Re: [patch V6a 01/19] x86/cpu: Provide cpuid_read() et al.

[Andy Shevchenko]

On Wed, Feb 14, 2024 at 10:29 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> Provide a few helper functions to read CPUID leafs or individual registers
> into a data structure without requiring unions.

..

> +#define cpuid_subleaf(leaf, subleaf, regs) {           \
> +       BUILD_BUG_ON(sizeof(*(regs)) != 16);            \
> +       __cpuid_read(leaf, subleaf, (u32 *)(regs));     \
> +}
> +
> +#define cpuid_leaf(leaf, regs) {                       \
> +       BUILD_BUG_ON(sizeof(*(regs)) != 16);            \
> +       __cpuid_read(leaf, 0, (u32 *)(regs));           \
> +}

..

> +#define cpuid_subleaf_reg(leaf, subleaf, regidx, reg) {                \
> +       BUILD_BUG_ON(sizeof(*(reg)) != 4);                      \
> +       __cpuid_read_reg(leaf, subleaf, regidx, (u32 *)(reg));  \
> +}
> +
> +#define cpuid_leaf_reg(leaf, regidx, reg) {                    \
> +       BUILD_BUG_ON(sizeof(*(reg)) != 4);                      \
> +       __cpuid_read_reg(leaf, 0, regidx, (u32 *)(reg));        \
> +}

I'm wondering if we can use static_assert() instead of BUILD_BUG_ON()
in the above macros.

-- 
With Best Regards,
Andy Shevchenko