CoreSight

coresight@lists.linaro.org

6 participants
2350 discussions

Re: [PATCH 1/3] perf tests test_arm_coresight: Fix the shellcheck warning in latest test_arm_coresight.sh

by James Clark

On 29/09/2023 05:11, Athira Rajeev wrote: > Running shellcheck on tests/shell/test_arm_coresight.sh > throws below warnings: > > In tests/shell/test_arm_coresight.sh line 15: > cs_etm_path=$(find /sys/bus/event_source/devices/cs_etm/ -name cpu* -print -quit) > ^--^ SC2061: Quote the parameter to -name so the shell won't interpret it. > > In tests/shell/test_arm_coresight.sh line 20: > if [ $archhver -eq 5 -a "$(printf "0x%X\n" $archpart)" = "0xA13" ] ; then > ^-- SC2166: Prefer [ p ] && [ q ] as [ p -a q ] is not well defined > > This warning is observed after commit: > "commit bb350847965d ("perf test: Update cs_etm testcase for Arm ETE")" > > Fixed this issue by using quoting 'cpu*' for SC2061 and > using "&&" in line number 20 for SC2166 warning > > Fixes: bb350847965d ("perf test: Update cs_etm testcase for Arm ETE") > Signed-off-by: Athira Rajeev <atrajeev(a)linux.vnet.ibm.com> > --- > tools/perf/tests/shell/test_arm_coresight.sh | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/tools/perf/tests/shell/test_arm_coresight.sh b/tools/perf/tests/shell/test_arm_coresight.sh > index fe78c4626e45..f2115dfa24a5 100755 > --- a/tools/perf/tests/shell/test_arm_coresight.sh > +++ b/tools/perf/tests/shell/test_arm_coresight.sh > @@ -12,12 +12,12 @@ > glb_err=0 > > cs_etm_dev_name() { > - cs_etm_path=$(find /sys/bus/event_source/devices/cs_etm/ -name cpu* -print -quit) > + cs_etm_path=$(find /sys/bus/event_source/devices/cs_etm/ -name 'cpu*' -print -quit) > trcdevarch=$(cat ${cs_etm_path}/mgmt/trcdevarch) > archhver=$((($trcdevarch >> 12) & 0xf)) > archpart=$(($trcdevarch & 0xfff)) > > - if [ $archhver -eq 5 -a "$(printf "0x%X\n" $archpart)" = "0xA13" ] ; then > + if [ $archhver -eq 5 ] && [ "$(printf "0x%X\n" $archpart)" = "0xA13" ] ; then > echo "ete" > else > echo "etm" Reviewed-by: James Clark <james.clark(a)arm.com>

1 year, 7 months

RE: [EXT] Re: [PATCH 1/7] dt-bindings: arm: coresight-tmc: Add "memory-region" property

by Linu Cherian

Hi Krzysztof, > -----Original Message----- > From: Krzysztof Kozlowski <krzysztof.kozlowski(a)linaro.org> > Sent: Saturday, September 30, 2023 8:59 PM > To: Linu Cherian <lcherian(a)marvell.com>; suzuki.poulose(a)arm.com; > mike.leach(a)linaro.org; james.clark(a)arm.com; leo.yan(a)linaro.org > Cc: linux-arm-kernel(a)lists.infradead.org; coresight(a)lists.linaro.org; linux- > kernel(a)vger.kernel.org; robh+dt(a)kernel.org; > krzysztof.kozlowski+dt(a)linaro.org; conor+dt(a)kernel.org; > devicetree(a)vger.kernel.org; Sunil Kovvuri Goutham > <sgoutham(a)marvell.com>; George Cherian <gcherian(a)marvell.com> > Subject: [EXT] Re: [PATCH 1/7] dt-bindings: arm: coresight-tmc: Add > "memory-region" property > > External Email > > ---------------------------------------------------------------------- > On 29/09/2023 15:37, Linu Cherian wrote: > > memory-region 0: Reserved trace buffer memory > > > > TMC ETR: When available, use this reserved memory region for > > trace data capture. Same region is used for trace data > > retention after a panic or watchdog reset. > > > > TMC ETF: When available, use this reserved memory region for > > trace data retention synced from internal SRAM after a panic or > > watchdog reset. > > > > memory-region 1: Reserved meta data memory > > > > TMC ETR, ETF: When available, use this memory for register > > snapshot retention synced from hardware registers after a panic > > or watchdog reset. > > > > Signed-off-by: Linu Cherian <lcherian(a)marvell.com> > > --- > > Where is the changelog? This is supposed to be v4 or something later. > Please, keep proper versioning and changelog. Sure, will add the changelog from next version onwards. Yeah, the last version was RFC v3 and the RFC tag has been dropped from this version onwards. Hence started this version with V1. > > > .../bindings/arm/arm,coresight-tmc.yaml | 19 +++++++++++++++++++ > > 1 file changed, 19 insertions(+) > > > > diff --git a/Documentation/devicetree/bindings/arm/arm,coresight- > tmc.yaml b/Documentation/devicetree/bindings/arm/arm,coresight- > tmc.yaml > > index cb8dceaca70e..45ca4d02d73e 100644 > > --- a/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml > > +++ b/Documentation/devicetree/bindings/arm/arm,coresight-tmc.yaml > > @@ -101,6 +101,22 @@ properties: > > and ETF configurations. > > $ref: /schemas/graph.yaml#/properties/port > > > > + memory-region: > > + items: > > + - description: Reserved trace buffer memory for ETR and ETF sinks. > > + For ETR, this reserved memory region is used for trace data capture. > > + Same region is used for trace data retention as well after a panic > > + or watchdog reset. > > + For ETF, this reserved memory region is used for retention of trace > > + data synced from internal SRAM after a panic or watchdog reset. > > + > > + - description: Reserved meta data memory. Used for ETR and ETF sinks. > > + > > + memory-region-names: > > + items: > > + - const: trace-mem > > + - const: metadata-mem > > Drop the 'mem' suffixes. > Ack. Will remove it in next version.

1 year, 7 months

[PATCH] coresight: Add mode check when enable/disable csdev source

by Junhao He

The commmit [1] replace "source_ops(csdev)::enable()" with coresight_enable_source(). After this patch, when enable ETM through perf mode, the csdev::enable will be set to true. Then if we to disable the ETM by sysfs mode at the time, the resource will be released incorrectly, kernel will report the following call trace. perf record -e cs_etm/@ultra_smb0/ -C 2 sleep 30 & echo 1 > /sys/bus/coresight/devices/ultra_smb0/enable_sink echo 1 > /sys/bus/coresight/devices/etm0/enable_source echo 0 > /sys/bus/coresight/devices/etm0/enable_source Unable to handle kernel NULL pointer dereference at virtual address 00000000000001d0 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP ... Call trace: etm4_disable+0x54/0x150 [coresight_etm4x] coresight_disable_source+0x6c/0x98 [coresight] coresight_disable+0x74/0x1c0 [coresight] enable_source_store+0x88/0xa0 [coresight] dev_attr_store+0x20/0x40 sysfs_kf_write+0x4c/0x68 kernfs_fop_write_iter+0x120/0x1b8 vfs_write+0x2dc/0x3b0 ksys_write+0x70/0x108 __arm64_sys_write+0x24/0x38 invoke_syscall+0x50/0x128 el0_svc_common.constprop.0+0x104/0x130 do_el0_svc+0x40/0xb8 el0_svc+0x2c/0xb8 el0t_64_sync_handler+0xc0/0xc8 el0t_64_sync+0x1a4/0x1a8 Code: d53cd042 91002000 b9402a81 b8626800 (f940ead5) ---[ end trace 0000000000000000 ]--- The csdev::enable specify the device is currently part of an active path, when enabling source via perf mode, csdev::enable also should be set to true. We can add mode check in etm4_disable() to fix that, if it's done, the sysfs cannot report busy when sysfs to enable ETM that has been enabled by perf. Struct coresight_device add member of mode to check device busy in coresight_(enable/disable)_source function to fixes handle kernel NULL pointer, and sysfs report busy if perf session is already using the ETM. By the way, inperhaps another cleanup patch may be upload to remove the etmv4_drvdata::mode tmc_drvdata::mode or others. Test: perf record -e cs_etm/@ultra_smb0/ -C 2 sleep 30 & cat /sys/bus/coresight/devices/etm2/enable_source 1 echo 1 > /sys/bus/coresight/devices/etm2/enable_source -bash: echo: write error: Device or resource busy echo 0 > /sys/bus/coresight/devices/etm2/enable_source coresight etm2: Someone is already using the tracer cat /sys/bus/coresight/devices/etm2/enable_source 1 [1] "coresight: Enable and disable helper devices adjacent to the path" Fixes: 6148652807ba ("coresight: Enable and disable helper devices adjacent to the path") Signed-off-by: Junhao He <hejunhao3(a)huawei.com> --- drivers/hwtracing/coresight/coresight-core.c | 18 ++++++++++++++++-- .../hwtracing/coresight/coresight-etm-perf.c | 6 +++++- drivers/hwtracing/coresight/coresight-priv.h | 3 ++- include/linux/coresight.h | 14 ++++++++------ 4 files changed, 31 insertions(+), 10 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c index 206f17826399..7b485fc2ed19 100644 --- a/drivers/hwtracing/coresight/coresight-core.c +++ b/drivers/hwtracing/coresight/coresight-core.c @@ -388,6 +388,7 @@ int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode, return ret; } csdev->enable = true; + csdev->mode = mode; } atomic_inc(&csdev->refcnt); @@ -446,18 +447,26 @@ static void coresight_disable_helpers(struct coresight_device *csdev) * the device if there are no users left. * * @csdev: The coresight device to disable + * @mode: How the coresight device is being used, perf mode or sysfs mode. * @data: Opaque data to pass on to the disable function of the source device. * For example in perf mode this is a pointer to the struct perf_event. * * Returns true if the device has been disabled. */ -bool coresight_disable_source(struct coresight_device *csdev, void *data) +bool coresight_disable_source(struct coresight_device *csdev, enum cs_mode mode, + void *data) { + if (csdev->mode && csdev->mode != mode) { + dev_err(&csdev->dev, "Someone is already using the tracer\n"); + return false; + } + if (atomic_dec_return(&csdev->refcnt) == 0) { if (source_ops(csdev)->disable) source_ops(csdev)->disable(csdev, data); coresight_disable_helpers(csdev); csdev->enable = false; + csdev->mode = CS_MODE_DISABLED; } return !csdev->enable; } @@ -1117,6 +1126,11 @@ int coresight_enable(struct coresight_device *csdev) if (ret) goto out; + if (csdev->mode == CS_MODE_PERF) { + ret = -EBUSY; + goto out; + } + if (csdev->enable) { /* * There could be multiple applications driving the software @@ -1202,7 +1216,7 @@ void coresight_disable(struct coresight_device *csdev) if (ret) goto out; - if (!csdev->enable || !coresight_disable_source(csdev, NULL)) + if (!csdev->enable || !coresight_disable_source(csdev, CS_MODE_SYSFS, NULL)) goto out; switch (csdev->subtype.source_subtype) { diff --git a/drivers/hwtracing/coresight/coresight-etm-perf.c b/drivers/hwtracing/coresight/coresight-etm-perf.c index 5ca6278baff4..015aea9f2b22 100644 --- a/drivers/hwtracing/coresight/coresight-etm-perf.c +++ b/drivers/hwtracing/coresight/coresight-etm-perf.c @@ -459,6 +459,10 @@ static void etm_event_start(struct perf_event *event, int flags) if (WARN_ON(ctxt->event_data)) goto fail; + /* Sysfs is already using the tracer */ + if (csdev->mode == CS_MODE_SYSFS) + goto fail; + /* * Deal with the ring buffer API and get a handle on the * session's information. @@ -587,7 +591,7 @@ static void etm_event_stop(struct perf_event *event, int mode) return; /* stop tracer */ - coresight_disable_source(csdev, event); + coresight_disable_source(csdev, CS_MODE_PERF, event); /* tell the core */ event->hw.state = PERF_HES_STOPPED; diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index 767076e07970..1f8b512ba5ac 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -233,6 +233,7 @@ void coresight_set_percpu_sink(int cpu, struct coresight_device *csdev); struct coresight_device *coresight_get_percpu_sink(int cpu); int coresight_enable_source(struct coresight_device *csdev, enum cs_mode mode, void *data); -bool coresight_disable_source(struct coresight_device *csdev, void *data); +bool coresight_disable_source(struct coresight_device *csdev, enum cs_mode mode, + void *data); #endif diff --git a/include/linux/coresight.h b/include/linux/coresight.h index a269fffaf991..acbbedb9abf3 100644 --- a/include/linux/coresight.h +++ b/include/linux/coresight.h @@ -216,6 +216,12 @@ struct coresight_sysfs_link { const char *target_name; }; +enum cs_mode { + CS_MODE_DISABLED, + CS_MODE_SYSFS, + CS_MODE_PERF, +}; + /** * struct coresight_device - representation of a device as used by the framework * @pdata: Platform data with device connections associated to this device. @@ -228,6 +234,7 @@ struct coresight_sysfs_link { * @refcnt: keep track of what is in use. * @orphan: true if the component has connections that haven't been linked. * @enable: 'true' if component is currently part of an active path. + * @mode: This tracer's mode, i.e sysFS, Perf or disabled. * @activated: 'true' only if a _sink_ has been activated. A sink can be * activated but not yet enabled. Enabling for a _sink_ * happens when a source has been selected and a path is enabled @@ -252,6 +259,7 @@ struct coresight_device { atomic_t refcnt; bool orphan; bool enable; /* true only if configured as part of a path */ + enum cs_mode mode; /* sink specific fields */ bool activated; /* true only if a sink is part of a path */ struct dev_ext_attribute *ea; @@ -290,12 +298,6 @@ static struct coresight_dev_list (var) = { \ #define to_coresight_device(d) container_of(d, struct coresight_device, dev) -enum cs_mode { - CS_MODE_DISABLED, - CS_MODE_SYSFS, - CS_MODE_PERF, -}; - #define source_ops(csdev) csdev->ops->source_ops #define sink_ops(csdev) csdev->ops->sink_ops #define link_ops(csdev) csdev->ops->link_ops -- 2.30.0

1 year, 7 months

[GIT PULL] coresight: Fixes for v6.6

by Suzuki K Poulose

Hi Greg Please find a couple of fixes for coresight subsystem targetting v6.6 Kindly pull Suzuki The following changes since commit 0bb80ecc33a8fb5a682236443c1e740d5c917d1d: Linux 6.6-rc1 (2023-09-10 16:28:41 -0700) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git tags/coresight-fixes-v6.6-1 for you to fetch changes up to e5028011885a85032aa3c1b7e3e493bcdacb4a0a: coresight: tmc-etr: Disable warnings for allocation failures (2023-09-20 10:46:30 +0100) ---------------------------------------------------------------- coresight: Fixes for v6.6 Couple of fixes for the CoreSight self-hosted tracing targeting v6.6. Includes : - Fix runtime warnings while reusing the TMC-ETR buffer - Fix (disable) warning when a large buffer is allocated in the flat mode. ---------------------------------------------------------------- Linu Cherian (1): coresight: Fix run time warnings while reusing ETR buffer Suzuki K Poulose (1): coresight: tmc-etr: Disable warnings for allocation failures drivers/hwtracing/coresight/coresight-tmc-etr.c | 27 ++++++++++++++----------- 1 file changed, 15 insertions(+), 12 deletions(-)

1 year, 7 months

Re: [PATCH v1 3/5] arm64: KVM: Add interface to set guest value for TRFCR register

by James Clark

On 29/09/2023 11:17, Marc Zyngier wrote: > On Thu, 28 Sep 2023 16:16:07 +0100, > James Clark <james.clark(a)arm.com> wrote: >> >> Add an interface for the Coresight driver to use to set the value of the >> TRFCR register for the guest. This register controls the exclude >> settings for trace at different exception levels, and is used to >> honor the exclude_host and exclude_guest parameters from the Perf >> session. This will be used to later write TRFCR_EL1 on nVHE at guest >> switch. For VHE, TRFCR_EL1 is written immediately. Because guest writes >> to the register are trapped, the value will persist and can't be >> modified. >> >> The settings must be copied to the vCPU before each run in the same >> way that PMU events are because the per-cpu struct isn't accessible in >> protected mode. >> >> Now that both guest and host values are saved, rename trfcr_el1 to >> host_trfcr_el1 to make it clear that's the value that should be restored >> on return to the host. >> >> Reviewed-by: Mark Brown <broonie(a)kernel.org> (sysreg) >> Signed-off-by: James Clark <james.clark(a)arm.com> >> --- >> arch/arm64/include/asm/kvm_host.h | 6 +++++- >> arch/arm64/kvm/arm.c | 1 + >> arch/arm64/kvm/debug.c | 21 +++++++++++++++++++++ >> arch/arm64/kvm/hyp/nvhe/debug-sr.c | 4 ++-- >> arch/arm64/tools/sysreg | 4 ++++ >> 5 files changed, 33 insertions(+), 3 deletions(-) >> >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h >> index 498f922f4f41..0e57827a0cf2 100644 >> --- a/arch/arm64/include/asm/kvm_host.h >> +++ b/arch/arm64/include/asm/kvm_host.h >> @@ -547,7 +547,8 @@ struct kvm_vcpu_arch { >> /* Statistical profiling extension */ >> u64 pmscr_el1; >> /* Self-hosted trace */ >> - u64 trfcr_el1; >> + u64 host_trfcr_el1; >> + u64 guest_trfcr_el1; >> } host_debug_state; > > I think it is high time we stop having *guest* state in a structure > that is obviously for the host, starting by moving the breakpoint and > watchpoint out, and into the sysreg array. > It looks like host_debug_state::regs is actually the host debug state, despite the type being called "struct kvm_guest_debug_arch". But yeah I can move pmscr_el1 and trfcr_el1 to the guest and host sysreg arrays, that would make sense. host_debug_state::regs seems to be a bit more intertwined with the kvm_arch_vcpu_ioctl_set_guest_debug() ioctl and the pattern to support two different sets of guest debug state, so I'm not sure if it's worth touching that at this point: * We maintain more than a single set of debug registers to support * debugging the guest ... * debug_ptr points to the set of debug registers that should be loaded * onto the hardware when running the guest. */ struct kvm_guest_debug_arch *debug_ptr; struct kvm_guest_debug_arch vcpu_debug_state; struct kvm_guest_debug_arch external_debug_state; > And then TRFCR_EL1 can join the fun. But it is pretty unclear whether > that's actually the guest state. > It has an effect on the guest, but can never actually be read or written by the guest. Not sure if that pattern exists elsewhere... >> >> /* VGIC state */ >> @@ -1097,6 +1098,8 @@ void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu); >> void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr); >> void kvm_clr_pmu_events(u32 clr); >> bool kvm_set_pmuserenr(u64 val); >> +void kvm_etm_set_guest_trfcr(u64 trfcr_guest); >> +void kvm_etm_update_vcpu_events(struct kvm_vcpu *vcpu); >> #else >> static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {} >> static inline void kvm_clr_pmu_events(u32 clr) {} >> @@ -1104,6 +1107,7 @@ static inline bool kvm_set_pmuserenr(u64 val) >> { >> return false; >> } >> +static inline void kvm_etm_set_guest_trfcr(u64 trfcr_guest) {} >> #endif >> >> void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu); >> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c >> index 1bfdd583b261..65e805dc1d7a 100644 >> --- a/arch/arm64/kvm/arm.c >> +++ b/arch/arm64/kvm/arm.c >> @@ -958,6 +958,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) >> kvm_vgic_flush_hwstate(vcpu); >> >> kvm_pmu_update_vcpu_events(vcpu); >> + kvm_etm_update_vcpu_events(vcpu); >> >> /* >> * Ensure we set mode to IN_GUEST_MODE after we disable >> diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c >> index 6a1bad1a921b..379d2677961f 100644 >> --- a/arch/arm64/kvm/debug.c >> +++ b/arch/arm64/kvm/debug.c >> @@ -22,6 +22,7 @@ >> DBG_MDSCR_MDE) >> >> static DEFINE_PER_CPU(u64, mdcr_el2); >> +static DEFINE_PER_CPU(u64, guest_trfcr); > > Hold on a sec. Why is that global? I'd expect the tracing to be > specific to a vcpu, and not to affect *everything*. > I suppose because it is a property of the host CPU rather than the vcpu. The vcpu might not even exist yet when the Perf session starts, and Perf sessions only care about the host CPU's perspective. It's defining the guest trfcr value for any vcpu that might or might not run on this core in the future, rather than any one specific vcpu. I copied the pattern from the existing Perf PMU settings in arch/arm64/kvm/pmu.c: static DEFINE_PER_CPU(struct kvm_pmu_events, kvm_pmu_events); We could flip it around and make KVM say "what's the guest trfcr value for this core?" to the Coresight driver at the point of guest switch, but all that would mean is that the global would be in the Coresight driver instead. >> >> /** >> * save/restore_guest_debug_regs >> @@ -342,3 +343,23 @@ void kvm_arch_vcpu_put_debug_state_flags(struct kvm_vcpu *vcpu) >> vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_SPE); >> vcpu_clear_flag(vcpu, DEBUG_STATE_SAVE_TRFCR); >> } >> + >> +void kvm_etm_set_guest_trfcr(u64 trfcr_guest) >> +{ >> + if (has_vhe()) >> + write_sysreg_s(trfcr_guest, SYS_TRFCR_EL12); >> + else >> + *this_cpu_ptr(&guest_trfcr) = trfcr_guest; >> +} >> +EXPORT_SYMBOL_GPL(kvm_etm_set_guest_trfcr); > > In what context can this be called? What if we want to expose TRFCR to > guests instead? It looks to me that this ultimately precludes such > use. > Yes it does, but currently Coresight isn't exposed to guests at all so it's not a problem. In the future if we did decide to do it, there would be significant work to somehow share the components between the host and the guest. But even if they were shared, in the case where the guest isn't using trace the trfcr and exclude guest settings would still need to work, so something of this form would still be required. >> + >> +/* >> + * Updates the vcpu's view of the etm events for this cpu. Must be >> + * called before every vcpu run after disabling interrupts, to ensure >> + * that an interrupt cannot fire and update the structure. >> + */ >> +void kvm_etm_update_vcpu_events(struct kvm_vcpu *vcpu) >> +{ >> + if (!has_vhe() && vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRFCR)) >> + vcpu->arch.host_debug_state.guest_trfcr_el1 = *this_cpu_ptr(&guest_trfcr); > > But what is the point of this per-vcpu field if all you care about is > some per-CPU data? > This was the only way I could find to share data between the host and have it available to EL2 on the guest switch. I saw it was also done that way for PMUs in kvm_pmu_update_vcpu_events(). Maybe it could be done by exposing the guest_trfcr global to both sides with some annotation? But I assumed that wasn't idomatic as it wasn't done for PMUs. >> +} >> diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c >> index 89c208112eb7..55bc01e9808f 100644 >> --- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c >> +++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c >> @@ -86,7 +86,7 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu) >> __debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1); >> /* Disable and flush Self-Hosted Trace generation */ >> if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRFCR)) >> - __debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1); >> + __debug_save_trace(&vcpu->arch.host_debug_state.host_trfcr_el1); >> } > `<> >> void __debug_switch_to_guest(struct kvm_vcpu *vcpu) >> @@ -99,7 +99,7 @@ void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu) >> if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE)) >> __debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1); >> if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRFCR)) >> - __debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1); >> + __debug_restore_trace(vcpu->arch.host_debug_state.host_trfcr_el1); >> } >> >> void __debug_switch_to_host(struct kvm_vcpu *vcpu) >> diff --git a/arch/arm64/tools/sysreg b/arch/arm64/tools/sysreg >> index 992722c0c23b..295a4a625b8b 100644 >> --- a/arch/arm64/tools/sysreg >> +++ b/arch/arm64/tools/sysreg >> @@ -2661,3 +2661,7 @@ EndSysreg >> Sysreg TRFCR_EL2 3 4 1 2 1 >> Fields TRFCR_EL2 >> EndSysreg >> + >> +Sysreg TRFCR_EL12 3 5 1 2 1 >> +Fields TRFCR_ELx >> +EndSysreg > > Please move this to the first patch. > > M. > Will do. James

1 year, 7 months

Re: [PATCH] coresight: etm4x: Remove bogous __exit annotation for some functions

by James Clark

On 29/09/2023 09:16, Uwe Kleine-König wrote: > etm4_platform_driver (which lives in ".data" contains a reference to > etm4_remove_platform_dev(). So the latter must not be marked with __exit > which results in the function being discarded for a build with > CONFIG_CORESIGHT_SOURCE_ETM4X=y which in turn makes the remove pointer > contain invalid data. > > etm4x_amba_driver referencing etm4_remove_amba() has the same issue. > > Drop the __exit annotations for the two affected functions and a third > one that is called by the other two. > Makes sense to me, I can't see any other struct platform_driver callbacks marked with __init or __exit. Reviewed-by: James Clark <james.clark(a)arm.com> > For reasons I don't understand this isn't catched by building with > CONFIG_DEBUG_SECTION_MISMATCH=y. > > Fixes: c23bc382ef0e ("coresight: etm4x: Refactor probing routine") > Fixes: 5214b563588e ("coresight: etm4x: Add support for sysreg only devices") > Signed-off-by: Uwe Kleine-König <u.kleine-koenig(a)pengutronix.de> > --- > drivers/hwtracing/coresight/coresight-etm4x-core.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 77b0271ce6eb..34aee59dd147 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -2224,7 +2224,7 @@ static void clear_etmdrvdata(void *info) > per_cpu(delayed_probe, cpu) = NULL; > } > > -static void __exit etm4_remove_dev(struct etmv4_drvdata *drvdata) > +static void etm4_remove_dev(struct etmv4_drvdata *drvdata) > { > bool had_delayed_probe; > /* > @@ -2253,7 +2253,7 @@ static void __exit etm4_remove_dev(struct etmv4_drvdata *drvdata) > } > } > > -static void __exit etm4_remove_amba(struct amba_device *adev) > +static void etm4_remove_amba(struct amba_device *adev) > { > struct etmv4_drvdata *drvdata = dev_get_drvdata(&adev->dev); > > @@ -2261,7 +2261,7 @@ static void __exit etm4_remove_amba(struct amba_device *adev) > etm4_remove_dev(drvdata); > } > > -static int __exit etm4_remove_platform_dev(struct platform_device *pdev) > +static int etm4_remove_platform_dev(struct platform_device *pdev) > { > struct etmv4_drvdata *drvdata = dev_get_drvdata(&pdev->dev); > > > base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d

1 year, 7 months

[PATCH v1 0/5] kvm/coresight: Support exclude guest and exclude host

by James Clark

This is a combination of the RFC for nVHE here [1] and v3 of VHE version here [2]. After a few of the review comments it seemed much simpler for both versions to use the same interface and be in the same patchset. FEAT_TRF is a Coresight feature that allows trace capture to be completely filtered at different exception levels, unlike the existing TRCVICTLR controls which may still emit target addresses of branches, even if the following trace is filtered. Without FEAT_TRF, it was possible to start a trace session on a host and also collect trace from the guest as TRCVICTLR was never programmed to exclude guests (and it could still emit target addresses even if it was). With FEAT_TRF, the current behavior of trace in guests exists depends on whether nVHE or VHE are being used. Both of the examples below are from the host's point of view, as Coresight isn't accessible from guests. This patchset is only relevant to when FEAT_TRF exists, otherwise there is no change. nVHE: Because the host and the guest are both using TRFCR_EL1, trace will be generated in guests depending on the same filter rules the host is using. For example if the host is tracing userspace only, then guest userspace trace will also be collected. (This is further limited by whether TRBE is used because an issue with TRBE means that it's completely disabled in nVHE guests, but it's possible to have other tracing components.) VHE: With VHE, the host filters will be in TRFCR_EL2, but the filters in TRFCR_EL1 will be active when the guest is running. Because we don't write to TRFCR_EL1, guest trace will be completely disabled. With this change, the guest filtering rules from the Perf session are honored for both nVHE and VHE modes. This is done by either writing to TRFCR_EL12 at the start of the Perf session and doing nothing else further, or caching the guest value and writing it at guest switch for nVHE. The first commit moves the register to sysreg because I add the EL12 version in a later commit. --- Changes since nVHE RFC [1]: * Re-write just in terms of the register value to be written for the host and the guest. This removes some logic from the hyp code and a value of kvm_vcpu_arch:trfcr_el1 = 0 no longer means "don't restore". * Remove all the conditional compilation and new files. * Change the kvm_etm_update_vcpu_events macro to a function. * Re-use DEBUG_STATE_SAVE_TRFCR so iflags don't need to be expanded anymore. * Expand the cover letter. Changes since VHE v3 [2]: * Use the same interface as nVHE mode so TRFCR_EL12 is now written by kvm. [1]: https://lore.kernel.org/kvmarm/20230804101317.460697-1-james.clark@arm.com/ [2]: https://lore.kernel.org/kvmarm/20230905102117.2011094-1-james.clark@arm.com/ James Clark (5): arm64/sysreg: Move TRFCR definitions to sysreg arm64: KVM: Rename DEBUG_STATE_SAVE_TRBE to DEBUG_STATE_SAVE_TRFCR arm64: KVM: Add interface to set guest value for TRFCR register arm64: KVM: Write TRFCR value on guest switch with nVHE coresight: Pass guest TRFCR value to KVM arch/arm64/include/asm/kvm_host.h | 10 +++- arch/arm64/include/asm/sysreg.h | 12 ---- arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/debug.c | 38 +++++++++++- arch/arm64/kvm/hyp/nvhe/debug-sr.c | 60 +++++++++++-------- arch/arm64/tools/sysreg | 41 +++++++++++++ .../coresight/coresight-etm4x-core.c | 42 +++++++++++-- drivers/hwtracing/coresight/coresight-etm4x.h | 2 +- drivers/hwtracing/coresight/coresight-priv.h | 3 + 9 files changed, 160 insertions(+), 49 deletions(-) -- 2.34.1

1 year, 7 months

[PATCH v9 00/13] Add support to configure TPDM DSB subunit

by Tao Zhang

Introduction of TPDM DSB subunit DSB subunit is responsible for creating a dataset element, and is also optionally responsible for packing it to fit multiple elements on a single ATB transfer if possible in the configuration. The TPDM Core Datapath requests timestamps be stored by the TPDA and then delivering ATB sized data (depending on ATB width and element size, this could be smaller or larger than a dataset element) to the ATB Mast FSM. The DSB subunit must be configured prior to enablement. This series adds support for TPDM to configure the configure DSB subunit. Once this series patches are applied properly, the new tpdm nodes for should be observed at the tpdm path /sys/bus/coresight/devices/tpdm* which supports DSB subunit. e.g. root@qemuarm64:/sys/devices/platform/soc@0/6c08000.tpdm/tpdm1# ls -l drwxr-xr-x 2 root root 0 Jan 1 00:00 connections drwxr-xr-x 2 root root 0 Jan 1 00:00 dsb_edge -rw-r--r-- 1 root root 4096 Jan 1 00:00 dsb_mode drwxr-xr-x 2 root root 0 Jan 1 00:00 dsb_msr drwxr-xr-x 2 root root 0 Jan 1 00:00 dsb_patt -rw-r--r-- 1 root root 4096 Jan 1 00:00 dsb_patt_ts -rw-r--r-- 1 root root 4096 Jan 1 00:00 dsb_patt_type drwxr-xr-x 2 root root 0 Jan 1 00:00 dsb_trig_patt -rw-r--r-- 1 root root 4096 Jan 1 00:00 dsb_trig_ts -rw-r--r-- 1 root root 4096 Jan 1 00:00 dsb_trig_type -rw-r--r-- 1 root root 4096 Jan 1 00:02 enable_source --w------- 1 root root 4096 Jan 1 00:00 integration_test drwxr-xr-x 2 root root 0 Jan 1 00:00 power --w------- 1 root root 4096 Jan 1 00:02 reset_dataset lrwxrwxrwx 1 root root 0 Apr 5 2021 subsystem -> ../../../../../bus/coresight -rw-r--r-- 1 root root 4096 Apr 5 2021 uevent -r--r--r-- 1 root root 4096 Jan 1 00:00 waiting_for_supplier We can use the commands are similar to the below to configure the TPDMs which support DSB subunit. Enable coresight sink first. echo 1 > /sys/bus/coresight/devices/tmc_etf0/enable_sink echo 1 > /sys/bus/coresight/devices/tpdm1/reset_dataset echo 0x3 > /sys/bus/coresight/devices/tpdm1/dsb_edge/ctrl_idx echo 0x1 > /sys/bus/coresight/devices/tpdm1/dsb_edge/ctrl_mask echo 0x0 > /sys/bus/coresight/devices/tpdm1/dsb_edge/ctrl_val echo 1 > /sys/bus/coresight/devices/tpdm1/dsb_patt/enable_ts echo 1 > /sys/bus/coresight/devices/tpdm1/dsb_patt/set_type echo 0 > /sys/bus/coresight/devices/tpdm1/dsb_trig_ts echo 0xFFFFFFFF > /sys/bus/coresight/devices/tpdm1/dsb_patt/tpmr5 echo 0xFFFFFFFF > /sys/bus/coresight/devices/tpdm1/dsb_trig_patt/xpr2 echo 1 > /sys/bus/coresight/devices/tpdm1/enable_source TPDM_DSB commit tree: https://git.codelinaro.org/clo/linux-kernel/coresight/-/tree/tpdm-dsb-v9 https://git.codelinaro.org/clo/linux-kernel/coresight/-/commits/tpdm-dsb-v9 Changes in V9: 1. Adjust the alignment for all the patches in this series. -- Suzuki K Poulose 2. Initialize the variable "ret" to 0 in the patch#4. -- Suzuki K Poulose 3. Change the kernel version to 6.7 for all the sysfs files in the documents for this patch series. -- Suzuki K Poulose 4. Remove the parameter "max" from the general read/write functions in the patch#9 and patch#10. -- Suzuki K Poulose 5. Avoid releasing the lock in two different places in the patch#10. -- Suzuki K Poulose 6. Rename "dsb_patt_ts" to "enable_ts", and rename "dsb_patt_type" to "set_type" in the patch#11. Move these two sysfs files to the folder "dsb_patt". -- Suzuki K Poulose 7. Clear the relevant fields first in the function "set_dsb_tier". -- Suzuki K Poulose 8. Reading/writing the TIER register in the function "set_dsb_tier". -- Suzuki K Poulose 9. Read the property "qcom,dsb_msr_num" during probe. -- Suzuki K Poulose 10. Move the variable "dsb_msr_num" to "drvdata". -- Suzuki K Poulose 11. Move the msr number check to simple tpdm sysfs API. -- Suzuki K Poulose 12. Remove the needless "msr number" check in the function "tpdm_reset_datasets" -- Suzuki K Poulose Changes in V8: 1. Refine the function "tpda_set_element_size" and rename it to "tpda_get_element_size" in the patch#4. -- Suzuki K Poulose 2. Refine the functioin "tpda_enable_port" in the patch#4. -- Suzuki K Poulose 3. Write a helper to check if the TPDM has DSB dataset in the patch#5. -- Suzuki K Poulose 4. Move the function "tpdm_reset_datasets" to "datasets_setup" to call in the patch#5. -- Suzuki K Poulose 5. Refine the comment of DSB in "tpdm_drvdata" in the patch#5. -- Suzuki K Poulose 6. Refine the comments in the documents for this patch series. -- Suzuki K Poulose 7. Adjust the code alignment in this patch series. -- Suzuki K Poulose 8. Combine the mode related functions to one in the patch#8. -- Suzuki K Poulose 9. Refine the R/W functions of "dsb_mode" in the patch#8. -- Suzuki K Poulose 10. Adjust the macros of mode in the TPDM header file in the patch#8. -- Suzuki K Poulose 11. Remove the unused code and fix the warnings in compiling for the patch#9. -- kernel test robot 12. Use the following sysfs nodes to read/set edge control related value in the patch#9. dsb_edge/ \- ctrl_idx -> Set the index number \- ctrl_val -> Set the edge control value \- ctrl_mask -> Set the edge control mask \- edcr0 ... edcr15 -> Read the edge control value \- edcmr0 ... edcmr7 -> Read the edge control mask -- Suzuki K Poulose 13. Use the following sysfs nodes to read/set DSB trigger pattern value and mask in the patch#10. dsb_trig_patt/ \- xpr0 ... xpr15 -> (RW) Set/Get the value \- xpmr0 ... xpmr7 -> (RW) Set/Get the mask -- Suzuki K Poulose 14. Use the following sysfs nodes to read/set DSB pattern value and mask in the patch#11. dsb_patt/ \- tpr0 ... tpr15 -> (RW) Set/Get the value \- tpmr0 ... tpmr7 -> (RW) Set/Get the mask -- Suzuki K Poulose 15. Add "Acked-by" tag to the patch#12. -- Rob Herring 16. Use the following sysfs nodes to read/set DSB MSR in the patch#13. dsb_msr/ \- msr0 ... msr31 -> (RW) Set/Get the value -- Suzuki K Poulose 17. Create the maximal number of DSB MSR sysfs nodes if the TPDM supports DSB MSR. Write the values set by user space to the DSB MSR according to the number of MSR supported by the TPDM. -- Suzuki K Poulose Changes in V7: 1. Since the "One value" limitation on SysFs file usage, add the nodes to read/write the index number for configuring the DSB TPDM. The following index number nodes are added. "dsb_edge_ctrl_idx" in the patch #9 "dsb_trig_patt_idx" in the patch #10 "dsb_patt_idx" in the patch #11 "dsb_msr_idx" in the patch #13 -- Suzuki K Poulose Changes in V6: 1. Align the code to fix the styling issue. -- Suzuki K Poulose Changes in V5: 1. Correct data type for DSB element size in dt-bindings patch. 2. Refine the recursive function "tpda_set_element_size". -- Suzuki K Poulose 3. Get return value of the function "__tpda_enable" in "tpda_enable". -- Suzuki K Poulose 4. Refine the comments on "dsb_esize". -- Suzuki K Poulose 5. Split the chage that introduce the subtype "SUBTYPE_SOURCE_TPDM" to Coresight driver. -- Suzuki K Poulose 6. Inline the trigger type setting to "tpdm_enable_dsb" simply. -- Suzuki K Poulose 7. Split the change that remove the needless CS_{UN,}LOCK in the function "tpdm_datasets_setup". -- Suzuki K Poulose 8. Remove the disablement step in the reset node. -- Suzuki K Poulose 9. Update the kernel version to 6.5 in the sysfs document. -- Suzuki K Poulose 10. Remove the needless check in "tpdm_dsb_is_visible". -- Suzuki K Poulose 11. Change the macro to mask the mode of DSB TPDM. -- Suzuki K Poulose 12. Add a check to make sure "sysfs_emit_at" calling will not cause overflow. -- Suzuki K Poulose 13. Change the macro to get "edge_ctrl" value. -- Suzuki K Poulose 14. Remove the needless comments in the sysfs document. -- Suzuki K Poulose 15. Replace "TPDM_DSB_MAX_PATT" with "drvdata->dsb->msr_num" in "dsb_msr_show". -- Suzuki K Poulose 16. Update the check of MSR number in "dsb_msr_store". -- Suzuki K Poulose 17. Write data to the MSR registers in the DSB TPDM enablement function. -- Suzuki K Poulose Changes in V4: 1. Change the range of the property "qcom,dsb-element-size", and change the type to enumeration. -- Suzuki K Poulose, Krzysztof Kozlowski 2. Change dsb_esize from 32 bits to 8 bits. -- Suzuki K Poulose 3. Update the function tpda_set_element_size since James has updated the dependency series. Meanwhile, it will send out a warning if it detects more than one TPDM from the same TPDA input port. -- Suzuki K Poulose 4. Add a source_sub_type for TPDM to distinguish TPDM from the other coresight source. -- Suzuki K Poulose 5. Return error if the element size is not configured on devicetree in TPDA enablement. -- Suzuki K Poulose 6. Move memory allocation from "tpdm_init_datasets" to "tpdm_datasets_setup". Rename "tpdm_init_datasets" as "tpdm_reset_datasets". -- Suzuki K Poulose 7. Replace "coresight_disable" with "coresight_disable_source" to disable the TPDM in resetting. -- Suzuki K Poulose 8. Make sure "drvdata" is not NULL pointer before using it. -- Suzuki K Poulose 9. Change "set_dsb_cycacc_mode" to "set_dsb_test_mode" since cycle accurate mode is not supported on the current targets. It is replaced by test mode. 10. Document the value of "dsb_mode". -- Suzuki K Poulose 11. Macros are used to replace the formulas on dsb edge control nodes. -- Suzuki K Poulose 12. Document the values of "dsb_trig_patt_val" and "dsb_trig_patt_mask". -- Suzuki K Poulose 13. Combine two pattern related loops to one. And move DSB TIER register configurations to the new function "set_dsb_tier". -- Suzuki K Poulose 14. Rename the property "qcom,dsb_msr_num" to "qcom,dsb-msrs-num". -- Suzuki K Poulose, Krzysztof Kozlowski Changes in V3: 1. Move the property "qcom,dsb-element-size" to TPDM devicetree and update the TPDM yaml file for this item. -- Suzuki K Poulose 2. Add the error message when the DSB element size is not set to 32-bit or 64-bit. -- Suzuki K Poulose 3. Add more information to the comments of patch #3 -- Suzuki K Poulose 4. Combine the value updates to the TPDM_DSB_CR for TPDM. -- Suzuki K Poulose 5. Remove the function "tpdm_datasets_alloc", and fold its code to a new function "tpdm_init_datasets". It will complete the initialization of TPDM. -- Suzuki K Poulose 6. Change the method of qualifying input values. -- Suzuki K Poulose 7. Add the documentation of the new sysfs handles. -- Suzuki K Poulose 8. Provide the separate handles for the "mode bits". -- Suzuki K Poulose Changes in V2: 1. Change the name of the property "qcom,dsb-elem-size" to "qcom,dsb-element-size" -- Suzuki K Poulose 2. Update the TPDA yaml file for the item "qcom,dsb-elem-size". -- Krzysztof Kozlowski 3. Add the full name of DSB in the description of the item "qcom,dsb-elem-size". -- Rob Herring Changes in V1: 1. Change the definition of the property "qcom,dsb-elem-size" from "uint32-array" to "uint32-matrix". -- Krzysztof Kozlowski 2. Add the full name of DSB. -- Rob Herring 3. Deal with 2 entries in an iteration in TPDA driver. -- Suzuki K Poulose 4. Divide the function "tpdm_datasets_alloc" into two functions, "tpdm_datasets_setup" and "tpdm_datasets_alloc". 5. Detecte the input string with the conventional semantics automatically, and constrain the size of the input value. -- Suzuki K Poulose 6. Use the hook function "is_visible()" to hide the DSB related knobs if the data sets are missing. -- Suzuki K Poulose 7. Use the macros "FIELD_GET" and "FIELD_PREP" to set the values. -- Suzuki K Poulose 8. Update the definition of the macros in TPDM driver. 9. Update the comments of the values for the nodes which are for DSB element creation and onfigure pattern match output. -- Suzuki K Poulose 10. Use API "sysfs_emit" to "replace scnprintf". -- Suzuki K Poulose Tao Zhang (13): coresight-tpdm: Remove the unnecessary lock dt-bindings: arm: Add support for DSB element size coresight-tpdm: Introduce TPDM subtype to TPDM driver coresight-tpda: Add DSB dataset support coresight-tpdm: Initialize DSB subunit configuration coresight-tpdm: Add reset node to TPDM node coresight-tpdm: Add nodes to set trigger timestamp and type coresight-tpdm: Add node to set dsb programming mode coresight-tpdm: Add nodes for dsb edge control coresight-tpdm: Add nodes to configure pattern match output coresight-tpdm: Add nodes for timestamp request dt-bindings: arm: Add support for DSB MSR register coresight-tpdm: Add nodes for dsb msr support .../ABI/testing/sysfs-bus-coresight-devices-tpdm | 159 +++++ .../bindings/arm/qcom,coresight-tpdm.yaml | 20 + drivers/hwtracing/coresight/coresight-core.c | 3 + drivers/hwtracing/coresight/coresight-tpda.c | 126 +++- drivers/hwtracing/coresight/coresight-tpda.h | 2 + drivers/hwtracing/coresight/coresight-tpdm.c | 714 ++++++++++++++++++++- drivers/hwtracing/coresight/coresight-tpdm.h | 161 +++++ include/linux/coresight.h | 1 + 8 files changed, 1164 insertions(+), 22 deletions(-) -- 2.7.4

1 year, 7 months

[RFC PATCH v3 0/8] Coresight for Kernel panic and watchdog reset

by Linu Cherian

This RFC v3 patch series is rebased on v6.5-rc7 and is dependent on the below two patches. - coresight: tmc: Make etr buffer mode user configurable from sysfs[1] - coresight: Fix run time warnings while reusing ETR buffer[2] Changelog from v2: * ETR reserved buffer mode can be selected only through the new sysfs buffer mode and not by default. This would avoid any conflicts with normal usage. * ETR buffer size in reserved mode is now always fixed to the maximum size of the reserved buffer and not user configurable. This avoids any conflicts with the default buffer size used in other ETR buffer modes. * Introduced new ops called prevboot_ops to factor out common code in tmc_etr_prepare_prevboot() and tmc_etb_prepare_prevboot(). spin_lock/unlock invocations tmc_read_prepare_* are now in a single function. * Added more stringent checks for selecting READ_PREVBOOT mode Other misc changes: * Added more details to DT bindings documentation * Fixed unhandled case error in etm4_disable with CONFIG_WERROR * TMC register saving now uses standard accessor functions * Added panic notifier unregistration * memremap of reserved and metadata buffers are now with _WB attributes * Cover letter title has been shortened. Changelog from v1: * V2 is a complete patchset with kernel panic trace tested on Linux 6.4. Details on testing with relevant console logs has been added for reference. * Two additional patches(patch 6 & 7) has been included to manage stopping of trace at the time of kernel panic. * Few bug fixes. RFC v1 is posted here: https://lists.linaro.org/archives/list/coresight@lists.linaro.org/thread/6F… Using Coresight for Kernel panic and Watchdog reset =================================================== This RFC is about extending Linux coresight driver support to address kernel panic and watchdog reset scenarios. This would help coresight users to debug kernel panic and watchdog reset with the help of coresight trace data. Coresight trace capture: Kernel panic ------------------------------------- From the coresight driver point of view, addressing the kernel panic situation has four main requirements. a. Support for allocation of trace buffer pages from reserved memory area. Platform can advertise this using a new device tree property added to relevant coresight nodes. b. Support for stopping coresight blocks at the time of panic c. Saving required metadata in the specified format d. Support for reading trace data captured at the time of panic Allocation of trace buffer pages from reserved RAM ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A new optional device tree property "memory-region" is added to the ETR/ETF device nodes, that would give the base address and size of trace buffer. Static allocation of trace buffers would ensure that both IOMMU enabled and disabled cases are handled. Also, platforms that support persistent RAM will allow users to read trace data in the subsequent boot without booting the crashdump kernel. Note: For ETR sink devices, this reserved region will be used for both trace capture and trace data retrieval. For ETF sink devices, internal SRAM would be used for trace capture, and they would be synced to reserved region for retrieval. Note: Patches 1 & 2 adds support for this. Disabling coresight blocks at the time of panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In order to avoid the situation of losing relevant trace data after a kernel panic, it would be desirable to stop the coresight blocks at the time of panic. This can be achieved by configuring the comparator, CTI and sink devices as below, Comparator(triggers on kernel panic) --->External out --->CTI -- | ETR/ETF stop <------External In <-------------- Note: * Patch 6 provides the necessary ETR configuration. * Patch 7 provides the necessary ETM configuration. Saving metadata at the time of kernel panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Coresight metadata involves all additional data that are required for a successful trace decode in addition to the trace data. This involves ETR/ETF, ETE register snapshot etc. A new optional device property "memory-region" is added to the ETR/ETF/ETE device nodes for this. Note: Patches 3 & 4 adds support for this. Reading trace data captured at the time of panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Trace data captured at the time of panic, can be read from rebooted kernel or from crashdump kernel using the below mentioned interface. Note: Patch 5 adds support for this. Steps for reading trace data captured in previous boot ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1. cd /sys/bus/coresight/devices/tmc_etrXX/ 2. Change to special mode called, read_prevboot. #echo 1 > read_prevboot 3. Dump trace buffer data to a file, #dd if=/dev/tmc_etrXX of=~/cstrace.bin 4. Reset back to normal mode #echo 0 > read_prevboot General flow of trace capture and decode incase of kernel panic ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1. Enable source and sink on all the cores using the sysfs interface. ETR sink will have trace buffers allocated from reserved memory, by selecting "resrv" buffer mode from sysfs. 2. Run relevant tests. 3. On a kernel panic, all coresight blocks are disabled, necessary metadata is synced by kernel panic handler. System would eventually reboot or boot a crashdump kernel. 4. For platforms that supports crashdump kernel, raw trace data can be dumped using the coresight sysfs interface from the crashdump kernel itself. Persistent RAM is not a requirement in this case. 5. For platforms that supports persistent RAM, trace data can be dumped using the coresight sysfs interface in the subsequent Linux boot. Crashdump kernel is not a requirement in this case. Persistent RAM ensures that trace data is intact across reboot. Coresight trace capture: Watchdog reset --------------------------------------- The main difference between addressing the watchdog reset and kernel panic case are below, a. Saving coresight metadata need to be taken care by the SCP(system control processor) firmware in the specified format, instead of kernel. b. Reserved memory region given by firmware for trace buffer and metadata has to be in persistent RAM. Note: This is a requirement for watchdog reset case but optional in kernel panic case. Watchdog reset can be supported only on platforms that meet the above two requirements. Testing Kernel panic on Linux 6.5 --------------------------------- 1. Configure CTI using sysfs interface #./cti_setup.sh #cat cti_setup.sh cd /sys/bus/coresight/devices/ ap_cti_config () { #ETM trig out[0] trigger to Channel 0 echo 0 4 > channels/trigin_attach } etf_cti_config () { #ETF Flush in trigger from Channel 0 echo 0 1 > channels/trigout_attach echo 1 > channels/trig_filter_enable } etr_cti_config () { #ETR Flush in from Channel 0 echo 0 1 > channels/trigout_attach echo 1 > channels/trig_filter_enable } ctidevs=`find . -name "cti*"` for i in $ctidevs do cd $i connection=`find . -name "ete*"` if [ ! -z "$connection" ] then echo "AP CTI config for $i" ap_cti_config fi connection=`find . -name "tmc_etf*"` if [ ! -z "$connection" ] then echo "ETF CTI config for $i" etf_cti_config fi connection=`find . -name "tmc_etr*"` if [ ! -z "$connection" ] then echo "ETR CTI config for $i" etr_cti_config fi cd .. done Note: CTI connections are SOC specific and hence the above script is added just for reference. 2. Start Coresight tracing on cores 1 and 2 using sysfs interface 3. Run some application on core 1 #taskset -c 1 dd if=/dev/urandom of=/dev/null & 4. Invoke kernel panic on core 2 #echo 1 > /proc/sys/kernel/panic #taskset -c 2 echo c > /proc/sysrq-trigger 5. From rebooted kernel, enable previous boot mode #echo 1 > /sys/bus/coresight/devices/tmc_etr0/read_prevboot 6. Read trace data #dd if=/dev/tmc_etr0 of=/trace/cstrace.bin 7. Run opencsd decoder tools/scripts to generate the instruction trace. Core 1 instruction trace dump: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> A etm4_enable_hw: ffff800008ae1dd4 CONTEXT EL2 etm4_enable_hw: ffff800008ae1dd4 I etm4_enable_hw: ffff800008ae1dd4: d503201f nop I etm4_enable_hw: ffff800008ae1dd8: d503201f nop I etm4_enable_hw: ffff800008ae1ddc: d503201f nop I etm4_enable_hw: ffff800008ae1de0: d503201f nop I etm4_enable_hw: ffff800008ae1de4: d503201f nop I etm4_enable_hw: ffff800008ae1de8: d503233f paciasp I etm4_enable_hw: ffff800008ae1dec: a9be7bfd stp x29, x30, [sp, #-32]! I etm4_enable_hw: ffff800008ae1df0: 910003fd mov x29, sp I etm4_enable_hw: ffff800008ae1df4: a90153f3 stp x19, x20, [sp, #16] I etm4_enable_hw: ffff800008ae1df8: 2a0003f4 mov w20, w0 I etm4_enable_hw: ffff800008ae1dfc: 900085b3 adrp x19, ffff800009b95000 <reserved_mem+0xc48> I etm4_enable_hw: ffff800008ae1e00: 910f4273 add x19, x19, #0x3d0 I etm4_enable_hw: ffff800008ae1e04: f8747a60 ldr x0, [x19, x20, lsl #3] E etm4_enable_hw: ffff800008ae1e08: b4000140 cbz x0, ffff800008ae1e30 <etm4_starting_cpu+0x50> I 149.039572921 etm4_enable_hw: ffff800008ae1e30: a94153f3 ldp x19, x20, [sp, #16] I 149.039572921 etm4_enable_hw: ffff800008ae1e34: 52800000 mov w0, #0x0 // #0 I 149.039572921 etm4_enable_hw: ffff800008ae1e38: a8c27bfd ldp x29, x30, [sp], #32 ..snip 149.052324811 chacha_block_generic: ffff800008642d80: 9100a3e0 add x0, I 149.052324811 chacha_block_generic: ffff800008642d84: b86178a2 ldr w2, [x5, x1, lsl #2] I 149.052324811 chacha_block_generic: ffff800008642d88: 8b010803 add x3, x0, x1, lsl #2 I 149.052324811 chacha_block_generic: ffff800008642d8c: b85fc063 ldur w3, [x3, #-4] I 149.052324811 chacha_block_generic: ffff800008642d90: 0b030042 add w2, w2, w3 I 149.052324811 chacha_block_generic: ffff800008642d94: b8217882 str w2, [x4, x1, lsl #2] I 149.052324811 chacha_block_generic: ffff800008642d98: 91000421 add x1, x1, #0x1 I 149.052324811 chacha_block_generic: ffff800008642d9c: f100443f cmp x1, #0x11 Core 2 instruction trace dump(kernel panic triggered core): ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ A etm4_enable_hw: ffff800008ae1dd4 CONTEXT EL2 etm4_enable_hw: ffff800008ae1dd4 I etm4_enable_hw: ffff800008ae1dd4: d503201f nop I etm4_enable_hw: ffff800008ae1dd8: d503201f nop I etm4_enable_hw: ffff800008ae1ddc: d503201f nop I etm4_enable_hw: ffff800008ae1de0: d503201f nop I etm4_enable_hw: ffff800008ae1de4: d503201f nop I etm4_enable_hw: ffff800008ae1de8: d503233f paciasp I etm4_enable_hw: ffff800008ae1dec: a9be7bfd stp x29, x30, [sp, #-32]! I etm4_enable_hw: ffff800008ae1df0: 910003fd mov x29, sp I etm4_enable_hw: ffff800008ae1df4: a90153f3 stp x19, x20, [sp, #16] I etm4_enable_hw: ffff800008ae1df8: 2a0003f4 mov w20, w0 I etm4_enable_hw: ffff800008ae1dfc: 900085b3 adrp x19, ffff800009b95000 <reserved_mem+0xc48> I etm4_enable_hw: ffff800008ae1e00: 910f4273 add x19, x19, #0x3d0 I etm4_enable_hw: ffff800008ae1e04: f8747a60 ldr x0, [x19, x20, lsl #3] E etm4_enable_hw: ffff800008ae1e08: b4000140 cbz x0, ffff800008ae1e30 <etm4_starting_cpu+0x50> I 149.046243445 etm4_enable_hw: ffff800008ae1e30: a94153f3 ldp x19, x20, [sp, #16] I 149.046243445 etm4_enable_hw: ffff800008ae1e34: 52800000 mov w0, #0x0 // #0 I 149.046243445 etm4_enable_hw: ffff800008ae1e38: a8c27bfd ldp x29, x30, [sp], #32 I 149.046243445 etm4_enable_hw: ffff800008ae1e3c: d50323bf autiasp E 149.046243445 etm4_enable_hw: ffff800008ae1e40: d65f03c0 ret A ete_sysreg_write: ffff800008adfa18 ..snip I 149.05422547 panic: ffff800008096300: a90363f7 stp x23, x24, [sp, #48] I 149.05422547 panic: ffff800008096304: 6b00003f cmp w1, w0 I 149.05422547 panic: ffff800008096308: 3a411804 ccmn w0, #0x1, #0x4, ne // ne = any N 149.05422547 panic: ffff80000809630c: 540001e0 b.eq ffff800008096348 <panic+0xe0> // b.none I 149.05422547 panic: ffff800008096310: f90023f9 str x25, [sp, #64] E 149.05422547 panic: ffff800008096314: 97fe44ef bl ffff8000080276d0 <panic_smp_self_stop> A panic: ffff80000809634c I 149.05422547 panic: ffff80000809634c: 910102d5 add x21, x22, #0x40 I 149.05422547 panic: ffff800008096350: 52800020 mov w0, #0x1 // #1 E 149.05422547 panic: ffff800008096354: 94166b8b bl ffff800008631180 <bust_spinlocks> N 149.054225518 bust_spinlocks: ffff800008631180: 340000c0 cbz w0, ffff800008631198 <bust_spinlocks+0x18> I 149.054225518 bust_spinlocks: ffff800008631184: f000a321 adrp x1, ffff800009a98000 <pbufs.0+0xbb8> I 149.054225518 bust_spinlocks: ffff800008631188: b9405c20 ldr w0, [x1, #92] I 149.054225518 bust_spinlocks: ffff80000863118c: 11000400 add w0, w0, #0x1 I 149.054225518 bust_spinlocks: ffff800008631190: b9005c20 str w0, [x1, #92] E 149.054225518 bust_spinlocks: ffff800008631194: d65f03c0 ret A panic: ffff800008096358 TODO ---- * Change ETM configuration done in patch #7 to new system configuration manager profile * Change CTI sysfs script to system configuration manager profile * Reading tracedata from crashdump kernel is not tested. * Perf based trace capture and decode is not tested. 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 tracedata from previous boot coresight: tmc: Stop trace capture on FlIn coresight: etm4x: Configure ETM to trigger on panic coresight: cti: Add CTI id for Neoverse N2 core CTI .../bindings/arm/arm,coresight-tmc.yaml | 13 + drivers/hwtracing/coresight/coresight-core.c | 32 ++ .../hwtracing/coresight/coresight-cti-core.c | 1 + .../coresight/coresight-etm4x-core.c | 18 +- drivers/hwtracing/coresight/coresight-etm4x.h | 26 ++ .../hwtracing/coresight/coresight-tmc-core.c | 146 +++++++++- .../hwtracing/coresight/coresight-tmc-etf.c | 126 +++++++- .../hwtracing/coresight/coresight-tmc-etr.c | 274 +++++++++++++++++- drivers/hwtracing/coresight/coresight-tmc.h | 48 +++ include/linux/coresight.h | 25 ++ 10 files changed, 701 insertions(+), 8 deletions(-) Links: 1. https://lore.kernel.org/linux-arm-kernel/20230818082112.554638-1-anshuman.k… 2. https://lore.kernel.org/linux-arm-kernel/20230823042948.12879-1-lcherian@ma… -- 2.41.0

1 year, 7 months

Re: [PATCH] perf cs-etm: Fix missing decoder for per-process trace

by James Clark

On 19/09/2023 23:45, Besar Wicaksono wrote: > The decoder creation for raw trace uses metadata from the first CPU. > On per-process/per-thread traces, the first CPU is CPU0. If CPU0 trace > is not enabled, its metadata will be marked unused and the decoder is > not created. Perf report dump skips the decoding part because the > decoder is missing. > Hi Besar, It's not just per-process trace, the bug is also in per-cpu mode but it means that the metadata from CPU 0 is used for every decoder which is wrong. Although your change also fixes this issue. > To fix this, use metadata of the CPU associated with sample object. > > Signed-off-by: Besar Wicaksono <bwicaksono(a)nvidia.com> > --- > tools/perf/util/cs-etm.c | 130 +++++++++++++++++++++++---------------- > 1 file changed, 77 insertions(+), 53 deletions(-) > [...] > + if (!formatted) { > + /* > + * There is only one decoder when unformatted. Use metadata of > + * sample AUX cpu. > + */ > + t_param = t_params; > + metadata = get_cpu_data(etm, sample_cpu); > + if (!metadata) { > + pr_err("CS_ETM: invalid sample CPU: %d\n", sample_cpu); > return -EINVAL; > } Apart from Mike's comments, this looks ok. Thanks for fixing this it has been on our list for a while. One issue with calling get_cpu_data() with the sample CPU ID is that it won't work with old files that don't have the CPU sample flag set. Mike added the sample flag fairly recently, and I don't think that was a breaking change for old files at that time. It should be easy to avoid that by still returning the metadata from CPU 0 when CPU = -1 (Which isn't correct but is 99% likely to work). I checked the Coresight tests and they're all passing, at least on a system without ETE. If you could make sure they're all passing for you as well that would be great: sudo ./perf test coresight I think they currently only work from an in source build, if you get stuck there. Thanks James

1 year, 7 months

Jump to page:

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

CoreSight