[PATCH v2 08/25] x86: mp_init: Adjust bsp_init() to return more information

[Bin Meng]

On Mon, Jun 15, 2020 at 1:00 AM Simon Glass <sjg at chromium.org> wrote:
>
> This function is misnamed since it does not actually init the BSP. Also
> it is convenient to adjust it to return a little more information.
>
> Rename and update the function, to allow it to return the BSP CPU device
> and number, as well as the total number of CPUs.
>
> Signed-off-by: Simon Glass <sjg at chromium.org>
> Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
> ---
>
> Changes in v2:
> - Drop change to include/dm/uclass.h
> - Mention error return in get_bsp()
>
>  arch/x86/cpu/mp_init.c | 35 ++++++++++++++++++++++-------------
>  1 file changed, 22 insertions(+), 13 deletions(-)
>
> diff --git a/arch/x86/cpu/mp_init.c b/arch/x86/cpu/mp_init.c
> index e0270e71db..cd4cae559d 100644
> --- a/arch/x86/cpu/mp_init.c
> +++ b/arch/x86/cpu/mp_init.c
> @@ -421,9 +421,17 @@ static int bsp_do_flight_plan(struct udevice *cpu, struct mp_flight_plan *plan,
>         return ret;
>  }
>
> -static int init_bsp(struct udevice **devp)
> +/**
> + * get_bsp() - Get information about the bootstrap processor
> + *
> + * @devp: If non-NULL, returns CPU device corresponding to the BSP
> + * @cpu_countp: If non-NULL, returns the total number of CPUs
> + * @return CPU number of the BSP, or -ve on error

The return value of BSP CPU number seems not useful in this patch. But
I see it will be used in future patches.

> + */
> +static int get_bsp(struct udevice **devp, int *cpu_countp)
>  {
>         char processor_name[CPU_MAX_NAME_LEN];
> +       struct udevice *dev;
>         int apic_id;
>         int ret;
>
> @@ -431,13 +439,20 @@ static int init_bsp(struct udevice **devp)
>         debug("CPU: %s\n", processor_name);
>
>         apic_id = lapicid();
> -       ret = find_cpu_by_apic_id(apic_id, devp);
> -       if (ret) {
> +       ret = find_cpu_by_apic_id(apic_id, &dev);
> +       if (ret < 0) {
>                 printf("Cannot find boot CPU, APIC ID %d\n", apic_id);
>                 return ret;
>         }
> +       ret = cpu_get_count(dev);
> +       if (ret < 0)
> +               return log_msg_ret("count", ret);
> +       if (devp)
> +               *devp = dev;
> +       if (cpu_countp)
> +               *cpu_countp = ret;
>
> -       return 0;
> +       return dev->req_seq;
>  }
>
>  static int mp_init_cpu(struct udevice *cpu, void *unused)
> @@ -476,24 +491,18 @@ int mp_init(void)
>         uclass_id_foreach_dev(UCLASS_CPU, cpu, uc)
>                 cpu->req_seq = dev_read_u32_default(cpu, "reg", -1);
>
> -       ret = init_bsp(&cpu);
> -       if (ret) {
> +       ret = get_bsp(&cpu, &num_cpus);
> +       if (ret < 0) {
>                 debug("Cannot init boot CPU: err=%d\n", ret);
>                 return ret;
>         }
>
> -       num_cpus = cpu_get_count(cpu);
> -       if (num_cpus < 0) {
> -               debug("Cannot get number of CPUs: err=%d\n", num_cpus);
> -               return num_cpus;
> -       }
> -
>         if (num_cpus < 2)
>                 debug("Warning: Only 1 CPU is detected\n");
>
>         ret = check_cpu_devices(num_cpus);
>         if (ret)
> -               debug("Warning: Device tree does not describe all CPUs. Extra ones will not be started correctly\n");
> +               log_warning("Warning: Device tree does not describe all CPUs. Extra ones will not be started correctly\n");
>
>         /* Copy needed parameters so that APs have a reference to the plan */
>         mp_info.num_records = ARRAY_SIZE(mp_steps);
> --

Reviewed-by: Bin Meng <bmeng.cn at gmail.com>