3  * Performance event support for the System z CPU-measurement Sampling Facility
27  * At least one table is required for the sampling buffer structure.
48 /* Minimum and maximum sampling buffer sizes:
50  * This number represents the maximum size of the sampling buffer taking
52  * numbers apply to the basic-sampling function only.
54  * the diagnostic-sampling function is active.
56  * Sampling buffer size		Buffer characteristics
88 	/* CPU-measurement sampling information block */
90 	/* CPU-measurement sampling control block */
92 	struct sf_buffer sfb;	    /* Sampling buffer */
103  * sf_disable() - Switch off sampling facility
114  * sf_buffer_available() - Check for an allocated sampling buffer
122  * deallocate sampling facility buffer
145 			/* If the origin is reached, sampling buffer is freed */  in free_sampling_buffer()
184  * Allocates new sample-data-blocks and adds them to the specified sampling
187  * Important: This modifies the sampling buffer and must be called when the
188  *	      sampling facility is disabled.
204 	/* Append to the existing sampling buffer, overwriting the table-link  in realloc_sampling_buffer()
212 	 * the sampling buffer origin.  in realloc_sampling_buffer()
216 				    "sampling buffer is not linked: origin %#lx"  in realloc_sampling_buffer()
264 	/* Link sampling buffer to its origin */  in realloc_sampling_buffer()
277  * Allocates and initializes a sampling buffer structure using the
378 	/* Calculate sampling buffers using 4K pages  in allocate_buffers()
380 	 *    1. The sampling size is 32 bytes for basic sampling. This size  in allocate_buffers()
382 	 *	 sampling uses auxlilary data buffer setup which provides the  in allocate_buffers()
396 	 *    3. Use the sampling frequency as input.  in allocate_buffers()
399 	 *	 SDBs to handle a higher sampling rate.  in allocate_buffers()
411 	/* If there is already a sampling buffer allocated, it is very likely  in allocate_buffers()
412 	 * that the sampling facility is enabled too.  If the event to be  in allocate_buffers()
413 	 * initialized requires a greater sampling buffer, the allocation must  in allocate_buffers()
414 	 * be postponed.  Changing the sampling buffer requires the sampling  in allocate_buffers()
441 	/* Use a percentage-based approach to extend the sampling facility  in compute_sfb_extent()
490 /* extend_sampling_buffer() - Extend sampling buffer
491  * @sfb:	Sampling buffer structure (for local CPU)
494  * Use this function to extend the sampling buffer based on the overflow counter
497  * Important: This function disables the sampling facility in order to safely
498  *	      change the sampling buffer structure.  Do not call this function
512 	/* Disable the sampling facility to reset any states and also  in extend_sampling_buffer()
517 	/* Extend the sampling buffer.  in extend_sampling_buffer()
557 			pr_err("Switching off the sampling facility failed "  in setup_pmc_cpu()
567 			pr_err("Switching off the sampling facility failed "  in setup_pmc_cpu()
666 	 * Obtain the PID from the basic-sampling data entry and  in cpumsf_output_event_pid()
697 		/* The min/max sampling rates specifies the valid range  in getrate()
705 		 * sampling rate does not exceed this value.  This also helps  in getrate()
712 					    "Sampling rate exceeds maximum "  in getrate()
720 /* The sampling information (si) contains information about the
721  * min/max sampling intervals and the CPU speed.  So calculate the
722  * correct sampling interval and avoid the whole period adjust
725  * Since the CPU Measurement sampling facility can not handle frequency
726  * calculate the sampling interval when frequency is specified using
731  * set to the correct sampling rate.
772 	/* Reserve CPU-measurement sampling facility */  in __hw_perf_event_init()
787 	/* Access per-CPU sampling information (query sampling info) */  in __hw_perf_event_init()
791 	 * sampling info from the current CPU, otherwise use event->cpu to  in __hw_perf_event_init()
793 	 * Later, cpuhw indicates whether to allocate sampling buffers for a  in __hw_perf_event_init()
802 		 * sampling structure for accessing the CPU-specific QSI.  in __hw_perf_event_init()
808 	/* Check sampling facility authorization and, if not authorized,  in __hw_perf_event_init()
818 		pr_warn("CPU Measurement Facility sampling is temporarily not available\n");  in __hw_perf_event_init()
823 	/* Always enable basic sampling */  in __hw_perf_event_init()
826 	/* Check if diagnostic sampling is requested.  Deny if the required  in __hw_perf_event_init()
827 	 * sampling authorization is missing.  in __hw_perf_event_init()
837 	/* Check and set other sampling flags */  in __hw_perf_event_init()
853 	/* Allocate the per-CPU sampling buffer using the CPU information  in __hw_perf_event_init()
855 	 * CPU (event->cpu == -1; or cpuhw == NULL), allocate sampling  in __hw_perf_event_init()
862 		/* Event is not pinned, allocate sampling buffer on  in __hw_perf_event_init()
873 	/* If PID/TID sampling is active, replace the default overflow  in __hw_perf_event_init()
874 	 * handler to extract and resolve the PIDs from the basic-sampling  in __hw_perf_event_init()
896 	/* No support for taken branch sampling */  in cpumsf_pmu_event_init()
908 		/* Support sampling of CPU cycles in addition to the  in cpumsf_pmu_event_init()
911 		 * sampling events only.  in cpumsf_pmu_event_init()
953 	/* Check whether to extent the sampling buffer.  in cpumsf_pmu_enable()
955 	 * Two conditions trigger an increase of the sampling buffer for a  in cpumsf_pmu_enable()
958 	 *    2. Sampling overflows that contribute to pending allocations.  in cpumsf_pmu_enable()
960 	 * Note that the extend_sampling_buffer() function disables the sampling  in cpumsf_pmu_enable()
961 	 * facility, but it can be fully re-enabled using sampling controls that  in cpumsf_pmu_enable()
978 	/* (Re)enable the PMU and sampling facility */  in cpumsf_pmu_enable()
985 		pr_err("Loading sampling controls failed: op %i err %i\n",  in cpumsf_pmu_enable()
1013 	/* Switch off sampling activation control */  in cpumsf_pmu_disable()
1020 		pr_err("Loading sampling controls failed: op %i err %i\n",  in cpumsf_pmu_disable()
1028 		/* TEAR/DEAR values are valid only if the sampling facility is  in cpumsf_pmu_disable()
1030 		 * for a disabled sampling facility because cpumsf_pmu_enable()  in cpumsf_pmu_disable()
1157  * Walks through a sample-data-block and collects sampling data entries that are
1158  * then pushed to the perf event subsystem.  Depending on the sampling function,
1159  * there can be either basic-sampling or combined-sampling data entries.  A
1160  * combined-sampling data entry consists of a basic- and a diagnostic-sampling
1161  * data entry.	The sampling function is determined by the flags in the perf
1162  * event hardware structure.  The function always works with a combined-sampling
1165  * Note that the implementation focuses on basic-sampling data entries and, if
1166  * such an entry is not valid, the entire combined-sampling data entry is
1207 					    " sampling data entry: te->f %i"  in hw_collect_samples()
1213 			 * from a combined basic- and diagnostic-sampling.  in hw_collect_samples()
1214 			 * If only basic-sampling is then active, entries are  in hw_collect_samples()
1230 /* hw_perf_event_update() - Process sampling buffer
1234  * Processes the sampling buffer and create perf event samples.
1235  * The sampling buffer position are retrieved and saved in the TEAR_REG
1253 	 * AUX buffer is used when in diagnostic sampling mode.  in hw_perf_event_update()
1278 			 * is reached, extend the sampling buffer.  in hw_perf_event_update()
1366  * Finish sampling on the cpu. Called by cpumsf_pmu_del() with pmu
1402  * Start sampling on the CPU. Called by cpumsf_pmu_add() when an event
1581  * Measurement alert handler for diagnostic mode sampling.
1608 			       "diagnostic-sampling mode is full\n",  in hw_collect_aux()
1689  * aux_buffer_setup() - Setup AUX buffer for diagnostic mode sampling
1715 		       "maximum sampling buffer limit\n",  in aux_buffer_setup()
1720 		       "minimum sampling buffer limit\n",  in aux_buffer_setup()
1805 /* Check if the new sampling period/freqeuncy is appropriate.
1821 		 * sampling structure for accessing the CPU-specific QSI.  in cpumsf_pmu_check_period()
1843 /* Activate sampling control.
1844  * Next call of pmu_enable() starts sampling.
1864 /* Deactivate sampling control.
1865  * Next call of pmu_enable() stops sampling.
1903 	/* Set up sampling controls.  Always program the sampling register  in cpumsf_pmu_add()
1905 	 * that is used by hw_perf_event_update() to store the sampling buffer  in cpumsf_pmu_add()
1917 	/* Ensure sampling functions are in the disabled state.  If disabled,  in cpumsf_pmu_add()
1918 	 * switch on sampling enable control. */  in cpumsf_pmu_add()
1971  * The availablitiy depends on the CPU_MF sampling facility authorization
1973  * time by the sampling facility device driver.
1975  * also turned off for diagnostic sampling.
1978  * level for diagnostic sampling and installs the attribute
1979  * file for diagnostic sampling if necessary.
2072 	/* Sampling authorization change request */  in cpumf_measurement_alert()
2083 	/* Invalid sampling buffer entry */  in cpumf_measurement_alert()
2085 		pr_err("A sampling buffer entry is incorrect (alert=0x%x)\n",  in cpumf_measurement_alert()
2147 	pr_info("The sampling buffer limits have changed to: "  in param_set_sfb_size()
2165 	pr_err("Sampling facility support for perf is not available: "  in pr_cpumsf_err()
2193 		/* Sampling of diagnostic data authorized,  in init_cpum_sampling_pmu()