[PATCH v2 09/16] ARM: vexpress: Select the correct SMP operations at run-time

[Jon Medhurst (Tixy)]

On Thu, 2013-01-24 at 01:27 -0500, Nicolas Pitre wrote:
> From: Jon Medhurst <tixy at linaro.org>
> 
> Signed-off-by: Jon Medhurst <tixy at linaro.org>
> ---

Should this patch be split into two. One to introduce the new smp_init
hook, and one to make vexpress use it? With descriptions like:

-----------------------------------------------------------------------
ARM: kernel: Enable selection of SMP operations at boot time

Add a new 'smp_init' hook to machine_desc so platforms can specify a
function to be used to setup smp ops instead of having a statically
defined value.
-----------------------------------------------------------------------
ARM: vexpress: Select multi-cluster SMP operation if required
-----------------------------------------------------------------------

-- 
Tixy

>  arch/arm/include/asm/mach/arch.h |  3 +++
>  arch/arm/kernel/setup.c          |  5 ++++-
>  arch/arm/mach-vexpress/core.h    |  2 ++
>  arch/arm/mach-vexpress/platsmp.c | 12 ++++++++++++
>  arch/arm/mach-vexpress/v2m.c     |  2 +-
>  5 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/include/asm/mach/arch.h b/arch/arm/include/asm/mach/arch.h
> index 917d4fcfd9..3d01c6d6c3 100644
> --- a/arch/arm/include/asm/mach/arch.h
> +++ b/arch/arm/include/asm/mach/arch.h
> @@ -17,8 +17,10 @@ struct pt_regs;
>  struct smp_operations;
>  #ifdef CONFIG_SMP
>  #define smp_ops(ops) (&(ops))
> +#define smp_init_ops(ops) (&(ops))
>  #else
>  #define smp_ops(ops) (struct smp_operations *)NULL
> +#define smp_init_ops(ops) (void (*)(void))NULL
>  #endif
>  
>  struct machine_desc {
> @@ -42,6 +44,7 @@ struct machine_desc {
>  	unsigned char		reserve_lp2 :1;	/* never has lp2	*/
>  	char			restart_mode;	/* default restart mode	*/
>  	struct smp_operations	*smp;		/* SMP operations	*/
> +	void			(*smp_init)(void);
>  	void			(*fixup)(struct tag *, char **,
>  					 struct meminfo *);
>  	void			(*reserve)(void);/* reserve mem blocks	*/
> diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
> index 3f6cbb2e3e..41edca8582 100644
> --- a/arch/arm/kernel/setup.c
> +++ b/arch/arm/kernel/setup.c
> @@ -768,7 +768,10 @@ void __init setup_arch(char **cmdline_p)
>  	arm_dt_init_cpu_maps();
>  #ifdef CONFIG_SMP
>  	if (is_smp()) {
> -		smp_set_ops(mdesc->smp);
> +		if(mdesc->smp_init)
> +			(*mdesc->smp_init)();
> +		else
> +			smp_set_ops(mdesc->smp);
>  		smp_init_cpus();
>  	}
>  #endif
> diff --git a/arch/arm/mach-vexpress/core.h b/arch/arm/mach-vexpress/core.h
> index f134cd4a85..3a761fd76c 100644
> --- a/arch/arm/mach-vexpress/core.h
> +++ b/arch/arm/mach-vexpress/core.h
> @@ -6,6 +6,8 @@
>  
>  void vexpress_dt_smp_map_io(void);
>  
> +void vexpress_smp_init_ops(void);
> +
>  extern struct smp_operations	vexpress_smp_ops;
>  
>  extern void vexpress_cpu_die(unsigned int cpu);
> diff --git a/arch/arm/mach-vexpress/platsmp.c b/arch/arm/mach-vexpress/platsmp.c
> index c5d70de9bb..e62a08b561 100644
> --- a/arch/arm/mach-vexpress/platsmp.c
> +++ b/arch/arm/mach-vexpress/platsmp.c
> @@ -12,6 +12,7 @@
>  #include <linux/errno.h>
>  #include <linux/smp.h>
>  #include <linux/io.h>
> +#include <linux/of.h>
>  #include <linux/of_fdt.h>
>  #include <linux/vexpress.h>
>  
> @@ -206,3 +207,14 @@ struct smp_operations __initdata vexpress_smp_ops = {
>  	.cpu_die		= vexpress_cpu_die,
>  #endif
>  };
> +
> +void __init vexpress_smp_init_ops(void)
> +{
> +	struct smp_operations *ops = &vexpress_smp_ops;
> +#ifdef CONFIG_BIG_LITTLE
> +	extern struct smp_operations bL_smp_ops;
> +	if(of_find_compatible_node(NULL, NULL, "arm,cci"))
> +		ops = &bL_smp_ops;
> +#endif
> +	smp_set_ops(ops);
> +}
> diff --git a/arch/arm/mach-vexpress/v2m.c b/arch/arm/mach-vexpress/v2m.c
> index 011661a6c5..34172bd504 100644
> --- a/arch/arm/mach-vexpress/v2m.c
> +++ b/arch/arm/mach-vexpress/v2m.c
> @@ -494,7 +494,7 @@ static const char * const v2m_dt_match[] __initconst = {
>  
>  DT_MACHINE_START(VEXPRESS_DT, "ARM-Versatile Express")
>  	.dt_compat	= v2m_dt_match,
> -	.smp		= smp_ops(vexpress_smp_ops),
> +	.smp_init	= smp_init_ops(vexpress_smp_init_ops),
>  	.map_io		= v2m_dt_map_io,
>  	.init_early	= v2m_dt_init_early,
>  	.init_irq	= v2m_dt_init_irq,