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Diffstat (limited to 'arch/mips/kernel/smp.c')
-rw-r--r--arch/mips/kernel/smp.c44
1 files changed, 43 insertions, 1 deletions
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index faa46ebd9dda..d0744cc77ea7 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -63,6 +63,13 @@ 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 +110,29 @@ 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 */
+ 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);
@@ -146,6 +176,8 @@ asmlinkage void start_secondary(void)
set_cpu_sibling_map(cpu);
set_cpu_core_map(cpu);
+ calculate_cpu_foreign_map();
+
cpumask_set_cpu(cpu, &cpu_callin_map);
synchronise_count_slave(cpu);
@@ -173,9 +205,18 @@ void __irq_entry smp_call_function_interrupt(void)
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 +238,7 @@ 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