Commit 72730bfc authored by Srikar Dronamraju's avatar Srikar Dronamraju Committed by Michael Ellerman
Browse files

powerpc/smp: Create coregroup domain 



Add percpu coregroup maps and masks to create coregroup domain.
If a coregroup doesn't exist, the coregroup domain will be degenerated
in favour of SMT/CACHE domain. Do note this patch is only creating stubs
for cpu_to_coregroup_id. The actual cpu_to_coregroup_id implementation
would be in a subsequent patch.

Signed-off-by: default avatarSrikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: default avatarGautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200810071834.92514-10-srikar@linux.vnet.ibm.com
parent 6e086302

arch/powerpc/include/asm/topology.h

+10 −0
Original line number Diff line number Diff line
@@ -88,12 +88,22 @@ static inline int cpu_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc) 


#if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)

extern int find_and_online_cpu_nid(int cpu);

extern int cpu_to_coregroup_id(int cpu);

#else

static inline int find_and_online_cpu_nid(int cpu)

{

	return 0;

}



static inline int cpu_to_coregroup_id(int cpu)

{

#ifdef CONFIG_SMP

	return cpu_to_core_id(cpu);

#else

	return 0;

#endif

}



#endif /* CONFIG_NUMA && CONFIG_PPC_SPLPAR */



#include <asm-generic/topology.h>

arch/powerpc/kernel/smp.c

+53 −1
Original line number Diff line number Diff line
@@ -81,12 +81,22 @@ DEFINE_PER_CPU(cpumask_var_t, cpu_sibling_map); 
DEFINE_PER_CPU(cpumask_var_t, cpu_smallcore_map);

DEFINE_PER_CPU(cpumask_var_t, cpu_l2_cache_map);

DEFINE_PER_CPU(cpumask_var_t, cpu_core_map);

DEFINE_PER_CPU(cpumask_var_t, cpu_coregroup_map);



EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);

EXPORT_PER_CPU_SYMBOL(cpu_l2_cache_map);

EXPORT_PER_CPU_SYMBOL(cpu_core_map);

EXPORT_SYMBOL_GPL(has_big_cores);



enum {

#ifdef CONFIG_SCHED_SMT

	smt_idx,

#endif

	cache_idx,

	mc_idx,

	die_idx,

};



#define MAX_THREAD_LIST_SIZE	8

#define THREAD_GROUP_SHARE_L1   1

struct thread_groups {
@@ -862,11 +872,27 @@ static const struct cpumask *smallcore_smt_mask(int cpu) 
}

#endif



static struct cpumask *cpu_coregroup_mask(int cpu)

{

	return per_cpu(cpu_coregroup_map, cpu);

}



static bool has_coregroup_support(void)

{

	return coregroup_enabled;

}



static const struct cpumask *cpu_mc_mask(int cpu)

{

	return cpu_coregroup_mask(cpu);

}



static struct sched_domain_topology_level powerpc_topology[] = {

#ifdef CONFIG_SCHED_SMT

	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },

#endif

	{ shared_cache_mask, powerpc_shared_cache_flags, SD_INIT_NAME(CACHE) },

	{ cpu_mc_mask, SD_INIT_NAME(MC) },

	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },

	{ NULL, },

};
@@ -913,6 +939,10 @@ void __init smp_prepare_cpus(unsigned int max_cpus) 
					GFP_KERNEL, cpu_to_node(cpu));

		zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),

					GFP_KERNEL, cpu_to_node(cpu));

		if (has_coregroup_support())

			zalloc_cpumask_var_node(&per_cpu(cpu_coregroup_map, cpu),

						GFP_KERNEL, cpu_to_node(cpu));



#ifdef CONFIG_NEED_MULTIPLE_NODES

		/*

		 * numa_node_id() works after this.
@@ -930,6 +960,9 @@ void __init smp_prepare_cpus(unsigned int max_cpus) 
	cpumask_set_cpu(boot_cpuid, cpu_l2_cache_mask(boot_cpuid));

	cpumask_set_cpu(boot_cpuid, cpu_core_mask(boot_cpuid));



	if (has_coregroup_support())

		cpumask_set_cpu(boot_cpuid, cpu_coregroup_mask(boot_cpuid));



	init_big_cores();

	if (has_big_cores) {

		cpumask_set_cpu(boot_cpuid,
@@ -1234,6 +1267,8 @@ static void remove_cpu_from_masks(int cpu) 
		set_cpus_unrelated(cpu, i, cpu_sibling_mask);

		if (has_big_cores)

			set_cpus_unrelated(cpu, i, cpu_smallcore_mask);

		if (has_coregroup_support())

			set_cpus_unrelated(cpu, i, cpu_coregroup_mask);

	}

}

#endif
@@ -1294,6 +1329,20 @@ static void add_cpu_to_masks(int cpu) 
	add_cpu_to_smallcore_masks(cpu);

	update_mask_by_l2(cpu, cpu_l2_cache_mask);



	if (has_coregroup_support()) {

		int coregroup_id = cpu_to_coregroup_id(cpu);



		cpumask_set_cpu(cpu, cpu_coregroup_mask(cpu));

		for_each_cpu_and(i, cpu_online_mask, cpu_cpu_mask(cpu)) {

			int fcpu = cpu_first_thread_sibling(i);



			if (fcpu == first_thread)

				set_cpus_related(cpu, i, cpu_coregroup_mask);

			else if (coregroup_id == cpu_to_coregroup_id(i))

				set_cpus_related(cpu, i, cpu_coregroup_mask);

		}

	}



	if (pkg_id == -1) {

		struct cpumask *(*mask)(int) = cpu_sibling_mask;
@@ -1388,9 +1437,12 @@ static void fixup_topology(void) 
#ifdef CONFIG_SCHED_SMT

	if (has_big_cores) {

		pr_info("Big cores detected but using small core scheduling\n");

		powerpc_topology[0].mask = smallcore_smt_mask;

		powerpc_topology[smt_idx].mask = smallcore_smt_mask;

	}

#endif



	if (!has_coregroup_support())

		powerpc_topology[mc_idx].mask = powerpc_topology[cache_idx].mask;

}



void __init smp_cpus_done(unsigned int max_cpus)

arch/powerpc/mm/numa.c

+5 −0
Original line number Diff line number Diff line
@@ -1245,6 +1245,11 @@ int find_and_online_cpu_nid(int cpu) 
	return new_nid;

}



int cpu_to_coregroup_id(int cpu)

{

	return cpu_to_core_id(cpu);

}



static int topology_update_init(void)

{

	topology_inited = 1;