linux-kernel - Re: [PATCH v7 4/9] ACPI: APEI: EINJ: Remove redundant calls to einj_get_available_error

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Message-ID: <CAJZ5v0j-84MDP10YEL48GTPWy1SqHWAA_Dbq+X-k3PFi9brZPw@mail.gmail.com>
Date: Wed, 7 May 2025 13:34:35 +0200
From: "Rafael J. Wysocki" <rafael@...nel.org>
To: Zaid Alali <zaidal@...amperecomputing.com>
Cc: rafael@...nel.org, lenb@...nel.org, james.morse@....com, 
	tony.luck@...el.com, bp@...en8.de, robert.moore@...el.com, 
	Jonathan.Cameron@...wei.com, ira.weiny@...el.com, Benjamin.Cheatham@....com, 
	dan.j.williams@...el.com, arnd@...db.de, Avadhut.Naik@....com, 
	u.kleine-koenig@...gutronix.de, john.allen@....com, 
	linux-acpi@...r.kernel.org, linux-kernel@...r.kernel.org, 
	acpica-devel@...ts.linux.dev
Subject: Re: [PATCH v7 4/9] ACPI: APEI: EINJ: Remove redundant calls to einj_get_available_error_type

On Tue, May 6, 2025 at 11:38 PM Zaid Alali
<zaidal@...amperecomputing.com> wrote:
>
> A single call to einj_get_available_error_type in init function is
> sufficient to save the return value in a global variable to be used
> later in various places in the code. This commit does not introduce
> any functional changes, but only removing unnecessary redundant
> function calls.
>
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@...wei.com>
> Reviewed-by: Ira Weiny <ira.weiny@...el.com>
> Signed-off-by: Zaid Alali <zaidal@...amperecomputing.com>

Does this patch depend on patches [1-3/7]?  If not, I can pick it up
as an optimization.

> ---
>  drivers/acpi/apei/einj-core.c | 22 +++++++++-------------
>  1 file changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/acpi/apei/einj-core.c b/drivers/acpi/apei/einj-core.c
> index 47abd9317fef..ada1d7026af5 100644
> --- a/drivers/acpi/apei/einj-core.c
> +++ b/drivers/acpi/apei/einj-core.c
> @@ -83,6 +83,8 @@ static struct debugfs_blob_wrapper vendor_blob;
>  static struct debugfs_blob_wrapper vendor_errors;
>  static char vendor_dev[64];
>
> +static u32 available_error_type;
> +
>  /*
>   * Some BIOSes allow parameters to the SET_ERROR_TYPE entries in the
>   * EINJ table through an unpublished extension. Use with caution as
> @@ -662,14 +664,9 @@ static struct { u32 mask; const char *str; } const einj_error_type_string[] = {
>
>  static int available_error_type_show(struct seq_file *m, void *v)
>  {
> -       int rc;
> -       u32 error_type = 0;
>
> -       rc = einj_get_available_error_type(&error_type);
> -       if (rc)
> -               return rc;
>         for (int pos = 0; pos < ARRAY_SIZE(einj_error_type_string); pos++)
> -               if (error_type & einj_error_type_string[pos].mask)
> +               if (available_error_type & einj_error_type_string[pos].mask)
>                         seq_printf(m, "0x%08x\t%s\n", einj_error_type_string[pos].mask,
>                                    einj_error_type_string[pos].str);
>
> @@ -692,8 +689,7 @@ bool einj_is_cxl_error_type(u64 type)
>
>  int einj_validate_error_type(u64 type)
>  {
> -       u32 tval, vendor, available_error_type = 0;
> -       int rc;
> +       u32 tval, vendor;
>
>         /* Only low 32 bits for error type are valid */
>         if (type & GENMASK_ULL(63, 32))
> @@ -709,13 +705,9 @@ int einj_validate_error_type(u64 type)
>         /* Only one error type can be specified */
>         if (tval & (tval - 1))
>                 return -EINVAL;
> -       if (!vendor) {
> -               rc = einj_get_available_error_type(&available_error_type);
> -               if (rc)
> -                       return rc;
> +       if (!vendor)
>                 if (!(type & available_error_type))
>                         return -EINVAL;
> -       }
>
>         return 0;
>  }
> @@ -791,6 +783,10 @@ static int __init einj_probe(struct platform_device *pdev)
>                 goto err_put_table;
>         }
>
> +       rc = einj_get_available_error_type(&available_error_type);
> +       if (rc)
> +               return rc;
> +
>         rc = -ENOMEM;
>         einj_debug_dir = debugfs_create_dir("einj", apei_get_debugfs_dir());
>
> --
> 2.43.0
>