CoreSight July 2025

coresight@lists.linaro.org

9 participants
33 discussions

[PATCH v4 00/10] coresight: Fix and improve clock usage

by Leo Yan

This series fixes and improves clock usage in the Arm CoreSight drivers. Based on the DT binding documents, the trace clock (atclk) is defined in some CoreSight modules, but support is absent. In most cases, the issue is hidden because the atclk clock is shared by multiple CoreSight modules and the clock is enabled anyway by other drivers. The first three patches address this issue. The programming clock (pclk) management in CoreSight drivers does not use the devm_XXX() variant APIs, the drivers needs to manually disable and release clocks for errors and for normal module exit. However, the drivers miss to disable clocks during module exit. The atclk may also not be disabled in CoreSight drivers during module exit. By using devm APIs, patches 04 and 05 fix clock disabling issues. Another issue is pclk might be enabled twice in init phase - once by AMBA bus driver, and again by CoreSight drivers. This is fixed in patch 06. Patches 07 to 10 refactor the clock related code. Patch 07 consolidates the clock initialization into a central place. Patch 08 polishes driver data allocation. Patch 09 makes the clock enabling sequence consistent. Patch 09 removes redundant condition checks and adds error handling in runtime PM. This series has been verified on Arm64 Hikey960 and Juno platforms. Changes from v3: - Separated patch 07 into two patches, one is for clock consolidation and another is for polishing driver data allocation (Anshuman). Changes from v2: - Updated subjects for patches 04 and 05 (Anshuman). - Refined condition checking "if (dev_is_amba(dev))" in patch 07 (Anshuman). Changes from v1: - Moved the coresight_get_enable_clocks() function into CoreSight core layer (James). - Added comments for clock naming "apb_pclk" and "apb" (James). - Re-ordered patches for easier understanding (Anshuman). - Minor improvement for commit log in patch 01 (Anshuman). Signed-off-by: Leo Yan <leo.yan(a)arm.com> --- Leo Yan (10): coresight: tmc: Support atclk coresight: catu: Support atclk coresight: etm4x: Support atclk coresight: Appropriately disable programming clocks coresight: Appropriately disable trace bus clocks coresight: Avoid enable programming clock duplicately coresight: Consolidate clock enabling coresight: Refactor driver data allocation coresight: Make clock sequence consistent coresight: Refactor runtime PM drivers/hwtracing/coresight/coresight-catu.c | 53 ++++++++--------- drivers/hwtracing/coresight/coresight-catu.h | 1 + drivers/hwtracing/coresight/coresight-core.c | 46 +++++++++++++++ drivers/hwtracing/coresight/coresight-cpu-debug.c | 41 +++++--------- drivers/hwtracing/coresight/coresight-ctcu-core.c | 24 +++----- drivers/hwtracing/coresight/coresight-etb10.c | 18 ++---- drivers/hwtracing/coresight/coresight-etm3x-core.c | 17 ++---- drivers/hwtracing/coresight/coresight-etm4x-core.c | 32 ++++++----- drivers/hwtracing/coresight/coresight-etm4x.h | 4 +- drivers/hwtracing/coresight/coresight-funnel.c | 66 ++++++++-------------- drivers/hwtracing/coresight/coresight-replicator.c | 63 ++++++++------------- drivers/hwtracing/coresight/coresight-stm.c | 34 +++++------ drivers/hwtracing/coresight/coresight-tmc-core.c | 48 ++++++++-------- drivers/hwtracing/coresight/coresight-tmc.h | 2 + drivers/hwtracing/coresight/coresight-tpiu.c | 36 +++++------- include/linux/coresight.h | 30 +--------- 16 files changed, 226 insertions(+), 289 deletions(-) --- base-commit: 67a993863163cb88b1b68974c31b0d84ece4293e change-id: 20250627-arm_cs_fix_clock_v4-e24b1e1f8920 Best regards, -- Leo Yan <leo.yan(a)arm.com>

19 minutes

Re: [PATCH v6 0/7] Provides support for Trigger Generation Unit

by Mike Leach

Hi, On Wed, 9 Jul 2025 at 11:41, songchai <songchai(a)qti.qualcomm.com> wrote: > > From: Songwei Chai <quic_songchai(a)quicinc.com> > > Provide support for the TGU (Trigger Generation Unit), which can be > utilized to sense a plurality of signals and create a trigger into > the CTI or generate interrupts to processors once the input signal > meets the conditions. We can treat the TGU’s workflow as a flowsheet, > it has some “steps” regions for customization. In each step region, > we can set the signals that we want with priority in priority_group, set > the conditions in each step via condition_decode, and set the resultant > action by condition_select. Meanwhile, some TGUs (not all) also provide > timer/counter functionality. Based on the characteristics described > above, we consider the TGU as a helper in the CoreSight subsystem. > Its master device is the TPDM, which can transmit signals from other > subsystems, and we reuse the existing ports mechanism to link the TPDM to > the connected TGU. > > Here is a detailed example to explain how to use the TGU: > > In this example, the TGU is configured to use 2 conditions, 2 steps, and > the timer. The goal is to look for one of two patterns which are generated > from TPDM, giving priority to one, and then generate a trigger once the > timer reaches a certain value. In other words, two conditions are used > for the first step to look for the two patterns, where the one with the > highest priority is used in the first condition. Then, in the second step, > the timer is enabled and set to be compared to the given value at each > clock cycle. These steps are better shown below. > > |-----------------| > | | > | TPDM | > | | > |-----------------| > | > | > --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- --- ------ > | | | > | | |--------------------| | > | |---- ---> | | Go to next steps | | > | | | |--- ---> | Enable timer | | > | | v | | | | > | | |-----------------| | |--------------------| | > | | | | Yes | | | > | | | inputs==0xB | ----->| | <-------- | > | | | | | | No | | > | No | |-----------------| | v | | > | | | | |-----------------| | | > | | | | | | | | > | | | | | timer>=3 |-- | > | | v | | | | > | | |-----------------| | |-----------------| | > | | | | Yes | | | > | |--- | inputs==0xA | ----->| | Yes | > | | | | | > | |-----------------| v | > | |-----------------| | > | | | | > | | Trigger | | > | | | | > | |-----------------| | > | TGU | | > |--- --- --- --- --- --- --- --- --- --- --- --- --- --- |--- --- -- | > | > v > |-----------------| > |The controllers | > |which will use | > |triggers further | > |-----------------| > > steps: > 1. Reset TGU /*it will disable tgu and reset dataset*/ > - echo 1 > /sys/bus/coresight/devices/<tgu-name>/reset_tgu > > 2. Set the pattern match for priority0 to 0xA = 0b1010 and for > priority 1 to 0xB = 0b1011. > - echo 0x11113232 > /sys/bus/coresight/devices/<tgu-name>/step0_priority0/reg0 > - echo 0x11113233 > /sys/bus/coresight/devices/<tgu-name>/step0_priority1/reg0 > > Note: > Bit distribution diagram for each priority register > |-------------------------------------------------------------------| > | Bits | Field Nam | Description | > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 29:28 | SEL_BIT7_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 25:24 | SEL_BIT6_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 21:20 | SEL_BIT5_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 17:16 | SEL_BIT4_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 13:12 | SEL_BIT3_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 9:8 | SEL_BIT2_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 5:4 | SEL_BIT1_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > | | | 00 = bypass for OR output | > | 1:0 | SEL_BIT0_TYPE2 | 01 = bypass for AND output | > | | | 10 = sense input '0' is true| > | | | 11 = sense input '1' is true| > |-------------------------------------------------------------------| > These bits are used to identify the signals we want to sense, with > a maximum signal number of 140. For example, to sense the signal > 0xA (binary 1010), we set the value of bits 0 to 13 to 3232, which > represents 1010. The remaining bits are set to 1, as we want to use > AND gate to summarize all the signals we want to sense here. For > rising or falling edge detection of any input to the priority, set > the remaining bits to 0 to use an OR gate. > > 3. look for the pattern for priority_i i=0,1. > - echo 0x3 > /sys/bus/coresight/devices/<tgu-name>/step0_condition_decode/reg0 > - echo 0x30 > /sys/bus/coresight/devices/<tgu-name>/step0_condition_decode/reg1 > > |-------------------------------------------------------------------------------| > | Bits | Field Nam | Description | > |-------------------------------------------------------------------------------| > | | |For each decoded condition, this | > | 24 | NOT |inverts the output. If the condition | > | | |decodes to true, and the NOT field | > | | |is '1', then the output is NOT true. | > |-------------------------------------------------------------------------------| > | | |When '1' the output from the associated| > | 21 | BC0_COMP_ACTIVE |comparator will be actively included in| > | | |the decoding of this particular | > | | |condition. | > |-------------------------------------------------------------------------------| > | | |When '1' the output from the associated| > | | |comparator will need to be 1 to affect | > | 20 | BC0_COMP_HIGH |the decoding of this condition. | > | | |Conversely, a '0' here requires a '0' | > | | |from the comparator | > |-------------------------------------------------------------------------------| > | | |When '1' the output from the associated| > | 17 | |comparator will be actively included in| > | | TC0_COMP_ACTIVE |the decoding of this particular | > | | |condition. | > |-------------------------------------------------------------------------------| > | | |When '1' the output from the associated| > | | |comparator will need to be 1 to affect | > | 16 | TC0_COMP_HIGH |the decoding of this particular | > | | |condition.Conversely, a 0 here | > | | |requires a '0' from the comparator | > |-------------------------------------------------------------------------------| > | | |When '1' the output from Priority_n | > | | |OR logic will be actively | > | 4n+3 | Priority_n_OR_ACTIVE|included in the decoding of | > | | (n=0,1,2,3) |this particular condition. | > | | | | > |-------------------------------------------------------------------------------| > | | |When '1' the output from Priority_n | > | | |will need to be '1' to affect the | > | 4n+2 | Priority_n_OR_HIGH |decoding of this particular | > | | (n=0,1,2,3) |condition. Conversely, a '0' here | > | | |requires a '0' from Priority_n OR logic| > |-------------------------------------------------------------------------------| > | | |When '1' the output from Priority_n | > | | |AND logic will be actively | > | 4n+1 |Priority_n_AND_ACTIVE|included in the decoding of this | > | | (n=0,1,2,3) |particular condition. | > | | | | > |-------------------------------------------------------------------------------| > | | |When '1' the output from Priority_n | > | | |AND logic will need to be '1' to | > | 4n | Priority_n_AND_HIGH |affect the decoding of this | > | | (n=0,1,2,3) |particular condition. Conversely, | > | | |a '0' here requires a '0' from | > | | |Priority_n AND logic. | > |-------------------------------------------------------------------------------| > Since we use `priority_0` and `priority_1` with an AND output in step 2, we set `0x3` > and `0x30` here to activate them. > > 4. Set NEXT_STEP = 1 and TC0_ENABLE = 1 so that when the conditions > are met then the next step will be step 1 and the timer will be enabled. > - echo 0x20008 > /sys/bus/coresight/devices/<tgu-name>/step0_condition_select/reg0 > - echo 0x20008 > /sys/bus/coresight/devices/<tgu-name>/step0_condition_select/reg1 > > |-----------------------------------------------------------------------------| > | Bits | Field Nam | Description | > |-----------------------------------------------------------------------------| > | | |This field defines the next step the | > | 18:17 | NEXT_STEP |TGU will 'goto' for the associated | > | | |Condition and Step. | > |-----------------------------------------------------------------------------| > | | |For each possible output trigger | > | 13 | TRIGGER |available, set a '1' if you want | > | | |the trigger to go active for the | > | | |associated condition and Step. | > |-----------------------------------------------------------------------------| > | | |This will cause BC0 to increment if the| > | 9 | BC0_INC |associated Condition is decoded for | > | | |this step. | > |-----------------------------------------------------------------------------| > | | |This will cause BC0 to decrement if the| > | 8 | BC0_DEC |associated Condition is decoded for | > | | |this step. | > |-----------------------------------------------------------------------------| > | | |This will clear BC0 count value to 0 if| > | 7 | BC0_CLEAR |the associated Condition is decoded | > | | |for this step. | > |-----------------------------------------------------------------------------| > | | |This will cause TC0 to increment until | > | 3 | TC0_ENABLE |paused or cleared if the associated | > | | |Condition is decoded for this step. | > |-----------------------------------------------------------------------------| > | | |This will cause TC0 to pause until | > | 2 | TC0_PAUSE |enabled if the associated Condition | > | | |is decoded for this step. | > |-----------------------------------------------------------------------------| > | | |This will clear TC0 count value to 0 | > | 1 | TC0_CLEAR |if the associated Condition is | > | | |decoded for this step. | > |-----------------------------------------------------------------------------| > | | |This will set the done signal to the | > | 0 | DONE |TGU FSM if the associated Condition | > | | |is decoded for this step. | > |-----------------------------------------------------------------------------| > Based on the distribution diagram, we set `0x20008` for `priority0` and `priority1` to > achieve "jump to step 1 and enable TC0" once the signal is sensed. > > 5. activate the timer comparison for this step. > - echo 0x30000 > /sys/bus/coresight/devices/<tgu-name>/step1_condition_decode/reg0 > > |-------------------------------------------------------------------------------| > | | |When '1' the output from the associated| > | 17 | |comparator will be actively included in| > | | TC0_COMP_ACTIVE |the decoding of this particular | > | | |condition. | > |-------------------------------------------------------------------------------| > | | |When '1' the output from the associated| > | | |comparator will need to be 1 to affect | > | 16 | TC0_COMP_HIGH |the decoding of this particular | > | | |condition.Conversely, a 0 here | > | | |requires a '0' from the comparator | > |-------------------------------------------------------------------------------| > Accroding to the decode distribution diagram , we give 0x30000 here to set 16th&17th bit > to enable timer comparison. > > 6. Set the NEXT_STEP = 0 and TC0_PAUSE = 1 and TC0_CLEAR = 1 once the timer > has reached the given value. > - echo 0x6 > /sys/bus/coresight/devices/<tgu-name>/step1_condition_select/reg0 > > 7. Enable Trigger 0 for TGU when the condition 0 is met in step1, > i.e. when the timer reaches 3. > - echo 0x2000 > /sys/bus/coresight/devices/<tgu-name>/step1_condition_select/default > > Note: > 1. 'default' register allows for establishing the resultant action for > the default condition > > 2. Trigger:For each possible output trigger available from > the Design document, there are three triggers: interrupts, CTI, > and Cross-TGU mapping.All three triggers can occur, but > the choice of which trigger to use depends on the user's > needs. > > 8. Compare the timer to 3 in step 1. > - echo 0x3 > /sys/bus/coresight/devices/<tgu-name>/step1_timer/reg0 > > 9. enale tgu > - echo 1 > /sys/bus/coresight/devices/<tgu-name>/enable_tgu > --- > Link to V5: https://lore.kernel.org/all/20250529081949.26493-1-quic_songchai@quicinc.co… > > Changes in V6: > - Replace spinlock with guard(spinlock) in tgu_enable. > - Remove redundant blank line. > - Update publish date and contact member's name in "sysfs-bus-coresight-devices-tgu". > --- > Link to V4: https://patchwork.kernel.org/project/linux-arm-msm/cover/20250423101054.954… > > Changes in V5: > - Update publish date and kernel_version in "sysfs-bus-coresight-devices-tgu" > --- > Link to V3: https://lore.kernel.org/all/20250227092640.2666894-1-quic_songchai@quicinc.… > > Changes in V4: > - Add changlog in coverletter. > - Correct 'year' in Copyright in patch1. > - Correct port mechansim description in patch1. > - Remove 'tgu-steps','tgu-regs','tgu-conditions','tgu-timer-counters' from dt-binding > and set them through reading DEVID register as per Mike's suggestion. > - Modify tgu_disable func to make it have single return point in patch2 as per > Mike's suggestion. > - Use sysfs_emit in enable_tgu_show func in ptach2. > - Remove redundant judgement in enable_tgu_store in patch2. > - Correct typo in description in patch3. > - Set default ret as SYSFS_GROUP_INVISIBLE, and returnret at end in pacth3 as > per Mike's suggestion. > - Remove tgu_dataset_ro definition in patch3 > - Use #define constants with explanations of what they are rather than > arbitrary magic numbers in patch3 and patch4. > - Check -EINVAL before using 'calculate_array_location()' in array in patch4. > - Add 'default' in 'tgu_dataset_show''s switch part in patch4. > - Document the value needed to initiate the reset in pacth7. > - Check "value" in 'reset_tgu_store' and bail out with an error code if 0 in patch7. > - Remove dev_dbg in 'reset_tgu_store' in patch7. > --- > Link to V2: https://lore.kernel.org/all/20241010073917.16023-1-quic_songchai@quicinc.co… > > Changes in V3: > - Correct typo and format in dt-binding in patch1 > - Rebase to the latest kernel version > --- > Link to V1: https://lore.kernel.org/all/20240830092311.14400-1-quic_songchai@quicinc.co… > > Changes in V2: > - Use real name instead of login name, > - Correct typo and format in dt-binding and code. > - Bring order in tgu_prob(declarations with and without assignments) as per > Krzysztof's suggestion. > - Add module device table in patch2. > - Set const for tgu_common_grp and tgu_ids in patch2. > - Initialize 'data' in tgu_ids to fix the warning in pacth2. > --- > > Songwei Chai (7): > dt-bindings: arm: Add support for Coresight TGU trace > coresight: Add coresight TGU driver > coresight-tgu: Add signal priority support > coresight-tgu: Add TGU decode support > coresight-tgu: add support to configure next action > coresight-tgu: add timer/counter functionality for TGU > coresight-tgu: add reset node to initialize > > .../testing/sysfs-bus-coresight-devices-tgu | 51 ++ > .../bindings/arm/qcom,coresight-tgu.yaml | 92 +++ > drivers/hwtracing/coresight/Kconfig | 11 + > drivers/hwtracing/coresight/Makefile | 1 + > drivers/hwtracing/coresight/coresight-tgu.c | 776 ++++++++++++++++++ > drivers/hwtracing/coresight/coresight-tgu.h | 255 ++++++ > 6 files changed, 1186 insertions(+) > create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-tgu > create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-tgu.yaml > create mode 100644 drivers/hwtracing/coresight/coresight-tgu.c > create mode 100644 drivers/hwtracing/coresight/coresight-tgu.h > > As per the discussion here in v3 of this patchset https://lists.infradead.org/pipermail/linux-arm-kernel/2025-March/1012896.h… this component is primarily a part of the qualcom proprietary QPMDA subsystem, and is capable of operating independently from the CoreSight hardware trace generation system. The only link to Coresight is via the trigger input to CTI component(s). CTI triggers can either be part of the ARM architected or recommended connections between Coresight infrastructure from the coresight specs and TRM documents, or platform specific triggers from components external to coresight. For example on the Juno board a trigger from the PL011 serial port is input to one of the system CTIs on the board. Having Coresight management registers does not necessarily mean that the component should be maintained under the hwtracing/coresight. Some ARM Corelink interconnect components have the capability to generate ATB trace into the coresight subsystem, and have some of the coresight management registers. However, I would not expect the drivers for these components to appear in hwtracing/coresight. As such this component could probably be better managed and maintained as part of the /drivers/soc/qcom or similar area. The only changes to the Coresight infrastructure you should need to get this component connected, is to alter the CTI declaration in board device tree to add the incoming trigger as per the CTI bindings. Regards Mike -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK

48 minutes

Re: [PATCH next] coresight: Fix a NULL vs IS_ERR() bug in probe

by Suzuki K Poulose

On Wed, 16 Jul 2025 14:38:30 -0500, Dan Carpenter wrote: > The devm_ioremap_resource() function returns error pointers on error. > It never returns NULL. Update the error checking to match. > > Applied, thanks! [1/1] coresight: Fix a NULL vs IS_ERR() bug in probe https://git.kernel.org/coresight/c/f59b9437ac95 Best regards, -- Suzuki K Poulose <suzuki.poulose(a)arm.com>

3 hours, 4 minutes

Re: [PATCH next] coresight: Fix a NULL vs IS_ERR() bug in probe

by Anshuman Khandual

On 17/07/25 1:08 AM, Dan Carpenter wrote: > The devm_ioremap_resource() function returns error pointers on error. > It never returns NULL. Update the error checking to match. > > Fixes: 26e20622a8ae ("coresight: add coresight Trace Network On Chip driver") > Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org> > --- > drivers/hwtracing/coresight/coresight-tnoc.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c > index 0e4164707eea..d542df46ea39 100644 > --- a/drivers/hwtracing/coresight/coresight-tnoc.c > +++ b/drivers/hwtracing/coresight/coresight-tnoc.c > @@ -183,8 +183,8 @@ static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id) > dev_set_drvdata(dev, drvdata); > > drvdata->base = devm_ioremap_resource(dev, &adev->res); > - if (!drvdata->base) > - return -ENOMEM; > + if (IS_ERR(drvdata->base)) > + return PTR_ERR(drvdata->base); > > spin_lock_init(&drvdata->spinlock); > Do we still have more similar instances in coresight ?

3 hours, 11 minutes

Re: [PATCH v4] coresight: Replace scnprintf() with sysfs_emit() in sysfs show functions

by Suzuki K Poulose

On 19/07/2025 23:45, Chelsy Ratnawat wrote: > Documentation/filesystems/sysfs.rst mentions that show() should only > use sysfs_emit() or sysfs_emit_at() when formating the value to be > returned to user space. So replace scnprintf() with sysfs_emit(). > > Signed-off-by: Chelsy Ratnawat <chelsyratnawat2001(a)gmail.com> > --- > Changes in v4: > - Applied changes to 5 more files to replace sprintf/scnprintf with > sysfs_emit() and sysfs_emit_at() Please could you rebase this on coresight tree "next" branch ? There are conflicts. https://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git/log/?h=… Suzuki

5 hours, 52 minutes

[PATCH v2 0/3] Coresight TMC-ETR some bugfixes and cleanups

by Junhao He

This patchset builds upon Yicong's previous patches [1]. Introducing fix two race issues found by using TMC-ETR and CATU, Two cleanups found when debugging the issues. [1] https://lore.kernel.org/linux-arm-kernel/20241202092419.11777-1-yangyicong@… --- Changes in v2: - Updated the commit of patch2. - Rebase to v6.16-rc1 Junhao He (1): coresight: tmc: refactor the tmc-etr mode setting to avoid race conditions Yicong Yang (2): coresight: tmc: Add missing doc of tmc_drvdata::reading coresight: tmc: Decouple the perf buffer allocation from sysfs mode .../hwtracing/coresight/coresight-tmc-etr.c | 102 +++++++++--------- drivers/hwtracing/coresight/coresight-tmc.h | 1 + 2 files changed, 53 insertions(+), 50 deletions(-) -- 2.33.0

7 hours, 51 minutes

[PATCH v3 0/6] Refactoring finding CPU phandles in DT

by Alireza Sanaee

This series refactor the way CPU IDs are retrieved from the device tree. Usually, there is a for loop that goes over every single CPU that can be avoided. This also reduces the amount of NULL pointer checks in drivers. I have abstracted away that loop and introduced a new function (of_cpu_node_to_id) for this. This patchset is a subset of [1], where I removed content and patches relevant to hyper-threaded cores for DT. Based on the discussion, the code refactor is still useful, hence this patchset. [1] https://lore.kernel.org/all/20250512080715.82-1-alireza.sanaee@huawei.co Changes since v2: - Addressed Jonathan Cameron's comments. - Added reviewed-by tags. - Added a new commit where I suggest simplfing the code in arch_topology.c to remove the use of cpu_node on failure path. - Improve documentation. - Caught a bug in patch 1. - Commit message fixed for patch 2. Changes since v1: - Rebased on top of the latest mainline. - Addressed Krzysztof Kozlowski's comments -- Hopefully :-) - Addressed Jonathan Cameron's comments. Alireza Sanaee (6): of: add infra for finding CPU id from phandle arch_topology: drop the use of cpu_node in the pr_info arch_topology: update CPU map to use of_cpu_phandle_to_id coresight: cti: Use of_cpu_phandle_to_id for grabbing CPU id coresight: Use of_cpu_phandle_to_id for grabbing CPU ID perf/arm-dsu: refactor cpu id retrieval via new API of_cpu_phandle_to_id drivers/base/arch_topology.c | 22 ++++----- .../coresight/coresight-cti-platform.c | 13 +---- .../hwtracing/coresight/coresight-platform.c | 15 +----- drivers/of/cpu.c | 49 +++++++++++++++++++ drivers/perf/arm_dsu_pmu.c | 7 +-- include/linux/of.h | 9 ++++ 6 files changed, 72 insertions(+), 43 deletions(-) -- 2.43.0

3 days, 1 hour

Re: [PATCH next] coresight: Fix a NULL vs IS_ERR() bug in probe

by Mike Leach

On Wed, 16 Jul 2025 at 20:38, Dan Carpenter <dan.carpenter(a)linaro.org> wrote: > > The devm_ioremap_resource() function returns error pointers on error. > It never returns NULL. Update the error checking to match. > > Fixes: 26e20622a8ae ("coresight: add coresight Trace Network On Chip driver") > Signed-off-by: Dan Carpenter <dan.carpenter(a)linaro.org> > --- > drivers/hwtracing/coresight/coresight-tnoc.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tnoc.c b/drivers/hwtracing/coresight/coresight-tnoc.c > index 0e4164707eea..d542df46ea39 100644 > --- a/drivers/hwtracing/coresight/coresight-tnoc.c > +++ b/drivers/hwtracing/coresight/coresight-tnoc.c > @@ -183,8 +183,8 @@ static int trace_noc_probe(struct amba_device *adev, const struct amba_id *id) > dev_set_drvdata(dev, drvdata); > > drvdata->base = devm_ioremap_resource(dev, &adev->res); > - if (!drvdata->base) > - return -ENOMEM; > + if (IS_ERR(drvdata->base)) > + return PTR_ERR(drvdata->base); > > spin_lock_init(&drvdata->spinlock); > > -- > 2.47.2 > Reviewed-by: Mike Leach <mike.leach(a)linaro.org> -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK

3 days, 1 hour

Re: [PATCH v3 RESEND 02/10] coresight: core: add a new API to retrieve the helper device

by Mike Leach

Hi, On Mon, 14 Jul 2025 at 07:31, Jie Gan <jie.gan(a)oss.qualcomm.com> wrote: > > Retrieving the helper device of the specific coresight device based on > its helper_subtype because a single coresight device may has multiple types > of the helper devices. > > Signed-off-by: Jie Gan <jie.gan(a)oss.qualcomm.com> > --- > drivers/hwtracing/coresight/coresight-core.c | 30 ++++++++++++++++++++ > drivers/hwtracing/coresight/coresight-priv.h | 2 ++ > 2 files changed, 32 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c > index 5297a5ff7921..76e10c36a8a1 100644 > --- a/drivers/hwtracing/coresight/coresight-core.c > +++ b/drivers/hwtracing/coresight/coresight-core.c > @@ -580,6 +580,36 @@ struct coresight_device *coresight_get_sink(struct coresight_path *path) > } > EXPORT_SYMBOL_GPL(coresight_get_sink); > > +/** > + * coresight_get_helper: find the helper device of the assigned csdev. > + * > + * @csdev: The csdev the helper device is conntected to. > + * @type: helper_subtype of the expected helper device. > + * > + * Retrieve the helper device for the specific csdev based on its > + * helper_subtype. > + * > + * Return: the helper's csdev upon success or NULL for fail. > + */ > +struct coresight_device *coresight_get_helper(struct coresight_device *csdev, > + int type) > +{ > + int i; > + struct coresight_device *helper; > + > + for (i = 0; i < csdev->pdata->nr_outconns; ++i) { > + helper = csdev->pdata->out_conns[i]->dest_dev; > + if (!helper || !coresight_is_helper(helper)) > + continue; > + Manipulating the connections list almost certainly requires some locking. See other functions in this file Mike > + if (helper->subtype.helper_subtype == type) > + return helper; > + } > + > + return NULL; > +} > +EXPORT_SYMBOL_GPL(coresight_get_helper); > + > /** > * coresight_get_port_helper: get the in-port number of the helper device > * that is connected to the csdev. > diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h > index 07a5f03de81d..5b912eb60401 100644 > --- a/drivers/hwtracing/coresight/coresight-priv.h > +++ b/drivers/hwtracing/coresight/coresight-priv.h > @@ -158,6 +158,8 @@ void coresight_path_assign_trace_id(struct coresight_path *path, > enum cs_mode mode); > int coresight_get_port_helper(struct coresight_device *csdev, > struct coresight_device *helper); > +struct coresight_device *coresight_get_helper(struct coresight_device *csdev, > + int type); > > #if IS_ENABLED(CONFIG_CORESIGHT_SOURCE_ETM3X) > int etm_readl_cp14(u32 off, unsigned int *val); > -- > 2.34.1 > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK

3 days, 5 hours

[PATCH v9 0/2] coresight: Add label sysfs node support

by Mao Jinlong

Change since V8: 1. Add label in all documentations of coresight components. 2. Add control of the visibility of the label sysfs attribute. V8 link: https://lkml.org/lkml/2025/7/3/985 Change since V7: 1. Update the conflict when apply to coresight next. 2. Update the Date and version in ABI file. V7 link: https://patchwork.kernel.org/project/linux-arm-kernel/patch/20250226121926.… Change since V6: 1. Update the date and verison in ABI file. Change since V5: 1. Update the kernel version of ABI files. 2. Add link of different patch versions. V5 link: https://patchwork.kernel.org/project/linux-arm-msm/cover/20241210122253.319… Change since V4: 1. Add label in DT and add label sysfs node for each coresight device. V4 link: https://patchwork.kernel.org/project/linux-arm-msm/cover/20240703122340.268… Change since V3: 1. Change device-name to arm,cs-dev-name. 2. Add arm,cs-dev-name to only CTI and sources' dt-binding. V3 link: https://patchwork.kernel.org/project/linux-arm-msm/cover/20240131082628.628… Change since V2: 1. Fix the error in coresight core. drivers/hwtracing/coresight/coresight-core.c:1775:7: error: assigning to 'char *' from 'const char *' discards qualifiers 2. Fix the warning when run dtbinding check. Documentation/devicetree/bindings/arm/arm,coresight-cpu-debug.yaml: device-name: missing type definition V2 link: https://patchwork.kernel.org/project/linux-arm-msm/cover/20240115164252.265… Change since V1: 1. Change coresight-name to device name. 2. Add the device-name in coresight dt bindings. V1 link: https://patchwork.kernel.org/project/linux-arm-kernel/patch/20230208110716.… Mao Jinlong (2): dt-bindings: arm: Add label in the coresight components coresight: Add label sysfs node support .../testing/sysfs-bus-coresight-devices-cti | 6 ++ .../sysfs-bus-coresight-devices-dummy-source | 6 ++ .../testing/sysfs-bus-coresight-devices-etb10 | 6 ++ .../testing/sysfs-bus-coresight-devices-etm3x | 6 ++ .../testing/sysfs-bus-coresight-devices-etm4x | 6 ++ .../sysfs-bus-coresight-devices-funnel | 6 ++ .../testing/sysfs-bus-coresight-devices-stm | 6 ++ .../testing/sysfs-bus-coresight-devices-tmc | 6 ++ .../testing/sysfs-bus-coresight-devices-tpdm | 6 ++ .../testing/sysfs-bus-coresight-devices-trbe | 6 ++ .../bindings/arm/arm,coresight-cti.yaml | 4 ++ .../arm/arm,coresight-dummy-sink.yaml | 4 ++ .../arm/arm,coresight-dummy-source.yaml | 4 ++ .../arm/arm,coresight-dynamic-funnel.yaml | 4 ++ .../arm/arm,coresight-dynamic-replicator.yaml | 4 ++ .../bindings/arm/arm,coresight-etb10.yaml | 4 ++ .../bindings/arm/arm,coresight-etm.yaml | 4 ++ .../arm/arm,coresight-static-funnel.yaml | 4 ++ .../arm/arm,coresight-static-replicator.yaml | 4 ++ .../bindings/arm/arm,coresight-tmc.yaml | 4 ++ .../bindings/arm/arm,coresight-tpiu.yaml | 4 ++ .../bindings/arm/qcom,coresight-ctcu.yaml | 4 ++ .../arm/qcom,coresight-remote-etm.yaml | 4 ++ .../bindings/arm/qcom,coresight-tpda.yaml | 4 ++ .../bindings/arm/qcom,coresight-tpdm.yaml | 4 ++ drivers/hwtracing/coresight/coresight-sysfs.c | 71 ++++++++++++++++++- 26 files changed, 189 insertions(+), 2 deletions(-) -- 2.25.1

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CoreSight July 2025