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-rw-r--r--include/linux/cpumask.h15
-rw-r--r--lib/cpumask.c17
2 files changed, 23 insertions, 9 deletions
diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 4b29e508a0b6..f770039344c5 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -396,6 +396,12 @@ extern cpumask_t cpu_present_map;
#define cpu_present(cpu) ((cpu) == 0)
#endif
+#ifdef CONFIG_SMP
+int highest_possible_processor_id(void);
+#else
+#define highest_possible_processor_id() 0
+#endif
+
#define any_online_cpu(mask) \
({ \
int cpu; \
@@ -409,14 +415,5 @@ extern cpumask_t cpu_present_map;
#define for_each_online_cpu(cpu) for_each_cpu_mask((cpu), cpu_online_map)
#define for_each_present_cpu(cpu) for_each_cpu_mask((cpu), cpu_present_map)
-/* Find the highest possible smp_processor_id() */
-#define highest_possible_processor_id() \
-({ \
- unsigned int cpu, highest = 0; \
- for_each_cpu_mask(cpu, cpu_possible_map) \
- highest = cpu; \
- highest; \
-})
-
#endif /* __LINUX_CPUMASK_H */
diff --git a/lib/cpumask.c b/lib/cpumask.c
index ba2f8543052c..ea25a034276c 100644
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -14,3 +14,20 @@ int __next_cpu(int n, const cpumask_t *srcp)
return min_t(int, NR_CPUS, find_next_bit(srcp->bits, NR_CPUS, n+1));
}
EXPORT_SYMBOL(__next_cpu);
+
+/*
+ * Find the highest possible smp_processor_id()
+ *
+ * Note: if we're prepared to assume that cpu_possible_map never changes
+ * (reasonable) then this function should cache its return value.
+ */
+int highest_possible_processor_id(void)
+{
+ unsigned int cpu;
+ unsigned highest = 0;
+
+ for_each_cpu_mask(cpu, cpu_possible_map)
+ highest = cpu;
+ return highest;
+}
+EXPORT_SYMBOL(highest_possible_processor_id);