This series enables future IP trace features Embedded Trace Extension (ETE) and Trace Buffer Extension (TRBE). This series applies on v5.12-rc4 + some patches queued. A standalone tree is also available here [0]. The queued patches (almost there) are included in this posting for the sake of constructing a tree from the posting.
ETE is the PE (CPU) trace unit for CPUs, implementing future architecture extensions. ETE overlaps with the ETMv4 architecture, with additions to support the newer architecture features and some restrictions on the supported features w.r.t ETMv4. The ETE support is added by extending the ETMv4 driver to recognise the ETE and handle the features as exposed by the TRCIDRx registers. ETE only supports system instructions access from the host CPU. The ETE could be integrated with a TRBE (see below), or with the legacy CoreSight trace bus (e.g, ETRs). Thus the ETE follows same firmware description as the ETMs and requires a node per instance.
Trace Buffer Extensions (TRBE) implements a per CPU trace buffer, which is accessible via the system registers and can be combined with the ETE to provide a 1x1 configuration of source & sink. TRBE is being represented here as a CoreSight sink. Primary reason is that the ETE source could work with other traditional CoreSight sink devices. As TRBE captures the trace data which is produced by ETE, it cannot work alone.
TRBE representation here have some distinct deviations from a traditional CoreSight sink device. Coresight path between ETE and TRBE are not built during boot looking at respective DT or ACPI entries.
Unlike traditional sinks, TRBE can generate interrupts to signal including many other things, buffer got filled. The interrupt is a PPI and should be communicated from the platform. DT or ACPI entry representing TRBE should have the PPI number for a given platform. During perf session, the TRBE IRQ handler should capture trace for perf auxiliary buffer before restarting it back. System registers being used here to configure ETE and TRBE could be referred in the link below.
https://developer.arm.com/docs/ddi0601/g/aarch64-system-registers.
[0] https://gitlab.arm.com/linux-arm/linux-skp/-/tree/coresight/ete/v5/
Changes since V4:
https://lkml.kernel.org/r/20210225193543.2920532-1-suzuki.poulose@arm.com
- Split the documentation patches from the TRBE driver - Drop the patches already queued for v5.12. - Mark the buffer TRUNCATED in case of a WRAP event - Fix error code for vmap failure - Fix build break on arm32 for per-cpu sink patch - Address comments on ETE dts bindings. - Make ete_sysreg_read/write static (kernel test robot) - Merged ete sysreg definition patch with ete support, to avoid a "defined but unused warning" on build in part of the series. - Add new bindings to MAINTAINERS
Changes since V3:
https://lore.kernel.org/linux-arm-kernel/1611737738-1493-1-git-send-email-an...
- ETE and TRBE changes have been captured in the respective patches - Better support for nVHE - Re-ordered and splitted the patches to keep the changes separate for the generic/arm64 tree from CoreSight driver specific changes. - Fixes for KVM handling of Trace/SPE
Changes since V2:
https://lore.kernel.org/linux-arm-kernel/1610511498-4058-1-git-send-email-an...
- Rebased on coresight/next - Changed DT bindings for ETE - Included additional patches for arm64 nvhe, perf aux buffer flags etc - TRBE changes have been captured in the respective patches
Changes since V1:
https://lore.kernel.org/linux-arm-kernel/1608717823-18387-1-git-send-email-a...
- Converted both ETE and TRBE DT bindings into Yaml - TRBE changes have been captured in the respective patches
Changes since RFC:
- There are not much ETE changes from Suzuki apart from splitting of the ETE DTS patch - TRBE changes have been captured in the respective patches
RFC:
https://lore.kernel.org/linux-arm-kernel/1605012309-24812-1-git-send-email-a...
Cc: Will Deacon will@kernel.org Cc: Marc Zyngier maz@kernel.org Cc: Peter Zilstra peterz@infradead.org Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Suzuki K Poulose suzuki.poulose@arm.com Cc: Mike Leach mike.leach@linaro.org Cc: Linu Cherian lcherian@marvell.com Cc: coresight@lists.linaro.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org
Anshuman Khandual (5): arm64: Add TRBE definitions coresight: core: Add support for dedicated percpu sinks coresight: sink: Add TRBE driver Documentation: coresight: trbe: Sysfs ABI description Documentation: trace: Add documentation for TRBE
Suzuki K Poulose (14): [Queued] kvm: arm64: Hide system instruction access to Trace registers [Queued] kvm: arm64: Disable guest access to trace filter controls perf: aux: Add flags for the buffer format perf: aux: Add CoreSight PMU buffer formats arm64: Add support for trace synchronization barrier arm64: kvm: Enable access to TRBE support for host coresight: etm4x: Move ETM to prohibited region for disable coresight: etm-perf: Allow an event to use different sinks coresight: Do not scan for graph if none is present coresight: etm4x: Add support for PE OS lock coresight: ete: Add support for ETE tracing dts: bindings: Document device tree bindings for ETE coresight: etm-perf: Handle stale output handles dts: bindings: Document device tree bindings for Arm TRBE
.../testing/sysfs-bus-coresight-devices-trbe | 14 + .../devicetree/bindings/arm/ete.yaml | 75 ++ .../devicetree/bindings/arm/trbe.yaml | 49 + .../trace/coresight/coresight-trbe.rst | 38 + MAINTAINERS | 2 + arch/arm64/include/asm/barrier.h | 1 + arch/arm64/include/asm/el2_setup.h | 13 + arch/arm64/include/asm/kvm_arm.h | 3 + arch/arm64/include/asm/kvm_host.h | 2 + arch/arm64/include/asm/sysreg.h | 50 + arch/arm64/kernel/cpufeature.c | 1 - arch/arm64/kernel/hyp-stub.S | 3 +- arch/arm64/kvm/debug.c | 6 +- arch/arm64/kvm/hyp/nvhe/debug-sr.c | 42 + arch/arm64/kvm/hyp/nvhe/switch.c | 1 + drivers/hwtracing/coresight/Kconfig | 24 +- drivers/hwtracing/coresight/Makefile | 1 + drivers/hwtracing/coresight/coresight-core.c | 29 +- .../hwtracing/coresight/coresight-etm-perf.c | 119 +- .../coresight/coresight-etm4x-core.c | 161 ++- .../coresight/coresight-etm4x-sysfs.c | 19 +- drivers/hwtracing/coresight/coresight-etm4x.h | 83 +- .../hwtracing/coresight/coresight-platform.c | 6 + drivers/hwtracing/coresight/coresight-priv.h | 3 + drivers/hwtracing/coresight/coresight-trbe.c | 1157 +++++++++++++++++ drivers/hwtracing/coresight/coresight-trbe.h | 152 +++ include/linux/coresight.h | 13 + include/uapi/linux/perf_event.h | 13 +- 28 files changed, 2016 insertions(+), 64 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-trbe create mode 100644 Documentation/devicetree/bindings/arm/ete.yaml create mode 100644 Documentation/devicetree/bindings/arm/trbe.yaml create mode 100644 Documentation/trace/coresight/coresight-trbe.rst create mode 100644 drivers/hwtracing/coresight/coresight-trbe.c create mode 100644 drivers/hwtracing/coresight/coresight-trbe.h