hw/intc: sifive_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>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
Message-id: 0364190bfa935058a845c0fa1ecf650328840ad5.1630301632.git.alistair.francis@wdc.com

hw/intc/sifive_plic.c

@@ -29,6 +29,7 @@
 #include "hw/intc/sifive_plic.h"
 #include "target/riscv/cpu.h"
 #include "migration/vmstate.h"
+#include "hw/irq.h"
 
 #define RISCV_DEBUG_PLIC 0
 
@@ -139,18 +140,14 @@ static void sifive_plic_update(SiFivePLICState *plic)
     for (addrid = 0; addrid < plic->num_addrs; addrid++) {
         uint32_t hartid = plic->addr_config[addrid].hartid;
         PLICMode mode = plic->addr_config[addrid].mode;
-        CPUState *cpu = qemu_get_cpu(hartid);
-        CPURISCVState *env = cpu ? cpu->env_ptr : NULL;
-        if (!env) {
-            continue;
-        }
         int level = sifive_plic_irqs_pending(plic, addrid);
+
         switch (mode) {
         case PLICMode_M:
-            riscv_cpu_update_mip(RISCV_CPU(cpu), MIP_MEIP, BOOL_TO_MASK(level));
+            qemu_set_irq(plic->m_external_irqs[hartid - plic->hartid_base], level);
             break;
         case PLICMode_S:
-            riscv_cpu_update_mip(RISCV_CPU(cpu), MIP_SEIP, BOOL_TO_MASK(level));
+            qemu_set_irq(plic->s_external_irqs[hartid - plic->hartid_base], level);
             break;
         default:
             break;
@@ -456,6 +453,12 @@ static void sifive_plic_realize(DeviceState *dev, Error **errp)
     sysbus_init_mmio(SYS_BUS_DEVICE(dev), &plic->mmio);
     qdev_init_gpio_in(dev, sifive_plic_irq_request, plic->num_sources);
 
+    plic->s_external_irqs = g_malloc(sizeof(qemu_irq) * plic->num_harts);
+    qdev_init_gpio_out(dev, plic->s_external_irqs, plic->num_harts);
+
+    plic->m_external_irqs = g_malloc(sizeof(qemu_irq) * plic->num_harts);
+    qdev_init_gpio_out(dev, plic->m_external_irqs, plic->num_harts);
+
     /* 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
      * lost a interrupt in the case a PLIC is attached. The SEIP bit must be
@@ -520,6 +523,7 @@ type_init(sifive_plic_register_types)
  * Create PLIC device.
  */
 DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
+    uint32_t num_harts,
     uint32_t hartid_base, uint32_t num_sources,
     uint32_t num_priorities, uint32_t priority_base,
     uint32_t pending_base, uint32_t enable_base,
@@ -527,6 +531,8 @@ DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
     uint32_t context_stride, uint32_t aperture_size)
 {
     DeviceState *dev = qdev_new(TYPE_SIFIVE_PLIC);
+    int i;
+
     assert(enable_stride == (enable_stride & -enable_stride));
     assert(context_stride == (context_stride & -context_stride));
     qdev_prop_set_string(dev, "hart-config", hart_config);
@@ -542,5 +548,15 @@ DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
     qdev_prop_set_uint32(dev, "aperture-size", aperture_size);
     sysbus_realize_and_unref(SYS_BUS_DEVICE(dev), &error_fatal);
     sysbus_mmio_map(SYS_BUS_DEVICE(dev), 0, addr);
+
+    for (i = 0; i < num_harts; i++) {
+        CPUState *cpu = qemu_get_cpu(hartid_base + i);
+
+        qdev_connect_gpio_out(dev, i,
+                              qdev_get_gpio_in(DEVICE(cpu), IRQ_S_EXT));
+        qdev_connect_gpio_out(dev, num_harts + i,
+                              qdev_get_gpio_in(DEVICE(cpu), IRQ_M_EXT));
+    }
+
     return dev;
 }

hw/riscv/microchip_pfsoc.c

@@ -274,7 +274,7 @@ static void microchip_pfsoc_soc_realize(DeviceState *dev, Error **errp)
 
     /* PLIC */
     s->plic = sifive_plic_create(memmap[MICROCHIP_PFSOC_PLIC].base,
-        plic_hart_config, 0,
+        plic_hart_config, ms->smp.cpus, 0,
         MICROCHIP_PFSOC_PLIC_NUM_SOURCES,
         MICROCHIP_PFSOC_PLIC_NUM_PRIORITIES,
         MICROCHIP_PFSOC_PLIC_PRIORITY_BASE,

hw/riscv/shakti_c.c

@@ -106,13 +106,14 @@ type_init(shakti_c_machine_type_info_register)
 
 static void shakti_c_soc_state_realize(DeviceState *dev, Error **errp)
 {
+    MachineState *ms = MACHINE(qdev_get_machine());
     ShaktiCSoCState *sss = RISCV_SHAKTI_SOC(dev);
     MemoryRegion *system_memory = get_system_memory();
 
     sysbus_realize(SYS_BUS_DEVICE(&sss->cpus), &error_abort);
 
     sss->plic = sifive_plic_create(shakti_c_memmap[SHAKTI_C_PLIC].base,
-        (char *)SHAKTI_C_PLIC_HART_CONFIG, 0,
+        (char *)SHAKTI_C_PLIC_HART_CONFIG, ms->smp.cpus, 0,
         SHAKTI_C_PLIC_NUM_SOURCES,
         SHAKTI_C_PLIC_NUM_PRIORITIES,
         SHAKTI_C_PLIC_PRIORITY_BASE,

hw/riscv/sifive_e.c

@@ -197,7 +197,7 @@ static void sifive_e_soc_realize(DeviceState *dev, Error **errp)
 
     /* MMIO */
     s->plic = sifive_plic_create(memmap[SIFIVE_E_DEV_PLIC].base,
-        (char *)SIFIVE_E_PLIC_HART_CONFIG, 0,
+        (char *)SIFIVE_E_PLIC_HART_CONFIG, ms->smp.cpus, 0,
         SIFIVE_E_PLIC_NUM_SOURCES,
         SIFIVE_E_PLIC_NUM_PRIORITIES,
         SIFIVE_E_PLIC_PRIORITY_BASE,

hw/riscv/sifive_u.c

@@ -832,7 +832,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
 
     /* MMIO */
     s->plic = sifive_plic_create(memmap[SIFIVE_U_DEV_PLIC].base,
-        plic_hart_config, 0,
+        plic_hart_config, ms->smp.cpus, 0,
         SIFIVE_U_PLIC_NUM_SOURCES,
         SIFIVE_U_PLIC_NUM_PRIORITIES,
         SIFIVE_U_PLIC_PRIORITY_BASE,

hw/riscv/virt.c

@@ -625,7 +625,7 @@ static void virt_machine_init(MachineState *machine)
         /* Per-socket PLIC */
         s->plic[i] = sifive_plic_create(
             memmap[VIRT_PLIC].base + i * memmap[VIRT_PLIC].size,
-            plic_hart_config, base_hartid,
+            plic_hart_config, hart_count, base_hartid,
             VIRT_PLIC_NUM_SOURCES,
             VIRT_PLIC_NUM_PRIORITIES,
             VIRT_PLIC_PRIORITY_BASE,

include/hw/intc/sifive_plic.h

@@ -72,9 +72,13 @@ struct SiFivePLICState {
     uint32_t context_base;
     uint32_t context_stride;
     uint32_t aperture_size;
+
+    qemu_irq *m_external_irqs;
+    qemu_irq *s_external_irqs;
 };
 
 DeviceState *sifive_plic_create(hwaddr addr, char *hart_config,
+    uint32_t num_harts,
     uint32_t hartid_base, uint32_t num_sources,
     uint32_t num_priorities, uint32_t priority_base,
     uint32_t pending_base, uint32_t enable_base,