CoreSight September 2020

coresight@lists.linaro.org

21 participants
34 discussions

Re: [RFC PATCH v2] coresight: etm4x: Modify core-commit of cpu to avoid the overflow of HiSilicon ETM

by Mathieu Poirier

Hi Liu, On Wed, Aug 19, 2020 at 04:06:37PM +0800, Qi Liu wrote: > When too much trace information is generated on-chip, the ETM will > overflow, and cause data loss. This is a common phenomenon on ETM > devices. > > But sometimes we do not want to lose performance trace data, so we > suppress the speed of instructions sent from CPU core to ETM to > avoid the overflow of ETM. > > Signed-off-by: Qi Liu <liuqi115(a)huawei.com> > --- > > Changes since v1: > - ETM on HiSilicon Hip09 platform supports backpressure, so does > not need to modify core commit. > > drivers/hwtracing/coresight/coresight-etm4x.c | 43 +++++++++++++++++++++++++++ > 1 file changed, 43 insertions(+) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c > index 7797a57..7641f89 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x.c > @@ -43,6 +43,10 @@ MODULE_PARM_DESC(boot_enable, "Enable tracing on boot"); > #define PARAM_PM_SAVE_NEVER 1 /* never save any state */ > #define PARAM_PM_SAVE_SELF_HOSTED 2 /* save self-hosted state only */ > > +#define CORE_COMMIT_CLEAR 0x3000 > +#define CORE_COMMIT_SHIFT 12 > +#define HISI_ETM_AMBA_ID_V1 0x000b6d01 > + > static int pm_save_enable = PARAM_PM_SAVE_FIRMWARE; > module_param(pm_save_enable, int, 0444); > MODULE_PARM_DESC(pm_save_enable, > @@ -104,11 +108,40 @@ struct etm4_enable_arg { > int rc; > }; > > +static void etm4_cpu_actlr1_cfg(void *info) > +{ > + struct etm4_enable_arg *arg = (struct etm4_enable_arg *)info; > + u64 val; > + > + asm volatile("mrs %0,s3_1_c15_c2_5" : "=r"(val)); > + val &= ~CORE_COMMIT_CLEAR; > + val |= arg->rc << CORE_COMMIT_SHIFT; > + asm volatile("msr s3_1_c15_c2_5,%0" : : "r"(val)); > +} > + > +static void etm4_config_core_commit(int cpu, int val) > +{ > + struct etm4_enable_arg arg = {0}; > + > + arg.rc = val; > + smp_call_function_single(cpu, etm4_cpu_actlr1_cfg, &arg, 1); Function etm4_enable/disable_hw() are already running on the CPU they are supposed to so no need to call smp_call_function_single(). > +} > + > static int etm4_enable_hw(struct etmv4_drvdata *drvdata) > { > int i, rc; > + struct amba_device *adev; > struct etmv4_config *config = &drvdata->config; > struct device *etm_dev = &drvdata->csdev->dev; > + struct device *dev = drvdata->csdev->dev.parent; > + > + adev = container_of(dev, struct amba_device, dev); > + /* > + * If ETM device is HiSilicon ETM device, reduce the > + * core-commit to avoid ETM overflow. > + */ > + if (adev->periphid == HISI_ETM_AMBA_ID_V1) Do you have any documentation on this back pressure feature? I doubt this is specific to Hip09 platform and as such would prefer to have a more generic approach that works on any platform that supports it. Anyone on the CS mailing list that knows what this is about? Thanks, Mathieu > + etm4_config_core_commit(drvdata->cpu, 1); > > CS_UNLOCK(drvdata->base); > > @@ -472,10 +505,20 @@ static void etm4_disable_hw(void *info) > { > u32 control; > struct etmv4_drvdata *drvdata = info; > + struct device *dev = drvdata->csdev->dev.parent; > struct etmv4_config *config = &drvdata->config; > struct device *etm_dev = &drvdata->csdev->dev; > + struct amba_device *adev; > int i; > > + adev = container_of(dev, struct amba_device, dev); > + /* > + * If ETM device is HiSilicon ETM device, resume the > + * core-commit after ETM trace is complete. > + */ > + if (adev->periphid == HISI_ETM_AMBA_ID_V1) > + etm4_config_core_commit(drvdata->cpu, 0); > + > CS_UNLOCK(drvdata->base); > > if (!drvdata->skip_power_up) { > -- > 2.8.1 >

3 years, 11 months

[PATCH v4 0/2] Make sysFS functional on topologies with per core sink

by Linu Cherian

This patch series tries to fix the sysfs breakage on topologies with per core sink. Changes since v3: - References to coresight_get_enabled_sink in perf interface has been removed and marked deprecated as a new patch. - To avoid changes to coresight_find_sink for ease of maintenance, search function specific to sysfs usage has been added. - Sysfs being the only user for coresight_get_enabled sink, reset option is removed as well. Changes since v2: - Fixed checkpatch issue Changes since v1: - Misc fixes in commit message Applies on https://git.linaro.org/kernel/coresight.git/log/?h=next Linu Cherian (2): coresight: etm: perf: Sink selection using sysfs is deprecated coresight: Make sysFS functional on topologies with per core sink .../hwtracing/coresight/coresight-etm-perf.c | 2 - drivers/hwtracing/coresight/coresight-priv.h | 3 +- drivers/hwtracing/coresight/coresight.c | 58 +++++++++---------- 3 files changed, 29 insertions(+), 34 deletions(-) base-commit: 17f17c8f02a35a746376c2ecd054386575835b8b -- 2.25.1

3 years, 11 months

perf cs-etm: Multi-thread support

by Andrea Brunato

Good morning, Is tracing a multi-threaded program a supported use case for perf cs-etm? If yes, are there any flags that should be specified with perf? Thanks, Andrea IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

3 years, 11 months

[PATCH v5 0/9] perf cs-etm: Support thread stack and callchain

by Leo Yan

This patch series adds support for thread stack and callchain; this patch set depends on the instruction sample fix patch set [1]. This patch set get more complex, so before divide into small groups, I'd like to use this patch set version to include all relevant patches, hope this can give whole context for related code change. Briefly, this patch can be divided into three parts, which also can be reviewed separately for every part: Patches 01, 02 are used to fix samples for one corner case is for accessing the branch's target address and trigger an exception. Essentially, an extra branch sample is added to reflect this mediate branch between the previous branch and exception entry. Patches 03, 04, 05, 06 are coming from patch v4, which are used to support thread stack and callchain. Patches 07, 08, 09 are used to fixup for exception entry and exit. This is mainly used to fix two cases, one part is to fixup the thread stack and callchain for the case when access branch target address and trigger exception; another part is to fixup the thread stack for instruction emulation (and other single step cases). This patch set has been tested on Juno-r2 after applied on perf/core branch with latest commit 85fc95d75970 ("perf maps: Add missing unlock to maps__insert() error case"), and this patch set is also applied on top of instruction sample fix patch set [1]. Test for option '-F,+callindent': # perf script -F,+callindent main 3258 1 branches: main ffffad684d20 __libc_start_main+0xe0 (/usr/lib/aarch64-linux-gnu/libc-2.28.so) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: _dl_fixup ffffad811b4c _dl_runtime_resolve+0x40 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: _dl_lookup_symbol_x ffffad80c078 _dl_fixup+0xb8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: do_lookup_x ffffad80849c _dl_lookup_symbol_x+0x104 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: check_match ffffad807bf0 do_lookup_x+0x238 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: strcmp ffffad807888 check_match+0x70 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) main 3258 1 branches: lib_loop_test@plt aaaae2c4d78c main+0x18 (/root/coresight_test/main) [...] Test for option '--itrace=g': # perf script --itrace=g16l64i100 main 3258 100 instructions: ffffad816a80 memcpy+0x70 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad809468 _dl_new_object+0xa8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad801840 dl_main+0x778 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 100 instructions: ffffad80952c _dl_new_object+0x16c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad801840 dl_main+0x778 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 100 instructions: ffffad8018dc dl_main+0x814 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) main 3258 100 instructions: ffff8000100878d0 el0_sync_handler+0x168 ([kernel.kallsyms]) ffff800010082d00 el0_sync+0x140 ([kernel.kallsyms]) ffffad801910 dl_main+0x848 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad81384c _dl_sysdep_start+0x36c (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800884 _dl_start_final+0xac (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800b00 _dl_start+0x200 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) ffffad800048 _start+0x8 (/usr/lib/aarch64-linux-gnu/ld-2.28.so) [...] Changes from v4: * Addressed Mike's suggestion for performance improvement for function cs_etm__instr_addr() for quick calculation for non T32; * Removed the patch 'perf cs-etm: Synchronize instruction sample with the thread stack' (Mike); * Fixed the issue for exception is taken for branch target address accessing, for the branch sample and stack thread handling, the related patches are 01, 02, 07; * Fixed the stack thread handling for instruction emulation and single step with patches 08, 09. Changes from v3: * Split out separate patch set for instruction samples fixing. * Rebased on latest perf/core branch. Changes from v2: * Added patch 01 to fix the unsigned variable comparison to zero (Suzuki). * Refined commit logs. Changes from v1: * Added comments for task thread handling (Mathieu). * Split patch 02 into two patches, one is for support thread stack and another is for callchain support (Mathieu). * Added a new patch to support branch filter. [1] https://lkml.org/lkml/2020/2/18/1406 Leo Yan (9): perf cs-etm: Defer to assign exception sample flag perf cs-etm: Reflect branch prior to exception perf cs-etm: Refactor instruction size handling perf cs-etm: Support thread stack perf cs-etm: Support branch filter perf cs-etm: Support callchain for instruction sample perf cs-etm: Fixup exception entry for thread stack perf thread: Add helper to get top return address perf cs-etm: Fixup exception exit for thread stack .../perf/util/cs-etm-decoder/cs-etm-decoder.c | 1 + tools/perf/util/cs-etm.c | 290 ++++++++++++++++-- tools/perf/util/thread-stack.c | 10 + tools/perf/util/thread-stack.h | 1 + 4 files changed, 268 insertions(+), 34 deletions(-) -- 2.17.1

3 years, 11 months

[RFC PATCH v2 0/8] CoreSight complex config support; ETM strobing.

by Mike Leach

This patchset introduces initial concepts in CoreSight complex system configuration support. Configurations consist of 2 elements:- 1) Features - programming combinations for devices, applied to a class of device on the system (all ETMv4), or individual devices. 2) Configurations - a set of programmed features used when the named configuration is selected. Features and configurations are declared as a data table, a set of register, resource and parameter requirements. Features and configurations are loaded into the system by the virtual cs_syscfg device. This then matches features to any registered devices and loads the feature into them. Individual device classes that support feature and configuration register with cs_syscfg. Once loaded a configuration can be enabled for a specific trace run. Configurations are registered with the perf cs_etm event as entries in cs_etm/cs_config. These can be selected on the perf command line as follows:- perf record -e cs_etm/@<config_name>/ ... This patch set has one pre-loaded configuration and feature. A named "strobing" feature is provided for ETMv4. A named "autofdo" configuration is provided. This configuration enables strobing on any ETM in used. Thus the command: perf record -e cs_etm/@autofdo/ ... will trace the supplied application while enabling the "autofdo" configuation on each ETM as it is enabled by perf. This in turn will enable strobing for the ETM - with default parameters. (at present these default parameters can be altered using sysfs for each individual ETM - but this is under review). The sink used in the trace run will be automatically selected. A configuation can supply up to 15 of preset parameter values, which will subsitute in parameter values for any feature used in the configuration. Selection of preset values as follows perf record -e cs_etm/@autofdo,preset=1/ ... (valid presets 1-N, where N is the number supplied in the configuration, not exceeding 15. preset=0 is the same as not selecting a preset.) Changes since v1: 1) Moved preloaded configurations and features out of individual drivers. 2) Added cs_syscfg driver to manage configurations and features. Individual drivers register with cs_syscfg indicating support for config, and provide matching information that the system uses to load features into the drivers. This allows individual drivers to be updated on an as needed basis - and removes the need to consider devices that cannot benefit from configuration - static replicators, funnels, tpiu. 3) Added perf selection of configuarations. 4) Rebased onto the coresight module loading set. Applies to coresight/next (5.9-rc1 base) with the coresight module load set [1] applied. To follow in future revisions / sets:- a) load of additional config and features by loadable module. b) load of additional config and features by configfs c) enhanced resource management for ETMv4 and checking features have sufficient resources to be enabled. d) ECT and CTI support for configuration and features. e) documentation file. [1] https://lists.linaro.org/pipermail/coresight/2020-August/004704.html Mike Leach (8): coresight: syscfg: Initial coresight system configuration coresight: syscfg: Add loading of features and configurations coresight: syscfg: Add registration and feature loading for cs devices coresight: config: Add configuration and feature generic functions perf: cs_etm: update cs_etm processing to allow configuration selection coresight: etm-perf: update to handle configuration selection coresight: etm4x: Add complex configuration handlers to etmv4 coresight: config: Add preloaded configurations drivers/hwtracing/coresight/Makefile | 6 +- .../coresight/coresight-cfg-preload.c | 165 +++++ .../hwtracing/coresight/coresight-config.c | 565 ++++++++++++++++++ .../hwtracing/coresight/coresight-config.h | 289 +++++++++ drivers/hwtracing/coresight/coresight-core.c | 36 +- .../hwtracing/coresight/coresight-etm-perf.c | 91 ++- .../hwtracing/coresight/coresight-etm-perf.h | 8 +- .../hwtracing/coresight/coresight-etm4x-cfg.c | 226 +++++++ .../hwtracing/coresight/coresight-etm4x-cfg.h | 29 + .../coresight/coresight-etm4x-core.c | 30 +- .../coresight/coresight-etm4x-sysfs.c | 3 + .../hwtracing/coresight/coresight-syscfg.c | 527 ++++++++++++++++ .../hwtracing/coresight/coresight-syscfg.h | 90 +++ include/linux/coresight-pmu.h | 3 + include/linux/coresight.h | 8 + tools/include/linux/coresight-pmu.h | 3 + tools/perf/arch/arm/util/cs-etm.c | 17 +- 17 files changed, 2066 insertions(+), 30 deletions(-) create mode 100644 drivers/hwtracing/coresight/coresight-cfg-preload.c create mode 100644 drivers/hwtracing/coresight/coresight-config.c create mode 100644 drivers/hwtracing/coresight/coresight-config.h create mode 100644 drivers/hwtracing/coresight/coresight-etm4x-cfg.c create mode 100644 drivers/hwtracing/coresight/coresight-etm4x-cfg.h create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.c create mode 100644 drivers/hwtracing/coresight/coresight-syscfg.h -- 2.17.1

3 years, 11 months

Question about the Coresight ETM4 strobe patch

by Yabin Cui

Hi Mike, I am from the Android toolchain team. We are interested in using the ETM strobe feature in Android kernels. We noticed your patch "coresight: etmv4: Adds initial complex config with ETM4 strobe feature." in https://lists.linaro.org/pipermail/coresight/2020-June/004097.html. We tested it on Pixel devices with Qualcomm chips. It works pretty well. And I have a few questions: 1. The param setting of window and period seems doesn't take effect. Not sure if it is a bug or something I misunderstand. The only place I found moving feat->params to feat->regs is in cs_cfg_reset_feat(). But that function will also reset feat->params to default values in feat_desc->params. So if I write a value to /sys/.../window, it goes to feat->params, but can't change value in feat->regs. I tried a work-around by changing cs_cfg_param_store(): * static ssize_t cs_cfg_param_store(struct device *dev, {* * ... spin_lock(param->feat->dev_spinlock);* * if (!kstrtoull(buf, 0, &val)) {* * param->current_value = val; for (i = 0; i < feat->nr_regs; i++) { reg_desc = &feat_desc->regs[i];* * flags = reg_desc->flags;* * reg = &feat->regs[i];* * if (flags & CS_CFG_REG_VAL_PARAM) {* * if (param == &feat->params[reg_desc->value.val32]) {* * coresight_cfg_init_reg_param(reg, flags, param); }* * }* * }* * }* * spin_unlock(param->feat->dev_spinlock);* * }* 2. Is my understanding below correct? If I set the window param to 1000 and the period param to 10000, then etm will trace the last 1000 cpu cycles of every 10^7 cpu cycles? And since the strobe window/period counters are saved when disabling etm, the counting should continue from the saved value the next time I enable etm. And I should still get etm data even if the traced thread is scheduled off cpu before reaching 10^7 cpu cycles each time. 3. I want to +1 Mathieu's suggestion: *Perf sessions need to be able to choose which feature they want to use rather than defaulting to a system wide configuration.* We use perf sessions to trace ETM data in Android. It's better if we can configure ETM strobe params in the perf interface (like from perf_event_attr or ioctl). And It's better for each perf session to count separately. 4. The last update on the patch is Jun 24. And it seems the patch hasn't been landed in any branch yet. So what's the future plan? We need to wait until it lands to some upstream branches to cherry pick it to Android kernels. So I want to know when it will be ready. Thanks, Yabin

4 years

Context id tracing with kernel at EL2

by Al Grant

Hi, this is an incomplete patch for an issue with EL2 kernels, and I'm looking for feedback on how to complete it. The background is that to support tracing multiple address spaces we get ETM to embed the context id in the trace, and we build with CONFIG_PID_IN_CONTEXTIDR to get the scheduler to put the thread id in CONTEXTIDR_EL1. This is a known technique, it's what context id tracing is designed for. The problem is when the kernel is running not at EL1 (OS level) but at EL2 (hypervisor level), which is now becoming common. With HCR_EL2.E2H set, the kernel's writes to CONTEXTIDR_EL1 actually change a different physical register, CONTEXTIDR_EL2. However, ETM still traces CONTEXTIDR_EL1. So the context ids in the trace are zero, and trace cannot be reconstructed. ETM 4.1 has an option VMIDOPT to cause CONTEXTIDR_EL2 to be output in trace, in the VMID field replacing the value of VTTBR.VMID. So we can use that, but the trace follower, collecting events from OpenCSD, needs to be aware it needs to check the VMID field not the CID field. OpenCSD doesn't need to change but perf does. TRCCONFIGR is already in the metadata, so perf consumers can check it to see what's going on. The patch below does the kernel and userspace side but is not complete. The problem is that userspace perf creates the metadata copy of TRCCONFIGR based on its request (and fills in the other id registers by reading sysfs), but the detection of EL2/E2H happens in the kernel which adjusts TRCCONFIGR, and it's this config which is needed for decode. I see three ways round this: - have userspace test to see if the kernel is EL2 (somehow) and adjust the metadata to mirror what the kernel is doing - have the kernel pass the adjusted TRCCONFIGR back so perf can put it in the metadata - have the perf decoder get the thread id from whichever of VMID and CONTEXTID is available in a PE_CONTEXT element Obviously, the last is simplest, but it's a bodge, and means that OpenCSD will see VMIDs when its TRCCONFIGR says it won't. It's kind of cleanest to get the real TRCCONFIGR somehow, but how do we do that? Al diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index a128b5063f46..96488a0cfdcf 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -353,8 +353,32 @@ static int etm4_parse_event_config(struct etmv4_drvdata *drvdata, } if (attr->config & BIT(ETM_OPT_CTXTID)) - /* bit[6], Context ID tracing bit */ - config->cfg |= BIT(ETM4_CFG_BIT_CTXTID); + { + /* + * Enable context-id tracing. The assumption is that this + * will work with CONFIG_PID_IN_CONTEXTIDR to trace process + * id changes and support decode of multiple processes. + * But ETM's context id trace traces physical CONTEXTIDR_EL1, + * while the logical CONTEXTIDR_EL1 that is written to on + * process switch is either physical CONTEXTIDR_EL1 or + * CONTEXTIDR_EL2 depending on HCR_EL2.E2H. On principle + * we should continue to use logical CONTEXTIDR_EL1. + * In order to trace physical CONTEXTIDR_EL2, we need to + * enable VMID tracing and use the VMIDOPT flag to trace + * CONTEXTIDR_EL2 rather than VTTBR.VMID in the VMID field. + * Trace decoders will need to inspect TRCCONFIGR and use + * either the CID or the VMID field from the trace packet. + */ + if (!(is_kernel_in_hyp_mode() && + (read_sysreg(hcr_el2) & BIT(34)) != 0)) { + /* bit[6], Context ID tracing bit */ + config->cfg |= BIT(ETM4_CFG_BIT_CTXTID); + } else { + /* bits[7,15], trace CONTEXTID_EL2 in VMID field */ + config->cfg |= (BIT(ETM4_CFG_BIT_VMID) | + BIT(ETM4_CFG_BIT_VMIDOPT)); + } + } /* return stack - enable if selected and supported */ if ((attr->config & BIT(ETM_OPT_RETSTK)) && drvdata->retstack) diff --git a/include/linux/coresight-pmu.h b/include/linux/coresight-pmu.h index b0e35eec6499..c2f47b25daab 100644 --- a/include/linux/coresight-pmu.h +++ b/include/linux/coresight-pmu.h @@ -19,8 +19,10 @@ /* ETMv4 CONFIGR programming bits for the ETM OPTs */ #define ETM4_CFG_BIT_CYCACC 4 #define ETM4_CFG_BIT_CTXTID 6 +#define ETM4_CFG_BIT_VMID 7 #define ETM4_CFG_BIT_TS 11 #define ETM4_CFG_BIT_RETSTK 12 +#define ETM4_CFG_BIT_VMIDOPT 15 static inline int coresight_get_trace_id(int cpu) { diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h index b0e35eec6499..c2f47b25daab 100644 --- a/tools/include/linux/coresight-pmu.h +++ b/tools/include/linux/coresight-pmu.h @@ -19,8 +19,10 @@ /* ETMv4 CONFIGR programming bits for the ETM OPTs */ #define ETM4_CFG_BIT_CYCACC 4 #define ETM4_CFG_BIT_CTXTID 6 +#define ETM4_CFG_BIT_VMID 7 #define ETM4_CFG_BIT_TS 11 #define ETM4_CFG_BIT_RETSTK 12 +#define ETM4_CFG_BIT_VMIDOPT 15 static inline int coresight_get_trace_id(int cpu) { diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c index cd92a99eb89d..a54cad778841 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -35,6 +35,7 @@ struct cs_etm_decoder { dcd_tree_handle_t dcd_tree; cs_etm_mem_cb_type mem_access; ocsd_datapath_resp_t prev_return; + uint32 thread_id_in_vmid:1; }; static u32 @@ -496,17 +497,24 @@ cs_etm_decoder__buffer_exception_ret(struct cs_etm_packet_queue *queue, static ocsd_datapath_resp_t cs_etm_decoder__set_tid(struct cs_etm_queue *etmq, + struct cs_etm_decoder *decoder, struct cs_etm_packet_queue *packet_queue, const ocsd_generic_trace_elem *elem, const uint8_t trace_chan_id) { pid_t tid; - /* Ignore PE_CONTEXT packets that don't have a valid contextID */ - if (!elem->context.ctxt_id_valid) - return OCSD_RESP_CONT; + if (!decoder->thread_id_in_vmid) { + /* Ignore PE_CONTEXT packets that don't have a valid contextID */ + if (!elem->context.ctxt_id_valid) + return OCSD_RESP_CONT; + tid = elem->context.context_id; + } else { + if (!elem->context.vmid_valid) + return OCSD_RESP_CONT; + tid = elem->context.vmid; + } - tid = elem->context.context_id; if (cs_etm__etmq_set_tid(etmq, tid, trace_chan_id)) return OCSD_RESP_FATAL_SYS_ERR; @@ -561,7 +569,7 @@ static ocsd_datapath_resp_t cs_etm_decoder__gen_trace_elem_printer( trace_chan_id); break; case OCSD_GEN_TRC_ELEM_PE_CONTEXT: - resp = cs_etm_decoder__set_tid(etmq, packet_queue, + resp = cs_etm_decoder__set_tid(etmq, decoder, packet_queue, elem, trace_chan_id); break; case OCSD_GEN_TRC_ELEM_ADDR_NACC: @@ -595,11 +603,15 @@ static int cs_etm_decoder__create_etm_packet_decoder( OCSD_BUILTIN_DCD_ETMV3 : OCSD_BUILTIN_DCD_PTM; trace_config = &config_etmv3; + decoder->thread_id_in_vmid = 0; break; case CS_ETM_PROTO_ETMV4i: cs_etm_decoder__gen_etmv4_config(t_params, &trace_config_etmv4); decoder_name = OCSD_BUILTIN_DCD_ETMV4I; trace_config = &trace_config_etmv4; + /* If VMID and VMIDOPT are set, thread id is in VMID not CID */ + decoder->thread_id_in_vmid = + ((trace_config_etmv4.reg.configr & 0x8080) == 0x8080); break; default: return -1; IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.

4 years

[PATCH 00/19] coresight: Support for ETMv4.4 system instructions

by Suzuki K Poulose

CoreSight ETMv4.4 introduced system instructions for accessing the ETM. This also implies that they may not be on the amba bus. Right now all the CoreSight components are accessed via memory map. Also, we have some common routines in coresight generic code driver (e.g, CS_LOCK, claim/disclaim), which assume the mmio. In order to preserve the generic algorithms at a single place and to allow dynamic switch for ETMs, this series introduces an abstraction layer for accessing a coresight device. It is designed such that the mmio access are fast tracked (i.e, without an indirect function call). This will also help us to get rid of the driver+attribute specific sysfs show/store routines and replace them with a single routine to access a given register offset (which can be embedded in the dev_ext_attribute). This is not currently implemented in the series, but can be achieved. Further we switch the generic routines to work with the abstraction. With this in place, we refactor the etm4x code a bit to allow for supporting the system instructions with very little new code. The changes also switch to using the system instructions by default even when we may have an MMIO. We use TRCDEVARCH for the detection of the ETM component, which is a standard register as per CoreSight architecture, rather than the etm specific id register TRCIDR3. This is for making sure that we are able to detect the ETM via system instructions accurately, when the the trace unit could be anything (etm or a custom trace unit). The series has been mildly tested on a model. I would really appreciate any testing on real hardware. Applies on coresight/next Changes since V1: - Flip the switch for iomem from no_iomem to io_mem in csdev_access. - Split patches for claim/disclaim and CS_LOCK/UNLOCK conversions. - Move device access initialisation for etm4x to the target CPU - Cleanup secure exception level mask handling. - Switch to use TRCDEVARCH for ETM component discovery. This is for making - Check the availability of OS/Software Locks before using them. Suzuki K Poulose (19): coresight: Introduce device access abstraction coresight: tpiu: Prepare for using coresight device access abstraction coresight: Convert coresight_timeout to use access abstraction coresight: Convert claim/disclaim operations to use access wrappers coresight: Use device access layer for Software lock/unlock operations coresight: etm4x: Always read the registers on the host CPU coresight: etm4x: Convert all register accesses coresight: etm4x: Add commentary on the registers coresight: etm4x: Add sysreg access helpers coresight: etm4x: Define DEVARCH register fields coresight: etm4x: Check for OS and Software Lock coresight: etm4x: Cleanup secure exception level masks coresight: etm4x: Clean up exception level masks coresight: etm4x: Detect access early on the target CPU coresight: etm4x: Use TRCDEVARCH for component discovery coresight: etm4x: Detect system instructions support coresight: etm4x: Refactor probing routine coresight: etm4x: Add support for sysreg only devices dts: bindings: coresight: ETMv4.4 system register access only units .../devicetree/bindings/arm/coresight.txt | 6 +- drivers/hwtracing/coresight/coresight-catu.c | 24 +- .../hwtracing/coresight/coresight-cpu-debug.c | 22 +- .../hwtracing/coresight/coresight-cti-sysfs.c | 5 +- drivers/hwtracing/coresight/coresight-cti.c | 34 +- drivers/hwtracing/coresight/coresight-etb10.c | 29 +- .../coresight/coresight-etm3x-sysfs.c | 10 +- drivers/hwtracing/coresight/coresight-etm3x.c | 35 +- .../coresight/coresight-etm4x-sysfs.c | 44 +- drivers/hwtracing/coresight/coresight-etm4x.c | 716 +++++++++++------- drivers/hwtracing/coresight/coresight-etm4x.h | 440 ++++++++++- .../hwtracing/coresight/coresight-funnel.c | 22 +- drivers/hwtracing/coresight/coresight-priv.h | 9 +- .../coresight/coresight-replicator.c | 31 +- drivers/hwtracing/coresight/coresight-stm.c | 50 +- .../hwtracing/coresight/coresight-tmc-etf.c | 38 +- .../hwtracing/coresight/coresight-tmc-etr.c | 20 +- drivers/hwtracing/coresight/coresight-tmc.c | 16 +- drivers/hwtracing/coresight/coresight-tpiu.c | 32 +- drivers/hwtracing/coresight/coresight.c | 130 +++- include/linux/coresight.h | 230 +++++- 21 files changed, 1449 insertions(+), 494 deletions(-) -- 2.24.1

4 years

[PATCHv2 0/2] Coresight ETF perf NULL pointer dereference and ETM save/restore fixes

by Sai Prakash Ranjan

This 2 patch series provides fixes to ETF null pointer dereference crash and TRCVMIDCCTLR1 register save and restore fix. Patch 1 is an RFC since I am not sure of the fix provided since it looks more like a band-aid than the actual fix. Changes in v2: * Remove extra fixes tag (Suzuki) Sai Prakash Ranjan (2): coresight: tmc-etf: Fix NULL pointer dereference in tmc_enable_etf_sink_perf() coresight: etm4x: Fix save and restore of TRCVMIDCCTLR1 register drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 ++-- drivers/hwtracing/coresight/coresight-tmc-etf.c | 3 +++ 2 files changed, 5 insertions(+), 2 deletions(-) base-commit: e209e73bee253afe969410150248f0c300c13d84 -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

4 years

[PATCH 5.4 159/388] perf cs-etm: Correct synthesizing instruction samples

by Greg Kroah-Hartman

From: Leo Yan <leo.yan(a)linaro.org> [ Upstream commit c9f5baa136777b2c982f6f7a90c9da69a88be148 ] When 'etm->instructions_sample_period' is less than 'tidq->period_instructions', the function cs_etm__sample() cannot handle this case properly with its logic. Let's see below flow as an example: - If we set itrace option '--itrace=i4', then function cs_etm__sample() has variables with initialized values: tidq->period_instructions = 0 etm->instructions_sample_period = 4 - When the first packet is coming: packet->instr_count = 10; the number of instructions executed in this packet is 10, thus update period_instructions as below: tidq->period_instructions = 0 + 10 = 10 instrs_over = 10 - 4 = 6 offset = 10 - 6 - 1 = 3 tidq->period_instructions = instrs_over = 6 - When the second packet is coming: packet->instr_count = 10; in the second pass, assume 10 instructions in the trace sample again: tidq->period_instructions = 6 + 10 = 16 instrs_over = 16 - 4 = 12 offset = 10 - 12 - 1 = -3 -> the negative value tidq->period_instructions = instrs_over = 12 So after handle these two packets, there have below issues: The first issue is that cs_etm__instr_addr() returns the address within the current trace sample of the instruction related to offset, so the offset is supposed to be always unsigned value. But in fact, function cs_etm__sample() might calculate a negative offset value (in handling the second packet, the offset is -3) and pass to cs_etm__instr_addr() with u64 type with a big positive integer. The second issue is it only synthesizes 2 samples for sample period = 4. In theory, every packet has 10 instructions so the two packets have total 20 instructions, 20 instructions should generate 5 samples (4 x 5 = 20). This is because cs_etm__sample() only calls once cs_etm__synth_instruction_sample() to generate instruction sample per range packet. This patch fixes the logic in function cs_etm__sample(); the basic idea for handling coming packet is: - To synthesize the first instruction sample, it combines the left instructions from the previous packet and the head of the new packet; then generate continuous samples with sample period; - At the tail of the new packet, if it has the rest instructions, these instructions will be left for the sequential sample. Suggested-by: Mike Leach <mike.leach(a)linaro.org> Signed-off-by: Leo Yan <leo.yan(a)linaro.org> Reviewed-by: Mathieu Poirier <mathieu.poirier(a)linaro.org> Reviewed-by: Mike Leach <mike.leach(a)linaro.org> Cc: Alexander Shishkin <alexander.shishkin(a)linux.intel.com> Cc: Jiri Olsa <jolsa(a)redhat.com> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Namhyung Kim <namhyung(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Robert Walker <robert.walker(a)arm.com> Cc: Suzuki Poulouse <suzuki.poulose(a)arm.com> Cc: coresight ml <coresight(a)lists.linaro.org> Cc: linux-arm-kernel(a)lists.infradead.org Link: http://lore.kernel.org/lkml/20200219021811.20067-4-leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo <acme(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- tools/perf/util/cs-etm.c | 87 ++++++++++++++++++++++++++++++++-------- 1 file changed, 70 insertions(+), 17 deletions(-) diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 38298cbb07524..451eee24165ee 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -1359,9 +1359,12 @@ static int cs_etm__sample(struct cs_etm_queue *etmq, struct cs_etm_auxtrace *etm = etmq->etm; int ret; u8 trace_chan_id = tidq->trace_chan_id; - u64 instrs_executed = tidq->packet->instr_count; + u64 instrs_prev; - tidq->period_instructions += instrs_executed; + /* Get instructions remainder from previous packet */ + instrs_prev = tidq->period_instructions; + + tidq->period_instructions += tidq->packet->instr_count; /* * Record a branch when the last instruction in @@ -1379,26 +1382,76 @@ static int cs_etm__sample(struct cs_etm_queue *etmq, * TODO: allow period to be defined in cycles and clock time */ - /* Get number of instructions executed after the sample point */ - u64 instrs_over = tidq->period_instructions - - etm->instructions_sample_period; + /* + * Below diagram demonstrates the instruction samples + * generation flows: + * + * Instrs Instrs Instrs Instrs + * Sample(n) Sample(n+1) Sample(n+2) Sample(n+3) + * | | | | + * V V V V + * -------------------------------------------------- + * ^ ^ + * | | + * Period Period + * instructions(Pi) instructions(Pi') + * + * | | + * \---------------- -----------------/ + * V + * tidq->packet->instr_count + * + * Instrs Sample(n...) are the synthesised samples occurring + * every etm->instructions_sample_period instructions - as + * defined on the perf command line. Sample(n) is being the + * last sample before the current etm packet, n+1 to n+3 + * samples are generated from the current etm packet. + * + * tidq->packet->instr_count represents the number of + * instructions in the current etm packet. + * + * Period instructions (Pi) contains the the number of + * instructions executed after the sample point(n) from the + * previous etm packet. This will always be less than + * etm->instructions_sample_period. + * + * When generate new samples, it combines with two parts + * instructions, one is the tail of the old packet and another + * is the head of the new coming packet, to generate + * sample(n+1); sample(n+2) and sample(n+3) consume the + * instructions with sample period. After sample(n+3), the rest + * instructions will be used by later packet and it is assigned + * to tidq->period_instructions for next round calculation. + */ /* - * Calculate the address of the sampled instruction (-1 as - * sample is reported as though instruction has just been - * executed, but PC has not advanced to next instruction) + * Get the initial offset into the current packet instructions; + * entry conditions ensure that instrs_prev is less than + * etm->instructions_sample_period. */ - u64 offset = (instrs_executed - instrs_over - 1); - u64 addr = cs_etm__instr_addr(etmq, trace_chan_id, - tidq->packet, offset); + u64 offset = etm->instructions_sample_period - instrs_prev; + u64 addr; - ret = cs_etm__synth_instruction_sample( - etmq, tidq, addr, etm->instructions_sample_period); - if (ret) - return ret; + while (tidq->period_instructions >= + etm->instructions_sample_period) { + /* + * Calculate the address of the sampled instruction (-1 + * as sample is reported as though instruction has just + * been executed, but PC has not advanced to next + * instruction) + */ + addr = cs_etm__instr_addr(etmq, trace_chan_id, + tidq->packet, offset - 1); + ret = cs_etm__synth_instruction_sample( + etmq, tidq, addr, + etm->instructions_sample_period); + if (ret) + return ret; - /* Carry remaining instructions into next sample period */ - tidq->period_instructions = instrs_over; + offset += etm->instructions_sample_period; + tidq->period_instructions -= + etm->instructions_sample_period; + } } if (etm->sample_branches) { -- 2.25.1

4 years

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CoreSight September 2020