Re: [PATCH] ACPICA: actbl2: change to be16/be32 types for big endian data

[Rafael J. Wysocki]

On Mon, Jul 3, 2023 at 3:01 PM Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx> wrote:
>
> Some of the fields in struct acpi_nfit_control_region are used in big
> endian format, and thus are generatng warnings from spare where the
> member is passed to one of the conversion functions.
>
> Fix the following sparse warnings by changing the data types:
>
> drivers/acpi/nfit/core.c:1403:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1403:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1403:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1403:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1412:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1412:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1412:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1412:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1421:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1421:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1421:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1421:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1430:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1430:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1430:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1430:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1440:25: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1440:25: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1440:25: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1440:25: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1449:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1449:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1449:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1449:41: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1468:41: warning: cast to restricted __le16
> drivers/acpi/nfit/core.c:1502:41: warning: cast to restricted __le16
> drivers/acpi/nfit/core.c:1527:41: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1527:41: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1527:41: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1527:41: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1527:41: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1527:41: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1792:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1792:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1792:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1792:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1794:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1794:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1794:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1794:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1795:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1795:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1795:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1795:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1795:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1795:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1798:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1798:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1798:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1798:33: warning: cast to restricted __be16
> drivers/acpi/nfit/core.c:1799:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1799:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1799:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1799:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1799:33: warning: cast to restricted __be32
> drivers/acpi/nfit/core.c:1799:33: warning: cast to restricted __be32
>
> Signed-off-by: Ben Dooks <ben.dooks@xxxxxxxxxxxxxxx>

First off, this falls under the ACPICA rule mentioned before.

Second, all ACPI is little-endian by the spec, so I'm not sure what is
going on here.

> ---
>  drivers/acpi/nfit/core.c |  8 ++++----
>  include/acpi/actbl2.h    | 18 +++++++++---------
>  2 files changed, 13 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
> index 07204d482968..0fcc247fdfac 100644
> --- a/drivers/acpi/nfit/core.c
> +++ b/drivers/acpi/nfit/core.c
> @@ -2194,15 +2194,15 @@ static const struct attribute_group *acpi_nfit_region_attribute_groups[] = {
>  /* enough info to uniquely specify an interleave set */
>  struct nfit_set_info {
>         u64 region_offset;
> -       u32 serial_number;
> +       __be32 serial_number;
>         u32 pad;
>  };
>
>  struct nfit_set_info2 {
>         u64 region_offset;
> -       u32 serial_number;
> -       u16 vendor_id;
> -       u16 manufacturing_date;
> +       __be32 serial_number;
> +       __be16 vendor_id;
> +       __be16 manufacturing_date;
>         u8 manufacturing_location;
>         u8 reserved[31];
>  };
> diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
> index 0029336775a9..c1df59aa8855 100644
> --- a/include/acpi/actbl2.h
> +++ b/include/acpi/actbl2.h
> @@ -1716,18 +1716,18 @@ struct acpi_nfit_smbios {
>  struct acpi_nfit_control_region {
>         struct acpi_nfit_header header;
>         u16 region_index;
> -       u16 vendor_id;
> -       u16 device_id;
> -       u16 revision_id;
> -       u16 subsystem_vendor_id;
> -       u16 subsystem_device_id;
> -       u16 subsystem_revision_id;
> +       __be16 vendor_id;
> +       __be16 device_id;
> +       __be16  revision_id;
> +       __be16 subsystem_vendor_id;
> +       __be16 subsystem_device_id;
> +       __be16 subsystem_revision_id;
>         u8 valid_fields;
>         u8 manufacturing_location;
> -       u16 manufacturing_date;
> +       __be16 manufacturing_date;
>         u8 reserved[2];         /* Reserved, must be zero */
> -       u32 serial_number;
> -       u16 code;
> +       __be32 serial_number;
> +       __le16 code;
>         u16 windows;
>         u64 window_size;
>         u64 command_offset;
> --
> 2.40.1
>