perf, x86: P4 PMU - describe config format

Add description of .config in a sake of RAW events.
At least this should bring some light to those who
will be reading this code.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Reviewed-by: Stephane Eranian <eranian@google.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Cyrill Gorcunov 2010-11-26 14:32:09 +03:00 committed by Ingo Molnar
parent 004417a6d4
commit af86da5318

View File

@ -744,14 +744,6 @@ enum P4_ESCR_EMASKS {
};
/*
* P4 PEBS specifics (Replay Event only)
*
* Format (bits):
* 0-6: metric from P4_PEBS_METRIC enum
* 7 : reserved
* 8 : reserved
* 9-11 : reserved
*
* Note we have UOP and PEBS bits reserved for now
* just in case if we will need them once
*/
@ -788,5 +780,60 @@ enum P4_PEBS_METRIC {
P4_PEBS_METRIC__max
};
/*
* Notes on internal configuration of ESCR+CCCR tuples
*
* Since P4 has quite the different architecture of
* performance registers in compare with "architectural"
* once and we have on 64 bits to keep configuration
* of performance event, the following trick is used.
*
* 1) Since both ESCR and CCCR registers have only low
* 32 bits valuable, we pack them into a single 64 bit
* configuration. Low 32 bits of such config correspond
* to low 32 bits of CCCR register and high 32 bits
* correspond to low 32 bits of ESCR register.
*
* 2) The meaning of every bit of such config field can
* be found in Intel SDM but it should be noted that
* we "borrow" some reserved bits for own usage and
* clean them or set to a proper value when we do
* a real write to hardware registers.
*
* 3) The format of bits of config is the following
* and should be either 0 or set to some predefined
* values:
*
* Low 32 bits
* -----------
* 0-6: P4_PEBS_METRIC enum
* 7-11: reserved
* 12: reserved (Enable)
* 13-15: reserved (ESCR select)
* 16-17: Active Thread
* 18: Compare
* 19: Complement
* 20-23: Threshold
* 24: Edge
* 25: reserved (FORCE_OVF)
* 26: reserved (OVF_PMI_T0)
* 27: reserved (OVF_PMI_T1)
* 28-29: reserved
* 30: reserved (Cascade)
* 31: reserved (OVF)
*
* High 32 bits
* ------------
* 0: reserved (T1_USR)
* 1: reserved (T1_OS)
* 2: reserved (T0_USR)
* 3: reserved (T0_OS)
* 4: Tag Enable
* 5-8: Tag Value
* 9-24: Event Mask (may use P4_ESCR_EMASK_BIT helper)
* 25-30: enum P4_EVENTS
* 31: reserved (HT thread)
*/
#endif /* PERF_EVENT_P4_H */