[PATCH v4 03/29] mm: use ARCH_PKEY_BITS to define VM_PKEY_BITN

[Dave Hansen]

On 5/3/24 06:01, Joey Gouly wrote:
>  #ifdef CONFIG_ARCH_HAS_PKEYS
> -# define VM_PKEY_SHIFT	VM_HIGH_ARCH_BIT_0
> -# define VM_PKEY_BIT0	VM_HIGH_ARCH_0	/* A protection key is a 4-bit value */
> -# define VM_PKEY_BIT1	VM_HIGH_ARCH_1	/* on x86 and 5-bit value on ppc64   */
> -# define VM_PKEY_BIT2	VM_HIGH_ARCH_2
> -# define VM_PKEY_BIT3	VM_HIGH_ARCH_3
> -#ifdef CONFIG_PPC
> +# define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0
> +# define VM_PKEY_BIT0  VM_HIGH_ARCH_0
> +# define VM_PKEY_BIT1  VM_HIGH_ARCH_1
> +# define VM_PKEY_BIT2  VM_HIGH_ARCH_2
> +#if CONFIG_ARCH_PKEY_BITS > 3
> +# define VM_PKEY_BIT3  VM_HIGH_ARCH_3
> +#else
> +# define VM_PKEY_BIT3  0
> +#endif
> +#if CONFIG_ARCH_PKEY_BITS > 4

It's certainly not pretty, but it does get the arch #ifdef out of
generic code.  We might need to rethink this if we get another
architecture or two, but this seems manageable for now.

Acked-by: Dave Hansen <dave.hansen at linux.intel.com>