Re: [PATCH 1/4] MIPS: SMP: Constify smp ops

[Matt Redfearn <matt.redfearn@xxxxxxxxxx>]

On 14/02/17 14:37, Matt Redfearn wrote:
> smp_ops providers do not modify their ops structures, so they may be
> made const.
>
> This change saves 128 bytes of kernel text on a pistachio_defconfig.
> Before:
>     text	   data	    bss	    dec	    hex	filename
> 7187239	1772752	 470224	9430215	 8fe4c7	vmlinux
> After:
>     text	   data	    bss	    dec	    hex	filename
> 7187111	1772752	 470224	9430087	 8fe447	vmlinux
>
> Signed-off-by: Matt Redfearn <matt.redfearn@xxxxxxxxxx>

Forget this one, it misses a whole bunch of smp_ops providers. I'll send 
a v2 after the merge window.

Thanks,
Matt

> ---
>
>   arch/mips/include/asm/smp-ops.h | 10 +++++-----
>   arch/mips/include/asm/smp.h     | 10 +++++-----
>   arch/mips/kernel/smp-cps.c      |  4 ++--
>   arch/mips/kernel/smp-mt.c       |  2 +-
>   arch/mips/kernel/smp-up.c       |  2 +-
>   arch/mips/kernel/smp.c          |  4 ++--
>   6 files changed, 16 insertions(+), 16 deletions(-)
>
> diff --git a/arch/mips/include/asm/smp-ops.h b/arch/mips/include/asm/smp-ops.h
> index db7c322f057f..cf12bde3aa78 100644
> --- a/arch/mips/include/asm/smp-ops.h
> +++ b/arch/mips/include/asm/smp-ops.h
> @@ -35,11 +35,11 @@ struct plat_smp_ops {
>   #endif
>   };
>   
> -extern void register_smp_ops(struct plat_smp_ops *ops);
> +extern void register_smp_ops(const struct plat_smp_ops *ops);
>   
>   static inline void plat_smp_setup(void)
>   {
> -	extern struct plat_smp_ops *mp_ops;	/* private */
> +	extern const struct plat_smp_ops *mp_ops;	/* private */
>   
>   	mp_ops->smp_setup();
>   }
> @@ -66,7 +66,7 @@ static inline void register_smp_ops(struct plat_smp_ops *ops)
>   static inline int register_up_smp_ops(void)
>   {
>   #ifdef CONFIG_SMP_UP
> -	extern struct plat_smp_ops up_smp_ops;
> +	extern const struct plat_smp_ops up_smp_ops;
>   
>   	register_smp_ops(&up_smp_ops);
>   
> @@ -79,7 +79,7 @@ static inline int register_up_smp_ops(void)
>   static inline int register_cmp_smp_ops(void)
>   {
>   #ifdef CONFIG_MIPS_CMP
> -	extern struct plat_smp_ops cmp_smp_ops;
> +	extern const struct plat_smp_ops cmp_smp_ops;
>   
>   	if (!mips_cm_present())
>   		return -ENODEV;
> @@ -95,7 +95,7 @@ static inline int register_cmp_smp_ops(void)
>   static inline int register_vsmp_smp_ops(void)
>   {
>   #ifdef CONFIG_MIPS_MT_SMP
> -	extern struct plat_smp_ops vsmp_smp_ops;
> +	extern const struct plat_smp_ops vsmp_smp_ops;
>   
>   	register_smp_ops(&vsmp_smp_ops);
>   
> diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
> index 98a117a05fbc..572191ac2961 100644
> --- a/arch/mips/include/asm/smp.h
> +++ b/arch/mips/include/asm/smp.h
> @@ -58,7 +58,7 @@ extern void calculate_cpu_foreign_map(void);
>    */
>   static inline void smp_send_reschedule(int cpu)
>   {
> -	extern struct plat_smp_ops *mp_ops;	/* private */
> +	extern const struct plat_smp_ops *mp_ops;	/* private */
>   
>   	mp_ops->send_ipi_single(cpu, SMP_RESCHEDULE_YOURSELF);
>   }
> @@ -66,14 +66,14 @@ static inline void smp_send_reschedule(int cpu)
>   #ifdef CONFIG_HOTPLUG_CPU
>   static inline int __cpu_disable(void)
>   {
> -	extern struct plat_smp_ops *mp_ops;	/* private */
> +	extern const struct plat_smp_ops *mp_ops;	/* private */
>   
>   	return mp_ops->cpu_disable();
>   }
>   
>   static inline void __cpu_die(unsigned int cpu)
>   {
> -	extern struct plat_smp_ops *mp_ops;	/* private */
> +	extern const struct plat_smp_ops *mp_ops;	/* private */
>   
>   	mp_ops->cpu_die(cpu);
>   }
> @@ -97,14 +97,14 @@ int mips_smp_ipi_free(const struct cpumask *mask);
>   
>   static inline void arch_send_call_function_single_ipi(int cpu)
>   {
> -	extern struct plat_smp_ops *mp_ops;	/* private */
> +	extern const struct plat_smp_ops *mp_ops;	/* private */
>   
>   	mp_ops->send_ipi_mask(cpumask_of(cpu), SMP_CALL_FUNCTION);
>   }
>   
>   static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask)
>   {
> -	extern struct plat_smp_ops *mp_ops;	/* private */
> +	extern const struct plat_smp_ops *mp_ops;	/* private */
>   
>   	mp_ops->send_ipi_mask(mask, SMP_CALL_FUNCTION);
>   }
> diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
> index a2544c2394e4..77c0db4d46e2 100644
> --- a/arch/mips/kernel/smp-cps.c
> +++ b/arch/mips/kernel/smp-cps.c
> @@ -549,7 +549,7 @@ static void cps_cpu_die(unsigned int cpu)
>   
>   #endif /* CONFIG_HOTPLUG_CPU */
>   
> -static struct plat_smp_ops cps_smp_ops = {
> +static const struct plat_smp_ops cps_smp_ops = {
>   	.smp_setup		= cps_smp_setup,
>   	.prepare_cpus		= cps_prepare_cpus,
>   	.boot_secondary		= cps_boot_secondary,
> @@ -565,7 +565,7 @@ static struct plat_smp_ops cps_smp_ops = {
>   
>   bool mips_cps_smp_in_use(void)
>   {
> -	extern struct plat_smp_ops *mp_ops;
> +	extern const struct plat_smp_ops *mp_ops;
>   	return mp_ops == &cps_smp_ops;
>   }
>   
> diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
> index e077ea3e11fb..22db83be8349 100644
> --- a/arch/mips/kernel/smp-mt.c
> +++ b/arch/mips/kernel/smp-mt.c
> @@ -279,7 +279,7 @@ static void __init vsmp_prepare_cpus(unsigned int max_cpus)
>   	mips_mt_set_cpuoptions();
>   }
>   
> -struct plat_smp_ops vsmp_smp_ops = {
> +const struct plat_smp_ops vsmp_smp_ops = {
>   	.send_ipi_single	= vsmp_send_ipi_single,
>   	.send_ipi_mask		= vsmp_send_ipi_mask,
>   	.init_secondary		= vsmp_init_secondary,
> diff --git a/arch/mips/kernel/smp-up.c b/arch/mips/kernel/smp-up.c
> index 17878d71ef2b..4cf015a624d1 100644
> --- a/arch/mips/kernel/smp-up.c
> +++ b/arch/mips/kernel/smp-up.c
> @@ -63,7 +63,7 @@ static void up_cpu_die(unsigned int cpu)
>   }
>   #endif
>   
> -struct plat_smp_ops up_smp_ops = {
> +const struct plat_smp_ops up_smp_ops = {
>   	.send_ipi_single	= up_send_ipi_single,
>   	.send_ipi_mask		= up_send_ipi_mask,
>   	.init_secondary		= up_init_secondary,
> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
> index 8c60a296294c..9f01a6f28f49 100644
> --- a/arch/mips/kernel/smp.c
> +++ b/arch/mips/kernel/smp.c
> @@ -146,10 +146,10 @@ void calculate_cpu_foreign_map(void)
>   			       &temp_foreign_map, &cpu_sibling_map[i]);
>   }
>   
> -struct plat_smp_ops *mp_ops;
> +const struct plat_smp_ops *mp_ops;
>   EXPORT_SYMBOL(mp_ops);
>   
> -void register_smp_ops(struct plat_smp_ops *ops)
> +void register_smp_ops(const struct plat_smp_ops *ops)
>   {
>   	if (mp_ops)
>   		printk(KERN_WARNING "Overriding previously set SMP ops\n");