linux_dsm_epyc7002/arch/arm/mach-exynos/sleep.S
Tomasz Figa 2b9d9c321b ARM: EXYNOS: Add support for firmware-assisted suspend/resume
On a numer of Exynos-based boards Linux kernel is running in non-secure
mode under a secure firmware. This means that certain operations need to
be handled in special way, with firmware assistance. System-wide
suspend/resume is an example of such operations.

This patch adds support for firmware-assisted suspend/resume by
leveraging recently introduced suspend and resume firmware operations
and modifying existing suspend/resume paths to account for presence of
secure firmware.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
[kgene.kim@samsung.com: rebased]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2014-10-21 00:06:35 +09:00

86 lines
2.0 KiB
ArmAsm

/*
* Copyright (c) 2013 Samsung Electronics Co., Ltd.
* http://www.samsung.com
*
* Exynos low-level resume code
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/linkage.h>
#include "smc.h"
#define CPU_MASK 0xff0ffff0
#define CPU_CORTEX_A9 0x410fc090
/*
* The following code is located into the .data section. This is to
* allow l2x0_regs_phys to be accessed with a relative load while we
* can't rely on any MMU translation. We could have put l2x0_regs_phys
* in the .text section as well, but some setups might insist on it to
* be truly read-only. (Reference from: arch/arm/kernel/sleep.S)
*/
.data
.align
/*
* sleep magic, to allow the bootloader to check for an valid
* image to resume to. Must be the first word before the
* exynos_cpu_resume entry.
*/
.word 0x2bedf00d
/*
* exynos_cpu_resume
*
* resume code entry for bootloader to call
*/
ENTRY(exynos_cpu_resume)
#ifdef CONFIG_CACHE_L2X0
mrc p15, 0, r0, c0, c0, 0
ldr r1, =CPU_MASK
and r0, r0, r1
ldr r1, =CPU_CORTEX_A9
cmp r0, r1
bleq l2c310_early_resume
#endif
b cpu_resume
ENDPROC(exynos_cpu_resume)
.align
ENTRY(exynos_cpu_resume_ns)
mrc p15, 0, r0, c0, c0, 0
ldr r1, =CPU_MASK
and r0, r0, r1
ldr r1, =CPU_CORTEX_A9
cmp r0, r1
bne skip_cp15
adr r0, cp15_save_power
ldr r1, [r0]
adr r0, cp15_save_diag
ldr r2, [r0]
mov r0, #SMC_CMD_C15RESUME
dsb
smc #0
skip_cp15:
b cpu_resume
ENDPROC(exynos_cpu_resume_ns)
.globl cp15_save_diag
cp15_save_diag:
.long 0 @ cp15 diagnostic
.globl cp15_save_power
cp15_save_power:
.long 0 @ cp15 power control