s390/cpumf: Allow concurrent access for CPU Measurement Counter Facility
Commit cf6acb8b ("s390/cpumf: Add support for complete counter set extraction") allows access to the CPU Measurement Counter Facility via character device /dev/hwctr. The access was exclusive via this device or via perf_event_open() system call. Only one path at a time was permitted. The CPU Measurement Counter Facility device driver blocked access to other processes. This patch removes this restriction and allows concurrent access to the CPU Measurement Counter Facility from multiple processes at the same time via perf_event_open() SVC and via /dev/hwctr device. The access via /dev/hwctr device is still exclusive, only one process is allowed to access this device. This patch - moves the /dev/hwctr device access from file perf_cpum_cf_diag.c. to file perf_cpum_cf.c. - use only one trace buffer .../s390dbf/cpum_cf. - remove cfset_csd structure and includes its members it into the structure cpu_cf_events. This results in one data structure and simplifies the access. - rework function familiy ctr_set_enable, ctr_set_disable, ctr_set_start and ctr_set_stop which operate on a counter set number. Now they operate on a counter set bit mask. - move CF_DIAG event functionality to file perf_cpum_cf.c. It now contains the complete functionality of the CPU Measurement Counter Facility: - Performance measurement support for counters using perf stat. - Support for complete counter set extraction with device /dev/hwctr. - Support for counter set extraction event CF_DIAG attached to samples using perf record. - removes file perf_cpum_cf_diag.c Signed-off-by: NThomas Richter <tmricht@linux.ibm.com> Reviewed-by: NSumanth Korikkar <sumanthk@linux.ibm.com> Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>
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