CoreSight February 2025

coresight@lists.linaro.org

8 participants
45 discussions

Re: [PATCH v12 0/7] Coresight: Add Coresight TMC Control Unit driver

by James Clark

On 17/02/2025 9:30 am, Jie Gan wrote: > From: Jie Gan <jie.gan(a)oss.qualcomm.com> > > The Coresight TMC Control Unit(CTCU) device hosts miscellaneous configuration > registers to control various features related to TMC ETR device. > > The CTCU device works as a helper device physically connected to the TMC ETR device. > --------------------------------------------------------- > |ETR0| |ETR1| > . \ / . > . \ / . > . \ / . > . \ / . > --------------------------------------------------- > ETR0ATID0-ETR0ATID3 CTCU ETR1ATID0-ETR1ATID3 > --------------------------------------------------- > Each ETR has four ATID registers with 128 bits long in total. > e.g. ETR0ATID0-ETR0ATID3 registers are used by ETR0 device. > > Based on the trace id which is programed in CTCU ATID register of > specific ETR, trace data with that trace id can get into ETR's buffer > while other trace data gets ignored. The number of CTCU ATID registers > depends on the number of defined TMC ETR devices. For example, two TMC > ETR devices need eight ATID registers. ETR0 with ETR0ATID0-ETR0ATID3 > and ETR1 with ETR1ATID0-ETRATID3. > > The significant challenge in enabling the data filter function is how > to collect the trace ID of the source device. The introduction of > trace_id callback function addresses this challenge. The callback function > collects trace ID of the device and return it back. The trace ID will be > stored in the structure called coresight_path and transmitted to helper > and sink devices. > > The coresight_path structure is created to address how to transmit > parameters needs by coresight_enable_path/coresight_disbale_path > functions. > > Here is the definition of the struct coresight_path: > /** > * struct coresight_path - data needed by enable/disable path > * @path: path from source to sink. > * @trace_id: trace_id of the whole path. > */ > struct coresight_path { > struct list_head *path; > u8 trace_id; > }; > > The atid_offset mentioned before is the offset to ATID register in CTCU > device. > > Enabling the source device will configure one bit in the ATID register based > on its trace ID. > Disabling the source devices will reset the bit in the AITD register > based on its trace ID. > > Useage: > Enable: > STM device with trace ID 5 and ETR0 is activated. > Bitmap before the enablement: > ETR0ATID0: > 31..................543210 > ========================== > 0000000000000000000000...0 > ========================== > > Bitmap after the enablement: > 31..................543210 > ========================== > 0000000000000...0000100000 > ========================== > > The bit 5 of the ETR0ATID0 register is configured to 1 when enabling the > STM device. > > Disable: > STM device with trace ID 5 and ETR0 is activated. > Bitmap before the disablement: > ETR0ATID0: > 31................6543210 > ========================= > 000000000010111...0100000 > ========================= > > Bitmap after the disablement > ETR0ATID0: > 31................6543210 > ========================= > 000000000010111...0000000 > ========================= > > The bit 5 of the ETR0ATID0 register is reset to 0 when disabling the STM > device. > > Sincere thanks to James Clark for providing an excellent idea to handle > the trace_id of the path. > > Changes in V12: > 1. Update the method for allocating trace_id for perf mode. > Link to V11 - https://lore.kernel.org/linux-arm-msm/20250214024021.249655-1-quic_jiegan@q… > I tested the latest change, looks good to me.

2 weeks, 5 days

Re: [PATCH v12 3/7] Coresight: Use coresight_etm_get_trace_id() in traceid_show()

by James Clark

On 17/02/2025 9:30 am, Jie Gan wrote: > From: James Clark <james.clark(a)linaro.org> > > Use the new API, coresight_etm_get_trace_id, to read the traceid of the ETM > device when call traceid_show via sysfs node. > > Signed-off-by: James Clark <james.clark(a)linaro.org> > Signed-off-by: Jie Gan <quic_jiegan(a)quicinc.com> > --- > drivers/hwtracing/coresight/coresight-etm3x-sysfs.c | 3 +-- > drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 4 ++-- > 2 files changed, 3 insertions(+), 4 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > index 68c644be9813..b9006451f515 100644 > --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c > @@ -1190,10 +1190,9 @@ static DEVICE_ATTR_RO(cpu); > static ssize_t traceid_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > - int trace_id; > struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent); > + int trace_id = coresight_etm_get_trace_id(drvdata->csdev, CS_MODE_SYSFS, NULL); > > - trace_id = etm_read_alloc_trace_id(drvdata); > if (trace_id < 0) > return trace_id; > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > index c767f8ae4cf1..e5216c0f60da 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c > @@ -4,6 +4,7 @@ > * Author: Mathieu Poirier <mathieu.poirier(a)linaro.org> > */ > > +#include <linux/coresight.h> > #include <linux/pid_namespace.h> > #include <linux/pm_runtime.h> > #include <linux/sysfs.h> > @@ -2402,10 +2403,9 @@ static ssize_t trctraceid_show(struct device *dev, > struct device_attribute *attr, > char *buf) > { > - int trace_id; > struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); > + int trace_id = coresight_etm_get_trace_id(drvdata->csdev, CS_MODE_SYSFS, NULL); > > - trace_id = etm4_read_alloc_trace_id(drvdata); > if (trace_id < 0) > return trace_id; > Reviewed-by: James Clark <james.clark(a)linaro.org>

2 weeks, 5 days

Re: [PATCH v10 4/7] Coresight: Introduce a new struct coresight_path

by James Clark

On 17/02/2025 1:14 am, Jie Gan wrote: > > > On 2/14/2025 7:09 PM, James Clark wrote: >> >> >> On 14/02/2025 1:34 am, Jie Gan wrote: >>> >>> >>> On 2/14/2025 12:00 AM, James Clark wrote: >>>> >>>> >>>> On 07/02/2025 6:42 am, Jie Gan wrote: >>>>> Add 'struct coresight_path' to store the data that is needed by >>>>> coresight_enable_path/coresight_disable_path. The structure will be >>>>> transmitted to any required devices to enable related >>>>> funcationalities. >>>>> >>>>> The trace_id will be allocated after the path is built. Consequently, >>>>> The ETM3x and ETM4x devices will directly read the trace_id from path >>>>> which result in etm_read_alloc_trace_id and etm4_read_alloc_trace_id >>>>> being deleted. >>>>> >>>>> Co-developed-by: James Clark <james.clark(a)linaro.org> >>>>> Signed-off-by: James Clark <james.clark(a)linaro.org> >>>>> Signed-off-by: Jie Gan <quic_jiegan(a)quicinc.com> >>>>> --- >>>>> drivers/hwtracing/coresight/coresight-core.c | 106 ++++++++++++ >>>>> +----- >>>>> drivers/hwtracing/coresight/coresight-dummy.c | 5 +- >>>>> .../hwtracing/coresight/coresight-etm-perf.c | 30 +++-- >>>>> .../hwtracing/coresight/coresight-etm-perf.h | 2 +- >>>>> drivers/hwtracing/coresight/coresight-etm.h | 1 - >>>>> .../coresight/coresight-etm3x-core.c | 54 ++------- >>>>> .../coresight/coresight-etm4x-core.c | 54 ++------- >>>>> drivers/hwtracing/coresight/coresight-etm4x.h | 1 - >>>>> drivers/hwtracing/coresight/coresight-priv.h | 12 +- >>>>> drivers/hwtracing/coresight/coresight-stm.c | 3 +- >>>>> drivers/hwtracing/coresight/coresight-sysfs.c | 17 ++- >>>>> drivers/hwtracing/coresight/coresight-tpdm.c | 3 +- >>>>> include/linux/coresight.h | 12 +- >>>>> 13 files changed, 143 insertions(+), 157 deletions(-) >>>>> >>>> [...] >>>>> @@ -352,7 +352,7 @@ static void *etm_setup_aux(struct perf_event >>>>> *event, void **pages, >>>>> * CPUs, we can handle it and fail the session. >>>>> */ >>>>> for_each_cpu(cpu, mask) { >>>>> - struct list_head *path; >>>>> + struct coresight_path *path; >>>>> struct coresight_device *csdev; >>>>> csdev = per_cpu(csdev_src, cpu); >>>>> @@ -405,15 +405,15 @@ static void *etm_setup_aux(struct perf_event >>>>> *event, void **pages, >>>>> cpumask_clear_cpu(cpu, mask); >>>>> continue; >>>>> } >>>>> - >>>>> /* ensure we can allocate a trace ID for this CPU */ >>>>> - trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink- >>>>> >perf_sink_id_map); >>>>> - if (!IS_VALID_CS_TRACE_ID(trace_id)) { >>>>> + trace_id = coresight_path_assign_trace_id(path, >>>>> CS_MODE_PERF); >>>>> + >>>>> + /* Can be 0 and valid, ETE doesn't need an ID */ >>>>> + if (trace_id < 0) { >>>> >>>> Not sure why I wrote it like this, but I think we should leave it as >>>> it was with !IS_VALID_CS_TRACE_ID(). Even with ETE it calls the >>>> trace ID allocator, so nothing has changed here. >>>> >>> Sure, Will restore. For ETE or ETM, we dont need traverse the path, >>> just directly allocate the trace id based on cpu id. >>> >>> Jie >>> >>> >> >> Sorry I meant to only keep the !IS_VALID_CS_TRACE_ID() bit. We still >> need to call the new coresight_path_assign_trace_id() otherwise it >> doesn't get assigned to the path. I saw that got removed in v11. >> >> > Sorry for the misunderstanding, I was focused on "nothing has changed > here", lol. > > I got your point here. > So the updated codes should be: > ... > /* ensure we can allocate a trace ID for this CPU */ > trace_id = coresight_path_assign_trace_id(path, > CS_MODE_PERF); > if (!IS_VALID_CS_TRACE_ID(trace_id)) { > cpumask_clear_cpu(cpu, mask); > coresight_release_path(path); > continue; > } > ... > > > Thanks, > Jie Yes that looks good.

2 weeks, 6 days

Re: [PATCH v11 0/7] Coresight: Add Coresight TMC Control Unit driver

by James Clark

On 14/02/2025 2:40 am, Jie Gan wrote: > From: Jie Gan <jie.gan(a)oss.qualcomm.com> > > The Coresight TMC Control Unit(CTCU) device hosts miscellaneous configuration > registers to control various features related to TMC ETR device. > > The CTCU device works as a helper device physically connected to the TMC ETR device. > --------------------------------------------------------- > |ETR0| |ETR1| > . \ / . > . \ / . > . \ / . > . \ / . > --------------------------------------------------- > ETR0ATID0-ETR0ATID3 CTCU ETR1ATID0-ETR1ATID3 > --------------------------------------------------- > Each ETR has four ATID registers with 128 bits long in total. > e.g. ETR0ATID0-ETR0ATID3 registers are used by ETR0 device. > > Based on the trace id which is programed in CTCU ATID register of > specific ETR, trace data with that trace id can get into ETR's buffer > while other trace data gets ignored. The number of CTCU ATID registers > depends on the number of defined TMC ETR devices. For example, two TMC > ETR devices need eight ATID registers. ETR0 with ETR0ATID0-ETR0ATID3 > and ETR1 with ETR1ATID0-ETRATID3. > > The significant challenge in enabling the data filter function is how > to collect the trace ID of the source device. The introduction of > trace_id callback function addresses this challenge. The callback function > collects trace ID of the device and return it back. The trace ID will be > stored in the structure called coresight_path and transmitted to helper > and sink devices. > > The coresight_path structure is created to address how to transmit > parameters needs by coresight_enable_path/coresight_disbale_path > functions. > > Here is the definition of the struct coresight_path: > /** > * struct coresight_path - data needed by enable/disable path > * @path: path from source to sink. > * @trace_id: trace_id of the whole path. > */ > struct coresight_path { > struct list_head *path; > u8 trace_id; > }; > > The atid_offset mentioned before is the offset to ATID register in CTCU > device. > > Enabling the source device will configure one bit in the ATID register based > on its trace ID. > Disabling the source devices will reset the bit in the AITD register > based on its trace ID. > > Useage: > Enable: > STM device with trace ID 5 and ETR0 is activated. > Bitmap before the enablement: > ETR0ATID0: > 31..................543210 > ========================== > 0000000000000000000000...0 > ========================== > > Bitmap after the enablement: > 31..................543210 > ========================== > 0000000000000...0000100000 > ========================== > > The bit 5 of the ETR0ATID0 register is configured to 1 when enabling the > STM device. > > Disable: > STM device with trace ID 5 and ETR0 is activated. > Bitmap before the disablement: > ETR0ATID0: > 31................6543210 > ========================= > 000000000010111...0100000 > ========================= > > Bitmap after the disablement > ETR0ATID0: > 31................6543210 > ========================= > 000000000010111...0000000 > ========================= > > The bit 5 of the ETR0ATID0 register is reset to 0 when disabling the STM > device. > > Sincere thanks to James Clark for providing an excellent idea to handle > the trace_id of the path. > No worries! Thanks for working on Coresight too.

3 weeks, 2 days

Re: [PATCH v10 4/7] Coresight: Introduce a new struct coresight_path

by James Clark

On 14/02/2025 1:34 am, Jie Gan wrote: > > > On 2/14/2025 12:00 AM, James Clark wrote: >> >> >> On 07/02/2025 6:42 am, Jie Gan wrote: >>> Add 'struct coresight_path' to store the data that is needed by >>> coresight_enable_path/coresight_disable_path. The structure will be >>> transmitted to any required devices to enable related funcationalities. >>> >>> The trace_id will be allocated after the path is built. Consequently, >>> The ETM3x and ETM4x devices will directly read the trace_id from path >>> which result in etm_read_alloc_trace_id and etm4_read_alloc_trace_id >>> being deleted. >>> >>> Co-developed-by: James Clark <james.clark(a)linaro.org> >>> Signed-off-by: James Clark <james.clark(a)linaro.org> >>> Signed-off-by: Jie Gan <quic_jiegan(a)quicinc.com> >>> --- >>> drivers/hwtracing/coresight/coresight-core.c | 106 +++++++++++++----- >>> drivers/hwtracing/coresight/coresight-dummy.c | 5 +- >>> .../hwtracing/coresight/coresight-etm-perf.c | 30 +++-- >>> .../hwtracing/coresight/coresight-etm-perf.h | 2 +- >>> drivers/hwtracing/coresight/coresight-etm.h | 1 - >>> .../coresight/coresight-etm3x-core.c | 54 ++------- >>> .../coresight/coresight-etm4x-core.c | 54 ++------- >>> drivers/hwtracing/coresight/coresight-etm4x.h | 1 - >>> drivers/hwtracing/coresight/coresight-priv.h | 12 +- >>> drivers/hwtracing/coresight/coresight-stm.c | 3 +- >>> drivers/hwtracing/coresight/coresight-sysfs.c | 17 ++- >>> drivers/hwtracing/coresight/coresight-tpdm.c | 3 +- >>> include/linux/coresight.h | 12 +- >>> 13 files changed, 143 insertions(+), 157 deletions(-) >>> >> [...] >>> @@ -352,7 +352,7 @@ static void *etm_setup_aux(struct perf_event >>> *event, void **pages, >>> * CPUs, we can handle it and fail the session. >>> */ >>> for_each_cpu(cpu, mask) { >>> - struct list_head *path; >>> + struct coresight_path *path; >>> struct coresight_device *csdev; >>> csdev = per_cpu(csdev_src, cpu); >>> @@ -405,15 +405,15 @@ static void *etm_setup_aux(struct perf_event >>> *event, void **pages, >>> cpumask_clear_cpu(cpu, mask); >>> continue; >>> } >>> - >>> /* ensure we can allocate a trace ID for this CPU */ >>> - trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink- >>> >perf_sink_id_map); >>> - if (!IS_VALID_CS_TRACE_ID(trace_id)) { >>> + trace_id = coresight_path_assign_trace_id(path, CS_MODE_PERF); >>> + >>> + /* Can be 0 and valid, ETE doesn't need an ID */ >>> + if (trace_id < 0) { >> >> Not sure why I wrote it like this, but I think we should leave it as >> it was with !IS_VALID_CS_TRACE_ID(). Even with ETE it calls the trace >> ID allocator, so nothing has changed here. >> > Sure, Will restore. For ETE or ETM, we dont need traverse the path, just > directly allocate the trace id based on cpu id. > > Jie > > Sorry I meant to only keep the !IS_VALID_CS_TRACE_ID() bit. We still need to call the new coresight_path_assign_trace_id() otherwise it doesn't get assigned to the path. I saw that got removed in v11.

3 weeks, 2 days

Re: [PATCH v10 0/7] Coresight: Add Coresight TMC Control Unit driver

by James Clark

On 07/02/2025 6:42 am, Jie Gan wrote: > The Coresight TMC Control Unit(CTCU) device hosts miscellaneous configuration > registers to control various features related to TMC ETR device. > > The CTCU device works as a helper device physically connected to the TMC ETR device. > --------------------------------------------------------- > |ETR0| |ETR1| > . \ / . > . \ / . > . \ / . > . \ / . > --------------------------------------------------- > ETR0ATID0-ETR0ATID3 CTCU ETR1ATID0-ETR1ATID3 > --------------------------------------------------- > Each ETR has four ATID registers with 128 bits long in total. > e.g. ETR0ATID0-ETR0ATID3 registers are used by ETR0 device. > > Based on the trace id which is programed in CTCU ATID register of > specific ETR, trace data with that trace id can get into ETR's buffer > while other trace data gets ignored. The number of CTCU ATID registers > depends on the number of defined TMC ETR devices. For example, two TMC > ETR devices need eight ATID registers. ETR0 with ETR0ATID0-ETR0ATID3 > and ETR1 with ETR1ATID0-ETRATID3. > > The significant challenge in enabling the data filter function is how > to collect the trace ID of the source device. The introduction of > trace_id callback function addresses this challenge. The callback function > collects trace ID of the device and return it back. The trace ID will be > stored in the structure called coresight_path and transmitted to helper > and sink devices. > > The coresight_path structure is created to address how to transmit > parameters needs by coresight_enable_path/coresight_disbale_path > functions. > > Here is the definition of the struct coresight_path: > /** > * struct coresight_path - data needed by enable/disable path > * @path: path from source to sink. > * @trace_id: trace_id of the whole path. > */ > struct coresight_path { > struct list_head *path; > u8 trace_id; > }; > > The atid_offset mentioned before is the offset to ATID register in CTCU > device. > > Enabling the source device will configure one bit in the ATID register based > on its trace ID. > Disabling the source devices will reset the bit in the AITD register > based on its trace ID. > > Useage: > Enable: > STM device with trace ID 5 and ETR0 is activated. > Bitmap before the enablement: > ETR0ATID0: > 31..................543210 > ========================== > 0000000000000000000000...0 > ========================== > > Bitmap after the enablement: > 31..................543210 > ========================== > 0000000000000...0000100000 > ========================== > > The bit 5 of the ETR0ATID0 register is configured to 1 when enabling the > STM device. > > Disable: > STM device with trace ID 5 and ETR0 is activated. > Bitmap before the disablement: > ETR0ATID0: > 31................6543210 > ========================= > 000000000010111...0100000 > ========================= > > Bitmap after the disablement > ETR0ATID0: > 31................6543210 > ========================= > 000000000010111...0000000 > ========================= > > The bit 5 of the ETR0ATID0 register is reset to 0 when disabling the STM > device. > > Sincere thanks to James Clark for providing an excellent idea to handle > the trace_id of the path. > > Changes in V2: > 1. Rename the device to Coresight Control Unit. > 2. Introduce the trace_id function pointer to address the challeng how to > properly collect the trace ID of the device. > 3. Introduce a new way to define the qcom,ccu-atid-offset property in > device tree. > 4. Disabling the filter function blocked on acquiring the ATID-offset, > which will be addressed in a separate patch once it’s ready. > Link to V1 - https://lore.kernel.org/lkml/20240618072726.3767974-1-quic_jiegan@quicinc.c… > > Changes in V3: > 1. Rename the device to Coresight TMC Control Unit(CTCU). > 2. Introduce a new way to define the platform related configs. The new > structure, qcom_ctcu_config, is used to store configurations specific > to a platform. Each platform should have its own qcom_ctcu_config structure. > 3. In perf mode, the ETM devices allocate their trace IDs using the > perf_sink_id_map. In sysfs mode, the ETM devices allocate their trace > IDs using the id_map_default. > 4. Considering the scenario where both ETR devices might be enabled simultaneously > with multiple sources, retrieving and using trace IDs instead of id_map is more effective > for the CTCU device in sysfs mode. For example, We can configure one ETR as sink for high > throughput trace data like ETM and another ETR for low throughput trace data like STM. > In this case, STM data won’t be flushed out by ETM data quickly. However, if we use id_map to > manage the trace IDs, we need to create a separate id_map for each ETR device. Addtionally, We > would need to iterate through the entire id_map for each configuration. > 5. Add support for apb's clock name "apb". If the function fails to obtain the clock with > the name "apb_pclk", it will attempt to acquire the clock with the name "apb". > Link to V2 - https://lore.kernel.org/linux-arm-msm/20240705090049.1656986-1-quic_jiegan@… > > Changes in V4: > 1. Add TMC description in binding file. > 2. Restrict the number of ports for the CTCU device to a range of 0 to 1 in the binding file, > because the maximum number of CTCU devices is 2 for existing projects. > Link to V3 - https://lore.kernel.org/linux-arm-kernel/20240812024141.2867655-1-quic_jieg… > > Changes in V5: > 1. Fix the format issue for description paragrah in dt binding file. > 2. Previous discussion for why use "in-ports" property instead of "ports". > Link to V4 - https://lore.kernel.org/linux-arm-msm/20240828012706.543605-1-quic_jiegan@q… > > Changes in V6: > 1. Collected reviewed-by tag from Rob for dt-binding patch. > 2. Rebased on tag next-20241008. > 3. Dropped all depends-on tags. > Link to V5 - https://lore.kernel.org/linux-arm-msm/20240909033458.3118238-1-quic_jiegan@… > > Changes in V7: > 1. Rebased on tag next-20241204. > 2. Fix format issue for dts patch. > - Padding the address part to 8 digits > Link to V6 - https://lore.kernel.org/linux-arm-msm/20241009112503.1851585-1-quic_jiegan@… > > Changes in V8: > 1. Rebased on tag next-20241220. > 2. Use raw_spinlock_t instead of spinlock_t. > 3. Remove redundant codes in CTCU driver: > - Eliminate unnecessary parameter validations. > - Correct log level when an error occurs. > - Optimize codes. > 4. Correct the subject prefix for DT patch. > 5. Collected reviewed-by tag from Konrad Dybcib for DT patch. > Link to V7 - https://lore.kernel.org/all/20241210031545.3468561-1-quic_jiegan@quicinc.co… > > Changes in V9: > 1. Rebased on tag next-20250113. > 2. Separate the previous trace_id patch (patch 2/5 Coresight: Add trace_id function to > retrieving the trace ID) into two patches. > 3. Introduce a new struct coresight_path instead of cs_sink_data which was > created in previous version. The coresight_path will be initialized > and constructed in coresight_build_path function and released by > coresight_release_path function. > Detail of the struct coresight_path is shown below: > /** > * struct coresight_path - data needed by enable/disable path > * @path: path from source to sink. > * @trace_id: trace_id of the whole path. > */ > struct coresight_path { > struct list_head *path; > u8 trace_id; > }; > > 4. Introduce an array of atomic in CTCU driver to represent the refcnt or each > enabled trace_id for each sink. The reason is there is a scenario that more > than one TPDM device physically connected to the same TPDA device has > been enabled. The CTCU driver must verify the refcnt before resetting the > bit of the atid register according to the trace_id of the TPDA device. > 5. Remove redundant codes in CTCU driver. > 6. Add reviewed-by tag to the commit message for APB clock path(patch > 1/5). > Link to V8 - https://lore.kernel.org/all/20241226011022.1477160-1-quic_jiegan@quicinc.co… > > Changes in V10: > 1. Introduce a new API to allocate and read trace_id after path is built. > 2. Introduce a new API to allocate and read trace_id of ETM device. > 3. Add a new patch: [PATCH v10 3/7] Coresight: Use coresight_etm_get_trace_id() in traceid_show() > 4. Remove perf handle from coresight_path. > 5. Use u8 instead of atomic_t for traceid_refcnt. > 6. Optimize the part of code in CTCU drvier that is responsible for program atid register. > Link to V9 - https://lore.kernel.org/all/20250124072537.1801030-1-quic_jiegan@quicinc.co… > > Jie Gan (7): > Coresight: Add support for new APB clock name > Coresight: Add trace_id function to retrieving the trace ID > Coresight: Use coresight_etm_get_trace_id() in traceid_show() > Coresight: Introduce a new struct coresight_path > dt-bindings: arm: Add Coresight TMC Control Unit hardware > Coresight: Add Coresight TMC Control Unit driver > arm64: dts: qcom: sa8775p: Add CTCU and ETR nodes > > .../bindings/arm/qcom,coresight-ctcu.yaml | 84 ++++++ > arch/arm64/boot/dts/qcom/sa8775p.dtsi | 153 ++++++++++ > drivers/hwtracing/coresight/Kconfig | 12 + > drivers/hwtracing/coresight/Makefile | 1 + > drivers/hwtracing/coresight/coresight-core.c | 133 +++++++-- > drivers/hwtracing/coresight/coresight-ctcu.c | 268 ++++++++++++++++++ > drivers/hwtracing/coresight/coresight-ctcu.h | 24 ++ > drivers/hwtracing/coresight/coresight-dummy.c | 16 +- > .../hwtracing/coresight/coresight-etm-perf.c | 30 +- > .../hwtracing/coresight/coresight-etm-perf.h | 2 +- > drivers/hwtracing/coresight/coresight-etm.h | 1 - > .../coresight/coresight-etm3x-core.c | 55 +--- > .../coresight/coresight-etm3x-sysfs.c | 3 +- > .../coresight/coresight-etm4x-core.c | 55 +--- > .../coresight/coresight-etm4x-sysfs.c | 4 +- > drivers/hwtracing/coresight/coresight-etm4x.h | 1 - > drivers/hwtracing/coresight/coresight-priv.h | 12 +- > drivers/hwtracing/coresight/coresight-stm.c | 14 +- > drivers/hwtracing/coresight/coresight-sysfs.c | 17 +- > drivers/hwtracing/coresight/coresight-tpda.c | 11 + > drivers/hwtracing/coresight/coresight-tpdm.c | 3 +- > include/linux/coresight.h | 30 +- > 22 files changed, 765 insertions(+), 164 deletions(-) > create mode 100644 Documentation/devicetree/bindings/arm/qcom,coresight-ctcu.yaml > create mode 100644 drivers/hwtracing/coresight/coresight-ctcu.c > create mode 100644 drivers/hwtracing/coresight/coresight-ctcu.h > Just one small comment, and the kernel test bot report to fix. Otherwise looks good to me. Reviewed-by: James Clark <james.clark(a)linaro.org>

3 weeks, 2 days

Re: [PATCH v10 4/7] Coresight: Introduce a new struct coresight_path

by James Clark

On 07/02/2025 6:42 am, Jie Gan wrote: > Add 'struct coresight_path' to store the data that is needed by > coresight_enable_path/coresight_disable_path. The structure will be > transmitted to any required devices to enable related funcationalities. > > The trace_id will be allocated after the path is built. Consequently, > The ETM3x and ETM4x devices will directly read the trace_id from path > which result in etm_read_alloc_trace_id and etm4_read_alloc_trace_id > being deleted. > > Co-developed-by: James Clark <james.clark(a)linaro.org> > Signed-off-by: James Clark <james.clark(a)linaro.org> > Signed-off-by: Jie Gan <quic_jiegan(a)quicinc.com> > --- > drivers/hwtracing/coresight/coresight-core.c | 106 +++++++++++++----- > drivers/hwtracing/coresight/coresight-dummy.c | 5 +- > .../hwtracing/coresight/coresight-etm-perf.c | 30 +++-- > .../hwtracing/coresight/coresight-etm-perf.h | 2 +- > drivers/hwtracing/coresight/coresight-etm.h | 1 - > .../coresight/coresight-etm3x-core.c | 54 ++------- > .../coresight/coresight-etm4x-core.c | 54 ++------- > drivers/hwtracing/coresight/coresight-etm4x.h | 1 - > drivers/hwtracing/coresight/coresight-priv.h | 12 +- > drivers/hwtracing/coresight/coresight-stm.c | 3 +- > drivers/hwtracing/coresight/coresight-sysfs.c | 17 ++- > drivers/hwtracing/coresight/coresight-tpdm.c | 3 +- > include/linux/coresight.h | 12 +- > 13 files changed, 143 insertions(+), 157 deletions(-) > [...] > @@ -352,7 +352,7 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, > * CPUs, we can handle it and fail the session. > */ > for_each_cpu(cpu, mask) { > - struct list_head *path; > + struct coresight_path *path; > struct coresight_device *csdev; > > csdev = per_cpu(csdev_src, cpu); > @@ -405,15 +405,15 @@ static void *etm_setup_aux(struct perf_event *event, void **pages, > cpumask_clear_cpu(cpu, mask); > continue; > } > - > /* ensure we can allocate a trace ID for this CPU */ > - trace_id = coresight_trace_id_get_cpu_id_map(cpu, &sink->perf_sink_id_map); > - if (!IS_VALID_CS_TRACE_ID(trace_id)) { > + trace_id = coresight_path_assign_trace_id(path, CS_MODE_PERF); > + > + /* Can be 0 and valid, ETE doesn't need an ID */ > + if (trace_id < 0) { Not sure why I wrote it like this, but I think we should leave it as it was with !IS_VALID_CS_TRACE_ID(). Even with ETE it calls the trace ID allocator, so nothing has changed here.

3 weeks, 2 days

[PATCH 0/7] coresight: Clear self hosted claim tag on probe

by James Clark

I've gotten stuck a few times with unusable Coresight after a warm boot due to lingering claim tags, especially when testing the Coresight panic patchsets. This change does some tidy ups, adds some debug messages and clears the self hosted claim tag on probe. The last two commits are unrelated tidyups but they touch some of the same functions so to avoid extra conflicts I'm including them here. This gets as far as fixing the claim tag issue, but there is some other state not being cleared on probe that results in the following error. This can be fixed up as a later change: coresight tmc_etf0: timeout while waiting for TMC to be Ready coresight tmc_etf0: Failed to enable : TMC is not ready James Clark (7): coresight: Rename coresight_{set,clear}_claim_tags() coresight: Convert disclaim functions to take a struct cs_access coresight: Only check bottom two claim bits coresight: Add claim tag warnings and debug messages coresight: Clear self hosted claim tag on probe coresight: Remove inlines from static function definitions coresight: Remove extern from function declarations drivers/hwtracing/coresight/coresight-catu.c | 14 +- drivers/hwtracing/coresight/coresight-core.c | 132 +++++++++++------- .../hwtracing/coresight/coresight-cti-core.c | 8 +- drivers/hwtracing/coresight/coresight-etb10.c | 6 +- drivers/hwtracing/coresight/coresight-etm.h | 6 +- .../coresight/coresight-etm3x-core.c | 32 ++--- .../coresight/coresight-etm3x-sysfs.c | 8 +- .../coresight/coresight-etm4x-core.c | 12 +- .../coresight/coresight-etm4x-sysfs.c | 4 +- .../hwtracing/coresight/coresight-funnel.c | 4 +- .../hwtracing/coresight/coresight-platform.c | 26 ++-- drivers/hwtracing/coresight/coresight-priv.h | 20 +-- .../coresight/coresight-replicator.c | 7 +- drivers/hwtracing/coresight/coresight-stm.c | 6 +- .../coresight/coresight-syscfg-configfs.c | 2 +- .../hwtracing/coresight/coresight-tmc-core.c | 9 +- .../hwtracing/coresight/coresight-tmc-etf.c | 8 +- .../hwtracing/coresight/coresight-tmc-etr.c | 20 ++- drivers/hwtracing/coresight/coresight-trbe.c | 18 +-- include/linux/coresight.h | 32 ++--- 20 files changed, 209 insertions(+), 165 deletions(-) -- 2.34.1

3 weeks, 3 days

Re: [PATCH] coresight-tmc: stop disabling tmc when flush timeout

by Mike Leach

Hi, We are not seeing these problems on other systems with multiple ETMs. How are you using the system? Perf will strictly disable sources before sinks - which would mean that the ETMs will flush before the TMC requests a manual flush on stop. For sysfs use, we recommend the same, but even halting the TMC first should result in all sources being requested to flush at the same time (subject to propagation through connected trace funnels). On Fri, 7 Feb 2025 at 07:25, Yuanfang Zhang <quic_yuanfang(a)quicinc.com> wrote: > > > > On 2/6/2025 6:32 PM, Leo Yan wrote: > > Hi Yuanfang, > > > > On Fri, Jan 03, 2025 at 04:01:54PM +0800, Yuanfang Zhang wrote: > >> > >> When multiple ETMs are enabled simultaneously, the time required > >> to complete a flush in the process of reading the TMC device node > >> may exceed the default wait time of 100us. > > How do you know that it is the ETM flush process that is the issue? TMC ready can be delayed by issues in the memory system that prevent write to the memory buffer. The TMC flush complete will indicate completion of flush for all connected devices - so if flush complete is indicated by the TMC then a flush request cannot be the issue. With multiple ETMs, then the connected trace funnels arbitration will ensure flush is indicated complete on all connected inputs before transmitting to the output. The driver code to stop the TMC will first wait on flush complete before waiting on TMC ready. > > Have you tried how long time would be safe to wait for the > > TMCREADY_BIT bit to be set on your platform? > yes, 400000us. This is a huge amount of latency for a coresight system. This suggests some sort of contention issue. > > > >> If the TMC capture is stopped while any ETM has not completed its > >> flush, it can cause the corresponding CPU to hang. > >> There is nothing in the ETMv4 hardware specification /design that should cause an CPU to hang. There is an implementation dependent stall mechanism that if implemented can stall a PE when the ETM fifo approaches overflow, but this is switch off on the drivers, if implemented on the hardware. The flush process for the ETM is a purely internal process of clearing out all trace currently in the ETM, and is not dependent on the PE. > >> Fix the by checking the TMCReady bit after the flush. If TMCReady > >> bit is set, TraceCaptEn bit can be clear; otherwise, return directly > >> and stop the TMC read. > > > > When a timeout for TMC flush and stop is detected, if the driver > > arbitrarily bails out without disabling TMC, this would leave the > > hardware always on. > > I agree that this is not an acceptable solution - we cannot leave the TMC in an indeterminate state. Where clients such as perf are using the hardware there is no mechanism for re-trying if halt fails. The functions you have changed seem to relate to reading the buffer via sysfs. Do you see similar problems using perf to collect trace data? > > I would like first know if a longer timeout can fix the issue. > > > > Thanks, > > Leo > > > yes, longer timeout can fix this issue. > I think that a longer timeout will mask some underlying contention issue, but it should be possible to make the coresight driver timeout configurable, and set the value appropriately for your system. There is a new TMC logging patchset here: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/7Y… which improves the error reporting around timeouts. This might help establish if the error is in waiting for flush complete, or TMC ready. This API could be extended to add a timeout value parameter, that can be configured from the TMC driver, set via sysfs for the TMC in the initial case to further debugging of this issue on your system Regards Mike > >> Signed-off-by: Yuanfang Zhang <quic_yuanfang(a)quicinc.com> > >> --- > >> drivers/hwtracing/coresight/coresight-tmc-etf.c | 17 +++++++++++++++-- > >> drivers/hwtracing/coresight/coresight-tmc-etr.c | 22 +++++++++++++++++----- > >> 2 files changed, 32 insertions(+), 7 deletions(-) > >> > >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c > >> index d4f641cd9de69488fe3d1c1dc9b5a9eafb55ed59..bded290c42891d782344d9a6e63ebdbed6719133 100644 > >> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c > >> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c > >> @@ -80,11 +80,21 @@ static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata) > >> return; > >> } > >> > >> -static void __tmc_etb_disable_hw(struct tmc_drvdata *drvdata) > >> +static int __tmc_etb_disable_hw(struct tmc_drvdata *drvdata) > >> { > >> + int rc; > >> + > >> CS_UNLOCK(drvdata->base); > >> > >> tmc_flush_and_stop(drvdata); > >> + > >> + rc = tmc_wait_for_tmcready(drvdata); > >> + if (rc) { > >> + dev_err(&drvdata->csdev->dev, > >> + "Failed to disable : TMC is not ready\n"); > >> + CS_LOCK(drvdata->base); > >> + return rc; > >> + } > >> /* > >> * When operating in sysFS mode the content of the buffer needs to be > >> * read before the TMC is disabled. > >> @@ -94,6 +104,7 @@ static void __tmc_etb_disable_hw(struct tmc_drvdata *drvdata) > >> tmc_disable_hw(drvdata); > >> > >> CS_LOCK(drvdata->base); > >> + return 0; > >> } > >> > >> static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata) > >> @@ -650,7 +661,9 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata) > >> ret = -EINVAL; > >> goto out; > >> } > >> - __tmc_etb_disable_hw(drvdata); > >> + ret = __tmc_etb_disable_hw(drvdata); > >> + if (ret) > >> + goto out; > >> } > >> > >> drvdata->reading = true; > >> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > >> index a48bb85d0e7f44a25b813f3c828cc3d705d16012..63a1f7501562fa0b5c2fe6ea53dce4d82842bec3 100644 > >> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > >> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > >> @@ -1135,11 +1135,21 @@ static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata) > >> } > >> } > >> > >> -static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > >> +static int __tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > >> { > >> + int rc; > >> + > >> CS_UNLOCK(drvdata->base); > >> > >> tmc_flush_and_stop(drvdata); > >> + > >> + rc = tmc_wait_for_tmcready(drvdata); > >> + if (rc) { > >> + dev_err(&drvdata->csdev->dev, > >> + "Failed to disable : TMC is not ready\n"); > >> + CS_LOCK(drvdata->base); > >> + return rc; > >> + } > >> /* > >> * When operating in sysFS mode the content of the buffer needs to be > >> * read before the TMC is disabled. > >> @@ -1150,7 +1160,7 @@ static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > >> tmc_disable_hw(drvdata); > >> > >> CS_LOCK(drvdata->base); > >> - > >> + return 0; > >> } > >> > >> void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) > >> @@ -1779,9 +1789,11 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) > >> } > >> > >> /* Disable the TMC if we are trying to read from a running session. */ > >> - if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) > >> - __tmc_etr_disable_hw(drvdata); > >> - > >> + if (coresight_get_mode(drvdata->csdev) == CS_MODE_SYSFS) { > >> + ret = __tmc_etr_disable_hw(drvdata); > >> + if (ret) > >> + goto out; > >> + } > >> drvdata->reading = true; > >> out: > >> spin_unlock_irqrestore(&drvdata->spinlock, flags); > >> > >> --- > >> base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4 > >> change-id: 20250103-fix_cpu_hung-b5a95179ada4 > >> > >> Best regards, > >> -- > >> Yuanfang Zhang <quic_yuanfang(a)quicinc.com> > >> > >> > -- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK

3 weeks, 4 days

[PATCH v13 0/8] Coresight for Kernel panic and watchdog reset

by Linu Cherian

This patch series is rebased on coresight-next-v6.12.rc4 * Patches 1 & 2 adds support for allocation of trace buffer pages from reserved RAM * Patches 3 & 4 adds support for saving metadata at the time of kernel panic * Patch 5 adds support for reading trace data captured at the time of panic * Patches 6 & 7 adds support for disabling coresight blocks at the time of panic * Patch 8: Gives the full description about this feature as part of documentation v12 is posted here, https://lore.kernel.org/linux-arm-kernel/20241129084714.3057080-1-lcherian@… Changelog from v12: * Fixed wrong buffer pointer passed to coresigh_insert_barrier_packet * tmc_read_prepare/unprepare_crashdata need to be called only once and hence removed from read path and added to tmc_probe * tmc_read_prepare_crashdata renamed to tmc_prepare_crashdata and avoid taking locks as its moved to probe function. * Introduced read status flag, "reading" specific to reserved buffer to keep the reserved buffer reading independent of the regular buffer. * open/release ops for reserved buffer has to take care only about the set/unset the "reading" status flag as the reserved buffer is prepared during the probe time itself. * Few other trivial changes Changelog from v11: Convert all commands to literal code blocks, that was missed out in v11. No other code changes. Changelog from v10: * Converted all csdev_access_* to readl functions in tmc_panic_sync_* * Added "tmc" prefix for register snapshots in struct tmc_crash_metadata * Converted dev_info to dev_dbg in panic handlers * Converted dsb to dmb in panic handlers * Fixed marking metadata as invalid when a user is trying to use the reserved buffer. Earlier this was wrongly set at the time of reading reserved trace buffer. * Moved common validation checks to is_tmc_crashdata_valid and minor code rearrangements for efficiency * Got rid of sink specific prepare/unprepare invocations * Got rid of full from struct tmc_resrv_buf * While reading crashdata, size is now calculated from metadata instead of relying on reserved buffer size populated by dtb * Minor documenation fixes Changelog from v9: * Add common helper function of_tmc_get_reserved_resource_by_name for better code reuse * Reserved buffer validity and crashdata validity has been separated to avoid interdependence * New fields added to crash metadata: version, ffcr, ffsr, mode * Version checks added for metadata validation * Special file /dev/crash_tmc_xxx would be available only when crash metadata is valid * Removed READ_CRASHDATA mode meant for special casing crashdata reads. Instead, dedicated read function added for crashdata reads from reserved buffer which is common for both ETR and ETF sinks as well. * Documentation added to Documentation/tracing/coresight/panic.rst Changelog from v8: * Added missing exit path on error in __tmc_probe. * Few whitespace fixes, checkpatch fixes. * With perf sessions honouring stop_on_flush sysfs attribute, removed redundant variable stop_on_flush_en. Changelog from v7: * Fixed breakage on perf test -vvvv "arm coresight". No issues seen with and without "resrv" buffer mode * Moved the crashdev registration into a separate function. * Removed redundant variable in tmc_etr_setup_crashdata_buf * Avoided a redundant memcpy in tmc_panic_sync_etf. * Tested kernel panic with trace session started uisng perf. Please see the title "Perf based testing" below for details. For this, stop_on_flush sysfs attribute is taken into consideration while starting perf sessions as well. Changelog from v6: * Added special device files for reading crashdata, so that read_prevboot mode flag is removed. * Added new sysfs TMC device attribute, stop_on_flush. Stop on flush trigger event is disabled by default. User need to explicitly enable this from sysfs for panic stop to work. * Address parameter for panicstop ETM configuration is chosen as kernel "panic" address by default. * Added missing tmc_wait_for_tmcready during panic handling * Few other misc code rearrangements. Changelog from v5: * Fixed issues reported by CONFIG_DEBUG_ATOMIC_SLEEP * Fixed a memory leak while reading data from /dev/tmc_etrx in READ_PREVBOOT mode * Tested reading trace data from crashdump kernel Changelog from v4: * Device tree binding - Description is made more explicit on the usage of reserved memory region - Mismatch in memory region names in dts binding and driver fixed - Removed "mem" suffix from the memory region names * Rename "struct tmc_register_snapshot" -> "struct tmc_crash_metadata", since it contains more than register snapshot. Related variables are named accordingly. * Rename struct tmc_drvdata members resrv_buf -> crash_tbuf metadata -> crash_mdata * Size field in metadata refers to RSZ register and hence indicates the size in 32 bit words. ETR metadata follows this convention, the same has been extended to ETF metadata as well. * Added crc32 for more robust metadata and tracedata validation. * Added/modified dev_dbg messages during metadata validation * Fixed a typo in patch 5 commit description Changelog from v3: * Converted the Coresight ETM driver change to a named configuration. RFC tag has been removed with this change. * Fixed yaml issues reported by "make dt_binding_check" * Added names for reserved memory regions 0 and 1 * Added prevalidation checks for metadata processing * Fixed a regression introduced in RFC v3 - TMC Status register was getting saved wrongly * Reverted memremap attribute changes from _WB to _WC to match with the dma map attributes * Introduced reserved buffer mode specific .sync op. This fixes a possible crash when reserved buffer mode was used in normal trace capture, due to unwanted dma maintenance operations. Linu Cherian (8): dt-bindings: arm: coresight-tmc: Add "memory-region" property coresight: tmc-etr: Add support to use reserved trace memory coresight: core: Add provision for panic callbacks coresight: tmc: Enable panic sync handling coresight: tmc: Add support for reading crash data coresight: tmc: Stop trace capture on FlIn coresight: config: Add preloaded configuration Documentation: coresight: Panic support .../bindings/arm/arm,coresight-tmc.yaml | 26 ++ Documentation/trace/coresight/panic.rst | 362 ++++++++++++++++++ drivers/hwtracing/coresight/Makefile | 2 +- .../coresight/coresight-cfg-preload.c | 2 + .../coresight/coresight-cfg-preload.h | 2 + .../hwtracing/coresight/coresight-cfg-pstop.c | 83 ++++ drivers/hwtracing/coresight/coresight-core.c | 42 ++ .../hwtracing/coresight/coresight-tmc-core.c | 308 ++++++++++++++- .../hwtracing/coresight/coresight-tmc-etf.c | 92 ++++- .../hwtracing/coresight/coresight-tmc-etr.c | 184 ++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 105 +++++ include/linux/coresight.h | 12 + 12 files changed, 1208 insertions(+), 12 deletions(-) create mode 100644 Documentation/trace/coresight/panic.rst create mode 100644 drivers/hwtracing/coresight/coresight-cfg-pstop.c -- 2.34.1

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