1 files changed, 54 insertions, 0 deletions
diff --git a/arch/s390/include/uapi/asm/cmb.h b/arch/s390/include/uapi/asm/cmb.h
new file mode 100644
index 000000000..ecbe94941
--- /dev/null
+++ b/arch/s390/include/uapi/asm/cmb.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPIS390_CMB_H
+#define _UAPIS390_CMB_H
+
+#include <linux/types.h>
+
+/**
+ * struct cmbdata - channel measurement block data for user space
+ * @size: size of the stored data
+ * @elapsed_time: time since last sampling
+ * @ssch_rsch_count: number of ssch and rsch
+ * @sample_count: number of samples
+ * @device_connect_time: time of device connect
+ * @function_pending_time: time of function pending
+ * @device_disconnect_time: time of device disconnect
+ * @control_unit_queuing_time: time of control unit queuing
+ * @device_active_only_time: time of device active only
+ * @device_busy_time: time of device busy (ext. format)
+ * @initial_command_response_time: initial command response time (ext. format)
+ *
+ * All values are stored as 64 bit for simplicity, especially
+ * in 32 bit emulation mode. All time values are normalized to
+ * nanoseconds.
+ * Currently, two formats are known, which differ by the size of
+ * this structure, i.e. the last two members are only set when
+ * the extended channel measurement facility (first shipped in
+ * z990 machines) is activated.
+ * Potentially, more fields could be added, which would result in a
+ * new ioctl number.
+ */
+struct cmbdata {
+	__u64 size;
+	__u64 elapsed_time;
+ /* basic and exended format: */
+	__u64 ssch_rsch_count;
+	__u64 sample_count;
+	__u64 device_connect_time;
+	__u64 function_pending_time;
+	__u64 device_disconnect_time;
+	__u64 control_unit_queuing_time;
+	__u64 device_active_only_time;
+ /* extended format only: */
+	__u64 device_busy_time;
+	__u64 initial_command_response_time;
+};
+
+/* enable channel measurement */
+#define BIODASDCMFENABLE	_IO(DASD_IOCTL_LETTER, 32)
+/* enable channel measurement */
+#define BIODASDCMFDISABLE	_IO(DASD_IOCTL_LETTER, 33)
+/* read channel measurement data */
+#define BIODASDREADALLCMB	_IOWR(DASD_IOCTL_LETTER, 33, struct cmbdata)
+
+#endif /* _UAPIS390_CMB_H */