Unverified Commit 63b13e64 authored by Anup Patel's avatar Anup Patel Committed by Palmer Dabbelt
Browse files

RISC-V: Add arch functions for non-retentive suspend entry/exit 



The hart registers and CSRs are not preserved in non-retentative
suspend state so we provide arch specific helper functions which
will save/restore hart context upon entry/exit to non-retentive
suspend state. These helper functions can be used by cpuidle
drivers for non-retentive suspend entry/exit.

Signed-off-by: default avatarAnup Patel <anup.patel@wdc.com>
Signed-off-by: default avatarAnup Patel <apatel@ventanamicro.com>
Reviewed-by: default avatarGuo Ren <guoren@kernel.org>
Signed-off-by: default avatarPalmer Dabbelt <palmer@rivosinc.com>
parent e1de2c93

arch/riscv/include/asm/asm.h

+27 −0
Original line number Diff line number Diff line
@@ -67,4 +67,31 @@ 
#error "Unexpected __SIZEOF_SHORT__"

#endif



#ifdef __ASSEMBLY__



/* Common assembly source macros */



#ifdef CONFIG_XIP_KERNEL

.macro XIP_FIXUP_OFFSET reg

	REG_L t0, _xip_fixup

	add \reg, \reg, t0

.endm

.macro XIP_FIXUP_FLASH_OFFSET reg

	la t1, __data_loc

	li t0, XIP_OFFSET_MASK

	and t1, t1, t0

	li t1, XIP_OFFSET

	sub t0, t0, t1

	sub \reg, \reg, t0

.endm

_xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET

#else

.macro XIP_FIXUP_OFFSET reg

.endm

.macro XIP_FIXUP_FLASH_OFFSET reg

.endm

#endif /* CONFIG_XIP_KERNEL */



#endif /* __ASSEMBLY__ */



#endif /* _ASM_RISCV_ASM_H */

arch/riscv/include/asm/suspend.h

0 → 100644
+36 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

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

 * Copyright (c) 2022 Ventana Micro Systems Inc.

 */



#ifndef _ASM_RISCV_SUSPEND_H

#define _ASM_RISCV_SUSPEND_H



#include <asm/ptrace.h>



struct suspend_context {

	/* Saved and restored by low-level functions */

	struct pt_regs regs;

	/* Saved and restored by high-level functions */

	unsigned long scratch;

	unsigned long tvec;

	unsigned long ie;

#ifdef CONFIG_MMU

	unsigned long satp;

#endif

};



/* Low-level CPU suspend entry function */

int __cpu_suspend_enter(struct suspend_context *context);



/* High-level CPU suspend which will save context and call finish() */

int cpu_suspend(unsigned long arg,

		int (*finish)(unsigned long arg,

			      unsigned long entry,

			      unsigned long context));



/* Low-level CPU resume entry function */

int __cpu_resume_enter(unsigned long hartid, unsigned long context);



#endif

arch/riscv/kernel/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -48,6 +48,8 @@ obj-$(CONFIG_RISCV_BOOT_SPINWAIT) += cpu_ops_spinwait.o 
obj-$(CONFIG_MODULES)		+= module.o

obj-$(CONFIG_MODULE_SECTIONS)	+= module-sections.o



obj-$(CONFIG_CPU_PM)		+= suspend_entry.o suspend.o



obj-$(CONFIG_FUNCTION_TRACER)	+= mcount.o ftrace.o

obj-$(CONFIG_DYNAMIC_FTRACE)	+= mcount-dyn.o

arch/riscv/kernel/asm-offsets.c

+3 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <asm/thread_info.h>

#include <asm/ptrace.h>

#include <asm/cpu_ops_sbi.h>

#include <asm/suspend.h>



void asm_offsets(void);
@@ -113,6 +114,8 @@ void asm_offsets(void) 
	OFFSET(PT_BADADDR, pt_regs, badaddr);

	OFFSET(PT_CAUSE, pt_regs, cause);



	OFFSET(SUSPEND_CONTEXT_REGS, suspend_context, regs);



	OFFSET(KVM_ARCH_GUEST_ZERO, kvm_vcpu_arch, guest_context.zero);

	OFFSET(KVM_ARCH_GUEST_RA, kvm_vcpu_arch, guest_context.ra);

	OFFSET(KVM_ARCH_GUEST_SP, kvm_vcpu_arch, guest_context.sp);

arch/riscv/kernel/head.S

+0 −21
Original line number Diff line number Diff line
@@ -16,27 +16,6 @@ 
#include <asm/image.h>

#include "efi-header.S"



#ifdef CONFIG_XIP_KERNEL

.macro XIP_FIXUP_OFFSET reg

	REG_L t0, _xip_fixup

	add \reg, \reg, t0

.endm

.macro XIP_FIXUP_FLASH_OFFSET reg

	la t1, __data_loc

	li t0, XIP_OFFSET_MASK

	and t1, t1, t0

	li t1, XIP_OFFSET

	sub t0, t0, t1

	sub \reg, \reg, t0

.endm

_xip_fixup: .dword CONFIG_PHYS_RAM_BASE - CONFIG_XIP_PHYS_ADDR - XIP_OFFSET

#else

.macro XIP_FIXUP_OFFSET reg

.endm

.macro XIP_FIXUP_FLASH_OFFSET reg

.endm

#endif /* CONFIG_XIP_KERNEL */



__HEAD

ENTRY(_start)

	/*