[RFC PATCH 00/14] coresight: Support for ETMv4.4 system instructions

[Suzuki K Poulose]

CoreSight ETMv4.4 introduced system instructions for accessing
the ETM. This also implies that they may not be on the amba bus.
Right now all the CoreSight components are accessed via memory
map. Also, we have some common routines in coresight generic
code driver (e.g, CS_LOCK, claim/disclaim), which assume the
mmio. In order to preserve the generic algorithms at a single
place and to allow dynamic switch for ETMs, this series introduces
an abstraction layer for accessing a coresight device. It is
designed such that the mmio access are fast tracked (i.e, without
an indirect function call).

This will also help us to get rid of the driver+attribute specific
sysfs show/store routines and replace them with a single routine
to access a given register offset (which can be embedded in the
dev_ext_attribute). This is not currently implemented in the series,
but can be achieved.

Further we switch the generic routines to work with the abstraction.
With this in place, we refactor the etm4x code a bit to allow for
supporting the system instructions with very little new code. The
changes also switch to using the system instructions by default
even when we may have an MMIO.

The series has been mildly tested on a model. I would really 
appreciate any testing on real hardware.

Applies on coresight/next tree. The tree is also available here :

 git://linux-arm.org/linux-skp.git etm-4.4/rfc

Suzuki K Poulose (14):
  coresight: etm4x: Skip save/restore before device registration
  coresight: Introduce device access abstraction
  coresight: tpiu: Use coresight device access abstraction
  coresight: etm4x: Free up argument of etm4_init_arch_data
  coresight: Convert coresight_timeout to use access abstraction
  coresight: Convert claim and lock operations to use access wrappers
  coresight: etm4x: Always read the registers on the host CPU
  coresight: etm4x: Convert all register accesses
  coresight: etm4x: Add sysreg access helpers
  coresight: etm4x: Define DEVARCH register fields
  coresight: etm4x: Detect system register access support
  coresight: etm4x: Refactor probing routine
  coresight: etm4x: Add support for sysreg only devices
  dts: bindings: coresight: ETMv4.4 system register access only units

 .../devicetree/bindings/arm/coresight.txt     |   6 +-
 drivers/hwtracing/coresight/coresight-catu.c  |  17 +-
 .../hwtracing/coresight/coresight-cpu-debug.c |  26 +-
 .../hwtracing/coresight/coresight-cti-sysfs.c |   4 +-
 drivers/hwtracing/coresight/coresight-cti.c   |  31 +-
 drivers/hwtracing/coresight/coresight-etb10.c |  26 +-
 .../coresight/coresight-etm3x-sysfs.c         |   8 +-
 drivers/hwtracing/coresight/coresight-etm3x.c |  45 +-
 .../coresight/coresight-etm4x-sysfs.c         |  32 +-
 drivers/hwtracing/coresight/coresight-etm4x.c | 580 +++++++++++-------
 drivers/hwtracing/coresight/coresight-etm4x.h | 403 +++++++++++-
 .../hwtracing/coresight/coresight-funnel.c    |  19 +-
 drivers/hwtracing/coresight/coresight-priv.h  |   9 +-
 .../coresight/coresight-replicator.c          |  28 +-
 drivers/hwtracing/coresight/coresight-stm.c   |  49 +-
 .../hwtracing/coresight/coresight-tmc-etf.c   |  36 +-
 .../hwtracing/coresight/coresight-tmc-etr.c   |  19 +-
 drivers/hwtracing/coresight/coresight-tmc.c   |  10 +-
 drivers/hwtracing/coresight/coresight-tpiu.c  |  32 +-
 drivers/hwtracing/coresight/coresight.c       | 130 +++-
 include/linux/coresight.h                     | 189 +++++-
 21 files changed, 1273 insertions(+), 426 deletions(-)

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2.24.1