Re: [Qemu-devel] [PATCH v1 1/4] hw/riscv/sifive_u: Create a U54 SoC object

[Michael Clark <mjc@sifive.com>]

On Sat, May 5, 2018 at 8:12 AM, Alistair Francis <alistair.francis@wdc.com>
wrote:

> Create a SiFive Unleashed U54 SoC and use that in the sifive_u machine.
>
> We leave the SoC, RAM, device tree and reset/fdt loading as part of the
> machine. All the other device creation has been moved to the SoC.
>

There is a tiny problem that we will have to resolve with renaming,
otherwise we will end up with lots of SOCs that are the essentially same
with a different CPU.

There is an intention to add a HiFive1 and HiFiveU board in the future
however we were very explicit in renaming sifive_e300 and sifive_u500 to
sifive_e and sifive_u.

If you read the code more closely you'll notice that we instantiate the
sifive_u board with a U34 if 32-bit and a U54 if 64-bit.

#if defined(TARGET_RISCV32)
#define SIFIVE_U_CPU TYPE_RISCV_CPU_SIFIVE_U34
#elif defined(TARGET_RISCV64)
#define SIFIVE_U_CPU TYPE_RISCV_CPU_SIFIVE_U54
#endif

The rationale is that sifive_e and sifive_u can eventually be customized to
represent different configurations of SiFive Core IP. We won't want to end
up hardcoding specific models in sifive_e or sifive_u

SiFive have been talking internally about having sifive_e and sifive_u
reconfigurable, possibly even to the extend where we can configure with a
memory map. This is somewhat consistent with what SiFive do internally as
the FE310 and FU540 are configurations generated by a core generator.

Now comes the question of whether its the right time to add a 'hifive1' or
'hifiveu' machine. I don't think it is immediately necessary. The thought
being that we would be able to give a configuration string of file to sifive_u
e.g. "e51,u54,u54,u54". There is a different between the U54 and the U54-MC
which has an E51 core for management tasks. The PLIC has already been
written with this in mind, and is re-configurable to support the U54-MC
memory layout.

In anycase. The change is simply to use sifive_u_soc or sifive_u without
the 54 (given it configures with a U34 in 32-bit like the sifive_e
configures with an E51 in 64-bit mode, both valid configurations)

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  hw/riscv/sifive_u.c         | 90 ++++++++++++++++++++++++++++---------
>  include/hw/riscv/sifive_u.h | 16 ++++++-
>  2 files changed, 82 insertions(+), 24 deletions(-)
>
> diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> index 9f3d184b72..4924f92262 100644
> --- a/hw/riscv/sifive_u.c
> +++ b/hw/riscv/sifive_u.c
> @@ -114,10 +114,10 @@ static void create_fdt(SiFiveUState *s, const struct
> MemmapEntry *memmap,
>      qemu_fdt_setprop_cell(fdt, "/cpus", "#size-cells", 0x0);
>      qemu_fdt_setprop_cell(fdt, "/cpus", "#address-cells", 0x1);
>
> -    for (cpu = s->soc.num_harts - 1; cpu >= 0; cpu--) {
> +    for (cpu = s->soc.cpus.num_harts - 1; cpu >= 0; cpu--) {
>          nodename = g_strdup_printf("/cpus/cpu@%d", cpu);
>          char *intc = g_strdup_printf("/cpus/cpu@%d/interrupt-controller",
> cpu);
> -        char *isa = riscv_isa_string(&s->soc.harts[cpu]);
> +        char *isa = riscv_isa_string(&s->soc.cpus.harts[cpu]);
>          qemu_fdt_add_subnode(fdt, nodename);
>          qemu_fdt_setprop_cell(fdt, nodename, "clock-frequency",
>                                SIFIVE_U_CLOCK_FREQ);
> @@ -138,8 +138,8 @@ static void create_fdt(SiFiveUState *s, const struct
> MemmapEntry *memmap,
>          g_free(nodename);
>      }
>
> -    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
> -    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
> +    cells =  g_new0(uint32_t, s->soc.cpus.num_harts * 4);
> +    for (cpu = 0; cpu < s->soc.cpus.num_harts; cpu++) {
>          nodename =
>              g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
>          uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
> @@ -157,12 +157,12 @@ static void create_fdt(SiFiveUState *s, const struct
> MemmapEntry *memmap,
>          0x0, memmap[SIFIVE_U_CLINT].base,
>          0x0, memmap[SIFIVE_U_CLINT].size);
>      qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
> -        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
> +        cells, s->soc.cpus.num_harts * sizeof(uint32_t) * 4);
>      g_free(cells);
>      g_free(nodename);
>
> -    cells =  g_new0(uint32_t, s->soc.num_harts * 4);
> -    for (cpu = 0; cpu < s->soc.num_harts; cpu++) {
> +    cells =  g_new0(uint32_t, s->soc.cpus.num_harts * 4);
> +    for (cpu = 0; cpu < s->soc.cpus.num_harts; cpu++) {
>          nodename =
>              g_strdup_printf("/cpus/cpu@%d/interrupt-controller", cpu);
>          uint32_t intc_phandle = qemu_fdt_get_phandle(fdt, nodename);
> @@ -179,7 +179,7 @@ static void create_fdt(SiFiveUState *s, const struct
> MemmapEntry *memmap,
>      qemu_fdt_setprop_string(fdt, nodename, "compatible", "riscv,plic0");
>      qemu_fdt_setprop(fdt, nodename, "interrupt-controller", NULL, 0);
>      qemu_fdt_setprop(fdt, nodename, "interrupts-extended",
> -        cells, s->soc.num_harts * sizeof(uint32_t) * 4);
> +        cells, s->soc.cpus.num_harts * sizeof(uint32_t) * 4);
>      qemu_fdt_setprop_cells(fdt, nodename, "reg",
>          0x0, memmap[SIFIVE_U_PLIC].base,
>          0x0, memmap[SIFIVE_U_PLIC].size);
> @@ -215,17 +215,12 @@ static void riscv_sifive_u_init(MachineState
> *machine)
>      SiFiveUState *s = g_new0(SiFiveUState, 1);
>      MemoryRegion *system_memory = get_system_memory();
>      MemoryRegion *main_mem = g_new(MemoryRegion, 1);
> -    MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
>      int i;
>
> -    /* Initialize SOC */
> -    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_HART_ARRAY);
> +    /* Initialize SoC */
> +    object_initialize(&s->soc, sizeof(s->soc), TYPE_RISCV_U54_SOC);
>      object_property_add_child(OBJECT(machine), "soc", OBJECT(&s->soc),
>                                &error_abort);
> -    object_property_set_str(OBJECT(&s->soc), SIFIVE_U_CPU, "cpu-type",
> -                            &error_abort);
> -    object_property_set_int(OBJECT(&s->soc), smp_cpus, "num-harts",
> -                            &error_abort);
>      object_property_set_bool(OBJECT(&s->soc), true, "realized",
>                              &error_abort);
>
> @@ -233,17 +228,11 @@ static void riscv_sifive_u_init(MachineState
> *machine)
>      memory_region_init_ram(main_mem, NULL, "riscv.sifive.u.ram",
>                             machine->ram_size, &error_fatal);
>      memory_region_add_subregion(system_memory,
> memmap[SIFIVE_U_DRAM].base,
> -        main_mem);
> +                                main_mem);
>
>      /* create device tree */
>      create_fdt(s, memmap, machine->ram_size, machine->kernel_cmdline);
>
> -    /* boot rom */
> -    memory_region_init_rom(mask_rom, NULL, "riscv.sifive.u.mrom",
> -                           memmap[SIFIVE_U_MROM].size, &error_fatal);
> -    memory_region_add_subregion(system_memory,
> memmap[SIFIVE_U_MROM].base,
> -                                mask_rom);
> -
>      if (machine->kernel_filename) {
>          load_kernel(machine->kernel_filename);
>      }
> @@ -282,6 +271,39 @@ static void riscv_sifive_u_init(MachineState
> *machine)
>      rom_add_blob_fixed_as("mrom.fdt", s->fdt, s->fdt_size,
>                            memmap[SIFIVE_U_MROM].base + sizeof(reset_vec),
>                            &address_space_memory);
> +}
> +
> +static void riscv_sifive_u54_init(Object *obj)
> +{
> +    const struct MemmapEntry *memmap = sifive_u_memmap;
> +
> +    SiFiveU54State *s = RISCV_U54_SOC(obj);
> +    MemoryRegion *system_memory = get_system_memory();
> +    MemoryRegion *mask_rom = g_new(MemoryRegion, 1);
> +
> +    object_initialize(&s->cpus, sizeof(s->cpus), TYPE_RISCV_HART_ARRAY);
> +    object_property_add_child(obj, "cpus", OBJECT(&s->cpus),
> +                              &error_abort);
> +    object_property_set_str(OBJECT(&s->cpus), SIFIVE_U_CPU, "cpu-type",
> +                            &error_abort);
> +    object_property_set_int(OBJECT(&s->cpus), smp_cpus, "num-harts",
> +                            &error_abort);
> +
> +    /* boot rom */
> +    memory_region_init_rom(mask_rom, NULL, "riscv.sifive.u.mrom",
> +                           memmap[SIFIVE_U_MROM].size, &error_fatal);
> +    memory_region_add_subregion(system_memory,
> memmap[SIFIVE_U_MROM].base,
> +                                mask_rom);
> +}
> +
> +static void riscv_sifive_u54_realize(DeviceState *dev, Error **errp)
> +{
> +    SiFiveU54State *s = RISCV_U54_SOC(dev);
> +    const struct MemmapEntry *memmap = sifive_u_memmap;
> +    MemoryRegion *system_memory = get_system_memory();
> +
> +    object_property_set_bool(OBJECT(&s->cpus), true, "realized",
> +                             &error_abort);
>
>      /* MMIO */
>      s->plic = sifive_plic_create(memmap[SIFIVE_U_PLIC].base,
> @@ -312,3 +334,27 @@ static void riscv_sifive_u_machine_init(MachineClass
> *mc)
>  }
>
>  DEFINE_MACHINE("sifive_u", riscv_sifive_u_machine_init)
> +
> +static void riscv_sifive_u54_class_init(ObjectClass *oc, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(oc);
> +
> +    dc->realize = riscv_sifive_u54_realize;
> +    /* Reason: Uses serial_hds in realize function, thus can't be used
> twice */
> +    dc->user_creatable = false;
> +}
> +
> +static const TypeInfo riscv_sifive_u54_type_info = {
> +    .name = TYPE_RISCV_U54_SOC,
> +    .parent = TYPE_DEVICE,
> +    .instance_size = sizeof(SiFiveU54State),
> +    .instance_init = riscv_sifive_u54_init,
> +    .class_init = riscv_sifive_u54_class_init,
> +};
> +
> +static void riscv_sifive_u54_register_types(void)
> +{
> +    type_register_static(&riscv_sifive_u54_type_info);
> +}
> +
> +type_init(riscv_sifive_u54_register_types)
> diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
> index 94a390566e..0f8bdd8fab 100644
> --- a/include/hw/riscv/sifive_u.h
> +++ b/include/hw/riscv/sifive_u.h
> @@ -19,13 +19,25 @@
>  #ifndef HW_SIFIVE_U_H
>  #define HW_SIFIVE_U_H
>
> -typedef struct SiFiveUState {
> +#define TYPE_RISCV_U54_SOC "riscv.sifive.u54"
> +#define RISCV_U54_SOC(obj) \
> +    OBJECT_CHECK(SiFiveU54State, (obj), TYPE_RISCV_U54_SOC)
> +
> +typedef struct SiFiveU54State {
>      /*< private >*/
>      SysBusDevice parent_obj;
>
>      /*< public >*/
> -    RISCVHartArrayState soc;
> +    RISCVHartArrayState cpus;
>      DeviceState *plic;
> +} SiFiveU54State;
> +
> +typedef struct SiFiveUState {
> +    /*< private >*/
> +    SysBusDevice parent_obj;
> +
> +    /*< public >*/
> +    SiFiveU54State soc;
>      void *fdt;
>      int fdt_size;
>  } SiFiveUState;
> --
> 2.17.0
>
>