2 files changed, 59 insertions, 0 deletions

diff --git a/lib/Makefile b/lib/Makefile
index 89841dc9d91c..543f2502b60a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o
 obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o
 obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o
 obj-$(CONFIG_SMP) += percpu_counter.o
+obj-$(CONFIG_SMP) += pcounter.o
 obj-$(CONFIG_AUDIT_GENERIC) += audit.o
 
 obj-$(CONFIG_SWIOTLB) += swiotlb.o
diff --git a/lib/pcounter.c b/lib/pcounter.c
new file mode 100644
index 000000000000..9b56807da93b
--- /dev/null
+++ b/lib/pcounter.c
@@ -0,0 +1,58 @@
+/*
+ * Define default pcounter functions
+ * Note that often used pcounters use dedicated functions to get a speed increase.
+ * (see DEFINE_PCOUNTER/REF_PCOUNTER_MEMBER)
+ */
+
+#include <linux/module.h>
+#include <linux/pcounter.h>
+#include <linux/smp.h>
+#include <linux/cpumask.h>
+
+static void pcounter_dyn_add(struct pcounter *self, int inc)
+{
+        per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc;
+}
+
+static int pcounter_dyn_getval(const struct pcounter *self, int cpu)
+{
+        return per_cpu_ptr(self->per_cpu_values, cpu)[0];
+}
+
+int pcounter_getval(const struct pcounter *self)
+{
+        int res = 0, cpu;
+
+        for_each_possible_cpu(cpu)
+                res += self->getval(self, cpu);
+
+        return res;
+}
+EXPORT_SYMBOL_GPL(pcounter_getval);
+
+int pcounter_alloc(struct pcounter *self)
+{
+        int rc = 0;
+        if (self->add == NULL) {
+                self->per_cpu_values = alloc_percpu(int);
+                if (self->per_cpu_values != NULL) {
+                        self->add    = pcounter_dyn_add;
+                        self->getval = pcounter_dyn_getval;
+                } else
+                        rc = 1;
+        }
+        return rc;
+}
+EXPORT_SYMBOL_GPL(pcounter_alloc);
+
+void pcounter_free(struct pcounter *self)
+{
+        if (self->per_cpu_values != NULL) {
+                free_percpu(self->per_cpu_values);
+                self->per_cpu_values = NULL;
+                self->getval = NULL;
+                self->add = NULL;
+        }
+}
+EXPORT_SYMBOL_GPL(pcounter_free);
+