1 files changed, 115 insertions, 0 deletions
diff --git a/include/linux/part_stat.h b/include/linux/part_stat.h
new file mode 100644
index 000000000000..ece607607a86
--- /dev/null
+++ b/include/linux/part_stat.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_PART_STAT_H
+#define _LINUX_PART_STAT_H
+
+#include <linux/genhd.h>
+
+/*
+ * Macros to operate on percpu disk statistics:
+ *
+ * {disk|part|all}_stat_{add|sub|inc|dec}() modify the stat counters
+ * and should be called between disk_stat_lock() and
+ * disk_stat_unlock().
+ *
+ * part_stat_read() can be called at any time.
+ *
+ * part_stat_{add|set_all}() and {init|free}_part_stats are for
+ * internal use only.
+ */
+#ifdef	CONFIG_SMP
+#define part_stat_lock()	({ rcu_read_lock(); get_cpu(); })
+#define part_stat_unlock()	do { put_cpu(); rcu_read_unlock(); } while (0)
+
+#define part_stat_get_cpu(part, field, cpu)				\
+	(per_cpu_ptr((part)->dkstats, (cpu))->field)
+
+#define part_stat_get(part, field)					\
+	part_stat_get_cpu(part, field, smp_processor_id())
+
+#define part_stat_read(part, field)					\
+({									\
+	typeof((part)->dkstats->field) res = 0;				\
+	unsigned int _cpu;						\
+	for_each_possible_cpu(_cpu)					\
+		res += per_cpu_ptr((part)->dkstats, _cpu)->field;	\
+	res;								\
+})
+
+static inline void part_stat_set_all(struct hd_struct *part, int value)
+{
+	int i;
+
+	for_each_possible_cpu(i)
+		memset(per_cpu_ptr(part->dkstats, i), value,
+				sizeof(struct disk_stats));
+}
+
+static inline int init_part_stats(struct hd_struct *part)
+{
+	part->dkstats = alloc_percpu(struct disk_stats);
+	if (!part->dkstats)
+		return 0;
+	return 1;
+}
+
+static inline void free_part_stats(struct hd_struct *part)
+{
+	free_percpu(part->dkstats);
+}
+
+#else /* !CONFIG_SMP */
+#define part_stat_lock()	({ rcu_read_lock(); 0; })
+#define part_stat_unlock()	rcu_read_unlock()
+
+#define part_stat_get(part, field)		((part)->dkstats.field)
+#define part_stat_get_cpu(part, field, cpu)	part_stat_get(part, field)
+#define part_stat_read(part, field)		part_stat_get(part, field)
+
+static inline void part_stat_set_all(struct hd_struct *part, int value)
+{
+	memset(&part->dkstats, value, sizeof(struct disk_stats));
+}
+
+static inline int init_part_stats(struct hd_struct *part)
+{
+	return 1;
+}
+
+static inline void free_part_stats(struct hd_struct *part)
+{
+}
+
+#endif /* CONFIG_SMP */
+
+#define part_stat_read_accum(part, field)				\
+	(part_stat_read(part, field[STAT_READ]) +			\
+	 part_stat_read(part, field[STAT_WRITE]) +			\
+	 part_stat_read(part, field[STAT_DISCARD]))
+
+#define __part_stat_add(part, field, addnd)				\
+	(part_stat_get(part, field) += (addnd))
+
+#define part_stat_add(part, field, addnd)	do {			\
+	__part_stat_add((part), field, addnd);				\
+	if ((part)->partno)						\
+		__part_stat_add(&part_to_disk((part))->part0,		\
+				field, addnd);				\
+} while (0)
+
+#define part_stat_dec(gendiskp, field)					\
+	part_stat_add(gendiskp, field, -1)
+#define part_stat_inc(gendiskp, field)					\
+	part_stat_add(gendiskp, field, 1)
+#define part_stat_sub(gendiskp, field, subnd)				\
+	part_stat_add(gendiskp, field, -subnd)
+
+#define part_stat_local_dec(gendiskp, field)				\
+	local_dec(&(part_stat_get(gendiskp, field)))
+#define part_stat_local_inc(gendiskp, field)				\
+	local_inc(&(part_stat_get(gendiskp, field)))
+#define part_stat_local_read(gendiskp, field)				\
+	local_read(&(part_stat_get(gendiskp, field)))
+#define part_stat_local_read_cpu(gendiskp, field, cpu)			\
+	local_read(&(part_stat_get_cpu(gendiskp, field, cpu)))
+
+#endif /* _LINUX_PART_STAT_H */