[PATCH 2] Register read and writes tracing

[Prasad Sodagudi]

This patch series adds register read/write event tracing
support. Qualcomm team tried upstreaming the register
trace buffer solution - [1] with pstore and dynamic debug
feature but that patch series didn't merge. I have followed
Steve suggestion from -[2] and used tracepoint_enabled() API.

[1] - https://patchwork.kernel.org/project/linux-arm-msm/cover/cover.1536430404.git.saiprakash.ranjan@xxxxxxxxxxxxxx/
[2] - https://lore.kernel.org/lkml/20200928105501.7e29df65@xxxxxxxxxxxxxxxx/ 

Qualcomm teams uses these logs for debugging various issues
in the product life cycle and hopping that this logging
would help other silicon vendors as this is generic approach.

v1 -> v2:
- Removed _no_log variant
- tracepoint_enabled api is used.
- Added depends on ARM64


Prasad Sodagudi (1):
  tracing: Add register read and write tracing support

 arch/arm64/include/asm/io.h    |  9 ++++++++
 arch/arm64/kernel/image-vars.h |  8 +++++++
 include/linux/iorw.h           | 38 +++++++++++++++++++++++++++++++
 include/trace/events/rwio.h    | 51 ++++++++++++++++++++++++++++++++++++++++++
 kernel/trace/Kconfig           | 11 +++++++++
 kernel/trace/Makefile          |  1 +
 kernel/trace/trace_readwrite.c | 31 +++++++++++++++++++++++++
 7 files changed, 149 insertions(+)
 create mode 100644 include/linux/iorw.h
 create mode 100644 include/trace/events/rwio.h
 create mode 100644 kernel/trace/trace_readwrite.c

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