When tracing ETM data on multiple CPUs concurrently via the
perf interface, the CATU device is shared across different CPU
paths. This can lead to race conditions when multiple CPUs attempt
to enable or disable the CATU device simultaneously.
To address these race conditions, this patch introduces the
following changes:
1. The enable and disable operations for the CATU device are not
reentrant. Therefore, a spinlock is added to ensure that only
one CPU can enable or disable a given CATU device at any point
in time.
2. A reference counter is used to manage the enable/disable state
of the CATU device. The device is enabled when the first CPU
requires it and is only disabled when the last CPU finishes
using it. This ensures the device remains active as long as at
least one CPU needs it.
Fixes: fcacb5c154 ("coresight: Introduce support for Coresight Address Translation Unit")
Signed-off-by: Yabin Cui <yabinc@google.com>
Reviewed-by: James Clark <james.clark@linaro.org>
Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20250429231301.1952246-2-yabinc@google.com
Add support for the catu devices in a new platform driver, which can then
be used on ACPI based platforms. This change would now allow runtime power
management for ACPI based systems. The driver would try to enable the APB
clock if available. But first this renames and then refactors catu_probe()
and catu_remove(), making sure it can be used both for platform and AMBA
drivers. This also moves pm_runtime_put() from catu_probe() to the callers.
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: James Clark <james.clark@arm.com>
Cc: linux-acpi@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: coresight@lists.linaro.org
Acked-by: Sudeep Holla <sudeep.holla@arm.com> # For ACPI related changes
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20240314055843.2625883-8-anshuman.khandual@arm.com
New csdev_access functions were added as part of the previous
refactor. In order to make them more consistent with the
existing ones, change any signed offset types to be unsigned.
Now that they are unsigned, stop using hi_off = -1 to signify
a single 32bit access. Instead just call the existing 32bit
accessors. This is also applied to other parts of the codebase,
and the coresight_{read,write}_reg_pair() functions can be
deleted.
Signed-off-by: James Clark <james.clark@arm.com>
Reviewed-by: Mike Leach <mike.leach@linaro.org>
Link: https://lore.kernel.org/r/20220830172614.340962-6-james.clark@arm.com
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Make etr_catu_buf_ops static. Instead of directly accessing it in
etr_buf_ops[], add a function to let catu driver register the ops at
runtime. Break circular dependency between tmc-etr and catu drivers.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20200928163513.70169-23-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Switch to using the CoreSight device instead of the real
amba device.
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Clang points out a syntax error, as the etr_catu_buf_ops structure is
declared 'static' before the type is known:
In file included from drivers/hwtracing/coresight/coresight-tmc-etr.c:12:
drivers/hwtracing/coresight/coresight-catu.h:116:40: warning: tentative definition of variable with internal linkage has incomplete non-array type 'const struct etr_buf_operations' [-Wtentative-definition-incomplete-type]
static const struct etr_buf_operations etr_catu_buf_ops;
^
drivers/hwtracing/coresight/coresight-catu.h:116:21: note: forward declaration of 'struct etr_buf_operations'
static const struct etr_buf_operations etr_catu_buf_ops;
This seems worth fixing in the code, so replace pointer to the empty
constant structure with a NULL pointer. We need an extra NULL pointer
check here, but the result should be better object code otherwise,
avoiding the silly empty structure.
Fixes: 434d611cdd ("coresight: catu: Plug in CATU as a backend for ETR buffer")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[Fixed line over 80 characters]
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Now that we can use a CATU with a scatter gather table, add support
for the TMC ETR to make use of the connected CATU in translate mode.
This is done by adding CATU as new buffer mode.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the initial support for Coresight Address Translation Unit, which
augments the TMC in Coresight SoC-600 by providing an improved Scatter
Gather mechanism. CATU is always connected to a single TMC-ETR and
converts the AXI address with a translated address (from a given SG
table with specific format). The CATU should be programmed in pass
through mode and enabled even if the ETR doesn't use the translation
by CATU.
This patch provides mechanism to enable/disable the CATU always in the
pass through mode.
We reuse the existing ports mechanism to link the TMC-ETR to the
connected CATU.
i.e, TMC-ETR:output_port0 -> CATU:input_port0
Reference manual for CATU component is avilable in version r2p0 of :
"Arm Coresight System-on-Chip SoC-600 Technical Reference Manual".
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
