linux/arch/loongarch/power/suspend_asm.S
Jiaxun Yang e523a5a65f LoongArch: Add ACPI standard hardware register based S3 support
Most LoongArch 64 machines are using custom "SADR" ACPI extension to
perform ACPI S3 sleep. However the standard ACPI way to perform sleep
is to write a value to ACPI PM1/SLEEP_CTL register, and this is never
supported properly in kernel.

Add standard S3 sleep by providing a default DoSuspend function which
calls ACPI's acpi_enter_sleep_state() routine when SADR is not provided
by the firmware.

Also fix suspend assembly code so that ra is set properly before go
into sleep routine. (Previously linked address of jirl was set to a0,
some firmware do require return address in a0 but it's already set with
la.pcrel before).

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-07-20 22:41:06 +08:00

89 lines
1.9 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Sleep helper for Loongson-3 sleep mode.
*
* Author: Huacai Chen <chenhuacai@loongson.cn>
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/addrspace.h>
#include <asm/loongarch.h>
#include <asm/stackframe.h>
/* preparatory stuff */
.macro SETUP_SLEEP
addi.d sp, sp, -PT_SIZE
st.d $r1, sp, PT_R1
st.d $r2, sp, PT_R2
st.d $r3, sp, PT_R3
st.d $r4, sp, PT_R4
st.d $r21, sp, PT_R21
st.d $r22, sp, PT_R22
st.d $r23, sp, PT_R23
st.d $r24, sp, PT_R24
st.d $r25, sp, PT_R25
st.d $r26, sp, PT_R26
st.d $r27, sp, PT_R27
st.d $r28, sp, PT_R28
st.d $r29, sp, PT_R29
st.d $r30, sp, PT_R30
st.d $r31, sp, PT_R31
la.pcrel t0, acpi_saved_sp
st.d sp, t0, 0
.endm
.macro SETUP_WAKEUP
ld.d $r1, sp, PT_R1
ld.d $r2, sp, PT_R2
ld.d $r3, sp, PT_R3
ld.d $r4, sp, PT_R4
ld.d $r21, sp, PT_R21
ld.d $r22, sp, PT_R22
ld.d $r23, sp, PT_R23
ld.d $r24, sp, PT_R24
ld.d $r25, sp, PT_R25
ld.d $r26, sp, PT_R26
ld.d $r27, sp, PT_R27
ld.d $r28, sp, PT_R28
ld.d $r29, sp, PT_R29
ld.d $r30, sp, PT_R30
ld.d $r31, sp, PT_R31
.endm
.text
.align 12
/* Sleep/wakeup code for Loongson-3 */
SYM_FUNC_START(loongarch_suspend_enter)
SETUP_SLEEP
bl __flush_cache_all
/* Pass RA and SP to BIOS */
addi.d a1, sp, 0
la.pcrel a0, loongarch_wakeup_start
la.pcrel t0, loongarch_suspend_addr
ld.d t0, t0, 0
jirl ra, t0, 0 /* Call BIOS's STR sleep routine */
/*
* This is where we return upon wakeup.
* Reload all of the registers and return.
*/
SYM_INNER_LABEL(loongarch_wakeup_start, SYM_L_GLOBAL)
SETUP_DMWINS t0
JUMP_VIRT_ADDR t0, t1
/* Enable PG */
li.w t0, 0xb0 # PLV=0, IE=0, PG=1
csrwr t0, LOONGARCH_CSR_CRMD
la.pcrel t0, acpi_saved_sp
ld.d sp, t0, 0
SETUP_WAKEUP
addi.d sp, sp, PT_SIZE
jr ra
SYM_FUNC_END(loongarch_suspend_enter)