Re: [PATCH] hw/riscv: virt: Generate fw_cfg DT node correctly

[Alistair Francis]

On Fri, May 27, 2022 at 6:35 AM Atish Patra <atishp@rivosinc.com> wrote:
>
> fw_cfg DT node is generated after the create_fdt without any check
> if the DT is being loaded from the commandline. This results in
> FDT_ERR_EXISTS error if dtb is loaded from the commandline.
>
> Generate fw_cfg node only if the DT is not loaded from the commandline.
>
> Signed-off-by: Atish Patra <atishp@rivosinc.com>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  hw/riscv/virt.c | 28 ++++++++++++++++++----------
>  1 file changed, 18 insertions(+), 10 deletions(-)
>
> diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
> index c57617381517..07aeee3bf0c3 100644
> --- a/hw/riscv/virt.c
> +++ b/hw/riscv/virt.c
> @@ -975,6 +975,23 @@ static void create_fdt_flash(RISCVVirtState *s, const 
> MemMapEntry *memmap)
>      g_free(name);
>  }
>
> +static void create_fdt_fw_cfg(RISCVVirtState *s, const MemMapEntry *memmap)
> +{
> +    char *nodename;
> +    MachineState *mc = MACHINE(s);
> +    hwaddr base = memmap[VIRT_FW_CFG].base;
> +    hwaddr size = memmap[VIRT_FW_CFG].size;
> +
> +    nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
> +    qemu_fdt_add_subnode(mc->fdt, nodename);
> +    qemu_fdt_setprop_string(mc->fdt, nodename,
> +                            "compatible", "qemu,fw-cfg-mmio");
> +    qemu_fdt_setprop_sized_cells(mc->fdt, nodename, "reg",
> +                                 2, base, 2, size);
> +    qemu_fdt_setprop(mc->fdt, nodename, "dma-coherent", NULL, 0);
> +    g_free(nodename);
> +}
> +
>  static void create_fdt(RISCVVirtState *s, const MemMapEntry *memmap,
>                         uint64_t mem_size, const char *cmdline, bool 
> is_32_bit)
>  {
> @@ -1023,6 +1040,7 @@ static void create_fdt(RISCVVirtState *s, const 
> MemMapEntry *memmap,
>      create_fdt_rtc(s, memmap, irq_mmio_phandle);
>
>      create_fdt_flash(s, memmap);
> +    create_fdt_fw_cfg(s, memmap);
>
>  update_bootargs:
>      if (cmdline && *cmdline) {
> @@ -1082,22 +1100,12 @@ static inline DeviceState 
> *gpex_pcie_init(MemoryRegion *sys_mem,
>  static FWCfgState *create_fw_cfg(const MachineState *mc)
>  {
>      hwaddr base = virt_memmap[VIRT_FW_CFG].base;
> -    hwaddr size = virt_memmap[VIRT_FW_CFG].size;
>      FWCfgState *fw_cfg;
> -    char *nodename;
>
>      fw_cfg = fw_cfg_init_mem_wide(base + 8, base, 8, base + 16,
>                                    &address_space_memory);
>      fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)mc->smp.cpus);
>
> -    nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
> -    qemu_fdt_add_subnode(mc->fdt, nodename);
> -    qemu_fdt_setprop_string(mc->fdt, nodename,
> -                            "compatible", "qemu,fw-cfg-mmio");
> -    qemu_fdt_setprop_sized_cells(mc->fdt, nodename, "reg",
> -                                 2, base, 2, size);
> -    qemu_fdt_setprop(mc->fdt, nodename, "dma-coherent", NULL, 0);
> -    g_free(nodename);
>      return fw_cfg;
>  }
>
> --
> 2.25.1
>
>