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linux-next/arch/s390
Thomas Richter c432fefe8e s390/pai: Add support for PAI Extension 1 NNPA counters
PMU device driver perf_paiext supports Processor Activity
Instrumentation Extension (PAIE1), available with IBM z16:
- maps a 512 byte block to lowcore address 0x1508 called PAIE1 control
  block.
- maps a 1024 byte block at PAIE1 control block entry with index 2.
- uses control register bit 14 to enable PAIE1 control block lookup.
- turn PAIE1 nnpa counting on and off by setting bit 63 in
  PAIE1 control block entry with index 2.
- creates a sample with raw data on each context switch out when
  at context switch some mapped counters have a value of nonzero.
This device driver only supports CPU wide context, no task context
is allowed.

Support for counting:
- one or more counters can be specified using
  perf stat -e pai_ext/xxx/
  where xxx stands for the counter event name. Multiple invocation
  of this command is possible. The counter names are listed in
  /sys/devices/pai_ext/events directory.
- one special counters can be specified using
  perf stat -e pai_ext/NNPA_ALL/
  which returns the sum of all incremented nnpa counters.
- multiple counting events can run in parallel.

Support for Sampling:
- one event pai_ext/NNPA_ALL/ is reserved for sampling.
  The event collects data at context switch out and saves them in
  the ring buffer.
- no multiple invocations are possible.

The PAIE1 nnpa counter events are system wide. No task context is
supported.  Therefore some restrictions documented in function
paiext_busy() apply.

Extend qpaci assembly instruction to query supported memory mapped nnpa
counters. It returns the number of counters (no holes allowed in that
range).

PAIE1 nnpa counter events can not be created when a CPU hot plug
add is processed. This means a CPU hot plug add does not get
the necessary PAIE1 event to record PAIE1 nnpa counter increments
on the newly added CPU. CPU hot plug remove removes the event and
terminates the counting of PAIE1 counters immediately.

Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Sumanth Korikkar <sumanthk@linux.ibm.com>
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2022-09-16 18:36:25 +02:00
..
appldata s390/appldata: use struct_size() helper 2020-06-29 16:32:34 +02:00
boot s390/mm: rework memcpy_real() to avoid DAT-off mode 2022-09-14 16:46:01 +02:00
configs s390: update defconfigs 2022-08-30 21:57:07 +02:00
crypto s390 updates for 5.20 merge window 2022-08-06 17:05:21 -07:00
hypfs s390/hypfs: avoid error message under KVM 2022-08-15 17:19:51 +02:00
include s390/pai: Add support for PAI Extension 1 NNPA counters 2022-09-16 18:36:25 +02:00
kernel s390/pai: Add support for PAI Extension 1 NNPA counters 2022-09-16 18:36:25 +02:00
kvm KVM: s390: resetting the Topology-Change-Report 2022-07-20 10:57:37 +02:00
lib s390/delay: sync comment within __delay() with reality 2022-08-30 22:00:33 +02:00
mm s390/mm: fix no previous prototype warnings in maccess.c 2022-09-16 18:36:25 +02:00
net s390/bpf: Fix typo in comment 2022-05-23 11:25:53 -07:00
pci s390/pci: convert high_memory to physical address 2022-09-14 16:46:00 +02:00
purgatory s390/purgatory: remove duplicated build rule of kexec-purgatory.o 2022-06-30 14:18:16 +02:00
tools KVM: s390: Add facility 197 to the allow list 2022-07-13 15:25:25 +02:00
Kbuild kbuild: use more subdir- for visiting subdirectories while cleaning 2021-10-24 13:49:46 +09:00
Kconfig Random number generator updates for Linux 6.0-rc1. 2022-08-02 17:31:35 -07:00
Kconfig.debug s390/Kconfig.debug: fix indentation 2022-06-01 12:03:15 +02:00
Makefile s390/nospec: remove unneeded header includes 2022-07-13 15:21:55 +02:00