Re: [PATCH v1 4/5] hw/intc: sifive_plic: Convert the PLIC to use RISC-V CPU GPIO lines

[Anup Patel]

On Fri, Jul 9, 2021 at 9:06 AM Alistair Francis
<alistair.francis@wdc.com> wrote:
>
> 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>
> ---
>  include/hw/intc/sifive_plic.h |  4 ++++
>  hw/intc/sifive_plic.c         | 38 ++++++++++++++++++++++++++++-------
>  hw/riscv/microchip_pfsoc.c    |  2 +-
>  hw/riscv/shakti_c.c           |  3 ++-
>  hw/riscv/sifive_e.c           |  2 +-
>  hw/riscv/sifive_u.c           |  2 +-
>  hw/riscv/virt.c               |  3 ++-
>  7 files changed, 42 insertions(+), 12 deletions(-)
>
> diff --git a/include/hw/intc/sifive_plic.h b/include/hw/intc/sifive_plic.h
> index 1e451a270c..da1dc64c6d 100644
> --- a/include/hw/intc/sifive_plic.h
> +++ b/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 *s_external_irqs;
> +    qemu_irq *m_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,
> diff --git a/hw/intc/sifive_plic.c b/hw/intc/sifive_plic.c
> index 78903beb06..dc17b55408 100644
> --- a/hw/intc/sifive_plic.c
> +++ b/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 +140,22 @@ 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));
> +            if (level) {
> +                qemu_irq_raise(plic->m_external_irqs[hartid]);
> +            } else {
> +                qemu_irq_lower(plic->m_external_irqs[hartid]);
> +            }
>              break;
>          case PLICMode_S:
> -            riscv_cpu_update_mip(RISCV_CPU(cpu), MIP_SEIP, 
> BOOL_TO_MASK(level));
> +            if (level) {
> +                qemu_irq_raise(plic->s_external_irqs[hartid]);
> +            } else {
> +                qemu_irq_lower(plic->s_external_irqs[hartid]);
> +            }

All qemu_irq_xyz() calls are broken for multi-socket, just like CLINT.

Please use "hartid - plic->hartid_base" as index.

Regards,
Anup

>              break;
>          default:
>              break;
> @@ -456,6 +461,12 @@ 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 +531,7 @@ 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 +539,8 @@ 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 +556,15 @@ 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_named(dev, NULL, i,
> +                                    qdev_get_gpio_in(DEVICE(cpu), 
> IRQ_S_EXT));
> +        qdev_connect_gpio_out_named(dev, NULL, num_harts + i,
> +                                    qdev_get_gpio_in(DEVICE(cpu), 
> IRQ_M_EXT));
> +    }
> +
>      return dev;
>  }
> diff --git a/hw/riscv/microchip_pfsoc.c b/hw/riscv/microchip_pfsoc.c
> index eb8e79e0a1..eef55f69fd 100644
> --- a/hw/riscv/microchip_pfsoc.c
> +++ b/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,
> diff --git a/hw/riscv/shakti_c.c b/hw/riscv/shakti_c.c
> index 18f70fadaa..09d4e1433e 100644
> --- a/hw/riscv/shakti_c.c
> +++ b/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,
> diff --git a/hw/riscv/sifive_e.c b/hw/riscv/sifive_e.c
> index ddc658c8d6..03bff21527 100644
> --- a/hw/riscv/sifive_e.c
> +++ b/hw/riscv/sifive_e.c
> @@ -198,7 +198,7 @@ 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,
> diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> index 273c86418c..6d1f9464c2 100644
> --- a/hw/riscv/sifive_u.c
> +++ b/hw/riscv/sifive_u.c
> @@ -829,7 +829,7 @@ 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,
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index 4a3cd2599a..8bbafae429 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -548,6 +548,7 @@ static void virt_machine_init(MachineState *machine)
>      MemoryRegion *system_memory = get_system_memory();
>      MemoryRegion *main_mem = g_new(MemoryRegion, 1);
>      MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
> +    MachineState *ms = MACHINE(qdev_get_machine());
>      char *plic_hart_config, *soc_name;
>      size_t plic_hart_config_len;
>      target_ulong start_addr = memmap[VIRT_DRAM].base;
> @@ -619,7 +620,7 @@ 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, ms->smp.cpus, base_hartid,
>              VIRT_PLIC_NUM_SOURCES,
>              VIRT_PLIC_NUM_PRIORITIES,
>              VIRT_PLIC_PRIORITY_BASE,
> --
> 2.31.1
>
>