Re: [PATCH 13/19] MIPS: Unify checks for sibling CPUs

[Ralf Baechle <ralf@linux-mips.org>]

Hi,

Paul didn't cc the other maintainers.  Tglx gave me his Ack on IRC so I
now only still need one of a drivers/cpuidle/ maintainer.

Thanks,

  Ralf

On Sat, Aug 12, 2017 at 07:49:37PM -0700, Paul Burton wrote:
> Date:   Sat, 12 Aug 2017 19:49:37 -0700
> From: Paul Burton <paul.burton@imgtec.com>
> To: linux-mips@linux-mips.org
> CC: Ralf Baechle <ralf@linux-mips.org>, Paul Burton <paul.burton@imgtec.com>
> Subject: [PATCH 13/19] MIPS: Unify checks for sibling CPUs
> Content-Type: text/plain
> 
> Up until now we have open-coded checks for whether CPUs are siblings,
> with slight variations on whether we consider the package ID or not.
> 
> This will only get more complex when we introduce cluster support, so in
> preparation for that this patch introduces a cpus_are_siblings()
> function which can be used to check whether or not 2 CPUs are siblings
> in a consistent manner.
> 
> By checking globalnumber with the VP ID masked out this also has the
> neat side effect of being ready for multi-cluster systems already.
> 
> Signed-off-by: Paul Burton <paul.burton@imgtec.com>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: linux-mips@linux-mips.org
> ---
> 
>  arch/mips/include/asm/cpu-info.h | 17 +++++++++++++++++
>  arch/mips/kernel/smp-cps.c       |  8 ++++----
>  arch/mips/kernel/smp.c           | 12 +++++-------
>  drivers/cpuidle/cpuidle-cps.c    |  2 +-
>  drivers/irqchip/irq-mips-cpu.c   |  2 +-
>  5 files changed, 28 insertions(+), 13 deletions(-)
> 
> diff --git a/arch/mips/include/asm/cpu-info.h b/arch/mips/include/asm/cpu-info.h
> index 9ae927282b12..0c61bdc82a53 100644
> --- a/arch/mips/include/asm/cpu-info.h
> +++ b/arch/mips/include/asm/cpu-info.h
> @@ -158,6 +158,23 @@ static inline unsigned int cpu_vpe_id(struct cpuinfo_mips *cpuinfo)
>  extern void cpu_set_core(struct cpuinfo_mips *cpuinfo, unsigned int core);
>  extern void cpu_set_vpe_id(struct cpuinfo_mips *cpuinfo, unsigned int vpe);
>  
> +static inline bool cpus_are_siblings(int cpua, int cpub)
> +{
> +	struct cpuinfo_mips *infoa = &cpu_data[cpua];
> +	struct cpuinfo_mips *infob = &cpu_data[cpub];
> +	unsigned int gnuma, gnumb;
> +
> +	if (infoa->package != infob->package)
> +		return false;
> +
> +	gnuma = infoa->globalnumber & ~MIPS_GLOBALNUMBER_VP;
> +	gnumb = infob->globalnumber & ~MIPS_GLOBALNUMBER_VP;
> +	if (gnuma != gnumb)
> +		return false;
> +
> +	return true;
> +}
> +
>  static inline unsigned long cpu_asid_inc(void)
>  {
>  	return 1 << CONFIG_MIPS_ASID_SHIFT;
> diff --git a/arch/mips/kernel/smp-cps.c b/arch/mips/kernel/smp-cps.c
> index 699459ed293b..8cc508809466 100644
> --- a/arch/mips/kernel/smp-cps.c
> +++ b/arch/mips/kernel/smp-cps.c
> @@ -147,7 +147,7 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
>  			cpu_has_dc_aliases ? "dcache aliasing" : "");
>  
>  		for_each_present_cpu(c) {
> -			if (cpu_core(&cpu_data[c]))
> +			if (!cpus_are_siblings(smp_processor_id(), c))
>  				set_cpu_present(c, false);
>  		}
>  	}
> @@ -319,10 +319,10 @@ static void cps_boot_secondary(int cpu, struct task_struct *idle)
>  		mips_cm_unlock_other();
>  	}
>  
> -	if (core != cpu_core(&current_cpu_data)) {
> +	if (!cpus_are_siblings(cpu, smp_processor_id())) {
>  		/* Boot a VPE on another powered up core */
>  		for (remote = 0; remote < NR_CPUS; remote++) {
> -			if (cpu_core(&cpu_data[remote]) != core)
> +			if (!cpus_are_siblings(cpu, remote))
>  				continue;
>  			if (cpu_online(remote))
>  				break;
> @@ -431,7 +431,7 @@ void play_dead(void)
>  
>  		/* Look for another online VPE within the core */
>  		for_each_online_cpu(cpu_death_sibling) {
> -			if (cpu_core(&cpu_data[cpu_death_sibling]) != core)
> +			if (!cpus_are_siblings(cpu, cpu_death_sibling))
>  				continue;
>  
>  			/*
> diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
> index a54e5857c227..4cc43892b959 100644
> --- a/arch/mips/kernel/smp.c
> +++ b/arch/mips/kernel/smp.c
> @@ -96,8 +96,7 @@ static inline void set_cpu_sibling_map(int cpu)
>  
>  	if (smp_num_siblings > 1) {
>  		for_each_cpu(i, &cpu_sibling_setup_map) {
> -			if (cpu_data[cpu].package == cpu_data[i].package &&
> -			    cpu_core(&cpu_data[cpu]) == cpu_core(&cpu_data[i])) {
> +			if (cpus_are_siblings(cpu, i)) {
>  				cpumask_set_cpu(i, &cpu_sibling_map[cpu]);
>  				cpumask_set_cpu(cpu, &cpu_sibling_map[i]);
>  			}
> @@ -134,8 +133,7 @@ void calculate_cpu_foreign_map(void)
>  	for_each_online_cpu(i) {
>  		core_present = 0;
>  		for_each_cpu(k, &temp_foreign_map)
> -			if (cpu_data[i].package == cpu_data[k].package &&
> -			    cpu_core(&cpu_data[i]) == cpu_core(&cpu_data[k]))
> +			if (cpus_are_siblings(i, k))
>  				core_present = 1;
>  		if (!core_present)
>  			cpumask_set_cpu(i, &temp_foreign_map);
> @@ -186,11 +184,11 @@ void mips_smp_send_ipi_mask(const struct cpumask *mask, unsigned int action)
>  
>  	if (mips_cpc_present()) {
>  		for_each_cpu(cpu, mask) {
> -			core = cpu_core(&cpu_data[cpu]);
> -
> -			if (core == cpu_core(&current_cpu_data))
> +			if (cpus_are_siblings(cpu, smp_processor_id()))
>  				continue;
>  
> +			core = cpu_core(&cpu_data[cpu]);
> +
>  			while (!cpumask_test_cpu(cpu, &cpu_coherent_mask)) {
>  				mips_cm_lock_other(core, 0);
>  				mips_cpc_lock_other(core);
> diff --git a/drivers/cpuidle/cpuidle-cps.c b/drivers/cpuidle/cpuidle-cps.c
> index 6041b6104f3d..72b5e47286b4 100644
> --- a/drivers/cpuidle/cpuidle-cps.c
> +++ b/drivers/cpuidle/cpuidle-cps.c
> @@ -37,7 +37,7 @@ static int cps_nc_enter(struct cpuidle_device *dev,
>  	 * TODO: don't treat core 0 specially, just prevent the final core
>  	 * TODO: remap interrupt affinity temporarily
>  	 */
> -	if (!cpu_core(&cpu_data[dev->cpu]) && (index > STATE_NC_WAIT))
> +	if (cpus_are_siblings(0, dev->cpu) && (index > STATE_NC_WAIT))
>  		index = STATE_NC_WAIT;
>  
>  	/* Select the appropriate cps_pm_state */
> diff --git a/drivers/irqchip/irq-mips-cpu.c b/drivers/irqchip/irq-mips-cpu.c
> index 14461cbfab2f..66f97fde13d8 100644
> --- a/drivers/irqchip/irq-mips-cpu.c
> +++ b/drivers/irqchip/irq-mips-cpu.c
> @@ -101,7 +101,7 @@ static void mips_mt_send_ipi(struct irq_data *d, unsigned int cpu)
>  	local_irq_save(flags);
>  
>  	/* We can only send IPIs to VPEs within the local core */
> -	WARN_ON(cpu_data[cpu].core != current_cpu_data.core);
> +	WARN_ON(!cpus_are_siblings(smp_processor_id(), cpu));
>  
>  	vpflags = dvpe();
>  	settc(cpu_vpe_id(&cpu_data[cpu]));
> -- 
> 2.14.0
>