[PATCH v1 2/9] hw/intc: Remove the Ibex PLIC

[Alistair Francis]

From: Alistair Francis <alistair.francis@wdc.com>

The Ibex PLIC is now spec complient. Let's remove the Ibex PLIC and
instead use the SiFive PLIC.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 hw/intc/ibex_plic.c | 307 --------------------------------------------
 hw/intc/meson.build |   1 -
 2 files changed, 308 deletions(-)
 delete mode 100644 hw/intc/ibex_plic.c

diff --git a/hw/intc/ibex_plic.c b/hw/intc/ibex_plic.c
deleted file mode 100644
index ff430356f8..0000000000
--- a/hw/intc/ibex_plic.c
+++ /dev/null
@@ -1,307 +0,0 @@
-/*
- * QEMU RISC-V lowRISC Ibex PLIC
- *
- * Copyright (c) 2020 Western Digital
- *
- * Documentation avaliable: https://docs.opentitan.org/hw/ip/rv_plic/doc/
- *
- * 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 "hw/qdev-properties.h"
-#include "hw/core/cpu.h"
-#include "hw/boards.h"
-#include "hw/pci/msi.h"
-#include "target/riscv/cpu_bits.h"
-#include "target/riscv/cpu.h"
-#include "hw/intc/ibex_plic.h"
-#include "hw/irq.h"
-
-static bool addr_between(uint32_t addr, uint32_t base, uint32_t num)
-{
-    uint32_t end = base + (num * 0x04);
-
-    if (addr >= base && addr < end) {
-        return true;
-    }
-
-    return false;
-}
-
-static void ibex_plic_irqs_set_pending(IbexPlicState *s, int irq, bool level)
-{
-    int pending_num = irq / 32;
-
-    if (!level) {
-        /*
-         * If the level is low make sure we clear the hidden_pending.
-         */
-        s->hidden_pending[pending_num] &= ~(1 << (irq % 32));
-    }
-
-    if (s->claimed[pending_num] & 1 << (irq % 32)) {
-        /*
-         * The interrupt has been claimed, but not completed.
-         * The pending bit can't be set.
-         * Save the pending level for after the interrupt is completed.
-         */
-        s->hidden_pending[pending_num] |= level << (irq % 32);
-    } else {
-        s->pending[pending_num] |= level << (irq % 32);
-    }
-}
-
-static bool ibex_plic_irqs_pending(IbexPlicState *s, uint32_t context)
-{
-    int i;
-    uint32_t max_irq = 0;
-    uint32_t max_prio = s->threshold;
-
-    for (i = 0; i < s->pending_num; i++) {
-        uint32_t irq_num = ctz64(s->pending[i]) + (i * 32);
-
-        if (!(s->pending[i] & s->enable[i])) {
-            /* No pending and enabled IRQ */
-            continue;
-        }
-
-        if (s->priority[irq_num] > max_prio) {
-            max_irq = irq_num;
-            max_prio = s->priority[irq_num];
-        }
-    }
-
-    if (max_irq) {
-        s->claim = max_irq;
-        return true;
-    }
-
-    return false;
-}
-
-static void ibex_plic_update(IbexPlicState *s)
-{
-    int i;
-
-    for (i = 0; i < s->num_cpus; i++) {
-        qemu_set_irq(s->external_irqs[i], ibex_plic_irqs_pending(s, 0));
-    }
-}
-
-static void ibex_plic_reset(DeviceState *dev)
-{
-    IbexPlicState *s = IBEX_PLIC(dev);
-
-    s->threshold = 0x00000000;
-    s->claim = 0x00000000;
-}
-
-static uint64_t ibex_plic_read(void *opaque, hwaddr addr,
-                               unsigned int size)
-{
-    IbexPlicState *s = opaque;
-    int offset;
-    uint32_t ret = 0;
-
-    if (addr_between(addr, s->pending_base, s->pending_num)) {
-        offset = (addr - s->pending_base) / 4;
-        ret = s->pending[offset];
-    } else if (addr_between(addr, s->source_base, s->source_num)) {
-        qemu_log_mask(LOG_UNIMP,
-                      "%s: Interrupt source mode not supported\n", __func__);
-    } else if (addr_between(addr, s->priority_base, s->priority_num)) {
-        offset = (addr - s->priority_base) / 4;
-        ret = s->priority[offset];
-    } else if (addr_between(addr, s->enable_base, s->enable_num)) {
-        offset = (addr - s->enable_base) / 4;
-        ret = s->enable[offset];
-    } else if (addr_between(addr, s->threshold_base, 1)) {
-        ret = s->threshold;
-    } else if (addr_between(addr, s->claim_base, 1)) {
-        int pending_num = s->claim / 32;
-        s->pending[pending_num] &= ~(1 << (s->claim % 32));
-
-        /* Set the interrupt as claimed, but not completed */
-        s->claimed[pending_num] |= 1 << (s->claim % 32);
-
-        /* Return the current claimed interrupt */
-        ret = s->claim;
-
-        /* Clear the claimed interrupt */
-        s->claim = 0x00000000;
-
-        /* Update the interrupt status after the claim */
-        ibex_plic_update(s);
-    }
-
-    return ret;
-}
-
-static void ibex_plic_write(void *opaque, hwaddr addr,
-                            uint64_t value, unsigned int size)
-{
-    IbexPlicState *s = opaque;
-
-    if (addr_between(addr, s->pending_base, s->pending_num)) {
-        qemu_log_mask(LOG_GUEST_ERROR,
-                      "%s: Pending registers are read only\n", __func__);
-    } else if (addr_between(addr, s->source_base, s->source_num)) {
-        qemu_log_mask(LOG_UNIMP,
-                      "%s: Interrupt source mode not supported\n", __func__);
-    } else if (addr_between(addr, s->priority_base, s->priority_num)) {
-        uint32_t irq = ((addr - s->priority_base) >> 2) + 1;
-        s->priority[irq] = value & 7;
-        ibex_plic_update(s);
-    } else if (addr_between(addr, s->enable_base, s->enable_num)) {
-        uint32_t enable_reg = (addr - s->enable_base) / 4;
-
-        s->enable[enable_reg] = value;
-    } else if (addr_between(addr, s->threshold_base, 1)) {
-        s->threshold = value & 3;
-    } else if (addr_between(addr, s->claim_base, 1)) {
-        if (s->claim == value) {
-            /* Interrupt was completed */
-            s->claim = 0;
-        }
-        if (s->claimed[value / 32] & 1 << (value % 32)) {
-            int pending_num = value / 32;
-
-            /* This value was already claimed, clear it. */
-            s->claimed[pending_num] &= ~(1 << (value % 32));
-
-            if (s->hidden_pending[pending_num] & (1 << (value % 32))) {
-                /*
-                 * If the bit in hidden_pending is set then that means we
-                 * received an interrupt between claiming and completing
-                 * the interrupt that hasn't since been de-asserted.
-                 * On hardware this would trigger an interrupt, so let's
-                 * trigger one here as well.
-                 */
-                s->pending[pending_num] |= 1 << (value % 32);
-            }
-        }
-    }
-
-    ibex_plic_update(s);
-}
-
-static const MemoryRegionOps ibex_plic_ops = {
-    .read = ibex_plic_read,
-    .write = ibex_plic_write,
-    .endianness = DEVICE_NATIVE_ENDIAN,
-    .valid = {
-        .min_access_size = 4,
-        .max_access_size = 4
-    }
-};
-
-static void ibex_plic_irq_request(void *opaque, int irq, int level)
-{
-    IbexPlicState *s = opaque;
-
-    ibex_plic_irqs_set_pending(s, irq, level > 0);
-    ibex_plic_update(s);
-}
-
-static Property ibex_plic_properties[] = {
-    DEFINE_PROP_UINT32("num-cpus", IbexPlicState, num_cpus, 1),
-    DEFINE_PROP_UINT32("num-sources", IbexPlicState, num_sources, 176),
-
-    DEFINE_PROP_UINT32("pending-base", IbexPlicState, pending_base, 0),
-    DEFINE_PROP_UINT32("pending-num", IbexPlicState, pending_num, 6),
-
-    DEFINE_PROP_UINT32("source-base", IbexPlicState, source_base, 0x18),
-    DEFINE_PROP_UINT32("source-num", IbexPlicState, source_num, 6),
-
-    DEFINE_PROP_UINT32("priority-base", IbexPlicState, priority_base, 0x30),
-    DEFINE_PROP_UINT32("priority-num", IbexPlicState, priority_num, 177),
-
-    DEFINE_PROP_UINT32("enable-base", IbexPlicState, enable_base, 0x300),
-    DEFINE_PROP_UINT32("enable-num", IbexPlicState, enable_num, 6),
-
-    DEFINE_PROP_UINT32("threshold-base", IbexPlicState, threshold_base, 0x318),
-
-    DEFINE_PROP_UINT32("claim-base", IbexPlicState, claim_base, 0x31c),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
-static void ibex_plic_init(Object *obj)
-{
-    IbexPlicState *s = IBEX_PLIC(obj);
-
-    memory_region_init_io(&s->mmio, obj, &ibex_plic_ops, s,
-                          TYPE_IBEX_PLIC, 0x400);
-    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
-}
-
-static void ibex_plic_realize(DeviceState *dev, Error **errp)
-{
-    IbexPlicState *s = IBEX_PLIC(dev);
-    int i;
-
-    s->pending = g_new0(uint32_t, s->pending_num);
-    s->hidden_pending = g_new0(uint32_t, s->pending_num);
-    s->claimed = g_new0(uint32_t, s->pending_num);
-    s->source = g_new0(uint32_t, s->source_num);
-    s->priority = g_new0(uint32_t, s->priority_num);
-    s->enable = g_new0(uint32_t, s->enable_num);
-
-    qdev_init_gpio_in(dev, ibex_plic_irq_request, s->num_sources);
-
-    s->external_irqs = g_malloc(sizeof(qemu_irq) * s->num_cpus);
-    qdev_init_gpio_out(dev, s->external_irqs, s->num_cpus);
-
-    /*
-     * We can't allow the supervisor to control SEIP as this would allow the
-     * supervisor to clear a pending external interrupt which will result in
-     * a lost interrupt in the case a PLIC is attached. The SEIP bit must be
-     * hardware controlled when a PLIC is attached.
-     */
-    MachineState *ms = MACHINE(qdev_get_machine());
-    unsigned int smp_cpus = ms->smp.cpus;
-    for (i = 0; i < smp_cpus; i++) {
-        RISCVCPU *cpu = RISCV_CPU(qemu_get_cpu(i));
-        if (riscv_cpu_claim_interrupts(cpu, MIP_SEIP) < 0) {
-            error_report("SEIP already claimed");
-            exit(1);
-        }
-    }
-
-    msi_nonbroken = true;
-}
-
-static void ibex_plic_class_init(ObjectClass *klass, void *data)
-{
-    DeviceClass *dc = DEVICE_CLASS(klass);
-
-    dc->reset = ibex_plic_reset;
-    device_class_set_props(dc, ibex_plic_properties);
-    dc->realize = ibex_plic_realize;
-}
-
-static const TypeInfo ibex_plic_info = {
-    .name          = TYPE_IBEX_PLIC,
-    .parent        = TYPE_SYS_BUS_DEVICE,
-    .instance_size = sizeof(IbexPlicState),
-    .instance_init = ibex_plic_init,
-    .class_init    = ibex_plic_class_init,
-};
-
-static void ibex_plic_register_types(void)
-{
-    type_register_static(&ibex_plic_info);
-}
-
-type_init(ibex_plic_register_types)
diff --git a/hw/intc/meson.build b/hw/intc/meson.build
index a1d00aa48d..c89d2ca180 100644
--- a/hw/intc/meson.build
+++ b/hw/intc/meson.build
@@ -32,7 +32,6 @@ specific_ss.add(when: 'CONFIG_ARM_V7M', if_true: 
files('armv7m_nvic.c'))
 specific_ss.add(when: 'CONFIG_ASPEED_SOC', if_true: files('aspeed_vic.c'))
 specific_ss.add(when: 'CONFIG_EXYNOS4', if_true: files('exynos4210_gic.c', 
'exynos4210_combiner.c'))
 specific_ss.add(when: 'CONFIG_GRLIB', if_true: files('grlib_irqmp.c'))
-specific_ss.add(when: 'CONFIG_IBEX', if_true: files('ibex_plic.c'))
 specific_ss.add(when: 'CONFIG_IOAPIC', if_true: files('ioapic.c'))
 specific_ss.add(when: 'CONFIG_LOONGSON_LIOINTC', if_true: 
files('loongson_liointc.c'))
 specific_ss.add(when: 'CONFIG_MIPS_CPS', if_true: files('mips_gic.c'))
-- 
2.31.1