Re: [PATCH 09/11] 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.

Cc: linuxppc-dev <redacted>
Cc: Michael Ellerman <redacted>
Cc: Nick Piggin <redacted>
Cc: Oliver OHalloran <redacted>
Cc: Nathan Lynch <redacted>
Cc: Michael Neuling <redacted>
Cc: Anton Blanchard <redacted>
Cc: Gautham R Shenoy <redacted>
Cc: Vaidyanathan Srinivasan <redacted>
Signed-off-by: Srikar Dronamraju <redacted>
---
 arch/powerpc/include/asm/topology.h | 10 ++++++++
 arch/powerpc/kernel/smp.c           | 37 +++++++++++++++++++++++++++++
 arch/powerpc/mm/numa.c              |  5 ++++
 3 files changed, 52 insertions(+)

diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index 2db7ba789720..34812c35018e 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h

@@ -98,6 +98,7 @@ extern int stop_topology_update(void);
 extern int prrn_is_enabled(void);
 extern int find_and_online_cpu_nid(int cpu);
 extern int timed_topology_update(int nsecs);
+extern int cpu_to_coregroup_id(int cpu);
 #else
 static inline int start_topology_update(void)
 {

@@ -120,6 +121,15 @@ static inline int timed_topology_update(int nsecs)
 	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>

diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ef19eeccd21e..bb25c13bbb79 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c

@@ -80,6 +80,7 @@ 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);

@@ -91,6 +92,7 @@ enum {
 	smt_idx,
 #endif
 	bigcore_idx,
+	mc_idx,
 	die_idx,
 };

@@ -869,6 +871,21 @@ 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 const struct cpumask *cpu_bigcore_mask(int cpu)
 {
 	return cpu_core_mask(cpu);

@@ -879,6 +896,7 @@ static struct sched_domain_topology_level powerpc_topology[] = {
 	{ cpu_smt_mask, powerpc_smt_flags, SD_INIT_NAME(SMT) },
 #endif
 	{ cpu_bigcore_mask, SD_INIT_NAME(BIGCORE) },
+	{ cpu_mc_mask, SD_INIT_NAME(MC) },
 	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },
 	{ NULL, },
 };

@@ -933,6 +951,10 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 					GFP_KERNEL, node);
 		zalloc_cpumask_var_node(&per_cpu(cpu_core_map, cpu),
 					GFP_KERNEL, node);
+		if (has_coregroup_support())
+			zalloc_cpumask_var_node(&per_cpu(cpu_coregroup_map, cpu),
+						GFP_KERNEL, node);
+
 #ifdef CONFIG_NEED_MULTIPLE_NODES
 		/*
 		 * numa_node_id() works after this.

@@ -950,6 +972,11 @@ 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));
+	else
+		powerpc_topology[mc_idx].mask = cpu_bigcore_mask;
+

 	init_big_cores();
 	if (has_big_cores) {
 		cpumask_set_cpu(boot_cpuid,

@@ -1241,6 +1268,8 @@ 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

@@ -1301,6 +1330,14 @@ 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()) {
+		cpumask_set_cpu(cpu, cpu_coregroup_mask(cpu));
+		for_each_cpu(i, cpu_online_mask) {
+			if (cpu_to_coregroup_id(cpu) == cpu_to_coregroup_id(i))
+				set_cpus_related(cpu, i, cpu_coregroup_mask);
+		}
+	}
+
 	if (pkg_id == -1) {
 		struct cpumask *(*mask)(int) = cpu_sibling_mask;

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index a43eab455be4..d9ab9da85eab 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c

@@ -1695,6 +1695,11 @@ static const struct proc_ops topology_proc_ops = {
 	.proc_release	= single_release,
 };

+int cpu_to_coregroup_id(int cpu)
+{
+	return cpu_to_core_id(cpu);
+}