Review of ETMV4 sysfs code resulted in a number of minor issues being discovered. Patchset fixed these and updated docs.
Applies to coresight/next
Changes since v3 First 8 patches of v3 have been accepted onto coresight/next. The patch series is now documents only Docs .txt files changed to .rst by unrelated patch. This set reflects this change and updates the added docs to match. Indexing changed for new coresight docs directory.
Changes since v2 (reviews from Mathieu and Leo):- Patch 0002 now adds stable tag. Tested on 4.9, 4.14, 4.19 Applies to coresight/next (5.4-rc1) Documentation changed to .rst format to match recent updates that converted other CoreSight .txt files. Misc typo / comment changes.
Changes since v1 (from reviews by Mathieu and Leo):- Usability patch split into 2 separate functional patches. Docs patch split into 3 patches. Misc style and comment typo fixes.
Mike Leach (4): coresight: etm4x: docs: Update ABI doc for new sysfs name scheme. coresight: etm4x: docs: Update ABI doc for new sysfs etm4 attributes coresight: docs: Create common sub-directory for coresight trace. coresight: etm4x: docs: Adds detailed document for programming etm4x.
.../testing/sysfs-bus-coresight-devices-etm4x | 183 ++-- .../{ => coresight}/coresight-cpu-debug.rst | 0 .../coresight/coresight-etm4x-reference.rst | 798 ++++++++++++++++++ .../trace/{ => coresight}/coresight.rst | 2 +- Documentation/trace/coresight/index.rst | 9 + Documentation/trace/index.rst | 3 +- MAINTAINERS | 3 +- 7 files changed, 925 insertions(+), 73 deletions(-) rename Documentation/trace/{ => coresight}/coresight-cpu-debug.rst (100%) create mode 100644 Documentation/trace/coresight/coresight-etm4x-reference.rst rename Documentation/trace/{ => coresight}/coresight.rst (99%) create mode 100644 Documentation/trace/coresight/index.rst
Recent updates to CoreSight drivers have changed the component naming schema used in sysfs.
This updates the ABI document to reflect the new naming schema.
Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Mike Leach mike.leach@linaro.org --- .../testing/sysfs-bus-coresight-devices-etm4x | 136 +++++++++--------- 1 file changed, 68 insertions(+), 68 deletions(-)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x index 36258bc1b473..9290010e973e 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x @@ -1,4 +1,4 @@ -What: /sys/bus/coresight/devices/<memory_map>.etm/enable_source +What: /sys/bus/coresight/devices/etm<N>/enable_source Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org @@ -8,82 +8,82 @@ Description: (RW) Enable/disable tracing on this specific trace entiry. of coresight components linking the source to the sink is configured and managed automatically by the coresight framework.
-What: /sys/bus/coresight/devices/<memory_map>.etm/cpu +What: /sys/bus/coresight/devices/etm<N>/cpu Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) The CPU this tracing entity is associated with.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nr_pe_cmp +What: /sys/bus/coresight/devices/etm<N>/nr_pe_cmp Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of PE comparator inputs that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nr_addr_cmp +What: /sys/bus/coresight/devices/etm<N>/nr_addr_cmp Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of address comparator pairs that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nr_cntr +What: /sys/bus/coresight/devices/etm<N>/nr_cntr Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of counters that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nr_ext_inp +What: /sys/bus/coresight/devices/etm<N>/nr_ext_inp Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates how many external inputs are implemented.
-What: /sys/bus/coresight/devices/<memory_map>.etm/numcidc +What: /sys/bus/coresight/devices/etm<N>/numcidc Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of Context ID comparators that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/numvmidc +What: /sys/bus/coresight/devices/etm<N>/numvmidc Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of VMID comparators that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nrseqstate +What: /sys/bus/coresight/devices/etm<N>/nrseqstate Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of sequencer states that are implemented.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nr_resource +What: /sys/bus/coresight/devices/etm<N>/nr_resource Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of resource selection pairs that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/nr_ss_cmp +What: /sys/bus/coresight/devices/etm<N>/nr_ss_cmp Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Indicates the number of single-shot comparator controls that are available for tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/reset +What: /sys/bus/coresight/devices/etm<N>/reset Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (W) Cancels all configuration on a trace unit and set it back to its boot configuration.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mode +What: /sys/bus/coresight/devices/etm<N>/mode Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org @@ -91,302 +91,302 @@ Description: (RW) Controls various modes supported by this ETM, for example P0 instruction tracing, branch broadcast, cycle counting and context ID tracing.
-What: /sys/bus/coresight/devices/<memory_map>.etm/pe +What: /sys/bus/coresight/devices/etm<N>/pe Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls which PE to trace.
-What: /sys/bus/coresight/devices/<memory_map>.etm/event +What: /sys/bus/coresight/devices/etm<N>/event Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls the tracing of arbitrary events from bank 0 to 3.
-What: /sys/bus/coresight/devices/<memory_map>.etm/event_instren +What: /sys/bus/coresight/devices/etm<N>/event_instren Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls the behavior of the events in bank 0 to 3.
-What: /sys/bus/coresight/devices/<memory_map>.etm/event_ts +What: /sys/bus/coresight/devices/etm<N>/event_ts Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls the insertion of global timestamps in the trace streams.
-What: /sys/bus/coresight/devices/<memory_map>.etm/syncfreq +What: /sys/bus/coresight/devices/etm<N>/syncfreq Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls how often trace synchronization requests occur.
-What: /sys/bus/coresight/devices/<memory_map>.etm/cyc_threshold +What: /sys/bus/coresight/devices/etm<N>/cyc_threshold Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Sets the threshold value for cycle counting.
-What: /sys/bus/coresight/devices/<memory_map>.etm/bb_ctrl +What: /sys/bus/coresight/devices/etm<N>/bb_ctrl Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls which regions in the memory map are enabled to use branch broadcasting.
-What: /sys/bus/coresight/devices/<memory_map>.etm/event_vinst +What: /sys/bus/coresight/devices/etm<N>/event_vinst Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls instruction trace filtering.
-What: /sys/bus/coresight/devices/<memory_map>.etm/s_exlevel_vinst +What: /sys/bus/coresight/devices/etm<N>/s_exlevel_vinst Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) In Secure state, each bit controls whether instruction tracing is enabled for the corresponding exception level.
-What: /sys/bus/coresight/devices/<memory_map>.etm/ns_exlevel_vinst +What: /sys/bus/coresight/devices/etm<N>/ns_exlevel_vinst Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) In non-secure state, each bit controls whether instruction tracing is enabled for the corresponding exception level.
-What: /sys/bus/coresight/devices/<memory_map>.etm/addr_idx +What: /sys/bus/coresight/devices/etm<N>/addr_idx Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Select which address comparator or pair (of comparators) to work with.
-What: /sys/bus/coresight/devices/<memory_map>.etm/addr_instdatatype +What: /sys/bus/coresight/devices/etm<N>/addr_instdatatype Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls what type of comparison the trace unit performs.
-What: /sys/bus/coresight/devices/<memory_map>.etm/addr_single +What: /sys/bus/coresight/devices/etm<N>/addr_single Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Used to setup single address comparator values.
-What: /sys/bus/coresight/devices/<memory_map>.etm/addr_range +What: /sys/bus/coresight/devices/etm<N>/addr_range Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Used to setup address range comparator values.
-What: /sys/bus/coresight/devices/<memory_map>.etm/seq_idx +What: /sys/bus/coresight/devices/etm<N>/seq_idx Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Select which sequensor.
-What: /sys/bus/coresight/devices/<memory_map>.etm/seq_state +What: /sys/bus/coresight/devices/etm<N>/seq_state Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Use this to set, or read, the sequencer state.
-What: /sys/bus/coresight/devices/<memory_map>.etm/seq_event +What: /sys/bus/coresight/devices/etm<N>/seq_event Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Moves the sequencer state to a specific state.
-What: /sys/bus/coresight/devices/<memory_map>.etm/seq_reset_event +What: /sys/bus/coresight/devices/etm<N>/seq_reset_event Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Moves the sequencer to state 0 when a programmed event occurs.
-What: /sys/bus/coresight/devices/<memory_map>.etm/cntr_idx +What: /sys/bus/coresight/devices/etm<N>/cntr_idx Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Select which counter unit to work with.
-What: /sys/bus/coresight/devices/<memory_map>.etm/cntrldvr +What: /sys/bus/coresight/devices/etm<N>/cntrldvr Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) This sets or returns the reload count value of the specific counter.
-What: /sys/bus/coresight/devices/<memory_map>.etm/cntr_val +What: /sys/bus/coresight/devices/etm<N>/cntr_val Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) This sets or returns the current count value of the specific counter.
-What: /sys/bus/coresight/devices/<memory_map>.etm/cntr_ctrl +What: /sys/bus/coresight/devices/etm<N>/cntr_ctrl Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls the operation of the selected counter.
-What: /sys/bus/coresight/devices/<memory_map>.etm/res_idx +What: /sys/bus/coresight/devices/etm<N>/res_idx Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Select which resource selection unit to work with.
-What: /sys/bus/coresight/devices/<memory_map>.etm/res_ctrl +What: /sys/bus/coresight/devices/etm<N>/res_ctrl Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Controls the selection of the resources in the trace unit.
-What: /sys/bus/coresight/devices/<memory_map>.etm/ctxid_idx +What: /sys/bus/coresight/devices/etm<N>/ctxid_idx Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Select which context ID comparator to work with.
-What: /sys/bus/coresight/devices/<memory_map>.etm/ctxid_pid +What: /sys/bus/coresight/devices/etm<N>/ctxid_pid Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Get/Set the context ID comparator value to trigger on.
-What: /sys/bus/coresight/devices/<memory_map>.etm/ctxid_masks +What: /sys/bus/coresight/devices/etm<N>/ctxid_masks Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Mask for all 8 context ID comparator value registers (if implemented).
-What: /sys/bus/coresight/devices/<memory_map>.etm/vmid_idx +What: /sys/bus/coresight/devices/etm<N>/vmid_idx Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Select which virtual machine ID comparator to work with.
-What: /sys/bus/coresight/devices/<memory_map>.etm/vmid_val +What: /sys/bus/coresight/devices/etm<N>/vmid_val Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Get/Set the virtual machine ID comparator value to trigger on.
-What: /sys/bus/coresight/devices/<memory_map>.etm/vmid_masks +What: /sys/bus/coresight/devices/etm<N>/vmid_masks Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Mask for all 8 virtual machine ID comparator value registers (if implemented).
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcoslsr +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcoslsr Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the OS Lock Status Register (0x304). The value it taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcpdcr +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcpdcr Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Power Down Control Register (0x310). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcpdsr +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcpdsr Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Power Down Status Register (0x314). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trclsr +What: /sys/bus/coresight/devices/etm<N>/mgmt/trclsr Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the SW Lock Status Register (0xFB4). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcauthstatus +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcauthstatus Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Authentication Status Register (0xFB8). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcdevid +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcdevid Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Device ID Register (0xFC8). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcdevtype +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcdevtype Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Device Type Register (0xFCC). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcpidr0 +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcpidr0 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Peripheral ID0 Register (0xFE0). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcpidr1 +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcpidr1 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Peripheral ID1 Register (0xFE4). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcpidr2 +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcpidr2 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Peripheral ID2 Register (0xFE8). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcpidr3 +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcpidr3 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the Peripheral ID3 Register (0xFEC). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trcconfig +What: /sys/bus/coresight/devices/etm<N>/mgmt/trcconfig Date: February 2016 KernelVersion: 4.07 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the trace configuration register (0x010) as currently set by SW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/mgmt/trctraceid +What: /sys/bus/coresight/devices/etm<N>/mgmt/trctraceid Date: February 2016 KernelVersion: 4.07 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Print the content of the trace ID register (0x040).
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr0 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr0 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns the tracing capabilities of the trace unit (0x1E0). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr1 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr1 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns the tracing capabilities of the trace unit (0x1E4). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr2 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr2 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org @@ -394,7 +394,7 @@ Description: (R) Returns the maximum size of the data value, data address, VMID, context ID and instuction address in the trace unit (0x1E8). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr3 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr3 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org @@ -403,42 +403,42 @@ Description: (R) Returns the value associated with various resources architecture specification for more details (0x1E8). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr4 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr4 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns how many resources the trace unit supports (0x1F0). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr5 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr5 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns how many resources the trace unit supports (0x1F4). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr8 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr8 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns the maximum speculation depth of the instruction trace stream. (0x180). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr9 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr9 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns the number of P0 right-hand keys that the trace unit can use (0x184). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr10 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr10 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (R) Returns the number of P1 right-hand keys that the trace unit can use (0x188). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr11 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr11 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org @@ -446,7 +446,7 @@ Description: (R) Returns the number of special P1 right-hand keys that the trace unit can use (0x18C). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr12 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr12 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org @@ -454,7 +454,7 @@ Description: (R) Returns the number of conditional P1 right-hand keys that the trace unit can use (0x190). The value is taken directly from the HW.
-What: /sys/bus/coresight/devices/<memory_map>.etm/trcidr/trcidr13 +What: /sys/bus/coresight/devices/etm<N>/trcidr/trcidr13 Date: April 2015 KernelVersion: 4.01 Contact: Mathieu Poirier mathieu.poirier@linaro.org
This updates the ABI document to reflect recent additions to the ETM4.X driver sysfs interface.
Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Mike Leach mike.leach@linaro.org --- .../testing/sysfs-bus-coresight-devices-etm4x | 47 +++++++++++++++++++ 1 file changed, 47 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x index 9290010e973e..112c50ae9986 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x @@ -282,6 +282,53 @@ Contact: Mathieu Poirier mathieu.poirier@linaro.org Description: (RW) Mask for all 8 virtual machine ID comparator value registers (if implemented).
+What: /sys/bus/coresight/devices/etm<N>/addr_exlevel_s_ns +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (RW) Set the Exception Level matching bits for secure and + non-secure exception levels. + +What: /sys/bus/coresight/devices/etm<N>/vinst_pe_cmp_start_stop +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (RW) Access the start stop control register for PE input + comparators. + +What: /sys/bus/coresight/devices/etm<N>/addr_cmp_view +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (R) Print the current settings for the selected address + comparator. + +What: /sys/bus/coresight/devices/etm<N>/sshot_idx +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (RW) Select the single shot control register to access. + +What: /sys/bus/coresight/devices/etm<N>/sshot_ctrl +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (RW) Access the selected single shot control register. + +What: /sys/bus/coresight/devices/etm<N>/sshot_status +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (R) Print the current value of the selected single shot + status register. + +What: /sys/bus/coresight/devices/etm<N>/sshot_pe_ctrl +Date: August 2019 +KernelVersion: 5.4 +Contact: Mathieu Poirier mathieu.poirier@linaro.org +Description: (RW) Access the selected single show PE comparator control + register. + What: /sys/bus/coresight/devices/etm<N>/mgmt/trcoslsr Date: April 2015 KernelVersion: 4.01
There are two files in the Documentation/trace directory relating to coresight, with more to follow, so create a Documentation/trace/coresight directory and move existing files there. Fixup index to reference new location.
Update MAINTAINERS to reference this sub-directory rather than the individual files.
Signed-off-by: Mike Leach mike.leach@linaro.org --- .../trace/{ => coresight}/coresight-cpu-debug.rst | 0 Documentation/trace/{ => coresight}/coresight.rst | 2 +- Documentation/trace/coresight/index.rst | 9 +++++++++ Documentation/trace/index.rst | 3 +-- MAINTAINERS | 3 +-- 5 files changed, 12 insertions(+), 5 deletions(-) rename Documentation/trace/{ => coresight}/coresight-cpu-debug.rst (100%) rename Documentation/trace/{ => coresight}/coresight.rst (99%) create mode 100644 Documentation/trace/coresight/index.rst
diff --git a/Documentation/trace/coresight-cpu-debug.rst b/Documentation/trace/coresight/coresight-cpu-debug.rst similarity index 100% rename from Documentation/trace/coresight-cpu-debug.rst rename to Documentation/trace/coresight/coresight-cpu-debug.rst diff --git a/Documentation/trace/coresight.rst b/Documentation/trace/coresight/coresight.rst similarity index 99% rename from Documentation/trace/coresight.rst rename to Documentation/trace/coresight/coresight.rst index 72f4b7ef1bad..a566719f8e7e 100644 --- a/Documentation/trace/coresight.rst +++ b/Documentation/trace/coresight/coresight.rst @@ -489,7 +489,7 @@ interface provided for that purpose by the generic STM API:: crw------- 1 root root 10, 61 Jan 3 18:11 /dev/stm0 root@genericarmv8:~#
-Details on how to use the generic STM API can be found here [#second]_. +Details on how to use the generic STM API can be found here:- :doc:`../stm` [#second]_.
.. [#first] Documentation/ABI/testing/sysfs-bus-coresight-devices-stm
diff --git a/Documentation/trace/coresight/index.rst b/Documentation/trace/coresight/index.rst new file mode 100644 index 000000000000..8d31b155a87c --- /dev/null +++ b/Documentation/trace/coresight/index.rst @@ -0,0 +1,9 @@ +============================== +CoreSight - ARM Hardware Trace +============================== + +.. toctree:: + :maxdepth: 2 + :glob: + + * diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst index b7891cb1ab4d..04acd277c5f6 100644 --- a/Documentation/trace/index.rst +++ b/Documentation/trace/index.rst @@ -23,5 +23,4 @@ Linux Tracing Technologies intel_th stm sys-t - coresight - coresight-cpu-debug + coresight/index diff --git a/MAINTAINERS b/MAINTAINERS index 296de2b51c83..f903160b507c 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1608,8 +1608,7 @@ R: Suzuki K Poulose suzuki.poulose@arm.com L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) S: Maintained F: drivers/hwtracing/coresight/* -F: Documentation/trace/coresight.rst -F: Documentation/trace/coresight-cpu-debug.rst +F: Documentation/trace/coresight/* F: Documentation/devicetree/bindings/arm/coresight.txt F: Documentation/devicetree/bindings/arm/coresight-cpu-debug.txt F: Documentation/ABI/testing/sysfs-bus-coresight-devices-*
Add in detailed programmers reference for users wanting to program the CoreSight ETM 4.x driver using sysfs.
Reviewed-by: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Mike Leach mike.leach@linaro.org --- .../coresight/coresight-etm4x-reference.rst | 798 ++++++++++++++++++ 1 file changed, 798 insertions(+) create mode 100644 Documentation/trace/coresight/coresight-etm4x-reference.rst
diff --git a/Documentation/trace/coresight/coresight-etm4x-reference.rst b/Documentation/trace/coresight/coresight-etm4x-reference.rst new file mode 100644 index 000000000000..b64d9a9c79df --- /dev/null +++ b/Documentation/trace/coresight/coresight-etm4x-reference.rst @@ -0,0 +1,798 @@ +=============================================== +ETMv4 sysfs linux driver programming reference. +=============================================== + + :Author: Mike Leach mike.leach@linaro.org + :Date: October 11th, 2019 + +Supplement to existing ETMv4 driver documentation. + +Sysfs files and directories +--------------------------- + +Root: ``/sys/bus/coresight/devices/etm<N>`` + + +The following paragraphs explain the association between sysfs files and the +ETMv4 registers that they effect. Note the register names are given without +the ‘TRC’ prefix. + +---- + +:File: ``mode`` (rw) +:Trace Registers: {CONFIGR + others} +:Notes: + Bit select trace features. See ‘mode’ section below. Bits + in this will cause equivalent programming of trace config and + other registers to enable the features requested. + +:Syntax & eg: + ``echo bitfield > mode`` + + bitfield up to 32 bits setting trace features. + +:Example: + ``$> echo 0x012 > mode`` + +---- + +:File: ``reset`` (wo) +:Trace Registers: All +:Notes: + Reset all programming to trace nothing / no logic programmed. + +:Syntax: + ``echo 1 > reset`` + +---- + +:File: ``enable_source`` (wo) +:Trace Registers: PRGCTLR, All hardware regs. +:Notes: + - > 0 : Programs up the hardware with the current values held in the driver + and enables trace. + + - = 0 : disable trace hardware. + +:Syntax: + ``echo 1 > enable_source`` + +---- + +:File: ``cpu`` (ro) +:Trace Registers: None. +:Notes: + CPU ID that this ETM is attached to. + +:Example: + ``$> cat cpu`` + + ``$> 0`` + +---- + +:File: ``addr_idx`` (rw) +:Trace Registers: None. +:Notes: + Virtual register to index address comparator and range + features. Set index for first of the pair in a range. + +:Syntax: + ``echo idx > addr_idx`` + + Where idx < nr_addr_cmp x 2 + +---- + +:File: ``addr_range`` (rw) +:Trace Registers: ACVR[idx, idx+1], VIIECTLR +:Notes: + Pair of addresses for a range selected by addr_idx. Include + / exclude according to the optional parameter, or if omitted + uses the current ‘mode’ setting. Select comparator range in + control register. Error if index is odd value. + +:Depends: ``mode, addr_idx`` +:Syntax: + ``echo addr1 addr2 [exclude] > addr_range`` + + Where addr1 and addr2 define the range and addr1 < addr2. + + Optional exclude value:- + + - 0 for include + - 1 for exclude. +:Example: + ``$> echo 0x0000 0x2000 0 > addr_range`` + +---- + +:File: ``addr_single`` (rw) +:Trace Registers: ACVR[idx] +:Notes: + Set a single address comparator according to addr_idx. This + is used if the address comparator is used as part of event + generation logic etc. + +:Depends: ``addr_idx`` +:Syntax: + ``echo addr1 > addr_single`` + +---- + +:File: ``addr_start`` (rw) +:Trace Registers: ACVR[idx], VISSCTLR +:Notes: + Set a trace start address comparator according to addr_idx. + Select comparator in control register. + +:Depends: ``addr_idx`` +:Syntax: + ``echo addr1 > addr_start`` + +---- + +:File: ``addr_stop`` (rw) +:Trace Registers: ACVR[idx], VISSCTLR +:Notes: + Set a trace stop address comparator according to addr_idx. + Select comparator in control register. + +:Depends: ``addr_idx`` +:Syntax: + ``echo addr1 > addr_stop`` + +---- + +:File: ``addr_context`` (rw) +:Trace Registers: ACATR[idx,{6:4}] +:Notes: + Link context ID comparator to address comparator addr_idx + +:Depends: ``addr_idx`` +:Syntax: + ``echo ctxt_idx > addr_context`` + + Where ctxt_idx is the index of the linked context id / vmid + comparator. + +---- + +:File: ``addr_ctxtype`` (rw) +:Trace Registers: ACATR[idx,{3:2}] +:Notes: + Input value string. Set type for linked context ID comparator + +:Depends: ``addr_idx`` +:Syntax: + ``echo type > addr_ctxtype`` + + Type one of {all, vmid, ctxid, none} +:Example: + ``$> echo ctxid > addr_ctxtype`` + +---- + +:File: ``addr_exlevel_s_ns`` (rw) +:Trace Registers: ACATR[idx,{14:8}] +:Notes: + Set the ELx secure and non-secure matching bits for the + selected address comparator + +:Depends: ``addr_idx`` +:Syntax: + ``echo val > addr_exlevel_s_ns`` + + val is a 7 bit value for exception levels to exclude. Input + value shifted to correct bits in register. +:Example: + ``$> echo 0x4F > addr_exlevel_s_ns`` + +---- + +:File: ``addr_instdatatype`` (rw) +:Trace Registers: ACATR[idx,{1:0}] +:Notes: + Set the comparator address type for matching. Driver only + supports setting instruction address type. + +:Depends: ``addr_idx`` + +---- + +:File: ``addr_cmp_view`` (ro) +:Trace Registers: ACVR[idx, idx+1], ACATR[idx], VIIECTLR +:Notes: + Read the currently selected address comparator. If part of + address range then display both addresses. + +:Depends: ``addr_idx`` +:Syntax: + ``cat addr_cmp_view`` +:Example: + ``$> cat addr_cmp_view`` + + ``addr_cmp[0] range 0x0 0xffffffffffffffff include ctrl(0x4b00)`` + +---- + +:File: ``nr_addr_cmp`` (ro) +:Trace Registers: From IDR4 +:Notes: + Number of address comparator pairs + +---- + +:File: ``sshot_idx`` (rw) +:Trace Registers: None +:Notes: + Select single shot register set. + +---- + +:File: ``sshot_ctrl`` (rw) +:Trace Registers: SSCCR[idx] +:Notes: + Access a single shot comparator control register. + +:Depends: ``sshot_idx`` +:Syntax: + ``echo val > sshot_ctrl`` + + Writes val into the selected control register. + +---- + +:File: ``sshot_status`` (ro) +:Trace Registers: SSCSR[idx] +:Notes: + Read a single shot comparator status register + +:Depends: ``sshot_idx`` +:Syntax: + ``cat sshot_status`` + + Read status. +:Example: + ``$> cat sshot_status`` + + ``0x1`` + +---- + +:File: ``sshot_pe_ctrl`` (rw) +:Trace Registers: SSPCICR[idx] +:Notes: + Access a single shot PE comparator input control register. + +:Depends: ``sshot_idx`` +:Syntax: + ``echo val > sshot_pe_ctrl`` + + Writes val into the selected control register. + +---- + +:File: ``ns_exlevel_vinst`` (rw) +:Trace Registers: VICTLR{23:20} +:Notes: + Program non-secure exception level filters. Set / clear NS + exception filter bits. Setting ‘1’ excludes trace from the + exception level. + +:Syntax: + ``echo bitfield > ns_exlevel_viinst`` + + Where bitfield contains bits to set clear for EL0 to EL2 +:Example: + ``%> echo 0x4 > ns_exlevel_viinst`` + + Excludes EL2 NS trace. + +---- + +:File: ``vinst_pe_cmp_start_stop`` (rw) +:Trace Registers: VIPCSSCTLR +:Notes: + Access PE start stop comparator input control registers + +---- + +:File: ``bb_ctrl`` (rw) +:Trace Registers: BBCTLR +:Notes: + Define ranges that Branch Broadcast will operate in. + Default (0x0) is all addresses. + +:Depends: BB enabled. + +---- + +:File: ``cyc_threshold`` (rw) +:Trace Registers: CCCTLR +:Notes: + Set the threshold for which cycle counts will be emitted. + Error if attempt to set below minimum defined in IDR3, masked + to width of valid bits. + +:Depends: CC enabled. + +---- + +:File: ``syncfreq`` (rw) +:Trace Registers: SYNCPR +:Notes: + Set trace synchronisation period. Power of 2 value, 0 (off) + or 8-20. Driver defaults to 12 (every 4096 bytes). + +---- + +:File: ``cntr_idx`` (rw) +:Trace Registers: none +:Notes: + Select the counter to access + +:Syntax: + ``echo idx > cntr_idx`` + + Where idx < nr_cntr + +---- + +:File: ``cntr_ctrl`` (rw) +:Trace Registers: CNTCTLR[idx] +:Notes: + Set counter control value. + +:Depends: ``cntr_idx`` +:Syntax: + ``echo val > cntr_ctrl`` + + Where val is per ETMv4 spec. + +---- + +:File: ``cntrldvr`` (rw) +:Trace Registers: CNTRLDVR[idx] +:Notes: + Set counter reload value. + +:Depends: ``cntr_idx`` +:Syntax: + ``echo val > cntrldvr`` + + Where val is per ETMv4 spec. + +---- + +:File: ``nr_cntr`` (ro) +:Trace Registers: From IDR5 + +:Notes: + Number of counters implemented. + +---- + +:File: ``ctxid_idx`` (rw) +:Trace Registers: None +:Notes: + Select the context ID comparator to access + +:Syntax: + ``echo idx > ctxid_idx`` + + Where idx < numcidc + +---- + +:File: ``ctxid_pid`` (rw) +:Trace Registers: CIDCVR[idx] +:Notes: + Set the context ID comparator value + +:Depends: ``ctxid_idx`` + +---- + +:File: ``ctxid_masks`` (rw) +:Trace Registers: CIDCCTLR0, CIDCCTLR1, CIDCVR<0-7> +:Notes: + Pair of values to set the byte masks for 1-8 context ID + comparators. Automatically clears masked bytes to 0 in CID + value registers. + +:Syntax: + ``echo m3m2m1m0 [m7m6m5m4] > ctxid_masks`` + + 32 bit values made up of mask bytes, where mN represents a + byte mask value for Context ID comparator N. + + Second value not required on systems that have fewer than 4 + context ID comparators + +---- + +:File: ``numcidc`` (ro) +:Trace Registers: From IDR4 +:Notes: + Number of Context ID comparators + +---- + +:File: ``vmid_idx`` (rw) +:Trace Registers: None +:Notes: + Select the VM ID comparator to access. + +:Syntax: + ``echo idx > vmid_idx`` + + Where idx < numvmidc + +---- + +:File: ``vmid_val`` (rw) +:Trace Registers: VMIDCVR[idx] +:Notes: + Set the VM ID comparator value + +:Depends: ``vmid_idx`` + +---- + +:File: ``vmid_masks`` (rw) +:Trace Registers: VMIDCCTLR0, VMIDCCTLR1, VMIDCVR<0-7> +:Notes: + Pair of values to set the byte masks for 1-8 VM ID comparators. + Automatically clears masked bytes to 0 in VMID value registers. + +:Syntax: + ``echo m3m2m1m0 [m7m6m5m4] > vmid_masks`` + + Where mN represents a byte mask value for VMID comparator N. + Second value not required on systems that have fewer than 4 + VMID comparators. + +---- + +:File: ``numvmidc`` (ro) +:Trace Registers: From IDR4 +:Notes: + Number of VMID comparators + +---- + +:File: ``res_idx`` (rw) +:Trace Registers: None. +:Notes: + Select the resource selector control to access. Must be 2 or + higher as selectors 0 and 1 are hardwired. + +:Syntax: + ``echo idx > res_idx`` + + Where 2 <= idx < nr_resource x 2 + +---- + +:File: ``res_ctrl`` (rw) +:Trace Registers: RSCTLR[idx] +:Notes: + Set resource selector control value. Value per ETMv4 spec. + +:Depends: ``res_idx`` +:Syntax: + ``echo val > res_cntr`` + + Where val is per ETMv4 spec. + +---- + +:File: ``nr_resource`` (ro) +:Trace Registers: From IDR4 +:Notes: + Number of resource selector pairs + +---- + +:File: ``event`` (rw) +:Trace Registers: EVENTCTRL0R +:Notes: + Set up to 4 implemented event fields. + +:Syntax: + ``echo ev3ev2ev1ev0 > event`` + + Where evN is an 8 bit event field. Up to 4 event fields make up the + 32-bit input value. Number of valid fields is implementation dependent, + defined in IDR0. + +---- + +:File: ``event_instren`` (rw) +:Trace Registers: EVENTCTRL1R +:Notes: + Choose events which insert event packets into trace stream. + +:Depends: EVENTCTRL0R +:Syntax: + ``echo bitfield > event_instren`` + + Where bitfield is up to 4 bits according to number of event fields. + +---- + +:File: ``event_ts`` (rw) +:Trace Registers: TSCTLR +:Notes: + Set the event that will generate timestamp requests. + +:Depends: ``TS activated`` +:Syntax: + ``echo evfield > event_ts`` + + Where evfield is an 8 bit event selector. + +---- + +:File: ``seq_idx`` (rw) +:Trace Registers: None +:Notes: + Sequencer event register select - 0 to 2 + +---- + +:File: ``seq_state`` (rw) +:Trace Registers: SEQSTR +:Notes: + Sequencer current state - 0 to 3. + +---- + +:File: ``seq_event`` (rw) +:Trace Registers: SEQEVR[idx] +:Notes: + State transition event registers + +:Depends: ``seq_idx`` +:Syntax: + ``echo evBevF > seq_event`` + + Where evBevF is a 16 bit value made up of two event selectors, + + - evB : back + - evF : forwards. + +---- + +:File: ``seq_reset_event`` (rw) +:Trace Registers: SEQRSTEVR +:Notes: + Sequencer reset event + +:Syntax: + ``echo evfield > seq_reset_event`` + + Where evfield is an 8 bit event selector. + +---- + +:File: ``nrseqstate`` (ro) +:Trace Registers: From IDR5 +:Notes: + Number of sequencer states (0 or 4) + +---- + +:File: ``nr_pe_cmp`` (ro) +:Trace Registers: From IDR4 +:Notes: + Number of PE comparator inputs + +---- + +:File: ``nr_ext_inp`` (ro) +:Trace Registers: From IDR5 +:Notes: + Number of external inputs + +---- + +:File: ``nr_ss_cmp`` (ro) +:Trace Registers: From IDR4 +:Notes: + Number of Single Shot control registers + +---- + +*Note:* When programming any address comparator the driver will tag the +comparator with a type used - i.e. RANGE, SINGLE, START, STOP. Once this tag +is set, then only the values can be changed using the same sysfs file / type +used to program it. + +Thus:: + + % echo 0 > addr_idx ; select address comparator 0 + % echo 0x1000 0x5000 0 > addr_range ; set address range on comparators 0, 1. + % echo 0x2000 > addr_start ; error as comparator 0 is a range comparator + % echo 2 > addr_idx ; select address comparator 2 + % echo 0x2000 > addr_start ; this is OK as comparator 2 is unused. + % echo 0x3000 > addr_stop ; error as comparator 2 set as start address. + % echo 2 > addr_idx ; select address comparator 3 + % echo 0x3000 > addr_stop ; this is OK + +To remove programming on all the comparators (and all the other hardware) use +the reset parameter:: + + % echo 1 > reset + + + +The ‘mode’ sysfs parameter. +--------------------------- + +This is a bitfield selection parameter that sets the overall trace mode for the +ETM. The table below describes the bits, using the defines from the driver +source file, along with a description of the feature these represent. Many +features are optional and therefore dependent on implementation in the +hardware. + +Bit assignments shown below:- + +---- + +**bit (0):** + ETM_MODE_EXCLUDE + +**description:** + This is the default value for the include / exclude function when + setting address ranges. Set 1 for exclude range. When the mode + parameter is set this value is applied to the currently indexed + address range. + + +**bit (4):** + ETM_MODE_BB + +**description:** + Set to enable branch broadcast if supported in hardware [IDR0]. + + +**bit (5):** + ETMv4_MODE_CYCACC + +**description:** + Set to enable cycle accurate trace if supported [IDR0]. + + +**bit (6):** + ETMv4_MODE_CTXID + +**description:** + Set to enable context ID tracing if supported in hardware [IDR2]. + + +**bit (7):** + ETM_MODE_VMID + +**description:** + Set to enable virtual machine ID tracing if supported [IDR2]. + + +**bit (11):** + ETMv4_MODE_TIMESTAMP + +**description:** + Set to enable timestamp generation if supported [IDR0]. + + +**bit (12):** + ETM_MODE_RETURNSTACK +**description:** + Set to enable trace return stack use if supported [IDR0]. + + +**bit (13-14):** + ETM_MODE_QELEM(val) + +**description:** + ‘val’ determines level of Q element support enabled if + implemented by the ETM [IDR0] + + +**bit (19):** + ETM_MODE_ATB_TRIGGER + +**description:** + Set to enable the ATBTRIGGER bit in the event control register + [EVENTCTLR1] if supported [IDR5]. + + +**bit (20):** + ETM_MODE_LPOVERRIDE + +**description:** + Set to enable the LPOVERRIDE bit in the event control register + [EVENTCTLR1], if supported [IDR5]. + + +**bit (21):** + ETM_MODE_ISTALL_EN + +**description:** + Set to enable the ISTALL bit in the stall control register + [STALLCTLR] + + +**bit (23):** + ETM_MODE_INSTPRIO + +**description:** + Set to enable the INSTPRIORITY bit in the stall control register + [STALLCTLR] , if supported [IDR0]. + + +**bit (24):** + ETM_MODE_NOOVERFLOW + +**description:** + Set to enable the NOOVERFLOW bit in the stall control register + [STALLCTLR], if supported [IDR3]. + + +**bit (25):** + ETM_MODE_TRACE_RESET + +**description:** + Set to enable the TRCRESET bit in the viewinst control register + [VICTLR] , if supported [IDR3]. + + +**bit (26):** + ETM_MODE_TRACE_ERR + +**description:** + Set to enable the TRCCTRL bit in the viewinst control register + [VICTLR]. + + +**bit (27):** + ETM_MODE_VIEWINST_STARTSTOP + +**description:** + Set the initial state value of the ViewInst start / stop logic + in the viewinst control register [VICTLR] + + +**bit (30):** + ETM_MODE_EXCL_KERN + +**description:** + Set default trace setup to exclude kernel mode trace (see note a) + + +**bit (31):** + ETM_MODE_EXCL_USER + +**description:** + Set default trace setup to exclude user space trace (see note a) + +---- + +*Note a)* On startup the ETM is programmed to trace the complete address space +using address range comparator 0. ‘mode’ bits 30 / 31 modify this setting to +set EL exclude bits for NS state in either user space (EL0) or kernel space +(EL1) in the address range comparator. (the default setting excludes all +secure EL, and NS EL2) + +Once the reset parameter has been used, and/or custom programming has been +implemented - using these bits will result in the EL bits for address +comparator 0 being set in the same way. + +*Note b)* Bits 2-3, 8-10, 15-16, 18, 22, control features that only work with +data trace. As A-profile data trace is architecturally prohibited in ETMv4, +these have been omitted here. Possible uses could be where a kernel has +support for control of R or M profile infrastructure as part of a heterogeneous +system. + +Bits 17, 28-29 are unused.
-
Mike Leach