Unverified Commit f6e64b66 authored by Anup Patel's avatar Anup Patel Committed by Palmer Dabbelt
Browse files

RISC-V: Enable CPU_IDLE drivers 



We force select CPU_PM and provide asm/cpuidle.h so that we can
use CPU IDLE drivers for Linux RISC-V kernel.

Signed-off-by: default avatarAnup Patel <anup.patel@wdc.com>
Signed-off-by: default avatarAnup Patel <apatel@vetanamicro.com>
Reviewed-by: default avatarGuo Ren <guoren@kernel.org>
Reviewed-by: default avatarAtish Patra <atishp@rivosinc.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent e783362e

arch/riscv/Kconfig

+7 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ config RISCV 
	select CLONE_BACKWARDS

	select CLINT_TIMER if !MMU

	select COMMON_CLK

	select CPU_PM if CPU_IDLE

	select EDAC_SUPPORT

	select GENERIC_ARCH_TOPOLOGY if SMP

	select GENERIC_ATOMIC64 if !64BIT
@@ -547,4 +548,10 @@ source "kernel/power/Kconfig" 


endmenu



menu "CPU Power Management"



source "drivers/cpuidle/Kconfig"



endmenu



source "arch/riscv/kvm/Kconfig"

arch/riscv/configs/defconfig

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ CONFIG_SOC_SIFIVE=y 
CONFIG_SOC_VIRT=y

CONFIG_SMP=y

CONFIG_HOTPLUG_CPU=y

CONFIG_CPU_IDLE=y

CONFIG_VIRTUALIZATION=y

CONFIG_KVM=m

CONFIG_JUMP_LABEL=y

arch/riscv/configs/rv32_defconfig

+1 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ CONFIG_SOC_VIRT=y 
CONFIG_ARCH_RV32I=y

CONFIG_SMP=y

CONFIG_HOTPLUG_CPU=y

CONFIG_CPU_IDLE=y

CONFIG_VIRTUALIZATION=y

CONFIG_KVM=m

CONFIG_JUMP_LABEL=y

arch/riscv/include/asm/cpuidle.h

0 → 100644
+24 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */

/*

 * Copyright (C) 2021 Allwinner Ltd

 * Copyright (C) 2021 Western Digital Corporation or its affiliates.

 */



#ifndef _ASM_RISCV_CPUIDLE_H

#define _ASM_RISCV_CPUIDLE_H



#include <asm/barrier.h>

#include <asm/processor.h>



static inline void cpu_do_idle(void)

{

	/*

	 * Add mb() here to ensure that all

	 * IO/MEM accesses are completed prior

	 * to entering WFI.

	 */

	mb();

	wait_for_interrupt();

}



#endif

arch/riscv/kernel/process.c

+2 −1
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <asm/string.h>

#include <asm/switch_to.h>

#include <asm/thread_info.h>

#include <asm/cpuidle.h>



register unsigned long gp_in_global __asm__("gp");
@@ -37,7 +38,7 @@ extern asmlinkage void ret_from_kernel_thread(void); 


void arch_cpu_idle(void)

{

	wait_for_interrupt();

	cpu_do_idle();

	raw_local_irq_enable();

}