linux-kernel - Re: [PATCH] ACPI / CPPC: clean up acpi_get_psd

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Date:   Sat, 28 Mar 2020 13:26:48 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     luanshi <zhangliguang@...ux.alibaba.com>
Cc:     "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Len Brown <lenb@...nel.org>,
        ACPI Devel Maling List <linux-acpi@...r.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ACPI / CPPC: clean up acpi_get_psd_map

On Thu, Mar 26, 2020 at 3:29 PM luanshi <zhangliguang@...ux.alibaba.com> wrote:
>
> This patch cleans up acpi_get_psd_map function. If got here,
> variable all_cpu_data[] can't be NULL. Variable match_cpc_ptr has been
> checked before, no need check again at the end of the funchtion. Then
> some code logic should be optimized.
>
> Signed-off-by: Liguang Zhang <zhangliguang@...ux.alibaba.com>
> ---
>  drivers/acpi/cppc_acpi.c | 33 +++++++--------------------------
>  1 file changed, 7 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/acpi/cppc_acpi.c b/drivers/acpi/cppc_acpi.c
> index a1a858a..8b2e89c 100644
> --- a/drivers/acpi/cppc_acpi.c
> +++ b/drivers/acpi/cppc_acpi.c
> @@ -438,13 +438,10 @@ int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data)
>          * domain info.
>          */
>         for_each_possible_cpu(i) {
> -               pr = all_cpu_data[i];
> -               if (!pr)
> -                       continue;
> -
>                 if (cpumask_test_cpu(i, covered_cpus))
>                         continue;
>
> +               pr = all_cpu_data[i];
>                 cpc_ptr = per_cpu(cpc_desc_ptr, i);
>                 if (!cpc_ptr) {
>                         retval = -EFAULT;
> @@ -495,44 +492,28 @@ int acpi_get_psd_map(struct cppc_cpudata **all_cpu_data)
>                         cpumask_set_cpu(j, pr->shared_cpu_map);
>                 }
>
> -               for_each_possible_cpu(j) {
> +               for_each_cpu(j, pr->shared_cpu_map) {
>                         if (i == j)
>                                 continue;
>
>                         match_pr = all_cpu_data[j];
> -                       if (!match_pr)
> -                               continue;
> -
> -                       match_cpc_ptr = per_cpu(cpc_desc_ptr, j);
> -                       if (!match_cpc_ptr) {
> -                               retval = -EFAULT;
> -                               goto err_ret;
> -                       }
> -
> -                       match_pdomain = &(match_cpc_ptr->domain_info);
> -                       if (match_pdomain->domain != pdomain->domain)
> -                               continue;
> -
>                         match_pr->shared_type = pr->shared_type;
>                         cpumask_copy(match_pr->shared_cpu_map,
>                                      pr->shared_cpu_map);
>                 }
>         }
> +       goto out;
>
>  err_ret:
>         for_each_possible_cpu(i) {
>                 pr = all_cpu_data[i];
> -               if (!pr)
> -                       continue;
>
>                 /* Assume no coordination on any error parsing domain info */
> -               if (retval) {
> -                       cpumask_clear(pr->shared_cpu_map);
> -                       cpumask_set_cpu(i, pr->shared_cpu_map);
> -                       pr->shared_type = CPUFREQ_SHARED_TYPE_ALL;
> -               }
> +               cpumask_clear(pr->shared_cpu_map);
> +               cpumask_set_cpu(i, pr->shared_cpu_map);
> +               pr->shared_type = CPUFREQ_SHARED_TYPE_ALL;
>         }
> -
> +out:
>         free_cpumask_var(covered_cpus);
>         return retval;
>  }
> --

Applied as 5.7 material with some changes in the changelog and subject, thanks!