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-rw-r--r--arch/mips/include/asm/smp.h1
-rw-r--r--arch/mips/kernel/smp.c44
-rw-r--r--arch/mips/mm/c-r4k.c14
3 files changed, 55 insertions, 4 deletions
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index 2b25d1ba1ea0..16f1ea9ab191 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -23,6 +23,7 @@
extern int smp_num_siblings;
extern cpumask_t cpu_sibling_map[];
extern cpumask_t cpu_core_map[];
+extern cpumask_t cpu_foreign_map;
#define raw_smp_processor_id() (current_thread_info()->cpu)
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
diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index 7f660dc67596..a5974ddba44b 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -37,6 +37,7 @@
#include <asm/cacheflush.h> /* for run_uncached() */
#include <asm/traps.h>
#include <asm/dma-coherence.h>
+#include <asm/mips-cm.h>
/*
* Special Variant of smp_call_function for use by cache functions:
@@ -51,9 +52,16 @@ static inline void r4k_on_each_cpu(void (*func) (void *info), void *info)
{
preempt_disable();
-#ifndef CONFIG_MIPS_MT_SMP
- smp_call_function(func, info, 1);
-#endif
+ /*
+ * The Coherent Manager propagates address-based cache ops to other
+ * cores but not index-based ops. However, r4k_on_each_cpu is used
+ * in both cases so there is no easy way to tell what kind of op is
+ * executed to the other cores. The best we can probably do is
+ * to restrict that call when a CM is not present because both
+ * CM-based SMP protocols (CMP & CPS) restrict index-based cache ops.
+ */
+ if (!mips_cm_present())
+ smp_call_function_many(&cpu_foreign_map, func, info, 1);
func(info);
preempt_enable();
}