[PATCH V5 0/8] perf: Expand perf_branch_entry

[Anshuman Khandual]

Branch Record Buffer Extension (BRBE) implementation on arm64 captures more
branch type classification which cannot be accommodated in the current perf
branch record format via perf_branch_entry.type element (4 bit field). Also
it captures privilege information which does not have a corresponding slot
in perf_branch_entry. This series expands struct perf_branch_entry, to meet
both these requirements without breaking the existing user space ABI for
perf tools.

All architecture specific branch types added via perf_branch_entry.new_type
field in [PATCH 3/4] will be used in BRBE implementation on arm64 platform
later on with the following map.

#ifdef CONFIG_ARM64
#define PERF_BR_FIQ		PERF_BR_NEW_ARCH_1
#define PERF_BR_DEBUG_HALT	PERF_BR_NEW_ARCH_2
#define PERF_BR_DEBUG_EXIT	PERF_BR_NEW_ARCH_3
#define PERF_BR_DEBUG_INST	PERF_BR_NEW_ARCH_4
#define PERF_BR_DEBUG_DATA	PERF_BR_NEW_ARCH_5
#endif

This actually combines following patches and series into a single series.

- https://lore.kernel.org/all/1642998653-21377-12-git-send-email-anshuman.khandual@xxxxxxx/
- https://lore.kernel.org/all/1643348653-24367-1-git-send-email-anshuman.khandual@xxxxxxx/
- https://lore.kernel.org/all/1645681014-3346-1-git-send-email-anshuman.khandual@xxxxxxx/

This series applies on v5.18-rc1

perf API

The series being applied

- Clean : tools/perf/check-headers.sh
- Clean : diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Todo

- Update perf report tool to process PERF_BR_EXTEND_ABI (when available),
  then fetch and report branch types from perf_branch_entry.new_type field.

References

- BRBE captured branch record information

https://developer.arm.com/documentation/ddi0601/2021-12/AArch64-Registers/BRBINF-n--EL1--Branch-Record-Buffer-Information-Register--n-?lang=en

- BRBE based perf branch stack implementation on arm64 platform

https://lore.kernel.org/all/1642998653-21377-1-git-send-email-anshuman.khandual@xxxxxxx/

Changes in V5:

- Dropped patches [PATCH 1/10] and [PATCH 6/10] related to PERF_BR_[RET|IRQ] - merged
  via the commit cedd3614e5d9c809 ("perf: Add irq and exception return branch types")

- Rebased series on v5.18-rc1

Changes in V4:

https://lore.kernel.org/all/20220315053516.431515-1-anshuman.khandual@xxxxxxx/

- Modified the struct branch_flags as required
- Dropped CONFIG_ARM64 from perf header file to avoid build problem
- Renamed PERF_BR_NEW_<BRANCH_TYPE> as PERF_BR_ARM64_<BRANCH_TYPE>

Changes in V3:

https://lore.kernel.org/all/20220314055857.125421-1-anshuman.khandual@xxxxxxx/

- Fixed small typo s/privillege/privilege in include/uapi/linux/perf_event.h
- Added PRIV_SHIFT in __p_branch_sample_type()
- Added arm64 platform override of the new arch specific branch types
- Renamed s/PERF_BR_XXX/PERF_BR_PRIV_XXX/ for privilege level branch types
- Added PERF_BR_PRIV_UNKNOWN as the starting value
- Expanded perf_branch_entry.priv into a 3 bits field 

Changes in V2:

https://lore.kernel.org/all/20220309033642.144769-1-anshuman.khandual@xxxxxxx/

Cc: Robin Murphy <robin.murphy@xxxxxxx> 
Cc: Suzuki Poulose <suzuki.poulose@xxxxxxx>
Cc: James Clark <james.clark@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-perf-users@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Anshuman Khandual (8):
  perf: Add system error and not in transaction branch types
  perf: Extend branch type classification
  perf: Capture branch privilege information
  perf: Add PERF_BR_NEW_ARCH_[N] map for BRBE on arm64 platform
  perf/tools: Add system error and not in transaction branch types
  perf/tools: Extend branch type classification
  perf/tools: Add branch privilege information request flag
  perf/tools: Add PERF_BR_NEW_ARCH_[N] map for BRBE on arm64 platform

 arch/x86/events/intel/lbr.c               |  2 +-
 include/uapi/linux/perf_event.h           | 36 ++++++++++++++++++++++-
 tools/include/uapi/linux/perf_event.h     | 36 ++++++++++++++++++++++-
 tools/perf/Documentation/perf-record.txt  |  1 +
 tools/perf/util/branch.c                  |  5 +++-
 tools/perf/util/branch.h                  |  4 ++-
 tools/perf/util/parse-branch-options.c    |  1 +
 tools/perf/util/perf_event_attr_fprintf.c |  2 +-
 8 files changed, 81 insertions(+), 6 deletions(-)

-- 
2.25.1