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From:   Nick Desaulniers <ndesaulniers@google.com>
Date:   Mon, 24 Sep 2018 14:44:20 -0700
Message-ID: <CAKwvOdkf4pBpoLSHiWg0CZfnmCzMvUAT_Zsc4QFOUk9No5qGrA@mail.gmail.com>
Subject: Re: [PATCH] crypto: ccp: Remove forward declaration
To:     ghook@amd.com
Cc:     Nathan Chancellor <natechancellor@gmail.com>,
        Thomas.Lendacky@amd.com, Gary.Hook@amd.com,
        Herbert Xu <herbert@gondor.apana.org.au>,
        linux-crypto@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>
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On Mon, Sep 24, 2018 at 2:27 PM Gary R Hook <ghook@amd.com> wrote:
>
> On 09/24/2018 03:24 PM, Nick Desaulniers wrote:
> > On Mon, Sep 24, 2018 at 12:18 PM Gary R Hook <ghook@amd.com> wrote:
> >>
> >> On 09/24/2018 12:26 PM, Nathan Chancellor wrote:
> >>> Clang emits a warning about this construct:
> >>>
> >>> drivers/crypto/ccp/sp-platform.c:36:36: warning: tentative array
> >>> definition assumed to have one element
> >>> static const struct acpi_device_id sp_acpi_match[];
> >>>                                      ^
> >>> 1 warning generated.
> >>>
> >>> Just remove the forward declarations and move the initializations up
> >>> so that they can be used in sp_get_of_version and sp_get_acpi_version.
> >>
> >> I'm not going to out and out object to this just yet.
> >
> > Tentative array definitions need to have the correct length specified;
> > it should either be forward declared as the correct length, or as this
> > patch does, skip the forward declare and move up the definition.
> > Thanks for this patch Nathan.
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
>
>
> Checked my C99, and using both static and [] to create a declaration

Note that the kernel uses gnu89, which is ISO C90 + gnu extensions (IIUC).

> (because it's really a definition) apparently isn't valid. I should have
> known that. Since I'm old school...
>
> Acked-by: Gary R Hook <gary.hook@amd.com>
>
>
> >
> >>
> >> I am not a clang expert. Can you please provide a make command that
> >> would explain how you precipitated this complaint?
> >>
> >>
> >>> Reported-by: Nick Desaulniers <ndesaulniers@google.com>
> >>> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> >>> ---
> >>>    drivers/crypto/ccp/sp-platform.c | 53 +++++++++++++++-----------------
> >>>    1 file changed, 25 insertions(+), 28 deletions(-)
> >>>
> >>> diff --git a/drivers/crypto/ccp/sp-platform.c b/drivers/crypto/ccp/sp-platform.c
> >>> index 71734f254fd1..b75dc7db2d4a 100644
> >>> --- a/drivers/crypto/ccp/sp-platform.c
> >>> +++ b/drivers/crypto/ccp/sp-platform.c
> >>> @@ -33,8 +33,31 @@ struct sp_platform {
> >>>        unsigned int irq_count;
> >>>    };
> >>>
> >>> -static const struct acpi_device_id sp_acpi_match[];
> >>> -static const struct of_device_id sp_of_match[];
> >>> +static const struct sp_dev_vdata dev_vdata[] = {
> >>> +     {
> >>> +             .bar = 0,
> >>> +#ifdef CONFIG_CRYPTO_DEV_SP_CCP
> >>> +             .ccp_vdata = &ccpv3_platform,
> >>> +#endif
> >>> +     },
> >>> +};
> >>> +
> >>> +#ifdef CONFIG_ACPI
> >>> +static const struct acpi_device_id sp_acpi_match[] = {
> >>> +     { "AMDI0C00", (kernel_ulong_t)&dev_vdata[0] },
> >>> +     { },
> >>> +};
> >>> +MODULE_DEVICE_TABLE(acpi, sp_acpi_match);
> >>> +#endif
> >>> +
> >>> +#ifdef CONFIG_OF
> >>> +static const struct of_device_id sp_of_match[] = {
> >>> +     { .compatible = "amd,ccp-seattle-v1a",
> >>> +       .data = (const void *)&dev_vdata[0] },
> >>> +     { },
> >>> +};
> >>> +MODULE_DEVICE_TABLE(of, sp_of_match);
> >>> +#endif
> >>>
> >>>    static struct sp_dev_vdata *sp_get_of_version(struct platform_device *pdev)
> >>>    {
> >>> @@ -201,32 +224,6 @@ static int sp_platform_resume(struct platform_device *pdev)
> >>>    }
> >>>    #endif
> >>>
> >>> -static const struct sp_dev_vdata dev_vdata[] = {
> >>> -     {
> >>> -             .bar = 0,
> >>> -#ifdef CONFIG_CRYPTO_DEV_SP_CCP
> >>> -             .ccp_vdata = &ccpv3_platform,
> >>> -#endif
> >>> -     },
> >>> -};
> >>> -
> >>> -#ifdef CONFIG_ACPI
> >>> -static const struct acpi_device_id sp_acpi_match[] = {
> >>> -     { "AMDI0C00", (kernel_ulong_t)&dev_vdata[0] },
> >>> -     { },
> >>> -};
> >>> -MODULE_DEVICE_TABLE(acpi, sp_acpi_match);
> >>> -#endif
> >>> -
> >>> -#ifdef CONFIG_OF
> >>> -static const struct of_device_id sp_of_match[] = {
> >>> -     { .compatible = "amd,ccp-seattle-v1a",
> >>> -       .data = (const void *)&dev_vdata[0] },
> >>> -     { },
> >>> -};
> >>> -MODULE_DEVICE_TABLE(of, sp_of_match);
> >>> -#endif
> >>> -
> >>>    static struct platform_driver sp_platform_driver = {
> >>>        .driver = {
> >>>                .name = "ccp",
> >>>
> >>
> >
> >
>


-- 
Thanks,
~Nick Desaulniers