Re: [PATCH] MIPS: Add platform specific secondary core init

[Qais Yousef <qais.yousef@xxxxxxxxxx>]

On 06/18/2015 03:05 PM, Tony Wu wrote:
> Define plat_smp_init_secondary() API, and move platform specific
> secondary core initialization to each platform.

I really can't see that this code being platform specific. Why would a 
platform care about the c0_status register when a secondary boot is 
initialised?

That comment about Malta in smp-mt.c is misleading.

Qais

> Signed-off-by: Tony Wu <tung7970@xxxxxxxxx>
> Cc: James Hogan <james.hogan@xxxxxxxxxx>
> Cc: Paul Burton <paul.burton@xxxxxxxxxx>
> Cc: linux-mips@xxxxxxxxxxxxxx
> ---
>   arch/mips/include/asm/smp-ops.h  |    1 +
>   arch/mips/kernel/smp-cmp.c       |    8 ++------
>   arch/mips/kernel/smp-cps.c       |    4 ++--
>   arch/mips/kernel/smp-mt.c        |   12 ++----------
>   arch/mips/mti-malta/malta-init.c |   13 +++++++++++++
>   5 files changed, 20 insertions(+), 18 deletions(-)
>
> diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h
> index 6ba1fb8..53ce7e1 100644
> --- a/arch/mips/include/asm/smp-ops.h
> +++ b/arch/mips/include/asm/smp-ops.h
> @@ -36,6 +36,7 @@ struct plat_smp_ops {
>   };
>   
>   extern void register_smp_ops(struct plat_smp_ops *ops);
> +extern void plat_smp_init_secondary(void)
>   
>   static inline void plat_smp_setup(void)
>   {
> diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c
> index d5e0f94..e8c0258 100644
> --- a/arch/mips/kernel/smp-cmp.c
> +++ b/arch/mips/kernel/smp-cmp.c
> @@ -43,17 +43,13 @@ static void cmp_init_secondary(void)
>   {
>   	struct cpuinfo_mips *c __maybe_unused = &current_cpu_data;
>   
> -	/* Assume GIC is present */
> -	change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | STATUSF_IP4 |
> -				 STATUSF_IP5 | STATUSF_IP6 | STATUSF_IP7);
> -
> -	/* Enable per-cpu interrupts: platform specific */
> -
>   #ifdef CONFIG_MIPS_MT_SMP
>   	if (cpu_has_mipsmt)
>   		c->vpe_id = (read_c0_tcbind() >> TCBIND_CURVPE_SHIFT) &
>   			TCBIND_CURVPE;
>   #endif
> +	/* Call platform specific init secondary */
> +	plat_smp_init_secondary();
>   }
>   
>   static void cmp_smp_finish(void)
> diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
> index 4251d39..5570bc8 100644
> --- a/arch/mips/kernel/smp-cps.c
> +++ b/arch/mips/kernel/smp-cps.c
> @@ -279,8 +279,8 @@ static void cps_init_secondary(void)
>   	if (cpu_has_mipsmt)
>   		dmt();
>   
> -	change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 | STATUSF_IP4 |
> -				 STATUSF_IP5 | STATUSF_IP6 | STATUSF_IP7);
> +	/* Call platform specific init secondary */
> +	plat_smp_init_secondary();
>   }
>   
>   static void cps_smp_finish(void)
> diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
> index 86311a1..3d1e32a 100644
> --- a/arch/mips/kernel/smp-mt.c
> +++ b/arch/mips/kernel/smp-mt.c
> @@ -158,16 +158,8 @@ static void vsmp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
>   
>   static void vsmp_init_secondary(void)
>   {
> -#ifdef CONFIG_MIPS_GIC
> -	/* This is Malta specific: IPI,performance and timer interrupts */
> -	if (gic_present)
> -		change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 |
> -					 STATUSF_IP4 | STATUSF_IP5 |
> -					 STATUSF_IP6 | STATUSF_IP7);
> -	else
> -#endif
> -		change_c0_status(ST0_IM, STATUSF_IP0 | STATUSF_IP1 |
> -					 STATUSF_IP6 | STATUSF_IP7);
> +	/* Call platform specific init secondary */
> +	plat_smp_init_secondary();
>   }
>   
>   static void vsmp_smp_finish(void)
> diff --git a/arch/mips/mti-malta/malta-init.c b/arch/mips/mti-malta/malta-init.c
> index cec3e18..3385ad9 100644
> --- a/arch/mips/mti-malta/malta-init.c
> +++ b/arch/mips/mti-malta/malta-init.c
> @@ -116,6 +116,19 @@ phys_addr_t mips_cpc_default_phys_base(void)
>   	return CPC_BASE_ADDR;
>   }
>   
> +void plat_smp_init_secondary(void)
> +{
> +#ifdef CONFIG_MIPS_GIC
> +	if (gic_present)
> +		change_c0_status(ST0_IM, STATUSF_IP2 | STATUSF_IP3 |
> +					 STATUSF_IP4 | STATUSF_IP5 |
> +					 STATUSF_IP6 | STATUSF_IP7);
> +	else
> +#endif
> +		change_c0_status(ST0_IM, STATUSF_IP0 | STATUSF_IP1 |
> +					 STATUSF_IP6 | STATUSF_IP7);
> +}
> +
>   void __init prom_init(void)
>   {
>   	mips_display_message("LINUX");