[PATCH V5 5/5] arm: mvebu: Added SMP support for Armada XP

[gregory.clement@free-electrons.com (Gregory CLEMENT)]

On 11/21/2012 11:41 AM, Will Deacon wrote:
> On Tue, Nov 20, 2012 at 09:15:49PM +0000, Gregory CLEMENT wrote:
>> From: Yehuda Yitschak <yehuday@marvell.com>
>>
>> 1. added smp init functions in platsmp.c
>> 2. added secondary cpu entry point in headsmp.S
>> 3. added hotplog initial support in hotplug.c
> 
> hotplug
> 
>> 4. added SMP support for PJ4B cpu
> 
> Again, I think the commit message could probably be improved from a numbered
> list...
> 
>> Signed-off-by: Yehuda Yitschak <yehuday@marvell.com>
>> Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
>> ---
>>  arch/arm/configs/mvebu_defconfig    |    3 +
>>  arch/arm/mach-mvebu/Kconfig         |    1 +
>>  arch/arm/mach-mvebu/Makefile        |    2 +
>>  arch/arm/mach-mvebu/armada-370-xp.c |    3 +
>>  arch/arm/mach-mvebu/common.h        |    3 +
>>  arch/arm/mach-mvebu/headsmp.S       |   50 +++++++++++++++
>>  arch/arm/mach-mvebu/hotplug.c       |   30 +++++++++
>>  arch/arm/mach-mvebu/platsmp.c       |  121 +++++++++++++++++++++++++++++++++++
>>  8 files changed, 213 insertions(+)
>>  create mode 100644 arch/arm/mach-mvebu/headsmp.S
>>  create mode 100644 arch/arm/mach-mvebu/hotplug.c
>>  create mode 100644 arch/arm/mach-mvebu/platsmp.c
>>
>> diff --git a/arch/arm/configs/mvebu_defconfig b/arch/arm/configs/mvebu_defconfig
>> index 3458752..da598d3 100644
>> --- a/arch/arm/configs/mvebu_defconfig
>> +++ b/arch/arm/configs/mvebu_defconfig
>> @@ -12,6 +12,9 @@ CONFIG_ARCH_MVEBU=y
>>  CONFIG_MACH_ARMADA_370=y
>>  CONFIG_MACH_ARMADA_XP=y
>>  # CONFIG_CACHE_L2X0 is not set
>> +# CONFIG_SWP_EMULATE is not set
>> +CONFIG_SMP=y
>> +# CONFIG_LOCAL_TIMERS is not set
>>  CONFIG_AEABI=y
>>  CONFIG_HIGHMEM=y
>>  # CONFIG_COMPACTION is not set
>> diff --git a/arch/arm/mach-mvebu/Kconfig b/arch/arm/mach-mvebu/Kconfig
>> index f4c3bf8..c934e1d 100644
>> --- a/arch/arm/mach-mvebu/Kconfig
>> +++ b/arch/arm/mach-mvebu/Kconfig
>> @@ -21,6 +21,7 @@ menu "Marvell SOC with device tree"
>>  config MACH_ARMADA_370_XP
>>  	bool
>>  	select ARMADA_370_XP_TIMER
>> +	select HAVE_SMP
>>  	select CPU_PJ4B
>>  
>>  config MACH_ARMADA_370
>> diff --git a/arch/arm/mach-mvebu/Makefile b/arch/arm/mach-mvebu/Makefile
>> index 2e3ec11..5dcb369 100644
>> --- a/arch/arm/mach-mvebu/Makefile
>> +++ b/arch/arm/mach-mvebu/Makefile
>> @@ -3,3 +3,5 @@ ccflags-$(CONFIG_ARCH_MULTIPLATFORM) := -I$(srctree)/$(src)/include \
>>  
>>  obj-y += system-controller.o
>>  obj-$(CONFIG_MACH_ARMADA_370_XP) += armada-370-xp.o irq-armada-370-xp.o addr-map.o coherency.o coherency_ll.o pmsu.o
>> +obj-$(CONFIG_SMP)                += platsmp.o headsmp.o
>> +obj-$(CONFIG_HOTPLUG_CPU)        += hotplug.o
>> diff --git a/arch/arm/mach-mvebu/armada-370-xp.c b/arch/arm/mach-mvebu/armada-370-xp.c
>> index 3292d6d..472e70f 100644
>> --- a/arch/arm/mach-mvebu/armada-370-xp.c
>> +++ b/arch/arm/mach-mvebu/armada-370-xp.c
>> @@ -23,6 +23,7 @@
>>  #include <asm/mach/time.h>
>>  #include "armada-370-xp.h"
>>  #include "common.h"
>> +#include "coherency.h"
>>  
>>  static struct map_desc armada_370_xp_io_desc[] __initdata = {
>>  	{
>> @@ -51,6 +52,7 @@ struct sys_timer armada_370_xp_timer = {
>>  static void __init armada_370_xp_dt_init(void)
>>  {
>>  	of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL);
>> +	coherency_init();
>>  }
>>  
>>  static const char * const armada_370_xp_dt_board_dt_compat[] = {
>> @@ -60,6 +62,7 @@ static const char * const armada_370_xp_dt_board_dt_compat[] = {
>>  };
>>  
>>  DT_MACHINE_START(ARMADA_XP_DT, "Marvell Aramada 370/XP (Device Tree)")
>> +	.smp		= smp_ops(armada_xp_smp_ops),
>>  	.init_machine	= armada_370_xp_dt_init,
>>  	.map_io		= armada_370_xp_map_io,
>>  	.init_irq	= armada_370_xp_init_irq,
>> diff --git a/arch/arm/mach-mvebu/common.h b/arch/arm/mach-mvebu/common.h
>> index b5cd7e7..b711869 100644
>> --- a/arch/arm/mach-mvebu/common.h
>> +++ b/arch/arm/mach-mvebu/common.h
>> @@ -20,7 +20,10 @@ void mvebu_restart(char mode, const char *cmd);
>>  void armada_370_xp_init_irq(void);
>>  void armada_370_xp_handle_irq(struct pt_regs *regs);
>>  
>> +void armada_xp_cpu_die(unsigned int cpu);
>>  
>>  int armada_370_xp_coherency_init(void);
>>  int armada_370_xp_pmsu_init(void);
>> +void armada_xp_secondary_startup(void);
>> +extern struct smp_operations armada_xp_smp_ops;
>>  #endif
>> diff --git a/arch/arm/mach-mvebu/headsmp.S b/arch/arm/mach-mvebu/headsmp.S
>> new file mode 100644
>> index 0000000..994eecc
>> --- /dev/null
>> +++ b/arch/arm/mach-mvebu/headsmp.S
>> @@ -0,0 +1,50 @@
>> +/*
>> + * SMP support: Entry point for secondary CPUs
>> + *
>> + * Copyright (C) 2012 Marvell
>> + *
>> + * Yehuda Yitschak <yehuday@marvell.com>
>> + * Gregory CLEMENT <gregory.clement@free-electrons.com>
>> + * Thomas Petazzoni <thomas.petazzoni@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.
>> + *
>> + * This file implements the assembly entry point for secondary CPUs in
>> + * an SMP kernel. The only thing we need to do is to add the CPU to
>> + * the coherency fabric by writing to 2 registers. Currently the base
>> + * register addresses are hard coded due to the early initialisation
>> + * problems.
>> + */
>> +
>> +#include <linux/linkage.h>
>> +#include <linux/init.h>
>> +
>> +/*
>> + * At this stage the secondary CPUs don't have acces yet to the MMU, so
>> + * we have to provide physical addresses
>> + */
>> +#define ARMADA_XP_CFB_BASE	     0xD0020200
>> +
>> +	__CPUINIT
>> +
>> +/*
>> + * Armada XP specific entry point for secondary CPUs.
>> + * We add the CPU to the coherency fabric and then jump to secondary
>> + * startup
>> + */
>> +ENTRY(armada_xp_secondary_startup)
>> +
>> +	/* Read CPU id */
>> + 	mrc     p15, 0, r1, c0, c0, 5
>> +	and     r1, r1, #0xF
>> +
>> +	/* Add CPU to coherency fabric */
>> +	ldr     r0, = ARMADA_XP_CFB_BASE
>> +	mov	lr, pc
>> +
>> +	b	ll_set_cpu_coherent
>> +	b	secondary_startup
> 
> Why didn't you use my adr suggestion here?

Because when I used BSYM(secondary_startup), I get the following
message during compilation:

Error: undefined symbol secondary_startup used as an immediate value

And I didn't want to miss the merge window for something which could be
fixed during the v3.8-rc1 if needed.

> 
> Will
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com