[patch 33/38] powerpc: Select ARCH_HAS_RANDOM_ENTROPY

[Mukesh Kumar Chaurasiya]

On Fri, Apr 10, 2026 at 02:21:09PM +0200, Thomas Gleixner wrote:
> The only remaining usage of get_cycles() is to provide random_get_entropy().
> 
> Switch powerpc over to the new scheme of selecting ARCH_HAS_RANDOM_ENTROPY
> and providing random_get_entropy() in asm/random.h.
> 
> Remove asm/timex.h as it has no functionality anymore.
> 
> Signed-off-by: Thomas Gleixner <tglx at kernel.org>
> Cc: Michael Ellerman <mpe at ellerman.id.au>
> Cc: linuxppc-dev at lists.ozlabs.org
> ---
>  arch/powerpc/Kconfig              |    1 +
>  arch/powerpc/include/asm/random.h |   13 +++++++++++++
>  arch/powerpc/include/asm/timex.h  |   21 ---------------------
>  3 files changed, 14 insertions(+), 21 deletions(-)
> 
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -150,6 +150,7 @@ config PPC
>  	select ARCH_HAS_PREEMPT_LAZY
>  	select ARCH_HAS_PTDUMP
>  	select ARCH_HAS_PTE_SPECIAL
> +	select ARCH_HAS_RANDOM_ENTROPY
>  	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE && PPC_BOOK3S_64
>  	select ARCH_HAS_SET_MEMORY
>  	select ARCH_HAS_STRICT_KERNEL_RWX	if (PPC_BOOK3S || PPC_8xx) && !HIBERNATION
> --- /dev/null
> +++ b/arch/powerpc/include/asm/random.h
> @@ -0,0 +1,13 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +#ifndef _ASM_POWERPC_RANDOM_H
> +#define _ASM_POWERPC_RANDOM_H
> +
> +#include <asm/cputable.h>
> +#include <asm/vdso/timebase.h>
> +
> +static inline unsigned long random_get_entropy(void)
> +{
> +	return mftb();
> +}
> +
> +#endif	/* _ASM_POWERPC_RANDOM_H */
> --- a/arch/powerpc/include/asm/timex.h
> +++ b/arch/powerpc/include/asm/timex.h
> @@ -1,21 +0,0 @@
> -/* SPDX-License-Identifier: GPL-2.0 */
> -#ifndef _ASM_POWERPC_TIMEX_H
> -#define _ASM_POWERPC_TIMEX_H
> -
> -#ifdef __KERNEL__
> -
> -/*
> - * PowerPC architecture timex specifications
> - */
> -
> -#include <asm/cputable.h>
> -#include <asm/vdso/timebase.h>
> -
> -ostatic inline cycles_t get_cycles(void)
> -{
R> -	return mftb();
> -}
> -#define get_cycles get_cycles
> -
> -#endif	/* __KERNEL__ */
> -#endif	/* _ASM_POWERPC_TIMEX_H */
> 
Build tested for this series with allmodconfig and allyesconfig on ppc64le
machine for ppc64le.
tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git getcycles-v1

Boot tested for this series on powernv9 qemu, powernv10 qemu and pSeries
power11 hardware.

Tested-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras at gmail.com>
Reviewed-by: Mukesh Kumar Chaurasiya (IBM) <mkchauras at gmail.com>