[0/2] coresight: tmc: Add shutdown callback for TMC ETR/ETF

Message

Sai Prakash Ranjan June 1, 2020, 8:02 a.m. UTC

This series adds a shutdown callback to TMC ETR/ETF to ensure that
it is properly shutdown in reboot/shutdown path. This is required
for ETR/ETF which has SMMU address translation enabled like on SC7180
SoC and few others. If the hardware is still accessing memory after
SMMU translation is disabled as part of SMMU shutdown callback in
system reboot or shutdown path, then IOVAs(I/O virtual address)
which it was using will go on the bus as the physical addresses which
might result in unknown crashes (NoC/interconnect errors). So we make
sure from this shutdown callback that the ETR/ETF is shutdown before
SMMU translation is disabled and device_link in SMMU driver will take
care of ordering of shutdown callbacks such that SMMU shutdown callback
is not called before any of its consumer shutdown callbacks.

Sai Prakash Ranjan (2):
  coresight: tmc: Add enable flag to indicate the status of ETR/ETF
  coresight: tmc: Add shutdown callback for TMC ETR/ETF

 .../hwtracing/coresight/coresight-tmc-etf.c   |  4 +--
 .../hwtracing/coresight/coresight-tmc-etr.c   |  2 +-
 drivers/hwtracing/coresight/coresight-tmc.c   | 31 +++++++++++++++++++
 drivers/hwtracing/coresight/coresight-tmc.h   |  5 +++
 4 files changed, 39 insertions(+), 3 deletions(-)


base-commit: 059e38815950dbec65beafe03757bce9436e89a4