renegade-project/linux-next
2
0
Fork 0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-27 14:43:58 +08:00
Code
6fda93b95e
linux-next/arch/arm/mach-mvebu/pmsu_ll.S

76 lines
2.0 KiB
ArmAsm
Raw Normal View History

ARM: mvebu: fix cpuidle implementation to work on big-endian systems On Marvell Armada XP, when a CPU comes back from deep idle state of cpuidle, it restarts its execution at armada_370_xp_cpu_resume(), which puts back the CPU into the coherency, and then calls the generic cpu_resume() function. While this works on little-endian configurations, it doesn't work on big-endian configurations because the CPU restarts in little-endian, and therefore must be switched back to big-endian to operate properly. To achieve this, a 'setend be' instruction must be executed in big-endian configurations. However, the ARM_BE8() macro that is used to implement nice compile-time conditional for ARM LE vs. ARM BE8 is not easily usable in inline assembly. Therefore, this patch moves the armada_370_xp_cpu_resume() C function, which was anyway just a block of inline assembly, into a proper pmsu_ll.S file, and adds the appropriate ARM_BE8(setend be) instruction. Without this patch, an Armada XP big endian configuration with cpuidle enabled fails to boot, as it hangs as soon as one of the CPU hits the deep idle state. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1404130165-3593-1-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 20:09:25 +08:00
/*
* 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>
ARM: mvebu: Move SCU power up in a function This will allow reusing the same function in the secondary_startup for the Cortex A9 SoC. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1414669184-16785-3-git-send-email-gregory.clement@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-10-30 19:39:42 +08:00
ENTRY(armada_38x_scu_power_up)
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
ret lr
ENDPROC(armada_38x_scu_power_up)
ARM: mvebu: fix cpuidle implementation to work on big-endian systems On Marvell Armada XP, when a CPU comes back from deep idle state of cpuidle, it restarts its execution at armada_370_xp_cpu_resume(), which puts back the CPU into the coherency, and then calls the generic cpu_resume() function. While this works on little-endian configurations, it doesn't work on big-endian configurations because the CPU restarts in little-endian, and therefore must be switched back to big-endian to operate properly. To achieve this, a 'setend be' instruction must be executed in big-endian configurations. However, the ARM_BE8() macro that is used to implement nice compile-time conditional for ARM LE vs. ARM BE8 is not easily usable in inline assembly. Therefore, this patch moves the armada_370_xp_cpu_resume() C function, which was anyway just a block of inline assembly, into a proper pmsu_ll.S file, and adds the appropriate ARM_BE8(setend be) instruction. Without this patch, an Armada XP big endian configuration with cpuidle enabled fails to boot, as it hangs as soon as one of the CPU hits the deep idle state. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1404130165-3593-1-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 20:09:25 +08:00
/*
* 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
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>
2014-11-22 00:00:09 +08:00
/*
* 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
ARM: mvebu: fix cpuidle implementation to work on big-endian systems On Marvell Armada XP, when a CPU comes back from deep idle state of cpuidle, it restarts its execution at armada_370_xp_cpu_resume(), which puts back the CPU into the coherency, and then calls the generic cpu_resume() function. While this works on little-endian configurations, it doesn't work on big-endian configurations because the CPU restarts in little-endian, and therefore must be switched back to big-endian to operate properly. To achieve this, a 'setend be' instruction must be executed in big-endian configurations. However, the ARM_BE8() macro that is used to implement nice compile-time conditional for ARM LE vs. ARM BE8 is not easily usable in inline assembly. Therefore, this patch moves the armada_370_xp_cpu_resume() C function, which was anyway just a block of inline assembly, into a proper pmsu_ll.S file, and adds the appropriate ARM_BE8(setend be) instruction. Without this patch, an Armada XP big endian configuration with cpuidle enabled fails to boot, as it hangs as soon as one of the CPU hits the deep idle state. Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1404130165-3593-1-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-06-30 20:09:25 +08:00
bl ll_add_cpu_to_smp_group
bl ll_enable_coherency
b cpu_resume
ENDPROC(armada_370_xp_cpu_resume)
ARM: mvebu: add cpuidle support for Armada 38x Unlike the Armada XP and the Armada 370, this SoC uses a Cortex A9 core. Consequently, the procedure to enter the idle state is different: interaction with the SCU, not disabling snooping, etc. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1406120453-29291-16-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-07-23 21:00:52 +08:00
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
ARM: mvebu: Move SCU power up in a function This will allow reusing the same function in the secondary_startup for the Cortex A9 SoC. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Tested-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Reviewed-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1414669184-16785-3-git-send-email-gregory.clement@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-10-30 19:39:42 +08:00
bl armada_38x_scu_power_up
ARM: mvebu: add cpuidle support for Armada 38x Unlike the Armada XP and the Armada 370, this SoC uses a Cortex A9 core. Consequently, the procedure to enter the idle state is different: interaction with the SCU, not disabling snooping, etc. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1406120453-29291-16-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-07-23 21:00:52 +08:00
b cpu_resume
ENDPROC(armada_38x_cpu_resume)
ARM: mvebu: add a common function for the boot address work around On some of the mvebu SoCs and due to internal BootROM issue, the CPU initial jump code must be placed in the SRAM memory of the SoC. In order to achieve this, we have to unmap the BootROM and at some specific location where the BootROM was placed, create a dedicated MBus window for the SRAM. This SRAM is initialized with a few instructions of code that allows to jump to the real secondary CPU boot address. The SRAM used is the Crypto engine one. This work around is currently needed for booting SMP on Armada 375 Z1 and will be needed for cpuidle support on Armada 370. Instead of duplicating the same code, this commit introduces a common function to handle it: mvebu_setup_boot_addr_wa(). Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> Link: https://lkml.kernel.org/r/1406120453-29291-4-git-send-email-thomas.petazzoni@free-electrons.com Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-07-23 21:00:40 +08:00
.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)
Copy Permalink