1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 #ifndef _UAPIS390_CMB_H 3 #define _UAPIS390_CMB_H 4 5 #include <linux/types.h> 6 7 /** 8 * struct cmbdata - channel measurement block data for user space 9 * @size: size of the stored data 10 * @elapsed_time: time since last sampling 11 * @ssch_rsch_count: number of ssch and rsch 12 * @sample_count: number of samples 13 * @device_connect_time: time of device connect 14 * @function_pending_time: time of function pending 15 * @device_disconnect_time: time of device disconnect 16 * @control_unit_queuing_time: time of control unit queuing 17 * @device_active_only_time: time of device active only 18 * @device_busy_time: time of device busy (ext. format) 19 * @initial_command_response_time: initial command response time (ext. format) 20 * 21 * All values are stored as 64 bit for simplicity, especially 22 * in 32 bit emulation mode. All time values are normalized to 23 * nanoseconds. 24 * Currently, two formats are known, which differ by the size of 25 * this structure, i.e. the last two members are only set when 26 * the extended channel measurement facility (first shipped in 27 * z990 machines) is activated. 28 * Potentially, more fields could be added, which would result in a 29 * new ioctl number. 30 */ 31 struct cmbdata { 32 __u64 size; 33 __u64 elapsed_time; 34 /* basic and exended format: */ 35 __u64 ssch_rsch_count; 36 __u64 sample_count; 37 __u64 device_connect_time; 38 __u64 function_pending_time; 39 __u64 device_disconnect_time; 40 __u64 control_unit_queuing_time; 41 __u64 device_active_only_time; 42 /* extended format only: */ 43 __u64 device_busy_time; 44 __u64 initial_command_response_time; 45 }; 46 47 /* enable channel measurement */ 48 #define BIODASDCMFENABLE _IO(DASD_IOCTL_LETTER, 32) 49 /* enable channel measurement */ 50 #define BIODASDCMFDISABLE _IO(DASD_IOCTL_LETTER, 33) 51 /* read channel measurement data */ 52 #define BIODASDREADALLCMB _IOWR(DASD_IOCTL_LETTER, 33, struct cmbdata) 53 54 #endif /* _UAPIS390_CMB_H */ 55