hw/intc: ibex_plic: Convert the PLIC to use RISC-V CPU GPIO lines

Instead of using riscv_cpu_update_mip() let's instead use the new RISC-V
CPU GPIO lines to set the external MIP bits.

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 0a76946981852f5bd15f0c37ab35b253371027a8.1630301632.git.alistair.francis@wdc.com

hw/intc/ibex_plic.c

@@ -27,6 +27,7 @@
 #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)
 {
@@ -92,19 +93,10 @@ static bool ibex_plic_irqs_pending(IbexPlicState *s, uint32_t context)
 
 static void ibex_plic_update(IbexPlicState *s)
 {
-    CPUState *cpu;
+    int i;
-    int level, i;
 
     for (i = 0; i < s->num_cpus; i++) {
-        cpu = qemu_get_cpu(i);
+        qemu_set_irq(s->external_irqs[i], ibex_plic_irqs_pending(s, 0));
-
-        if (!cpu) {
-            continue;
-        }
-
-        level = ibex_plic_irqs_pending(s, 0);
-
-        riscv_cpu_update_mip(RISCV_CPU(cpu), MIP_MEIP, BOOL_TO_MASK(level));
     }
 }
 
@@ -268,6 +260,9 @@ static void ibex_plic_realize(DeviceState *dev, Error **errp)
 
     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

hw/riscv/opentitan.c

@@ -118,6 +118,7 @@ static void lowrisc_ibex_soc_realize(DeviceState *dev_soc, Error **errp)
     MachineState *ms = MACHINE(qdev_get_machine());
     LowRISCIbexSoCState *s = RISCV_IBEX_SOC(dev_soc);
     MemoryRegion *sys_mem = get_system_memory();
+    int i;
 
     object_property_set_str(OBJECT(&s->cpus), "cpu-type", ms->cpu_type,
                             &error_abort);
@@ -149,6 +150,13 @@ static void lowrisc_ibex_soc_realize(DeviceState *dev_soc, Error **errp)
     }
     sysbus_mmio_map(SYS_BUS_DEVICE(&s->plic), 0, memmap[IBEX_DEV_PLIC].base);
 
+    for (i = 0; i < ms->smp.cpus; i++) {
+        CPUState *cpu = qemu_get_cpu(i);
+
+        qdev_connect_gpio_out(DEVICE(&s->plic), i,
+                              qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
+    }
+
     /* UART */
     qdev_prop_set_chr(DEVICE(&(s->uart)), "chardev", serial_hd(0));
     if (!sysbus_realize(SYS_BUS_DEVICE(&s->uart), errp)) {

include/hw/intc/ibex_plic.h

@@ -60,6 +60,8 @@ struct IbexPlicState {
     uint32_t threshold_base;
 
     uint32_t claim_base;
+
+    qemu_irq *external_irqs;
 };
 
 #endif /* HW_IBEX_PLIC_H */