lkml.org 
[lkml]   [2020]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] cpuidle: add riscv cpuidle driver
From
Date
On 14/09/2020 03:52, liush wrote:
> This patch adds a cpuidle driver for systems based RISCV architecture.
> This patch supports state WFI. Other states will be supported in the
> future.
>
> Signed-off-by: liush <liush@allwinnertech.com>
> ---

[ ... ]

>
> obj-$(CONFIG_RISCV_M_MODE) += traps_misaligned.o
> diff --git a/arch/riscv/kernel/cpuidle.c b/arch/riscv/kernel/cpuidle.c
> new file mode 100644
> index 00000000..a3289e7
> --- /dev/null
> +++ b/arch/riscv/kernel/cpuidle.c
> @@ -0,0 +1,8 @@
> +// SPDX-License-Identifier: GPL-2.0
> +#include <asm/cpuidle.h>
> +
> +void cpu_do_idle(void)
> +{
> + __asm__ __volatile__ ("wfi");
> +

extra line

> +}

As for the next deeper states should end up with the cpu_do_idle
function, isn't there an extra operation with the wfi() like flushing
the l1 cache?

> diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
> index c0aeedd..f6be0fd 100644
> --- a/drivers/cpuidle/Kconfig
> +++ b/drivers/cpuidle/Kconfig
> @@ -62,6 +62,11 @@ depends on PPC
> source "drivers/cpuidle/Kconfig.powerpc"
> endmenu
>
> +menu "RISCV CPU Idle Drivers"
> +depends on RISCV
> +source "drivers/cpuidle/Kconfig.riscv"
> +endmenu
> +
> config HALTPOLL_CPUIDLE
> tristate "Halt poll cpuidle driver"
> depends on X86 && KVM_GUEST
> diff --git a/drivers/cpuidle/Kconfig.riscv b/drivers/cpuidle/Kconfig.riscv
> new file mode 100644
> index 00000000..e86d36b
> --- /dev/null
> +++ b/drivers/cpuidle/Kconfig.riscv
> @@ -0,0 +1,11 @@
> +# SPDX-License-Identifier: GPL-2.0-only
> +#
> +# RISCV CPU Idle drivers
> +#
> +config RISCV_CPUIDLE
> + bool "Generic RISCV CPU idle Driver"
> + select DT_IDLE_STATES
> + select CPU_IDLE_MULTIPLE_DRIVERS
> + help
> + Select this option to enable generic cpuidle driver for RISCV.
> + Now only support C0 State.

Identation

Rest looks ok for me.


--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

\
 
 \ /
  Last update: 2020-09-14 07:48    [W:0.111 / U:0.600 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site