tree 9215ff9fe51201ee5a9893aeb1fdae592b9c8588
parent 253877635ba008d376f8addc1e5d1f51f2269ad5
author Anshuman Khandual <anshuman.khandual@arm.com> 1604495212 +0530
committer Todd Kjos <tkjos@google.com> 1614631936 -0800

FROMLIST: coresight: sink: Add TRBE driver

Trace Buffer Extension (TRBE) implements a trace buffer per CPU which is
accessible via the system registers. The TRBE supports different addressing
modes including CPU virtual address and buffer modes including the circular
buffer mode. The TRBE buffer is addressed by a base pointer (TRBBASER_EL1),
an write pointer (TRBPTR_EL1) and a limit pointer (TRBLIMITR_EL1). But the
access to the trace buffer could be prohibited by a higher exception level
(EL3 or EL2), indicated by TRBIDR_EL1.P. The TRBE can also generate a CPU
private interrupt (PPI) on address translation errors and when the buffer
is full. Overall implementation here is inspired from the Arm SPE driver.

Bug: 174685394
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/linux-arm-kernel/20210225193543.2920532-19-suzuki.poulose@arm.com/
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Change-Id: I7b19c009c9f4b98d7d10d6e9c9a7ce76f9096eac