3  * Performance event support for the System z CPU-measurement Sampling Facility
28  * At least one table is required for the sampling buffer structure.
49 /* Minimum and maximum sampling buffer sizes:
51  * This number represents the maximum size of the sampling buffer taking
53  * numbers apply to the basic-sampling function only.
55  * the diagnostic-sampling function is active.
57  * Sampling buffer size		Buffer characteristics
89 	/* CPU-measurement sampling information block */
91 	/* CPU-measurement sampling control block */
93 	struct sf_buffer sfb;	    /* Sampling buffer */
103 /* Sampling control helper functions */
155  * sf_disable() - Switch off sampling facility
166  * sf_buffer_available() - Check for an allocated sampling buffer
174  * deallocate sampling facility buffer
197 			/* If the origin is reached, sampling buffer is freed */  in free_sampling_buffer()
237  * Allocates new sample-data-blocks and adds them to the specified sampling
240  * Important: This modifies the sampling buffer and must be called when the
241  *	      sampling facility is disabled.
257 	/* Append to the existing sampling buffer, overwriting the table-link  in realloc_sampling_buffer()
265 	 * the sampling buffer origin.  in realloc_sampling_buffer()
269 				    "sampling buffer is not linked: origin %#lx"  in realloc_sampling_buffer()
317 	/* Link sampling buffer to its origin */  in realloc_sampling_buffer()
330  * Allocates and initializes a sampling buffer structure using the
431 	/* Calculate sampling buffers using 4K pages  in allocate_buffers()
433 	 *    1. The sampling size is 32 bytes for basic sampling. This size  in allocate_buffers()
435 	 *	 sampling uses auxlilary data buffer setup which provides the  in allocate_buffers()
449 	 *    3. Use the sampling frequency as input.  in allocate_buffers()
452 	 *	 SDBs to handle a higher sampling rate.  in allocate_buffers()
464 	/* If there is already a sampling buffer allocated, it is very likely  in allocate_buffers()
465 	 * that the sampling facility is enabled too.  If the event to be  in allocate_buffers()
466 	 * initialized requires a greater sampling buffer, the allocation must  in allocate_buffers()
467 	 * be postponed.  Changing the sampling buffer requires the sampling  in allocate_buffers()
494 	/* Use a percentage-based approach to extend the sampling facility  in compute_sfb_extent()
543 /* extend_sampling_buffer() - Extend sampling buffer
544  * @sfb:	Sampling buffer structure (for local CPU)
547  * Use this function to extend the sampling buffer based on the overflow counter
550  * Important: This function disables the sampling facility in order to safely
551  *	      change the sampling buffer structure.  Do not call this function
565 	/* Disable the sampling facility to reset any states and also  in extend_sampling_buffer()
570 	/* Extend the sampling buffer.  in extend_sampling_buffer()
618 		pr_err("Switching off the sampling facility failed with rc %i\n", err);  in setup_pmc_cpu()
708 	 * Obtain the PID from the basic-sampling data entry and  in cpumsf_output_event_pid()
740 		/* The min/max sampling rates specifies the valid range  in getrate()
748 		 * sampling rate does not exceed this value.  This also helps  in getrate()
755 					    "Sampling rate exceeds maximum "  in getrate()
763 /* The sampling information (si) contains information about the
764  * min/max sampling intervals and the CPU speed.  So calculate the
765  * correct sampling interval and avoid the whole period adjust
768  * Since the CPU Measurement sampling facility can not handle frequency
769  * calculate the sampling interval when frequency is specified using
774  * set to the correct sampling rate.
815 	/* Reserve CPU-measurement sampling facility */  in __hw_perf_event_init()
830 	/* Access per-CPU sampling information (query sampling info) */  in __hw_perf_event_init()
834 	 * sampling info from the current CPU, otherwise use event->cpu to  in __hw_perf_event_init()
836 	 * Later, cpuhw indicates whether to allocate sampling buffers for a  in __hw_perf_event_init()
845 		 * sampling structure for accessing the CPU-specific QSI.  in __hw_perf_event_init()
851 	/* Check sampling facility authorization and, if not authorized,  in __hw_perf_event_init()
861 		pr_warn("CPU Measurement Facility sampling is temporarily not available\n");  in __hw_perf_event_init()
866 	/* Always enable basic sampling */  in __hw_perf_event_init()
869 	/* Check if diagnostic sampling is requested.  Deny if the required  in __hw_perf_event_init()
870 	 * sampling authorization is missing.  in __hw_perf_event_init()
892 	/* Allocate the per-CPU sampling buffer using the CPU information  in __hw_perf_event_init()
894 	 * CPU (event->cpu == -1; or cpuhw == NULL), allocate sampling  in __hw_perf_event_init()
901 		/* Event is not pinned, allocate sampling buffer on  in __hw_perf_event_init()
912 	/* If PID/TID sampling is active, replace the default overflow  in __hw_perf_event_init()
913 	 * handler to extract and resolve the PIDs from the basic-sampling  in __hw_perf_event_init()
935 	/* No support for taken branch sampling */  in cpumsf_pmu_event_init()
947 		/* Support sampling of CPU cycles in addition to the  in cpumsf_pmu_event_init()
950 		 * sampling events only.  in cpumsf_pmu_event_init()
988 	/* Check whether to extent the sampling buffer.  in cpumsf_pmu_enable()
990 	 * Two conditions trigger an increase of the sampling buffer for a  in cpumsf_pmu_enable()
993 	 *    2. Sampling overflows that contribute to pending allocations.  in cpumsf_pmu_enable()
995 	 * Note that the extend_sampling_buffer() function disables the sampling  in cpumsf_pmu_enable()
996 	 * facility, but it can be fully re-enabled using sampling controls that  in cpumsf_pmu_enable()
1013 	/* (Re)enable the PMU and sampling facility */  in cpumsf_pmu_enable()
1020 		pr_err("Loading sampling controls failed: op 1 err %i\n", err);  in cpumsf_pmu_enable()
1047 	/* Switch off sampling activation control */  in cpumsf_pmu_disable()
1054 		pr_err("Loading sampling controls failed: op 2 err %i\n", err);  in cpumsf_pmu_disable()
1061 		/* TEAR/DEAR values are valid only if the sampling facility is  in cpumsf_pmu_disable()
1063 		 * for a disabled sampling facility because cpumsf_pmu_enable()  in cpumsf_pmu_disable()
1190  * Walks through a sample-data-block and collects sampling data entries that are
1191  * then pushed to the perf event subsystem.  Depending on the sampling function,
1192  * there can be either basic-sampling or combined-sampling data entries.  A
1193  * combined-sampling data entry consists of a basic- and a diagnostic-sampling
1194  * data entry.	The sampling function is determined by the flags in the perf
1195  * event hardware structure.  The function always works with a combined-sampling
1198  * Note that the implementation focuses on basic-sampling data entries and, if
1199  * such an entry is not valid, the entire combined-sampling data entry is
1240 					    " sampling data entry: te->f %i"  in hw_collect_samples()
1246 			 * from a combined basic- and diagnostic-sampling.  in hw_collect_samples()
1247 			 * If only basic-sampling is then active, entries are  in hw_collect_samples()
1263 /* hw_perf_event_update() - Process sampling buffer
1267  * Processes the sampling buffer and create perf event samples.
1268  * The sampling buffer position are retrieved and saved in the TEAR_REG
1284 	 * AUX buffer is used when in diagnostic sampling mode.  in hw_perf_event_update()
1307 			 * is reached, extend the sampling buffer.  in hw_perf_event_update()
1415  * Finish sampling on the cpu. Called by cpumsf_pmu_del() with pmu
1451  * Start sampling on the CPU. Called by cpumsf_pmu_add() when an event
1633  * Measurement alert handler for diagnostic mode sampling.
1660 			       "diagnostic-sampling mode is full\n",  in hw_collect_aux()
1738  * aux_buffer_setup() - Setup AUX buffer for diagnostic mode sampling
1764 		       "maximum sampling buffer limit\n",  in aux_buffer_setup()
1769 		       "minimum sampling buffer limit\n",  in aux_buffer_setup()
1854 /* Check if the new sampling period/frequency is appropriate.
1870 		 * sampling structure for accessing the CPU-specific QSI.  in cpumsf_pmu_check_period()
1892 /* Activate sampling control.
1893  * Next call of pmu_enable() starts sampling.
1909 /* Deactivate sampling control.
1910  * Next call of pmu_enable() stops sampling.
1950 	/* Set up sampling controls.  Always program the sampling register  in cpumsf_pmu_add()
1952 	 * that is used by hw_perf_event_update() to store the sampling buffer  in cpumsf_pmu_add()
1964 	/* Ensure sampling functions are in the disabled state.  If disabled,  in cpumsf_pmu_add()
1965 	 * switch on sampling enable control. */  in cpumsf_pmu_add()
2018  * The availablitiy depends on the CPU_MF sampling facility authorization
2020  * time by the sampling facility device driver.
2022  * also turned off for diagnostic sampling.
2025  * level for diagnostic sampling and installs the attribute
2026  * file for diagnostic sampling if necessary.
2119 	/* Sampling authorization change request */  in cpumf_measurement_alert()
2130 	/* Invalid sampling buffer entry */  in cpumf_measurement_alert()
2132 		pr_err("A sampling buffer entry is incorrect (alert=0x%x)\n",  in cpumf_measurement_alert()
2194 	pr_info("The sampling buffer limits have changed to: "  in param_set_sfb_size()
2212 	pr_err("Sampling facility support for perf is not available: "  in pr_cpumsf_err()
2240 		/* Sampling of diagnostic data authorized,  in init_cpum_sampling_pmu()