X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Farch%2Fmips%2Fkernel%2Fsmp.c;h=7fef02a9eb85c7827284a490fd862dcf653d2a83;hb=refs%2Ftags%2Fdanube.1.0;hp=faa46ebd9ddae2fc43f20d6ff65f28688f665c4f;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git

diff --git a/kernel/arch/mips/kernel/smp.c b/kernel/arch/mips/kernel/smp.c
index faa46ebd9..7fef02a9e 100644
--- a/kernel/arch/mips/kernel/smp.c
+++ b/kernel/arch/mips/kernel/smp.c
@@ -42,6 +42,7 @@
 #include <asm/mmu_context.h>
 #include <asm/time.h>
 #include <asm/setup.h>
+#include <asm/maar.h>
 
 cpumask_t cpu_callin_map;		/* Bitmask of started secondaries */
 
@@ -63,6 +64,13 @@ EXPORT_SYMBOL(cpu_sibling_map);
 cpumask_t cpu_core_map[NR_CPUS] __read_mostly;
 EXPORT_SYMBOL(cpu_core_map);
 
+/*
+ * A logcal cpu mask containing only one VPE per core to
+ * reduce the number of IPIs on large MT systems.
+ */
+cpumask_t cpu_foreign_map __read_mostly;
+EXPORT_SYMBOL(cpu_foreign_map);
+
 /* representing cpus for which sibling maps can be computed */
 static cpumask_t cpu_sibling_setup_map;
 
@@ -103,6 +111,30 @@ static inline void set_cpu_core_map(int cpu)
 	}
 }
 
+/*
+ * Calculate a new cpu_foreign_map mask whenever a
+ * new cpu appears or disappears.
+ */
+static inline void calculate_cpu_foreign_map(void)
+{
+	int i, k, core_present;
+	cpumask_t temp_foreign_map;
+
+	/* Re-calculate the mask */
+	cpumask_clear(&temp_foreign_map);
+	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_data[i].core == cpu_data[k].core)
+				core_present = 1;
+		if (!core_present)
+			cpumask_set_cpu(i, &temp_foreign_map);
+	}
+
+	cpumask_copy(&cpu_foreign_map, &temp_foreign_map);
+}
+
 struct plat_smp_ops *mp_ops;
 EXPORT_SYMBOL(mp_ops);
 
@@ -127,6 +159,7 @@ asmlinkage void start_secondary(void)
 	mips_clockevent_init();
 	mp_ops->init_secondary();
 	cpu_report();
+	maar_init();
 
 	/*
 	 * XXX parity protection should be folded in here when it's converted
@@ -141,14 +174,15 @@ asmlinkage void start_secondary(void)
 	cpumask_set_cpu(cpu, &cpu_coherent_mask);
 	notify_cpu_starting(cpu);
 
+	cpumask_set_cpu(cpu, &cpu_callin_map);
+	synchronise_count_slave(cpu);
+
 	set_cpu_online(cpu, true);
 
 	set_cpu_sibling_map(cpu);
 	set_cpu_core_map(cpu);
 
-	cpumask_set_cpu(cpu, &cpu_callin_map);
-
-	synchronise_count_slave(cpu);
+	calculate_cpu_foreign_map();
 
 	/*
 	 * irq will be enabled in ->smp_finish(), enabling it too early
@@ -160,22 +194,21 @@ asmlinkage void start_secondary(void)
 	cpu_startup_entry(CPUHP_ONLINE);
 }
 
-/*
- * Call into both interrupt handlers, as we share the IPI for them
- */
-void __irq_entry smp_call_function_interrupt(void)
-{
-	irq_enter();
-	generic_smp_call_function_interrupt();
-	irq_exit();
-}
-
 static void stop_this_cpu(void *dummy)
 {
 	/*
-	 * Remove this CPU:
+	 * Remove this CPU. Be a bit slow here and
+	 * set the bits for every online CPU so we don't miss
+	 * any IPI whilst taking this VPE down.
 	 */
+
+	cpumask_copy(&cpu_foreign_map, cpu_online_mask);
+
+	/* Make it visible to every other CPU */
+	smp_mb();
+
 	set_cpu_online(smp_processor_id(), false);
+	calculate_cpu_foreign_map();
 	local_irq_disable();
 	while (1);
 }
@@ -197,6 +230,7 @@ void __init smp_prepare_cpus(unsigned int max_cpus)
 	mp_ops->prepare_cpus(max_cpus);
 	set_cpu_sibling_map(0);
 	set_cpu_core_map(0);
+	calculate_cpu_foreign_map();
 #ifndef CONFIG_HOTPLUG_CPU
 	init_cpu_present(cpu_possible_mask);
 #endif