perf: add support for parameterized events from sysfs (powerpc 24x7)

What this patchset does:

- the first patch (override sysfs in tools/perf via SYSFS_PATH) was sent out previously, but needed a resend anyhow. Having it is useful for testing the later changes to tools/perf.
- the second patch is a bugfix to the powerpc hv-24x7 code which was previously sent out, which is a good idea to have when testing these patches on POWER8 hardware.

- document perf sysfs and the changes to add parameterized events
- semi-notably: removes the growing list of specific POWER cpu events and begins documenting them generically, much like the docs for /sys/modules/MODULENAME do for modules.
- tools/perf changes to support parameterized events
- export some parameterized events from the powerpc pmus hv_24x7 and hv_gpci

Description of "event parameters" from the documentation patch:

Event parameters are a basic way for partial events to be specified in sysfs with per-event names given to the fields that need to be filled in when using a particular event.

It is intended for supporting cases where the single 'cpu' parameter is insufficient. For example, POWER 8 has events for physical sockets/cores/cpus that are accessible from with virtual machines. To keep using the single 'cpu' parameter we'd need to perform a mapping between Linux's cpus and the physical machine's cpus (in this case Linux is running under a hypervisor). This isn't possible because bindings between our cpus and physical cpus may not be fixed, and we probably won't have a "cpu" on each physical cpu.

Description of the sysfs contents when events are parameterized (copied from an included patch):

Examples:

domain=0x1,offset=0x8,starting_index=phys_cpu

In the case of the last example, a value replacing "phys_cpu" would need to be provided by the user selecting the particular event. This is refered to as "event parameterization". All non-numerical values indicate an event parameter.

Notes on how perf-list displays parameterized events (and how to use them, again culled from an included patch):

PARAMETERIZED EVENTS
--------------------

Some pmu events listed by 'perf-list' will be displayed with '?' in them. For example:

hv_gpci/dtbp_ptitc,phys_processor_idx=?/

This means that when provided as an event, a value for phys_processor_idx must also be supplied. For example:

perf stat -e 'hv_gpci/dtbp_ptitc,phys_processor_idx=0x2/' ...

Cody P Schafer (16):
tools/perf: allow overriding sysfs and proc finding with env var powerpc/perf/hv-24x7: use kmem_cache instead of aligned stack
allocations
perf Documentation: sysfs events/ interfaces
perf Documentation: remove duplicated docs for powerpc cpu specific
events
perf Documentation: add event parameters
tools/perf: annotate list_head with type info
tools/perf: support parsing parameterized events tools/perf: extend format_alias() to include event parameters tools/perf: document parameterized events and note symbolically formed
events
perf: provide sysfs_show for struct perf_pmu_events_attr
byteorder: provide a linux/byteorder.h with {be,le}_to_cpu() and

    cpu_to_{be,le}() macros

powerpc/perf/hv-24x7: parse catalog and populate sysfs with events powerpc/perf/hv-24x7: Documentaion for new sysfs entries which expose
descriptions
perf: add PMU_EVENT_ATTR_STRING() helper powerpc/perf/{hv-gpci,hv-common}: generate requests with counters
annotated
powerpc/perf/hv-gpci: add the remaining gpci requests

 .../testing/sysfs-bus-event_source-devices-events  | 617 ++--------------
 .../testing/sysfs-bus-event_source-devices-hv_24x7 |  22 +
 arch/powerpc/perf/hv-24x7-catalog.h                |  25 +
 arch/powerpc/perf/hv-24x7-domains.h                |  19 +
 arch/powerpc/perf/hv-24x7.c                        | 812 ++++++++++++++++++++-
 arch/powerpc/perf/hv-24x7.h                        |  12 +-
 arch/powerpc/perf/hv-common.c                      |  10 +-
 arch/powerpc/perf/hv-gpci-requests.h               | 258 +++++++
 arch/powerpc/perf/hv-gpci.c                        |   8 +
 arch/powerpc/perf/hv-gpci.h                        |  37 +-
 arch/powerpc/perf/req-gen/_begin.h                 |  13 +
 arch/powerpc/perf/req-gen/_clear.h                 |   5 +
 arch/powerpc/perf/req-gen/_end.h                   |   4 +
 arch/powerpc/perf/req-gen/_request-begin.h         |  15 +
 arch/powerpc/perf/req-gen/_request-end.h           |   8 +
 arch/powerpc/perf/req-gen/perf.h                   | 155 ++++
 include/linux/byteorder.h                          |  34 +
 include/linux/perf_event.h                         |  10 +
 kernel/events/core.c                               |   8 +
 tools/lib/api/fs/fs.c                              |  43 +-
 tools/perf/Documentation/perf-list.txt             |  13 +
 tools/perf/Documentation/perf-record.txt           |   5 +
 tools/perf/util/parse-events.h                     |   1 +
 tools/perf/util/pmu.c                              |  85 ++-
 tools/perf/util/pmu.h                              |   6 +-
 25 files changed, 1589 insertions(+), 636 deletions(-)
 create mode 100644 arch/powerpc/perf/hv-24x7-domains.h
 create mode 100644 arch/powerpc/perf/hv-gpci-requests.h
 create mode 100644 arch/powerpc/perf/req-gen/_begin.h
 create mode 100644 arch/powerpc/perf/req-gen/_clear.h
 create mode 100644 arch/powerpc/perf/req-gen/_end.h
 create mode 100644 arch/powerpc/perf/req-gen/_request-begin.h
 create mode 100644 arch/powerpc/perf/req-gen/_request-end.h
 create mode 100644 arch/powerpc/perf/req-gen/perf.h
 create mode 100644 include/linux/byteorder.h

1.9.3