->irqchip, s->base_irq + i);
+        sysbus_connect_irq(sysdev, i, irq);
+    }
+}
+
+static void riscv_iommu_sys_init(Object *obj)
+{
+    RISCVIOMMUStateSys *s = RISCV_IOMMU_SYS(obj);
+    RISCVIOMMUState *iommu = &s->iommu;
+
+    object_initialize_child(obj, "iommu", iommu, TYPE_RISCV_IOMMU);
+    qdev_alias_all_properties(DEVICE(iommu), obj);
+
+    iommu->icvec_avail_vectors = RISCV_IOMMU_SYSDEV_ICVEC_VECTORS;
+    riscv_iommu_set_cap_igs(iommu, RISCV_IOMMU_CAP_IGS_WSI);
+}
+
+static Property riscv_iommu_sys_properties[] = {
+    DEFINE_PROP_UINT64("addr", RISCVIOMMUStateSys, addr, 0),
+    DEFINE_PROP_UINT32("base-irq", RISCVIOMMUStateSys, base_irq, 0),
+    DEFINE_PROP_LINK("irqchip", RISCVIOMMUStateSys, irqchip,
+                     TYPE_DEVICE, DeviceState *),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void riscv_iommu_sys_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+    dc->realize = riscv_iommu_sys_realize;
+    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
+    device_class_set_props(dc, riscv_iommu_sys_properties);
+}
+
+static const TypeInfo riscv_iommu_sys = {
+    .name          = TYPE_RISCV_IOMMU_SYS,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .class_init    = riscv_iommu_sys_class_init,
+    .instance_init = riscv_iommu_sys_init,
+    .instance_size = sizeof(RISCVIOMMUStateSys),
+};
+
+static void riscv_iommu_register_sys(void)
+{
+    type_register_static(&riscv_iommu_sys);
+}
+
+type_init(riscv_iommu_register_sys)

hw/riscv/riscv-iommu.c

@@ -94,10 +94,9 @@ static uint8_t riscv_iommu_get_icvec_vector(uint32_t icvec, uint32_t vec_type)
 
 static void riscv_iommu_notify(RISCVIOMMUState *s, int vec_type)
 {
-    const uint32_t fctl = riscv_iommu_reg_get32(s, RISCV_IOMMU_REG_FCTL);
     uint32_t ipsr, icvec, vector;
 
-    if (fctl & RISCV_IOMMU_FCTL_WSI || !s->notify) {
+    if (!s->notify) {
         return;
     }
 

include/hw/riscv/iommu.h

@@ -33,4 +33,8 @@ typedef struct RISCVIOMMUSpace RISCVIOMMUSpace;
 OBJECT_DECLARE_SIMPLE_TYPE(RISCVIOMMUStatePci, RISCV_IOMMU_PCI)
 typedef struct RISCVIOMMUStatePci RISCVIOMMUStatePci;
 
+#define TYPE_RISCV_IOMMU_SYS "riscv-iommu-device"
+OBJECT_DECLARE_SIMPLE_TYPE(RISCVIOMMUStateSys, RISCV_IOMMU_SYS)
+typedef struct RISCVIOMMUStateSys RISCVIOMMUStateSys;
+
 #endif