1*4882a593Smuzhiyun===================================================================== 2*4882a593SmuzhiyunQualcomm Technologies Level-2 Cache Performance Monitoring Unit (PMU) 3*4882a593Smuzhiyun===================================================================== 4*4882a593Smuzhiyun 5*4882a593SmuzhiyunThis driver supports the L2 cache clusters found in Qualcomm Technologies 6*4882a593SmuzhiyunCentriq SoCs. There are multiple physical L2 cache clusters, each with their 7*4882a593Smuzhiyunown PMU. Each cluster has one or more CPUs associated with it. 8*4882a593Smuzhiyun 9*4882a593SmuzhiyunThere is one logical L2 PMU exposed, which aggregates the results from 10*4882a593Smuzhiyunthe physical PMUs. 11*4882a593Smuzhiyun 12*4882a593SmuzhiyunThe driver provides a description of its available events and configuration 13*4882a593Smuzhiyunoptions in sysfs, see /sys/devices/l2cache_0. 14*4882a593Smuzhiyun 15*4882a593SmuzhiyunThe "format" directory describes the format of the events. 16*4882a593Smuzhiyun 17*4882a593SmuzhiyunEvents can be envisioned as a 2-dimensional array. Each column represents 18*4882a593Smuzhiyuna group of events. There are 8 groups. Only one entry from each 19*4882a593Smuzhiyungroup can be in use at a time. If multiple events from the same group 20*4882a593Smuzhiyunare specified, the conflicting events cannot be counted at the same time. 21*4882a593Smuzhiyun 22*4882a593SmuzhiyunEvents are specified as 0xCCG, where CC is 2 hex digits specifying 23*4882a593Smuzhiyunthe code (array row) and G specifies the group (column) 0-7. 24*4882a593Smuzhiyun 25*4882a593SmuzhiyunIn addition there is a cycle counter event specified by the value 0xFE 26*4882a593Smuzhiyunwhich is outside the above scheme. 27*4882a593Smuzhiyun 28*4882a593SmuzhiyunThe driver provides a "cpumask" sysfs attribute which contains a mask 29*4882a593Smuzhiyunconsisting of one CPU per cluster which will be used to handle all the PMU 30*4882a593Smuzhiyunevents on that cluster. 31*4882a593Smuzhiyun 32*4882a593SmuzhiyunExamples for use with perf:: 33*4882a593Smuzhiyun 34*4882a593Smuzhiyun perf stat -e l2cache_0/config=0x001/,l2cache_0/config=0x042/ -a sleep 1 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun perf stat -e l2cache_0/config=0xfe/ -C 2 sleep 1 37*4882a593Smuzhiyun 38*4882a593SmuzhiyunThe driver does not support sampling, therefore "perf record" will 39*4882a593Smuzhiyunnot work. Per-task perf sessions are not supported. 40