linux/arch/arm/mach-mvebu/pmsu_ll.S
Thomas Petazzoni 77ea46d133 ARM: mvebu: make sure MMU is disabled in armada_370_xp_cpu_resume
The armada_370_xp_cpu_resume() until now was used only as the function
called by the SoC when returning from a deep idle state (as used in
cpuidle, or when the CPU is brought offline using CPU hotplug).

However, it is now also used when exiting the suspend to RAM state. In
this case, it is the bootloader that calls back into this function,
with the MMU left enabled by the BootROM. Having the MMU enabled when
entering this function confuses the kerrnel because we are not using
the kernel page tables at this point, but in other mvebu functions we
use the information on whether the MMU is enabled or not to find out
whether we should talk to the coherency fabric using a physical
address or a virtual address. To fix that, we simply disable the MMU
when entering this function, so that the kernel is in an expected
situation.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1416585613-2113-13-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-11-30 16:40:15 +00:00

70 lines
1.9 KiB
ArmAsm

/*
* Copyright (C) 2014 Marvell
*
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
* Gregory Clement <gregory.clement@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* This is the entry point through which CPUs exiting cpuidle deep
* idle state are going.
*/
ENTRY(armada_370_xp_cpu_resume)
ARM_BE8(setend be ) @ go BE8 if entered LE
/*
* Disable the MMU that might have been enabled in BootROM if
* this code is used in the resume path of a suspend/resume
* cycle.
*/
mrc p15, 0, r1, c1, c0, 0
bic r1, #1
mcr p15, 0, r1, c1, c0, 0
bl ll_add_cpu_to_smp_group
bl ll_enable_coherency
b cpu_resume
ENDPROC(armada_370_xp_cpu_resume)
ENTRY(armada_38x_cpu_resume)
/* do we need it for Armada 38x*/
ARM_BE8(setend be ) @ go BE8 if entered LE
bl v7_invalidate_l1
mrc p15, 4, r1, c15, c0 @ get SCU base address
orr r1, r1, #0x8 @ SCU CPU Power Status Register
mrc 15, 0, r0, cr0, cr0, 5 @ get the CPU ID
and r0, r0, #15
add r1, r1, r0
mov r0, #0x0
strb r0, [r1] @ switch SCU power state to Normal mode
b cpu_resume
ENDPROC(armada_38x_cpu_resume)
.global mvebu_boot_wa_start
.global mvebu_boot_wa_end
/* The following code will be executed from SRAM */
ENTRY(mvebu_boot_wa_start)
mvebu_boot_wa_start:
ARM_BE8(setend be)
adr r0, 1f
ldr r0, [r0] @ load the address of the
@ resume register
ldr r0, [r0] @ load the value in the
@ resume register
ARM_BE8(rev r0, r0) @ the value is stored LE
mov pc, r0 @ jump to this value
/*
* the last word of this piece of code will be filled by the physical
* address of the boot address register just after being copied in SRAM
*/
1:
.long .
mvebu_boot_wa_end:
ENDPROC(mvebu_boot_wa_end)