[PATCH v5 00/12] fix several inconsistencies with sysfs configuration in etmX

[PATCH v5 00/12] fix several inconsistencies with sysfs configuration in etmX

[Yeoreum Yun]

The current ETMx configuration via sysfs can lead to the following
inconsistencies:

  - If a configuration is modified via sysfs while a perf session is
    active, the running configuration may differ between before
    a sched-out and after a subsequent sched-in.

  - If a perf session and sysfs session tries to enable concurrently,
    configuration from configfs could be corrupted (etm4).

  - There is chance to corrupt drvdata->config if perf session tries
    to enabled among handling cscfg_csdev_disable_active_config()
    in etm4_disable_sysfs() (etm4).

To resolve these inconsistencies, the configuration should be separated into:

  - active_config, which is applied configuration for the current session
  - config, which stores the settings configured via sysfs.

and apply configuration from configfs after taking a mode.

Also, This patch set includes some small fixes:
  - missing trace id release in etm4x.
  - underflow issue for nrseqstate.
  - wrong check in etm4x_sspcicrn_present().

This patch based on v7.0

Patch History
=============
from v4 to v5:
  - add rb-tag.
  - fix underflow issue for nrseqstate.
  - fix wrong check in etm4_sspcicrn_present().
  - remove redundant fields on etmv4_save_state.
  - rename caps->ss_status to ss_cmp.
  - fix wrong location of etm4_release_trace_id.
  - https://lore.kernel.org/all/20260413142003.3549310-1-yeoreum.yun@arm.com/

from v3 to v4:
  - change etm_drvdata->spinlock type to raw_spin_lock_t
  - remove redundant call etmX_enable_hw() with starting_cpu() callsback.
  - fix missing trace id release.
  - add missing docs.
  - https://lore.kernel.org/all/20260412175506.412301-1-yeoreum.yun@arm.com/

from v2 to v3:
  - fix build error for etm3x.
  - fix checkpatch warning.
  - https://lore.kernel.org/all/20260410074310.2693385-1-yeoreum.yun@arm.com/

from v1 to v2
  - rebased to v7.0-rc7.
  - introduce etmX_caps structure to save etmX's capabilities.
  - remove ss_status from etmv4_config.
  - modify active_config after taking a mode (perf/sysfs).
  - https://lore.kernel.org/all/20260317181705.2456271-1-yeoreum.yun@arm.com/

Yeoreum Yun (12):
  coresight: etm4x: fix wrong check of etm4x_sspcicrn_present()
  coresight: etm4x: fix underflow for nrseqstate
  coresight: etm4x: introduce struct etm4_caps
  coresight: etm4x: exclude ss_status from drvdata->config
  coresight: etm4x: remove redundant fields in etmv4_save_state
  coresight: etm4x: fix leaked trace id
  coresight: etm4x: fix inconsistencies with sysfs configuration
  coresight: etm4x: remove redundant call etm4_enable_hw() with hotplug
  coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t
  coresight: etm3x: introduce struct etm_caps
  coresight: etm3x: fix inconsistencies with sysfs configuration
  coresight: etm3x: remove redundant call etm_enable_hw() with hotplug

 drivers/hwtracing/coresight/coresight-etm.h   |  46 ++-
 .../coresight/coresight-etm3x-core.c          | 100 ++---
 .../coresight/coresight-etm3x-sysfs.c         | 159 ++++----
 .../hwtracing/coresight/coresight-etm4x-cfg.c |   3 +-
 .../coresight/coresight-etm4x-core.c          | 374 ++++++++++--------
 .../coresight/coresight-etm4x-sysfs.c         | 199 ++++++----
 drivers/hwtracing/coresight/coresight-etm4x.h | 190 ++++-----
 7 files changed, 588 insertions(+), 483 deletions(-)


base-commit: 028ef9c96e96197026887c0f092424679298aae8
--
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 01/12] coresight: etm4x: fix wrong check of etm4x_sspcicrn_present()

[Yeoreum Yun]

According to Embedded Trace Macrocell Architecture Specification
ETMv4.0 to ETM4.6 [0], TRCSSPCICR<n> is present only if all of
the following are true:

  - TRCIDR4.NUMSSCC > n.
  - TRCIDR4.NUMPC > 0b0000.
  - TRCSSCSR<n>.PC == 0b1.

Comment for etm4x_sspcicrn_present() is align with the specification.
However, the check should use drvdata->nr_pe_cmp to check TRCIDR4.NUMPC
not nr_pe.

Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index d565a73f0042..74b7063d130e 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -89,7 +89,7 @@ static int etm4_probe_cpu(unsigned int cpu);
 static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
 {
 	return (n < drvdata->nr_ss_cmp) &&
-	       drvdata->nr_pe &&
+	       drvdata->nr_pe_cmp &&
 	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
 }
 
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

Re: [PATCH v5 01/12] coresight: etm4x: fix wrong check of etm4x_sspcicrn_present()

[Leo Yan]

On Wed, Apr 15, 2026 at 05:55:17PM +0100, Yeoreum Yun wrote:
> According to Embedded Trace Macrocell Architecture Specification
> ETMv4.0 to ETM4.6 [0], TRCSSPCICR<n> is present only if all of
> the following are true:
> 
>   - TRCIDR4.NUMSSCC > n.
>   - TRCIDR4.NUMPC > 0b0000.
>   - TRCSSCSR<n>.PC == 0b1.
> 
> Comment for etm4x_sspcicrn_present() is align with the specification.
> However, the check should use drvdata->nr_pe_cmp to check TRCIDR4.NUMPC
> not nr_pe.
> 
> Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>

Reviewed-by: Leo Yan <leo.yan@arm.com>

[PATCH v5 02/12] coresight: etm4x: fix underflow for nrseqstate

[Yeoreum Yun]

TCRSEQEVR<n> is implemented only when TCRIDR5.NUMSEQSTATE is 0b100,
in which case n ranges from 0 to 2; otherwise, TCRIDR5.NUMSEQSTATE is 0b000.

Therefore, drvdata->nrseqstate should be checked before entering the loop.

Link: https://developer.arm.com/documentation/ihi0064/latest/ [0]
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 .../hwtracing/coresight/coresight-etm4x-core.c | 18 ++++++++++--------
 .../coresight/coresight-etm4x-sysfs.c          |  2 ++
 2 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 74b7063d130e..ba5b8b423bd4 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -544,9 +544,11 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 	etm4x_relaxed_write32(csa, config->vissctlr, TRCVISSCTLR);
 	if (drvdata->nr_pe_cmp)
 		etm4x_relaxed_write32(csa, config->vipcssctlr, TRCVIPCSSCTLR);
-	for (i = 0; i < drvdata->nrseqstate - 1; i++)
-		etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i));
+
 	if (drvdata->nrseqstate) {
+		for (i = 0; i < drvdata->nrseqstate - 1; i++)
+			etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i));
+
 		etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR);
 		etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR);
 	}
@@ -1927,10 +1929,10 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	if (drvdata->nr_pe_cmp)
 		state->trcvipcssctlr = etm4x_read32(csa, TRCVIPCSSCTLR);
 
-	for (i = 0; i < drvdata->nrseqstate - 1; i++)
-		state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i));
-
 	if (drvdata->nrseqstate) {
+		for (i = 0; i < drvdata->nrseqstate - 1; i++)
+			state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i));
+
 		state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR);
 		state->trcseqstr = etm4x_read32(csa, TRCSEQSTR);
 	}
@@ -2058,10 +2060,10 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 	if (drvdata->nr_pe_cmp)
 		etm4x_relaxed_write32(csa, state->trcvipcssctlr, TRCVIPCSSCTLR);
 
-	for (i = 0; i < drvdata->nrseqstate - 1; i++)
-		etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i));
-
 	if (drvdata->nrseqstate) {
+		for (i = 0; i < drvdata->nrseqstate - 1; i++)
+			etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i));
+
 		etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR);
 		etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR);
 	}
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index e9eeea6240d5..d866dcfa2a36 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -1395,6 +1395,8 @@ static ssize_t seq_idx_store(struct device *dev,
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etmv4_config *config = &drvdata->config;
 
+	if (!drvdata->nrseqstate)
+		return -EINVAL;
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
 	if (val >= drvdata->nrseqstate - 1)
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

Re: [PATCH v5 02/12] coresight: etm4x: fix underflow for nrseqstate

[Leo Yan]

On Wed, Apr 15, 2026 at 05:55:18PM +0100, Yeoreum Yun wrote:
> TCRSEQEVR<n> is implemented only when TCRIDR5.NUMSEQSTATE is 0b100,
> in which case n ranges from 0 to 2; otherwise, TCRIDR5.NUMSEQSTATE is 0b000.

My suggestion in previous version is not quite right, thanks for
making this correct.

[...]

> @@ -1395,6 +1395,8 @@ static ssize_t seq_idx_store(struct device *dev,
>  	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
>  	struct etmv4_config *config = &drvdata->config;
>  
> +	if (!drvdata->nrseqstate)
> +		return -EINVAL;

For "nrseqstate = 0" case, would it return -EOPNOTSUPP instead?

Otherwise, LGTM:

Reviewed-by: Leo Yan <leo.yan@arm.com>

Re: [PATCH v5 02/12] coresight: etm4x: fix underflow for nrseqstate

[Yeoreum Yun]

Hi Leo,

> On Wed, Apr 15, 2026 at 05:55:18PM +0100, Yeoreum Yun wrote:
> > TCRSEQEVR<n> is implemented only when TCRIDR5.NUMSEQSTATE is 0b100,
> > in which case n ranges from 0 to 2; otherwise, TCRIDR5.NUMSEQSTATE is 0b000.
>
> My suggestion in previous version is not quite right, thanks for
> making this correct.
>
> [...]
>
> > @@ -1395,6 +1395,8 @@ static ssize_t seq_idx_store(struct device *dev,
> >  	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
> >  	struct etmv4_config *config = &drvdata->config;
> >
> > +	if (!drvdata->nrseqstate)
> > +		return -EINVAL;
>
> For "nrseqstate = 0" case, would it return -EOPNOTSUPP instead?
>
> Otherwise, LGTM:
>
> Reviewed-by: Leo Yan <leo.yan@arm.com>

Yeap. It's much better to return -ENOTSUPP in here.
I'll change it.

--
Sincerely,
Yeoreum Yun

[PATCH v5 03/12] coresight: etm4x: introduce struct etm4_caps

[Yeoreum Yun]

Introduce struct etm4_caps to describe ETMv4 capabilities
and move capabilities information into it.

Reviewed-by: Leo Yan <leo.yan@arm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 .../coresight/coresight-etm4x-core.c          | 234 +++++++++---------
 .../coresight/coresight-etm4x-sysfs.c         | 192 ++++++++------
 drivers/hwtracing/coresight/coresight-etm4x.h | 176 ++++++-------
 3 files changed, 329 insertions(+), 273 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index ba5b8b423bd4..b2b092a76eb5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -88,8 +88,9 @@ static int etm4_probe_cpu(unsigned int cpu);
  */
 static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
 {
-	return (n < drvdata->nr_ss_cmp) &&
-	       drvdata->nr_pe_cmp &&
+	const struct etmv4_caps *caps = &drvdata->caps;
+
+	return (n < caps->nr_ss_cmp) && caps->nr_pe_cmp &&
 	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
 }
 
@@ -160,17 +161,20 @@ static void ete_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit)
 static void etm_detect_os_lock(struct etmv4_drvdata *drvdata,
 			       struct csdev_access *csa)
 {
+	struct etmv4_caps *caps = &drvdata->caps;
 	u32 oslsr = etm4x_relaxed_read32(csa, TRCOSLSR);
 
-	drvdata->os_lock_model = ETM_OSLSR_OSLM(oslsr);
+	caps->os_lock_model = ETM_OSLSR_OSLM(oslsr);
 }
 
 static void etm_write_os_lock(struct etmv4_drvdata *drvdata,
 			      struct csdev_access *csa, u32 val)
 {
+	const struct etmv4_caps *caps = &drvdata->caps;
+
 	val = !!val;
 
-	switch (drvdata->os_lock_model) {
+	switch (caps->os_lock_model) {
 	case ETM_OSLOCK_PRESENT:
 		etm4x_relaxed_write32(csa, val, TRCOSLAR);
 		break;
@@ -179,7 +183,7 @@ static void etm_write_os_lock(struct etmv4_drvdata *drvdata,
 		break;
 	default:
 		pr_warn_once("CPU%d: Unsupported Trace OSLock model: %x\n",
-			     smp_processor_id(), drvdata->os_lock_model);
+			     smp_processor_id(), caps->os_lock_model);
 		fallthrough;
 	case ETM_OSLOCK_NI:
 		return;
@@ -494,6 +498,7 @@ static int etm4_enable_trace_unit(struct etmv4_drvdata *drvdata)
 static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 {
 	int i, rc;
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 	struct coresight_device *csdev = drvdata->csdev;
 	struct device *etm_dev = &csdev->dev;
@@ -525,14 +530,14 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 	if (etm4x_wait_status(csa, TRCSTATR_IDLE_BIT, 1))
 		dev_err(etm_dev,
 			"timeout while waiting for Idle Trace Status\n");
-	if (drvdata->nr_pe)
+	if (caps->nr_pe)
 		etm4x_relaxed_write32(csa, config->pe_sel, TRCPROCSELR);
 	etm4x_relaxed_write32(csa, config->cfg, TRCCONFIGR);
 	/* nothing specific implemented */
 	etm4x_relaxed_write32(csa, 0x0, TRCAUXCTLR);
 	etm4x_relaxed_write32(csa, config->eventctrl0, TRCEVENTCTL0R);
 	etm4x_relaxed_write32(csa, config->eventctrl1, TRCEVENTCTL1R);
-	if (drvdata->stallctl)
+	if (caps->stallctl)
 		etm4x_relaxed_write32(csa, config->stall_ctrl, TRCSTALLCTLR);
 	etm4x_relaxed_write32(csa, config->ts_ctrl, TRCTSCTLR);
 	etm4x_relaxed_write32(csa, config->syncfreq, TRCSYNCPR);
@@ -542,19 +547,19 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 	etm4x_relaxed_write32(csa, config->vinst_ctrl, TRCVICTLR);
 	etm4x_relaxed_write32(csa, config->viiectlr, TRCVIIECTLR);
 	etm4x_relaxed_write32(csa, config->vissctlr, TRCVISSCTLR);
-	if (drvdata->nr_pe_cmp)
+	if (caps->nr_pe_cmp)
 		etm4x_relaxed_write32(csa, config->vipcssctlr, TRCVIPCSSCTLR);
 
-	if (drvdata->nrseqstate) {
-		for (i = 0; i < drvdata->nrseqstate - 1; i++)
+	if (caps->nrseqstate) {
+		for (i = 0; i < caps->nrseqstate - 1; i++)
 			etm4x_relaxed_write32(csa, config->seq_ctrl[i], TRCSEQEVRn(i));
 
 		etm4x_relaxed_write32(csa, config->seq_rst, TRCSEQRSTEVR);
 		etm4x_relaxed_write32(csa, config->seq_state, TRCSEQSTR);
 	}
-	if (drvdata->numextinsel)
+	if (caps->numextinsel)
 		etm4x_relaxed_write32(csa, config->ext_inp, TRCEXTINSELR);
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		etm4x_relaxed_write32(csa, config->cntrldvr[i], TRCCNTRLDVRn(i));
 		etm4x_relaxed_write32(csa, config->cntr_ctrl[i], TRCCNTCTLRn(i));
 		etm4x_relaxed_write32(csa, config->cntr_val[i], TRCCNTVRn(i));
@@ -564,10 +569,10 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 	 * Resource selector pair 0 is always implemented and reserved.  As
 	 * such start at 2.
 	 */
-	for (i = 2; i < drvdata->nr_resource * 2; i++)
+	for (i = 2; i < caps->nr_resource * 2; i++)
 		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
 
-	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
+	for (i = 0; i < caps->nr_ss_cmp; i++) {
 		/* always clear status bit on restart if using single-shot */
 		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
 			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
@@ -576,23 +581,23 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 		if (etm4x_sspcicrn_present(drvdata, i))
 			etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
 	}
-	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
+	for (i = 0; i < caps->nr_addr_cmp * 2; i++) {
 		etm4x_relaxed_write64(csa, config->addr_val[i], TRCACVRn(i));
 		etm4x_relaxed_write64(csa, config->addr_acc[i], TRCACATRn(i));
 	}
-	for (i = 0; i < drvdata->numcidc; i++)
+	for (i = 0; i < caps->numcidc; i++)
 		etm4x_relaxed_write64(csa, config->ctxid_pid[i], TRCCIDCVRn(i));
 	etm4x_relaxed_write32(csa, config->ctxid_mask0, TRCCIDCCTLR0);
-	if (drvdata->numcidc > 4)
+	if (caps->numcidc > 4)
 		etm4x_relaxed_write32(csa, config->ctxid_mask1, TRCCIDCCTLR1);
 
-	for (i = 0; i < drvdata->numvmidc; i++)
+	for (i = 0; i < caps->numvmidc; i++)
 		etm4x_relaxed_write64(csa, config->vmid_val[i], TRCVMIDCVRn(i));
 	etm4x_relaxed_write32(csa, config->vmid_mask0, TRCVMIDCCTLR0);
-	if (drvdata->numvmidc > 4)
+	if (caps->numvmidc > 4)
 		etm4x_relaxed_write32(csa, config->vmid_mask1, TRCVMIDCCTLR1);
 
-	if (!drvdata->skip_power_up) {
+	if (!caps->skip_power_up) {
 		u32 trcpdcr = etm4x_relaxed_read32(csa, TRCPDCR);
 
 		/*
@@ -668,19 +673,20 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata,
 {
 	int ctridx;
 	int rselector;
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	/* No point in trying if we don't have at least one counter */
-	if (!drvdata->nr_cntr)
+	if (!caps->nr_cntr)
 		return -EINVAL;
 
 	/* Find a counter that hasn't been initialised */
-	for (ctridx = 0; ctridx < drvdata->nr_cntr; ctridx++)
+	for (ctridx = 0; ctridx < caps->nr_cntr; ctridx++)
 		if (config->cntr_val[ctridx] == 0)
 			break;
 
 	/* All the counters have been configured already, bail out */
-	if (ctridx == drvdata->nr_cntr) {
+	if (ctridx == caps->nr_cntr) {
 		pr_debug("%s: no available counter found\n", __func__);
 		return -ENOSPC;
 	}
@@ -696,11 +702,11 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata,
 	 * ETMIDR4 gives the number of resource selector _pairs_, hence multiply
 	 * by 2.
 	 */
-	for (rselector = 2; rselector < drvdata->nr_resource * 2; rselector++)
+	for (rselector = 2; rselector < caps->nr_resource * 2; rselector++)
 		if (!config->res_ctrl[rselector])
 			break;
 
-	if (rselector == drvdata->nr_resource * 2) {
+	if (rselector == caps->nr_resource * 2) {
 		pr_debug("%s: no available resource selector found\n",
 			 __func__);
 		return -ENOSPC;
@@ -751,6 +757,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
 {
 	int ret = 0;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 	struct perf_event_attr max_timestamp = {
 		.ATTR_CFG_FLD_timestamp_CFG = U64_MAX,
@@ -790,8 +797,8 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
 		cc_threshold = ATTR_CFG_GET_FLD(attr, cc_threshold);
 		if (!cc_threshold)
 			cc_threshold = ETM_CYC_THRESHOLD_DEFAULT;
-		if (cc_threshold < drvdata->ccitmin)
-			cc_threshold = drvdata->ccitmin;
+		if (cc_threshold < caps->ccitmin)
+			cc_threshold = caps->ccitmin;
 		config->ccctlr = cc_threshold;
 	}
 
@@ -839,7 +846,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
 	}
 
 	/* return stack - enable if selected and supported */
-	if (ATTR_CFG_GET_FLD(attr, retstack) && drvdata->retstack)
+	if (ATTR_CFG_GET_FLD(attr, retstack) && caps->retstack)
 		/* bit[12], Return stack enable bit */
 		config->cfg |= TRCCONFIGR_RS;
 
@@ -855,7 +862,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
 
 	/* branch broadcast - enable if selected and supported */
 	if (ATTR_CFG_GET_FLD(attr, branch_broadcast)) {
-		if (!drvdata->trcbb) {
+		if (!caps->trcbb) {
 			/*
 			 * Missing BB support could cause silent decode errors
 			 * so fail to open if it's not supported.
@@ -1030,6 +1037,7 @@ static void etm4_disable_trace_unit(struct etmv4_drvdata *drvdata)
 static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
 {
 	u32 control;
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 	struct coresight_device *csdev = drvdata->csdev;
 	struct csdev_access *csa = &csdev->access;
@@ -1038,7 +1046,7 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
 	etm4_cs_unlock(drvdata, csa);
 	etm4_disable_arch_specific(drvdata);
 
-	if (!drvdata->skip_power_up) {
+	if (!caps->skip_power_up) {
 		/* power can be removed from the trace unit now */
 		control = etm4x_relaxed_read32(csa, TRCPDCR);
 		control &= ~TRCPDCR_PU;
@@ -1048,13 +1056,13 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
 	etm4_disable_trace_unit(drvdata);
 
 	/* read the status of the single shot comparators */
-	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
+	for (i = 0; i < caps->nr_ss_cmp; i++) {
 		config->ss_status[i] =
 			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
 	}
 
 	/* read back the current counter values */
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		config->cntr_val[i] =
 			etm4x_relaxed_read32(csa, TRCCNTVRn(i));
 	}
@@ -1352,7 +1360,7 @@ static struct midr_range etm_wrong_ccitmin_cpus[] = {
 	{},
 };
 
-static void etm4_fixup_wrong_ccitmin(struct etmv4_drvdata *drvdata)
+static void etm4_fixup_wrong_ccitmin(struct etmv4_caps *caps)
 {
 	/*
 	 * Erratum affected cpus will read 256 as the minimum
@@ -1362,8 +1370,8 @@ static void etm4_fixup_wrong_ccitmin(struct etmv4_drvdata *drvdata)
 	 * this problem.
 	 */
 	if (is_midr_in_range_list(etm_wrong_ccitmin_cpus)) {
-		if (drvdata->ccitmin == 256)
-			drvdata->ccitmin = 4;
+		if (caps->ccitmin == 256)
+			caps->ccitmin = 4;
 	}
 }
 
@@ -1376,11 +1384,13 @@ static void etm4_init_arch_data(void *info)
 	u32 etmidr5;
 	struct etm4_init_arg *init_arg = info;
 	struct etmv4_drvdata *drvdata;
+	struct etmv4_caps *caps;
 	struct csdev_access *csa;
 	struct device *dev = init_arg->dev;
 	int i;
 
 	drvdata = dev_get_drvdata(init_arg->dev);
+	caps = &drvdata->caps;
 	csa = init_arg->csa;
 
 	/*
@@ -1393,7 +1403,7 @@ static void etm4_init_arch_data(void *info)
 
 	if (!csa->io_mem ||
 	    fwnode_property_present(dev_fwnode(dev), "qcom,skip-power-up"))
-		drvdata->skip_power_up = true;
+		caps->skip_power_up = true;
 
 	/* Detect the support for OS Lock before we actually use it */
 	etm_detect_os_lock(drvdata, csa);
@@ -1408,71 +1418,71 @@ static void etm4_init_arch_data(void *info)
 	etmidr0 = etm4x_relaxed_read32(csa, TRCIDR0);
 
 	/* INSTP0, bits[2:1] P0 tracing support field */
-	drvdata->instrp0 = !!(FIELD_GET(TRCIDR0_INSTP0_MASK, etmidr0) == 0b11);
+	caps->instrp0 = !!(FIELD_GET(TRCIDR0_INSTP0_MASK, etmidr0) == 0b11);
 	/* TRCBB, bit[5] Branch broadcast tracing support bit */
-	drvdata->trcbb = !!(etmidr0 & TRCIDR0_TRCBB);
+	caps->trcbb = !!(etmidr0 & TRCIDR0_TRCBB);
 	/* TRCCOND, bit[6] Conditional instruction tracing support bit */
-	drvdata->trccond = !!(etmidr0 & TRCIDR0_TRCCOND);
+	caps->trccond = !!(etmidr0 & TRCIDR0_TRCCOND);
 	/* TRCCCI, bit[7] Cycle counting instruction bit */
-	drvdata->trccci = !!(etmidr0 & TRCIDR0_TRCCCI);
+	caps->trccci = !!(etmidr0 & TRCIDR0_TRCCCI);
 	/* RETSTACK, bit[9] Return stack bit */
-	drvdata->retstack = !!(etmidr0 & TRCIDR0_RETSTACK);
+	caps->retstack = !!(etmidr0 & TRCIDR0_RETSTACK);
 	/* NUMEVENT, bits[11:10] Number of events field */
-	drvdata->nr_event = FIELD_GET(TRCIDR0_NUMEVENT_MASK, etmidr0);
+	caps->nr_event = FIELD_GET(TRCIDR0_NUMEVENT_MASK, etmidr0);
 	/* QSUPP, bits[16:15] Q element support field */
-	drvdata->q_support = FIELD_GET(TRCIDR0_QSUPP_MASK, etmidr0);
-	if (drvdata->q_support)
-		drvdata->q_filt = !!(etmidr0 & TRCIDR0_QFILT);
+	caps->q_support = FIELD_GET(TRCIDR0_QSUPP_MASK, etmidr0);
+	if (caps->q_support)
+		caps->q_filt = !!(etmidr0 & TRCIDR0_QFILT);
 	/* TSSIZE, bits[28:24] Global timestamp size field */
-	drvdata->ts_size = FIELD_GET(TRCIDR0_TSSIZE_MASK, etmidr0);
+	caps->ts_size = FIELD_GET(TRCIDR0_TSSIZE_MASK, etmidr0);
 
 	/* maximum size of resources */
 	etmidr2 = etm4x_relaxed_read32(csa, TRCIDR2);
 	/* CIDSIZE, bits[9:5] Indicates the Context ID size */
-	drvdata->ctxid_size = FIELD_GET(TRCIDR2_CIDSIZE_MASK, etmidr2);
+	caps->ctxid_size = FIELD_GET(TRCIDR2_CIDSIZE_MASK, etmidr2);
 	/* VMIDSIZE, bits[14:10] Indicates the VMID size */
-	drvdata->vmid_size = FIELD_GET(TRCIDR2_VMIDSIZE_MASK, etmidr2);
+	caps->vmid_size = FIELD_GET(TRCIDR2_VMIDSIZE_MASK, etmidr2);
 	/* CCSIZE, bits[28:25] size of the cycle counter in bits minus 12 */
-	drvdata->ccsize = FIELD_GET(TRCIDR2_CCSIZE_MASK, etmidr2);
+	caps->ccsize = FIELD_GET(TRCIDR2_CCSIZE_MASK, etmidr2);
 
 	etmidr3 = etm4x_relaxed_read32(csa, TRCIDR3);
 	/* CCITMIN, bits[11:0] minimum threshold value that can be programmed */
-	drvdata->ccitmin = FIELD_GET(TRCIDR3_CCITMIN_MASK, etmidr3);
-	etm4_fixup_wrong_ccitmin(drvdata);
+	caps->ccitmin = FIELD_GET(TRCIDR3_CCITMIN_MASK, etmidr3);
+	etm4_fixup_wrong_ccitmin(caps);
 
 	/* EXLEVEL_S, bits[19:16] Secure state instruction tracing */
-	drvdata->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3);
-	drvdata->config.s_ex_level = drvdata->s_ex_level;
+	caps->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3);
+	drvdata->config.s_ex_level = caps->s_ex_level;
 	/* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */
-	drvdata->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3);
+	caps->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3);
 	/*
 	 * TRCERR, bit[24] whether a trace unit can trace a
 	 * system error exception.
 	 */
-	drvdata->trc_error = !!(etmidr3 & TRCIDR3_TRCERR);
+	caps->trc_error = !!(etmidr3 & TRCIDR3_TRCERR);
 	/* SYNCPR, bit[25] implementation has a fixed synchronization period? */
-	drvdata->syncpr = !!(etmidr3 & TRCIDR3_SYNCPR);
+	caps->syncpr = !!(etmidr3 & TRCIDR3_SYNCPR);
 	/* STALLCTL, bit[26] is stall control implemented? */
-	drvdata->stallctl = !!(etmidr3 & TRCIDR3_STALLCTL);
+	caps->stallctl = !!(etmidr3 & TRCIDR3_STALLCTL);
 	/* SYSSTALL, bit[27] implementation can support stall control? */
-	drvdata->sysstall = !!(etmidr3 & TRCIDR3_SYSSTALL);
+	caps->sysstall = !!(etmidr3 & TRCIDR3_SYSSTALL);
 	/*
 	 * NUMPROC - the number of PEs available for tracing, 5bits
 	 *         = TRCIDR3.bits[13:12]bits[30:28]
 	 *  bits[4:3] = TRCIDR3.bits[13:12] (since etm-v4.2, otherwise RES0)
 	 *  bits[3:0] = TRCIDR3.bits[30:28]
 	 */
-	drvdata->nr_pe =  (FIELD_GET(TRCIDR3_NUMPROC_HI_MASK, etmidr3) << 3) |
-			   FIELD_GET(TRCIDR3_NUMPROC_LO_MASK, etmidr3);
+	caps->nr_pe = (FIELD_GET(TRCIDR3_NUMPROC_HI_MASK, etmidr3) << 3) |
+			       FIELD_GET(TRCIDR3_NUMPROC_LO_MASK, etmidr3);
 	/* NOOVERFLOW, bit[31] is trace overflow prevention supported */
-	drvdata->nooverflow = !!(etmidr3 & TRCIDR3_NOOVERFLOW);
+	caps->nooverflow = !!(etmidr3 & TRCIDR3_NOOVERFLOW);
 
 	/* number of resources trace unit supports */
 	etmidr4 = etm4x_relaxed_read32(csa, TRCIDR4);
 	/* NUMACPAIRS, bits[0:3] number of addr comparator pairs for tracing */
-	drvdata->nr_addr_cmp = FIELD_GET(TRCIDR4_NUMACPAIRS_MASK, etmidr4);
+	caps->nr_addr_cmp = FIELD_GET(TRCIDR4_NUMACPAIRS_MASK, etmidr4);
 	/* NUMPC, bits[15:12] number of PE comparator inputs for tracing */
-	drvdata->nr_pe_cmp = FIELD_GET(TRCIDR4_NUMPC_MASK, etmidr4);
+	caps->nr_pe_cmp = FIELD_GET(TRCIDR4_NUMPC_MASK, etmidr4);
 	/*
 	 * NUMRSPAIR, bits[19:16]
 	 * The number of resource pairs conveyed by the HW starts at 0, i.e a
@@ -1483,41 +1493,41 @@ static void etm4_init_arch_data(void *info)
 	 * the default TRUE and FALSE resource selectors are omitted.
 	 * Otherwise for values 0x1 and above the number is N + 1 as per v4.2.
 	 */
-	drvdata->nr_resource = FIELD_GET(TRCIDR4_NUMRSPAIR_MASK, etmidr4);
-	if ((drvdata->arch < ETM_ARCH_V4_3) || (drvdata->nr_resource > 0))
-		drvdata->nr_resource += 1;
+	caps->nr_resource = FIELD_GET(TRCIDR4_NUMRSPAIR_MASK, etmidr4);
+	if ((drvdata->arch < ETM_ARCH_V4_3) || (caps->nr_resource > 0))
+		caps->nr_resource += 1;
 	/*
 	 * NUMSSCC, bits[23:20] the number of single-shot
 	 * comparator control for tracing. Read any status regs as these
 	 * also contain RO capability data.
 	 */
-	drvdata->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
-	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
+	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
+	for (i = 0; i < caps->nr_ss_cmp; i++) {
 		drvdata->config.ss_status[i] =
 			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
 	}
 	/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
-	drvdata->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4);
+	caps->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4);
 	/* NUMVMIDC, bits[31:28] number of VMID comparators for tracing */
-	drvdata->numvmidc = FIELD_GET(TRCIDR4_NUMVMIDC_MASK, etmidr4);
+	caps->numvmidc = FIELD_GET(TRCIDR4_NUMVMIDC_MASK, etmidr4);
 
 	etmidr5 = etm4x_relaxed_read32(csa, TRCIDR5);
 	/* NUMEXTIN, bits[8:0] number of external inputs implemented */
-	drvdata->nr_ext_inp = FIELD_GET(TRCIDR5_NUMEXTIN_MASK, etmidr5);
-	drvdata->numextinsel = FIELD_GET(TRCIDR5_NUMEXTINSEL_MASK, etmidr5);
+	caps->nr_ext_inp = FIELD_GET(TRCIDR5_NUMEXTIN_MASK, etmidr5);
+	caps->numextinsel = FIELD_GET(TRCIDR5_NUMEXTINSEL_MASK, etmidr5);
 	/* TRACEIDSIZE, bits[21:16] indicates the trace ID width */
-	drvdata->trcid_size = FIELD_GET(TRCIDR5_TRACEIDSIZE_MASK, etmidr5);
+	caps->trcid_size = FIELD_GET(TRCIDR5_TRACEIDSIZE_MASK, etmidr5);
 	/* ATBTRIG, bit[22] implementation can support ATB triggers? */
-	drvdata->atbtrig = !!(etmidr5 & TRCIDR5_ATBTRIG);
+	caps->atbtrig = !!(etmidr5 & TRCIDR5_ATBTRIG);
 	/*
 	 * LPOVERRIDE, bit[23] implementation supports
 	 * low-power state override
 	 */
-	drvdata->lpoverride = (etmidr5 & TRCIDR5_LPOVERRIDE) && (!drvdata->skip_power_up);
+	caps->lpoverride = (etmidr5 & TRCIDR5_LPOVERRIDE) && (!caps->skip_power_up);
 	/* NUMSEQSTATE, bits[27:25] number of sequencer states implemented */
-	drvdata->nrseqstate = FIELD_GET(TRCIDR5_NUMSEQSTATE_MASK, etmidr5);
+	caps->nrseqstate = FIELD_GET(TRCIDR5_NUMSEQSTATE_MASK, etmidr5);
 	/* NUMCNTR, bits[30:28] number of counters available for tracing */
-	drvdata->nr_cntr = FIELD_GET(TRCIDR5_NUMCNTR_MASK, etmidr5);
+	caps->nr_cntr = FIELD_GET(TRCIDR5_NUMCNTR_MASK, etmidr5);
 
 	coresight_clear_self_claim_tag_unlocked(csa);
 	etm4_cs_lock(drvdata, csa);
@@ -1693,7 +1703,7 @@ static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type)
 	 * nr_addr_cmp holds the number of comparator _pair_, so time 2
 	 * for the total number of comparators.
 	 */
-	nr_comparator = drvdata->nr_addr_cmp * 2;
+	nr_comparator = drvdata->caps.nr_addr_cmp * 2;
 
 	/* Go through the tally of comparators looking for a free one. */
 	while (index < nr_comparator) {
@@ -1871,6 +1881,7 @@ static int etm4_dying_cpu(unsigned int cpu)
 static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 {
 	int i, ret = 0;
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_save_state *state;
 	struct coresight_device *csdev = drvdata->csdev;
 	struct csdev_access *csa;
@@ -1907,57 +1918,57 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 
 	state = drvdata->save_state;
 
-	if (drvdata->nr_pe)
+	if (caps->nr_pe)
 		state->trcprocselr = etm4x_read32(csa, TRCPROCSELR);
 	state->trcconfigr = etm4x_read32(csa, TRCCONFIGR);
 	state->trcauxctlr = etm4x_read32(csa, TRCAUXCTLR);
 	state->trceventctl0r = etm4x_read32(csa, TRCEVENTCTL0R);
 	state->trceventctl1r = etm4x_read32(csa, TRCEVENTCTL1R);
-	if (drvdata->stallctl)
+	if (caps->stallctl)
 		state->trcstallctlr = etm4x_read32(csa, TRCSTALLCTLR);
 	state->trctsctlr = etm4x_read32(csa, TRCTSCTLR);
 	state->trcsyncpr = etm4x_read32(csa, TRCSYNCPR);
 	state->trcccctlr = etm4x_read32(csa, TRCCCCTLR);
 	state->trcbbctlr = etm4x_read32(csa, TRCBBCTLR);
 	state->trctraceidr = etm4x_read32(csa, TRCTRACEIDR);
-	if (drvdata->q_filt)
+	if (caps->q_filt)
 		state->trcqctlr = etm4x_read32(csa, TRCQCTLR);
 
 	state->trcvictlr = etm4x_read32(csa, TRCVICTLR);
 	state->trcviiectlr = etm4x_read32(csa, TRCVIIECTLR);
 	state->trcvissctlr = etm4x_read32(csa, TRCVISSCTLR);
-	if (drvdata->nr_pe_cmp)
+	if (caps->nr_pe_cmp)
 		state->trcvipcssctlr = etm4x_read32(csa, TRCVIPCSSCTLR);
 
-	if (drvdata->nrseqstate) {
-		for (i = 0; i < drvdata->nrseqstate - 1; i++)
+	if (caps->nrseqstate) {
+		for (i = 0; i < caps->nrseqstate - 1; i++)
 			state->trcseqevr[i] = etm4x_read32(csa, TRCSEQEVRn(i));
 
 		state->trcseqrstevr = etm4x_read32(csa, TRCSEQRSTEVR);
 		state->trcseqstr = etm4x_read32(csa, TRCSEQSTR);
 	}
 
-	if (drvdata->numextinsel)
+	if (caps->numextinsel)
 		state->trcextinselr = etm4x_read32(csa, TRCEXTINSELR);
 
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		state->trccntrldvr[i] = etm4x_read32(csa, TRCCNTRLDVRn(i));
 		state->trccntctlr[i] = etm4x_read32(csa, TRCCNTCTLRn(i));
 		state->trccntvr[i] = etm4x_read32(csa, TRCCNTVRn(i));
 	}
 
 	/* Resource selector pair 0 is reserved */
-	for (i = 2; i < drvdata->nr_resource * 2; i++)
+	for (i = 2; i < caps->nr_resource * 2; i++)
 		state->trcrsctlr[i] = etm4x_read32(csa, TRCRSCTLRn(i));
 
-	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
+	for (i = 0; i < caps->nr_ss_cmp; i++) {
 		state->trcssccr[i] = etm4x_read32(csa, TRCSSCCRn(i));
 		state->trcsscsr[i] = etm4x_read32(csa, TRCSSCSRn(i));
 		if (etm4x_sspcicrn_present(drvdata, i))
 			state->trcsspcicr[i] = etm4x_read32(csa, TRCSSPCICRn(i));
 	}
 
-	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
+	for (i = 0; i < caps->nr_addr_cmp * 2; i++) {
 		state->trcacvr[i] = etm4x_read64(csa, TRCACVRn(i));
 		state->trcacatr[i] = etm4x_read64(csa, TRCACATRn(i));
 	}
@@ -1969,23 +1980,23 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	 * unit") of ARM IHI 0064D.
 	 */
 
-	for (i = 0; i < drvdata->numcidc; i++)
+	for (i = 0; i < caps->numcidc; i++)
 		state->trccidcvr[i] = etm4x_read64(csa, TRCCIDCVRn(i));
 
-	for (i = 0; i < drvdata->numvmidc; i++)
+	for (i = 0; i < caps->numvmidc; i++)
 		state->trcvmidcvr[i] = etm4x_read64(csa, TRCVMIDCVRn(i));
 
 	state->trccidcctlr0 = etm4x_read32(csa, TRCCIDCCTLR0);
-	if (drvdata->numcidc > 4)
+	if (caps->numcidc > 4)
 		state->trccidcctlr1 = etm4x_read32(csa, TRCCIDCCTLR1);
 
 	state->trcvmidcctlr0 = etm4x_read32(csa, TRCVMIDCCTLR0);
-	if (drvdata->numvmidc > 4)
+	if (caps->numvmidc > 4)
 		state->trcvmidcctlr0 = etm4x_read32(csa, TRCVMIDCCTLR1);
 
 	state->trcclaimset = etm4x_read32(csa, TRCCLAIMCLR);
 
-	if (!drvdata->skip_power_up)
+	if (!caps->skip_power_up)
 		state->trcpdcr = etm4x_read32(csa, TRCPDCR);
 
 	/* wait for TRCSTATR.IDLE to go up */
@@ -2002,7 +2013,7 @@ static int __etm4_cpu_save(struct etmv4_drvdata *drvdata)
 	 * potentially save power on systems that respect the TRCPDCR_PU
 	 * despite requesting software to save/restore state.
 	 */
-	if (!drvdata->skip_power_up)
+	if (!caps->skip_power_up)
 		etm4x_relaxed_write32(csa, (state->trcpdcr & ~TRCPDCR_PU),
 				      TRCPDCR);
 out:
@@ -2029,6 +2040,7 @@ static int etm4_cpu_save(struct etmv4_drvdata *drvdata)
 static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 {
 	int i;
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_save_state *state = drvdata->save_state;
 	struct csdev_access *csa = &drvdata->csdev->access;
 
@@ -2038,77 +2050,77 @@ static void __etm4_cpu_restore(struct etmv4_drvdata *drvdata)
 	etm4_cs_unlock(drvdata, csa);
 	etm4x_relaxed_write32(csa, state->trcclaimset, TRCCLAIMSET);
 
-	if (drvdata->nr_pe)
+	if (caps->nr_pe)
 		etm4x_relaxed_write32(csa, state->trcprocselr, TRCPROCSELR);
 	etm4x_relaxed_write32(csa, state->trcconfigr, TRCCONFIGR);
 	etm4x_relaxed_write32(csa, state->trcauxctlr, TRCAUXCTLR);
 	etm4x_relaxed_write32(csa, state->trceventctl0r, TRCEVENTCTL0R);
 	etm4x_relaxed_write32(csa, state->trceventctl1r, TRCEVENTCTL1R);
-	if (drvdata->stallctl)
+	if (caps->stallctl)
 		etm4x_relaxed_write32(csa, state->trcstallctlr, TRCSTALLCTLR);
 	etm4x_relaxed_write32(csa, state->trctsctlr, TRCTSCTLR);
 	etm4x_relaxed_write32(csa, state->trcsyncpr, TRCSYNCPR);
 	etm4x_relaxed_write32(csa, state->trcccctlr, TRCCCCTLR);
 	etm4x_relaxed_write32(csa, state->trcbbctlr, TRCBBCTLR);
 	etm4x_relaxed_write32(csa, state->trctraceidr, TRCTRACEIDR);
-	if (drvdata->q_filt)
+	if (caps->q_filt)
 		etm4x_relaxed_write32(csa, state->trcqctlr, TRCQCTLR);
 
 	etm4x_relaxed_write32(csa, state->trcvictlr, TRCVICTLR);
 	etm4x_relaxed_write32(csa, state->trcviiectlr, TRCVIIECTLR);
 	etm4x_relaxed_write32(csa, state->trcvissctlr, TRCVISSCTLR);
-	if (drvdata->nr_pe_cmp)
+	if (caps->nr_pe_cmp)
 		etm4x_relaxed_write32(csa, state->trcvipcssctlr, TRCVIPCSSCTLR);
 
-	if (drvdata->nrseqstate) {
-		for (i = 0; i < drvdata->nrseqstate - 1; i++)
+	if (caps->nrseqstate) {
+		for (i = 0; i < caps->nrseqstate - 1; i++)
 			etm4x_relaxed_write32(csa, state->trcseqevr[i], TRCSEQEVRn(i));
 
 		etm4x_relaxed_write32(csa, state->trcseqrstevr, TRCSEQRSTEVR);
 		etm4x_relaxed_write32(csa, state->trcseqstr, TRCSEQSTR);
 	}
-	if (drvdata->numextinsel)
+	if (caps->numextinsel)
 		etm4x_relaxed_write32(csa, state->trcextinselr, TRCEXTINSELR);
 
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		etm4x_relaxed_write32(csa, state->trccntrldvr[i], TRCCNTRLDVRn(i));
 		etm4x_relaxed_write32(csa, state->trccntctlr[i], TRCCNTCTLRn(i));
 		etm4x_relaxed_write32(csa, state->trccntvr[i], TRCCNTVRn(i));
 	}
 
 	/* Resource selector pair 0 is reserved */
-	for (i = 2; i < drvdata->nr_resource * 2; i++)
+	for (i = 2; i < caps->nr_resource * 2; i++)
 		etm4x_relaxed_write32(csa, state->trcrsctlr[i], TRCRSCTLRn(i));
 
-	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
+	for (i = 0; i < caps->nr_ss_cmp; i++) {
 		etm4x_relaxed_write32(csa, state->trcssccr[i], TRCSSCCRn(i));
 		etm4x_relaxed_write32(csa, state->trcsscsr[i], TRCSSCSRn(i));
 		if (etm4x_sspcicrn_present(drvdata, i))
 			etm4x_relaxed_write32(csa, state->trcsspcicr[i], TRCSSPCICRn(i));
 	}
 
-	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
+	for (i = 0; i < caps->nr_addr_cmp * 2; i++) {
 		etm4x_relaxed_write64(csa, state->trcacvr[i], TRCACVRn(i));
 		etm4x_relaxed_write64(csa, state->trcacatr[i], TRCACATRn(i));
 	}
 
-	for (i = 0; i < drvdata->numcidc; i++)
+	for (i = 0; i < caps->numcidc; i++)
 		etm4x_relaxed_write64(csa, state->trccidcvr[i], TRCCIDCVRn(i));
 
-	for (i = 0; i < drvdata->numvmidc; i++)
+	for (i = 0; i < caps->numvmidc; i++)
 		etm4x_relaxed_write64(csa, state->trcvmidcvr[i], TRCVMIDCVRn(i));
 
 	etm4x_relaxed_write32(csa, state->trccidcctlr0, TRCCIDCCTLR0);
-	if (drvdata->numcidc > 4)
+	if (caps->numcidc > 4)
 		etm4x_relaxed_write32(csa, state->trccidcctlr1, TRCCIDCCTLR1);
 
 	etm4x_relaxed_write32(csa, state->trcvmidcctlr0, TRCVMIDCCTLR0);
-	if (drvdata->numvmidc > 4)
+	if (caps->numvmidc > 4)
 		etm4x_relaxed_write32(csa, state->trcvmidcctlr0, TRCVMIDCCTLR1);
 
 	etm4x_relaxed_write32(csa, state->trcclaimset, TRCCLAIMSET);
 
-	if (!drvdata->skip_power_up)
+	if (!caps->skip_power_up)
 		etm4x_relaxed_write32(csa, state->trcpdcr, TRCPDCR);
 
 	/*
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index d866dcfa2a36..8bd28e71d4c9 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -62,8 +62,9 @@ static ssize_t nr_pe_cmp_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_pe_cmp;
+	val = caps->nr_pe_cmp;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_pe_cmp);
@@ -74,8 +75,9 @@ static ssize_t nr_addr_cmp_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_addr_cmp;
+	val = caps->nr_addr_cmp;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_addr_cmp);
@@ -86,8 +88,9 @@ static ssize_t nr_cntr_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_cntr;
+	val = caps->nr_cntr;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_cntr);
@@ -98,8 +101,9 @@ static ssize_t nr_ext_inp_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_ext_inp;
+	val = caps->nr_ext_inp;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_ext_inp);
@@ -110,8 +114,9 @@ static ssize_t numcidc_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->numcidc;
+	val = caps->numcidc;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(numcidc);
@@ -122,8 +127,9 @@ static ssize_t numvmidc_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->numvmidc;
+	val = caps->numvmidc;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(numvmidc);
@@ -134,8 +140,9 @@ static ssize_t nrseqstate_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nrseqstate;
+	val = caps->nrseqstate;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nrseqstate);
@@ -146,8 +153,9 @@ static ssize_t nr_resource_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_resource;
+	val = caps->nr_resource;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_resource);
@@ -158,8 +166,9 @@ static ssize_t nr_ss_cmp_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_ss_cmp;
+	val = caps->nr_ss_cmp;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_ss_cmp);
@@ -171,6 +180,7 @@ static ssize_t reset_store(struct device *dev,
 	int i;
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -200,7 +210,7 @@ static ssize_t reset_store(struct device *dev,
 	config->stall_ctrl = 0x0;
 
 	/* Reset trace synchronization period  to 2^8 = 256 bytes*/
-	if (drvdata->syncpr == false)
+	if (!caps->syncpr)
 		config->syncfreq = 0x8;
 
 	/*
@@ -209,7 +219,7 @@ static ssize_t reset_store(struct device *dev,
 	 * each trace run.
 	 */
 	config->vinst_ctrl = FIELD_PREP(TRCVICTLR_EVENT_MASK, 0x01);
-	if (drvdata->nr_addr_cmp > 0) {
+	if (caps->nr_addr_cmp > 0) {
 		config->mode |= ETM_MODE_VIEWINST_STARTSTOP;
 		/* SSSTATUS, bit[9] */
 		config->vinst_ctrl |= TRCVICTLR_SSSTATUS;
@@ -223,7 +233,7 @@ static ssize_t reset_store(struct device *dev,
 	config->vipcssctlr = 0x0;
 
 	/* Disable seq events */
-	for (i = 0; i < drvdata->nrseqstate-1; i++)
+	for (i = 0; i < caps->nrseqstate - 1; i++)
 		config->seq_ctrl[i] = 0x0;
 	config->seq_rst = 0x0;
 	config->seq_state = 0x0;
@@ -232,38 +242,38 @@ static ssize_t reset_store(struct device *dev,
 	config->ext_inp = 0x0;
 
 	config->cntr_idx = 0x0;
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		config->cntrldvr[i] = 0x0;
 		config->cntr_ctrl[i] = 0x0;
 		config->cntr_val[i] = 0x0;
 	}
 
 	config->res_idx = 0x0;
-	for (i = 2; i < 2 * drvdata->nr_resource; i++)
+	for (i = 2; i < 2 * caps->nr_resource; i++)
 		config->res_ctrl[i] = 0x0;
 
 	config->ss_idx = 0x0;
-	for (i = 0; i < drvdata->nr_ss_cmp; i++) {
+	for (i = 0; i < caps->nr_ss_cmp; i++) {
 		config->ss_ctrl[i] = 0x0;
 		config->ss_pe_cmp[i] = 0x0;
 	}
 
 	config->addr_idx = 0x0;
-	for (i = 0; i < drvdata->nr_addr_cmp * 2; i++) {
+	for (i = 0; i < caps->nr_addr_cmp * 2; i++) {
 		config->addr_val[i] = 0x0;
 		config->addr_acc[i] = 0x0;
 		config->addr_type[i] = ETM_ADDR_TYPE_NONE;
 	}
 
 	config->ctxid_idx = 0x0;
-	for (i = 0; i < drvdata->numcidc; i++)
+	for (i = 0; i < caps->numcidc; i++)
 		config->ctxid_pid[i] = 0x0;
 
 	config->ctxid_mask0 = 0x0;
 	config->ctxid_mask1 = 0x0;
 
 	config->vmid_idx = 0x0;
-	for (i = 0; i < drvdata->numvmidc; i++)
+	for (i = 0; i < caps->numvmidc; i++)
 		config->vmid_val[i] = 0x0;
 	config->vmid_mask0 = 0x0;
 	config->vmid_mask1 = 0x0;
@@ -297,6 +307,7 @@ static ssize_t mode_store(struct device *dev,
 {
 	unsigned long val, mode;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -305,7 +316,7 @@ static ssize_t mode_store(struct device *dev,
 	raw_spin_lock(&drvdata->spinlock);
 	config->mode = val & ETMv4_MODE_ALL;
 
-	if (drvdata->instrp0 == true) {
+	if (caps->instrp0) {
 		/* start by clearing instruction P0 field */
 		config->cfg  &= ~TRCCONFIGR_INSTP0_LOAD_STORE;
 		if (config->mode & ETM_MODE_LOAD)
@@ -323,45 +334,44 @@ static ssize_t mode_store(struct device *dev,
 	}
 
 	/* bit[3], Branch broadcast mode */
-	if ((config->mode & ETM_MODE_BB) && (drvdata->trcbb == true))
+	if ((config->mode & ETM_MODE_BB) && (caps->trcbb))
 		config->cfg |= TRCCONFIGR_BB;
 	else
 		config->cfg &= ~TRCCONFIGR_BB;
 
 	/* bit[4], Cycle counting instruction trace bit */
 	if ((config->mode & ETMv4_MODE_CYCACC) &&
-		(drvdata->trccci == true))
+		(caps->trccci == true))
 		config->cfg |= TRCCONFIGR_CCI;
 	else
 		config->cfg &= ~TRCCONFIGR_CCI;
 
 	/* bit[6], Context ID tracing bit */
-	if ((config->mode & ETMv4_MODE_CTXID) && (drvdata->ctxid_size))
+	if ((config->mode & ETMv4_MODE_CTXID) && (caps->ctxid_size))
 		config->cfg |= TRCCONFIGR_CID;
 	else
 		config->cfg &= ~TRCCONFIGR_CID;
 
-	if ((config->mode & ETM_MODE_VMID) && (drvdata->vmid_size))
+	if ((config->mode & ETM_MODE_VMID) && (caps->vmid_size))
 		config->cfg |= TRCCONFIGR_VMID;
 	else
 		config->cfg &= ~TRCCONFIGR_VMID;
 
 	/* bits[10:8], Conditional instruction tracing bit */
 	mode = ETM_MODE_COND(config->mode);
-	if (drvdata->trccond == true) {
+	if (caps->trccond) {
 		config->cfg &= ~TRCCONFIGR_COND_MASK;
 		config->cfg |= mode << __bf_shf(TRCCONFIGR_COND_MASK);
 	}
 
 	/* bit[11], Global timestamp tracing bit */
-	if ((config->mode & ETMv4_MODE_TIMESTAMP) && (drvdata->ts_size))
+	if ((config->mode & ETMv4_MODE_TIMESTAMP) && (caps->ts_size))
 		config->cfg |= TRCCONFIGR_TS;
 	else
 		config->cfg &= ~TRCCONFIGR_TS;
 
 	/* bit[12], Return stack enable bit */
-	if ((config->mode & ETM_MODE_RETURNSTACK) &&
-					(drvdata->retstack == true))
+	if ((config->mode & ETM_MODE_RETURNSTACK) && (caps->retstack))
 		config->cfg |= TRCCONFIGR_RS;
 	else
 		config->cfg &= ~TRCCONFIGR_RS;
@@ -375,31 +385,29 @@ static ssize_t mode_store(struct device *dev,
 	 * Always set the low bit for any requested mode. Valid combos are
 	 * 0b00, 0b01 and 0b11.
 	 */
-	if (mode && drvdata->q_support)
+	if (mode && caps->q_support)
 		config->cfg |= TRCCONFIGR_QE_W_COUNTS;
 	/*
 	 * if supported, Q elements with and without instruction
 	 * counts are enabled
 	 */
-	if ((mode & BIT(1)) && (drvdata->q_support & BIT(1)))
+	if ((mode & BIT(1)) && (caps->q_support & BIT(1)))
 		config->cfg |= TRCCONFIGR_QE_WO_COUNTS;
 
 	/* bit[11], AMBA Trace Bus (ATB) trigger enable bit */
-	if ((config->mode & ETM_MODE_ATB_TRIGGER) &&
-	    (drvdata->atbtrig == true))
+	if ((config->mode & ETM_MODE_ATB_TRIGGER) && (caps->atbtrig))
 		config->eventctrl1 |= TRCEVENTCTL1R_ATB;
 	else
 		config->eventctrl1 &= ~TRCEVENTCTL1R_ATB;
 
 	/* bit[12], Low-power state behavior override bit */
-	if ((config->mode & ETM_MODE_LPOVERRIDE) &&
-	    (drvdata->lpoverride == true))
+	if ((config->mode & ETM_MODE_LPOVERRIDE) && (caps->lpoverride))
 		config->eventctrl1 |= TRCEVENTCTL1R_LPOVERRIDE;
 	else
 		config->eventctrl1 &= ~TRCEVENTCTL1R_LPOVERRIDE;
 
 	/* bit[8], Instruction stall bit */
-	if ((config->mode & ETM_MODE_ISTALL_EN) && (drvdata->stallctl == true))
+	if ((config->mode & ETM_MODE_ISTALL_EN) && (caps->stallctl))
 		config->stall_ctrl |= TRCSTALLCTLR_ISTALL;
 	else
 		config->stall_ctrl &= ~TRCSTALLCTLR_ISTALL;
@@ -411,8 +419,7 @@ static ssize_t mode_store(struct device *dev,
 		config->stall_ctrl &= ~TRCSTALLCTLR_INSTPRIORITY;
 
 	/* bit[13], Trace overflow prevention bit */
-	if ((config->mode & ETM_MODE_NOOVERFLOW) &&
-		(drvdata->nooverflow == true))
+	if ((config->mode & ETM_MODE_NOOVERFLOW) && (caps->nooverflow))
 		config->stall_ctrl |= TRCSTALLCTLR_NOOVERFLOW;
 	else
 		config->stall_ctrl &= ~TRCSTALLCTLR_NOOVERFLOW;
@@ -430,8 +437,7 @@ static ssize_t mode_store(struct device *dev,
 		config->vinst_ctrl &= ~TRCVICTLR_TRCRESET;
 
 	/* bit[11], Whether a trace unit must trace a system error exception */
-	if ((config->mode & ETM_MODE_TRACE_ERR) &&
-		(drvdata->trc_error == true))
+	if ((config->mode & ETM_MODE_TRACE_ERR) && (caps->trc_error))
 		config->vinst_ctrl |= TRCVICTLR_TRCERR;
 	else
 		config->vinst_ctrl &= ~TRCVICTLR_TRCERR;
@@ -463,13 +469,14 @@ static ssize_t pe_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
-	if (val > drvdata->nr_pe) {
+	if (val > caps->nr_pe) {
 		raw_spin_unlock(&drvdata->spinlock);
 		return -EINVAL;
 	}
@@ -498,13 +505,14 @@ static ssize_t event_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
-	switch (drvdata->nr_event) {
+	switch (caps->nr_event) {
 	case 0x0:
 		/* EVENT0, bits[7:0] */
 		config->eventctrl0 = val & 0xFF;
@@ -547,6 +555,7 @@ static ssize_t event_instren_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -555,7 +564,7 @@ static ssize_t event_instren_store(struct device *dev,
 	raw_spin_lock(&drvdata->spinlock);
 	/* start by clearing all instruction event enable bits */
 	config->eventctrl1 &= ~TRCEVENTCTL1R_INSTEN_MASK;
-	switch (drvdata->nr_event) {
+	switch (caps->nr_event) {
 	case 0x0:
 		/* generate Event element for event 1 */
 		config->eventctrl1 |= val & TRCEVENTCTL1R_INSTEN_1;
@@ -603,11 +612,12 @@ static ssize_t event_ts_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (!drvdata->ts_size)
+	if (!caps->ts_size)
 		return -EINVAL;
 
 	config->ts_ctrl = val & ETMv4_EVENT_MASK;
@@ -633,11 +643,12 @@ static ssize_t syncfreq_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (drvdata->syncpr == true)
+	if (caps->syncpr)
 		return -EINVAL;
 
 	config->syncfreq = val & ETMv4_SYNC_MASK;
@@ -663,6 +674,7 @@ static ssize_t cyc_threshold_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -670,7 +682,7 @@ static ssize_t cyc_threshold_store(struct device *dev,
 
 	/* mask off max threshold before checking min value */
 	val &= ETM_CYC_THRESHOLD_MASK;
-	if (val < drvdata->ccitmin)
+	if (val < caps->ccitmin)
 		return -EINVAL;
 
 	config->ccctlr = val;
@@ -696,13 +708,14 @@ static ssize_t bb_ctrl_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (drvdata->trcbb == false)
+	if (!caps->trcbb)
 		return -EINVAL;
-	if (!drvdata->nr_addr_cmp)
+	if (!caps->nr_addr_cmp)
 		return -EINVAL;
 
 	/*
@@ -768,6 +781,7 @@ static ssize_t s_exlevel_vinst_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -777,7 +791,7 @@ static ssize_t s_exlevel_vinst_store(struct device *dev,
 	/* clear all EXLEVEL_S bits  */
 	config->vinst_ctrl &= ~TRCVICTLR_EXLEVEL_S_MASK;
 	/* enable instruction tracing for corresponding exception level */
-	val &= drvdata->s_ex_level;
+	val &= caps->s_ex_level;
 	config->vinst_ctrl |= val << __bf_shf(TRCVICTLR_EXLEVEL_S_MASK);
 	raw_spin_unlock(&drvdata->spinlock);
 	return size;
@@ -803,6 +817,7 @@ static ssize_t ns_exlevel_vinst_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -812,7 +827,7 @@ static ssize_t ns_exlevel_vinst_store(struct device *dev,
 	/* clear EXLEVEL_NS bits  */
 	config->vinst_ctrl &= ~TRCVICTLR_EXLEVEL_NS_MASK;
 	/* enable instruction tracing for corresponding exception level */
-	val &= drvdata->ns_ex_level;
+	val &= caps->ns_ex_level;
 	config->vinst_ctrl |= val << __bf_shf(TRCVICTLR_EXLEVEL_NS_MASK);
 	raw_spin_unlock(&drvdata->spinlock);
 	return size;
@@ -837,11 +852,12 @@ static ssize_t addr_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->nr_addr_cmp * 2)
+	if (val >= caps->nr_addr_cmp * 2)
 		return -EINVAL;
 
 	/*
@@ -1060,6 +1076,7 @@ static ssize_t addr_start_store(struct device *dev,
 	u8 idx;
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -1067,7 +1084,7 @@ static ssize_t addr_start_store(struct device *dev,
 
 	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
-	if (!drvdata->nr_addr_cmp) {
+	if (!caps->nr_addr_cmp) {
 		raw_spin_unlock(&drvdata->spinlock);
 		return -EINVAL;
 	}
@@ -1115,6 +1132,7 @@ static ssize_t addr_stop_store(struct device *dev,
 	u8 idx;
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -1122,7 +1140,7 @@ static ssize_t addr_stop_store(struct device *dev,
 
 	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
-	if (!drvdata->nr_addr_cmp) {
+	if (!caps->nr_addr_cmp) {
 		raw_spin_unlock(&drvdata->spinlock);
 		return -EINVAL;
 	}
@@ -1167,6 +1185,7 @@ static ssize_t addr_ctxtype_store(struct device *dev,
 	u8 idx;
 	char str[10] = "";
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (strlen(buf) >= 10)
@@ -1181,13 +1200,13 @@ static ssize_t addr_ctxtype_store(struct device *dev,
 		config->addr_acc[idx] &= ~TRCACATRn_CONTEXTTYPE_MASK;
 	else if (!strcmp(str, "ctxid")) {
 		/* 0b01 The trace unit performs a Context ID */
-		if (drvdata->numcidc) {
+		if (caps->numcidc) {
 			config->addr_acc[idx] |= TRCACATRn_CONTEXTTYPE_CTXID;
 			config->addr_acc[idx] &= ~TRCACATRn_CONTEXTTYPE_VMID;
 		}
 	} else if (!strcmp(str, "vmid")) {
 		/* 0b10 The trace unit performs a VMID */
-		if (drvdata->numvmidc) {
+		if (caps->numvmidc) {
 			config->addr_acc[idx] &= ~TRCACATRn_CONTEXTTYPE_CTXID;
 			config->addr_acc[idx] |= TRCACATRn_CONTEXTTYPE_VMID;
 		}
@@ -1196,9 +1215,9 @@ static ssize_t addr_ctxtype_store(struct device *dev,
 		 * 0b11 The trace unit performs a Context ID
 		 * comparison and a VMID
 		 */
-		if (drvdata->numcidc)
+		if (caps->numcidc)
 			config->addr_acc[idx] |= TRCACATRn_CONTEXTTYPE_CTXID;
-		if (drvdata->numvmidc)
+		if (caps->numvmidc)
 			config->addr_acc[idx] |= TRCACATRn_CONTEXTTYPE_VMID;
 	}
 	raw_spin_unlock(&drvdata->spinlock);
@@ -1230,14 +1249,15 @@ static ssize_t addr_context_store(struct device *dev,
 	u8 idx;
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if ((drvdata->numcidc <= 1) && (drvdata->numvmidc <= 1))
+	if ((caps->numcidc <= 1) && (caps->numvmidc <= 1))
 		return -EINVAL;
-	if (val >=  (drvdata->numcidc >= drvdata->numvmidc ?
-		     drvdata->numcidc : drvdata->numvmidc))
+	if (val >=  (caps->numcidc >= caps->numvmidc ?
+		     caps->numcidc : caps->numvmidc))
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
@@ -1348,9 +1368,10 @@ static ssize_t vinst_pe_cmp_start_stop_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
-	if (!drvdata->nr_pe_cmp)
+	if (!caps->nr_pe_cmp)
 		return -EINVAL;
 	val = config->vipcssctlr;
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
@@ -1361,11 +1382,12 @@ static ssize_t vinst_pe_cmp_start_stop_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (!drvdata->nr_pe_cmp)
+	if (!caps->nr_pe_cmp)
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
@@ -1393,13 +1415,14 @@ static ssize_t seq_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
-	if (!drvdata->nrseqstate)
+	if (!caps->nrseqstate)
 		return -EINVAL;
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->nrseqstate - 1)
+	if (val >= caps->nrseqstate - 1)
 		return -EINVAL;
 
 	/*
@@ -1431,11 +1454,12 @@ static ssize_t seq_state_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->nrseqstate)
+	if (val >= caps->nrseqstate)
 		return -EINVAL;
 
 	config->seq_state = val;
@@ -1498,11 +1522,12 @@ static ssize_t seq_reset_event_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (!(drvdata->nrseqstate))
+	if (!(caps->nrseqstate))
 		return -EINVAL;
 
 	config->seq_rst = val & ETMv4_EVENT_MASK;
@@ -1528,11 +1553,12 @@ static ssize_t cntr_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->nr_cntr)
+	if (val >= caps->nr_cntr)
 		return -EINVAL;
 
 	/*
@@ -1676,6 +1702,7 @@ static ssize_t res_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
@@ -1684,7 +1711,7 @@ static ssize_t res_idx_store(struct device *dev,
 	 * Resource selector pair 0 is always implemented and reserved,
 	 * namely an idx with 0 and 1 is illegal.
 	 */
-	if ((val < 2) || (val >= 2 * drvdata->nr_resource))
+	if ((val < 2) || (val >= 2 * caps->nr_resource))
 		return -EINVAL;
 
 	/*
@@ -1758,11 +1785,12 @@ static ssize_t sshot_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->nr_ss_cmp)
+	if (val >= caps->nr_ss_cmp)
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
@@ -1876,11 +1904,12 @@ static ssize_t ctxid_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->numcidc)
+	if (val >= caps->numcidc)
 		return -EINVAL;
 
 	/*
@@ -1924,6 +1953,7 @@ static ssize_t ctxid_pid_store(struct device *dev,
 	u8 idx;
 	unsigned long pid;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	/*
@@ -1943,7 +1973,7 @@ static ssize_t ctxid_pid_store(struct device *dev,
 	 * ctxid comparator is implemented and ctxid is greater than 0 bits
 	 * in length
 	 */
-	if (!drvdata->ctxid_size || !drvdata->numcidc)
+	if (!caps->ctxid_size || !caps->numcidc)
 		return -EINVAL;
 	if (kstrtoul(buf, 16, &pid))
 		return -EINVAL;
@@ -1985,6 +2015,7 @@ static ssize_t ctxid_masks_store(struct device *dev,
 	u8 i, j, maskbyte;
 	unsigned long val1, val2, mask;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 	int nr_inputs;
 
@@ -2000,11 +2031,11 @@ static ssize_t ctxid_masks_store(struct device *dev,
 	 * ctxid comparator is implemented and ctxid is greater than 0 bits
 	 * in length
 	 */
-	if (!drvdata->ctxid_size || !drvdata->numcidc)
+	if (!caps->ctxid_size || !caps->numcidc)
 		return -EINVAL;
 	/* one mask if <= 4 comparators, two for up to 8 */
 	nr_inputs = sscanf(buf, "%lx %lx", &val1, &val2);
-	if ((drvdata->numcidc > 4) && (nr_inputs != 2))
+	if ((caps->numcidc > 4) && (nr_inputs != 2))
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
@@ -2012,7 +2043,7 @@ static ssize_t ctxid_masks_store(struct device *dev,
 	 * each byte[0..3] controls mask value applied to ctxid
 	 * comparator[0..3]
 	 */
-	switch (drvdata->numcidc) {
+	switch (caps->numcidc) {
 	case 0x1:
 		/* COMP0, bits[7:0] */
 		config->ctxid_mask0 = val1 & 0xFF;
@@ -2059,7 +2090,7 @@ static ssize_t ctxid_masks_store(struct device *dev,
 	 * of ctxid comparator0 value (corresponding to byte 0) register.
 	 */
 	mask = config->ctxid_mask0;
-	for (i = 0; i < drvdata->numcidc; i++) {
+	for (i = 0; i < caps->numcidc; i++) {
 		/* mask value of corresponding ctxid comparator */
 		maskbyte = mask & ETMv4_EVENT_MASK;
 		/*
@@ -2102,11 +2133,12 @@ static ssize_t vmid_idx_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
-	if (val >= drvdata->numvmidc)
+	if (val >= caps->numvmidc)
 		return -EINVAL;
 
 	/*
@@ -2147,6 +2179,7 @@ static ssize_t vmid_val_store(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	/*
@@ -2160,7 +2193,7 @@ static ssize_t vmid_val_store(struct device *dev,
 	 * only implemented when vmid tracing is enabled, i.e. at least one
 	 * vmid comparator is implemented and at least 8 bit vmid size
 	 */
-	if (!drvdata->vmid_size || !drvdata->numvmidc)
+	if (!caps->vmid_size || !caps->numvmidc)
 		return -EINVAL;
 	if (kstrtoul(buf, 16, &val))
 		return -EINVAL;
@@ -2200,6 +2233,7 @@ static ssize_t vmid_masks_store(struct device *dev,
 	u8 i, j, maskbyte;
 	unsigned long val1, val2, mask;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 	int nr_inputs;
 
@@ -2214,11 +2248,11 @@ static ssize_t vmid_masks_store(struct device *dev,
 	 * only implemented when vmid tracing is enabled, i.e. at least one
 	 * vmid comparator is implemented and at least 8 bit vmid size
 	 */
-	if (!drvdata->vmid_size || !drvdata->numvmidc)
+	if (!caps->vmid_size || !caps->numvmidc)
 		return -EINVAL;
 	/* one mask if <= 4 comparators, two for up to 8 */
 	nr_inputs = sscanf(buf, "%lx %lx", &val1, &val2);
-	if ((drvdata->numvmidc > 4) && (nr_inputs != 2))
+	if ((caps->numvmidc > 4) && (nr_inputs != 2))
 		return -EINVAL;
 
 	raw_spin_lock(&drvdata->spinlock);
@@ -2227,7 +2261,7 @@ static ssize_t vmid_masks_store(struct device *dev,
 	 * each byte[0..3] controls mask value applied to vmid
 	 * comparator[0..3]
 	 */
-	switch (drvdata->numvmidc) {
+	switch (caps->numvmidc) {
 	case 0x1:
 		/* COMP0, bits[7:0] */
 		config->vmid_mask0 = val1 & 0xFF;
@@ -2275,7 +2309,7 @@ static ssize_t vmid_masks_store(struct device *dev,
 	 * of vmid comparator0 value (corresponding to byte 0) register.
 	 */
 	mask = config->vmid_mask0;
-	for (i = 0; i < drvdata->numvmidc; i++) {
+	for (i = 0; i < caps->numvmidc; i++) {
 		/* mask value of corresponding vmid comparator */
 		maskbyte = mask & ETMv4_EVENT_MASK;
 		/*
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 89d81ce4e04e..8168676f2945 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -812,6 +812,95 @@ enum etm_impdef_type {
 	ETM4_IMPDEF_FEATURE_MAX,
 };
 
+/**
+ * struct etmv4_caps - specifics ETM capabilities
+ * @nr_pe:	The number of processing entity available for tracing.
+ * @nr_pe_cmp:	The number of processing entity comparator inputs that are
+ *		available for tracing.
+ * @nr_addr_cmp:Number of pairs of address comparators available
+ *		as found in ETMIDR4 0-3.
+ * @nr_cntr:    Number of counters as found in ETMIDR5 bit 28-30.
+ * @nr_ext_inp: Number of external input.
+ * @numcidc:	Number of contextID comparators.
+ * @numextinsel: Number of external input selector resources.
+ * @numvmidc:	Number of VMID comparators.
+ * @nrseqstate: The number of sequencer states that are implemented.
+ * @nr_event:	Indicates how many events the trace unit support.
+ * @nr_resource:The number of resource selection pairs available for tracing.
+ * @nr_ss_cmp:	Number of single-shot comparator controls that are available.
+ * @trcid_size: Indicates the trace ID width.
+ * @ts_size:	Global timestamp size field.
+ * @ctxid_size:	Size of the context ID field to consider.
+ * @vmid_size:	Size of the VM ID comparator to consider.
+ * @ccsize:	Indicates the size of the cycle counter in bits.
+ * @ccitmin:	minimum value that can be programmed in
+ * @s_ex_level:	In secure state, indicates whether instruction tracing is
+ *		supported for the corresponding Exception level.
+ * @ns_ex_level:In non-secure state, indicates whether instruction tracing is
+ *		supported for the corresponding Exception level.
+ * @q_support:	Q element support characteristics.
+ * @os_lock_model: OSLock model.
+ * @instrp0:	Tracing of load and store instructions
+ *		as P0 elements is supported.
+ * @q_filt:	Q element filtering support, if Q elements are supported.
+ * @trcbb:	Indicates if the trace unit supports branch broadcast tracing.
+ * @trccond:	If the trace unit supports conditional
+ *		instruction tracing.
+ * @retstack:	Indicates if the implementation supports a return stack.
+ * @trccci:	Indicates if the trace unit supports cycle counting
+ *		for instruction.
+ * @trc_error:	Whether a trace unit can trace a system
+ *		error exception.
+ * @syncpr:	Indicates if an implementation has a fixed
+ *		synchronization period.
+ * @stallctl:	If functionality that prevents trace unit buffer overflows
+ *		is available.
+ * @sysstall:	Does the system support stall control of the PE?
+ * @nooverflow:	Indicate if overflow prevention is supported.
+ * @atbtrig:	If the implementation can support ATB triggers
+ * @lpoverride:	If the implementation can support low-power state over.
+ * @skip_power_up: Indicates if an implementation can skip powering up
+ *		   the trace unit.
+ */
+struct etmv4_caps {
+	u8	nr_pe;
+	u8	nr_pe_cmp;
+	u8	nr_addr_cmp;
+	u8	nr_cntr;
+	u8	nr_ext_inp;
+	u8	numcidc;
+	u8	numextinsel;
+	u8	numvmidc;
+	u8	nrseqstate;
+	u8	nr_event;
+	u8	nr_resource;
+	u8	nr_ss_cmp;
+	u8	trcid_size;
+	u8	ts_size;
+	u8	ctxid_size;
+	u8	vmid_size;
+	u8	ccsize;
+	u16	ccitmin;
+	u8	s_ex_level;
+	u8	ns_ex_level;
+	u8	q_support;
+	u8	os_lock_model;
+	bool	instrp0 : 1;
+	bool	q_filt : 1;
+	bool	trcbb : 1;
+	bool	trccond : 1;
+	bool	retstack : 1;
+	bool	trccci : 1;
+	bool	trc_error : 1;
+	bool	syncpr : 1;
+	bool	stallctl : 1;
+	bool	sysstall : 1;
+	bool	nooverflow : 1;
+	bool	atbtrig : 1;
+	bool	lpoverride : 1;
+	bool	skip_power_up : 1;
+};
+
 /**
  * struct etmv4_config - configuration information related to an ETMv4
  * @mode:	Controls various modes supported by this ETM.
@@ -819,8 +908,8 @@ enum etm_impdef_type {
  * @cfg:	Controls the tracing options.
  * @eventctrl0: Controls the tracing of arbitrary events.
  * @eventctrl1: Controls the behavior of the events that @event_ctrl0 selects.
- * @stallctl:	If functionality that prevents trace unit buffer overflows
- *		is available.
+ * @stall_ctrl:	Enables trace unit functionality that prevents trace
+ *		unit buffer overflows.
  * @ts_ctrl:	Controls the insertion of global timestamps in the
  *		trace streams.
  * @syncfreq:	Controls how often trace synchronization requests occur.
@@ -971,61 +1060,17 @@ struct etmv4_save_state {
  * @mode:	This tracer's mode, i.e sysFS, Perf or disabled.
  * @cpu:        The cpu this component is affined to.
  * @arch:       ETM architecture version.
- * @nr_pe:	The number of processing entity available for tracing.
- * @nr_pe_cmp:	The number of processing entity comparator inputs that are
- *		available for tracing.
- * @nr_addr_cmp:Number of pairs of address comparators available
- *		as found in ETMIDR4 0-3.
- * @nr_cntr:    Number of counters as found in ETMIDR5 bit 28-30.
- * @nr_ext_inp: Number of external input.
- * @numcidc:	Number of contextID comparators.
- * @numvmidc:	Number of VMID comparators.
- * @nrseqstate: The number of sequencer states that are implemented.
- * @nr_event:	Indicates how many events the trace unit support.
- * @nr_resource:The number of resource selection pairs available for tracing.
- * @nr_ss_cmp:	Number of single-shot comparator controls that are available.
+ * @caps:	ETM capabilities.
  * @trcid:	value of the current ID for this component.
- * @trcid_size: Indicates the trace ID width.
- * @ts_size:	Global timestamp size field.
- * @ctxid_size:	Size of the context ID field to consider.
- * @vmid_size:	Size of the VM ID comparator to consider.
- * @ccsize:	Indicates the size of the cycle counter in bits.
- * @ccitmin:	minimum value that can be programmed in
- * @s_ex_level:	In secure state, indicates whether instruction tracing is
- *		supported for the corresponding Exception level.
- * @ns_ex_level:In non-secure state, indicates whether instruction tracing is
- *		supported for the corresponding Exception level.
  * @sticky_enable: true if ETM base configuration has been done.
  * @boot_enable:True if we should start tracing at boot time.
  * @os_unlock:  True if access to management registers is allowed.
- * @instrp0:	Tracing of load and store instructions
- *		as P0 elements is supported.
- * @q_filt:	Q element filtering support, if Q elements are supported.
- * @trcbb:	Indicates if the trace unit supports branch broadcast tracing.
- * @trccond:	If the trace unit supports conditional
- *		instruction tracing.
- * @retstack:	Indicates if the implementation supports a return stack.
- * @trccci:	Indicates if the trace unit supports cycle counting
- *		for instruction.
- * @q_support:	Q element support characteristics.
- * @trc_error:	Whether a trace unit can trace a system
- *		error exception.
- * @syncpr:	Indicates if an implementation has a fixed
- *		synchronization period.
- * @stall_ctrl:	Enables trace unit functionality that prevents trace
- *		unit buffer overflows.
- * @sysstall:	Does the system support stall control of the PE?
- * @nooverflow:	Indicate if overflow prevention is supported.
- * @atbtrig:	If the implementation can support ATB triggers
- * @lpoverride:	If the implementation can support low-power state over.
  * @trfcr:	If the CPU supports FEAT_TRF, value of the TRFCR_ELx that
  *		allows tracing at all ELs. We don't want to compute this
  *		at runtime, due to the additional setting of TRFCR_CX when
  *		in EL2. Otherwise, 0.
  * @config:	structure holding configuration parameters.
  * @save_state:	State to be preserved across power loss
- * @skip_power_up: Indicates if an implementation can skip powering up
- *		   the trace unit.
  * @paused:	Indicates if the trace unit is paused.
  * @arch_features: Bitmap of arch features of etmv4 devices.
  */
@@ -1037,46 +1082,11 @@ struct etmv4_drvdata {
 	raw_spinlock_t			spinlock;
 	int				cpu;
 	u8				arch;
-	u8				nr_pe;
-	u8				nr_pe_cmp;
-	u8				nr_addr_cmp;
-	u8				nr_cntr;
-	u8				nr_ext_inp;
-	u8				numcidc;
-	u8				numextinsel;
-	u8				numvmidc;
-	u8				nrseqstate;
-	u8				nr_event;
-	u8				nr_resource;
-	u8				nr_ss_cmp;
+	struct etmv4_caps		caps;
 	u8				trcid;
-	u8				trcid_size;
-	u8				ts_size;
-	u8				ctxid_size;
-	u8				vmid_size;
-	u8				ccsize;
-	u16				ccitmin;
-	u8				s_ex_level;
-	u8				ns_ex_level;
-	u8				q_support;
-	u8				os_lock_model;
 	bool				sticky_enable : 1;
 	bool				boot_enable : 1;
 	bool				os_unlock : 1;
-	bool				instrp0 : 1;
-	bool				q_filt : 1;
-	bool				trcbb : 1;
-	bool				trccond : 1;
-	bool				retstack : 1;
-	bool				trccci : 1;
-	bool				trc_error : 1;
-	bool				syncpr : 1;
-	bool				stallctl : 1;
-	bool				sysstall : 1;
-	bool				nooverflow : 1;
-	bool				atbtrig : 1;
-	bool				lpoverride : 1;
-	bool				skip_power_up : 1;
 	bool				paused : 1;
 	u64				trfcr;
 	struct etmv4_config		config;
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

[Yeoreum Yun]

The purpose of TRCSSCSRn register is to show status of
the corresponding Single-shot Comparator Control and input supports.
That means writable field's purpose for reset or restore from idle status
not for configuration.

Therefore, exclude ss_status from drvdata->config, move it to etm4x_caps
and rename it to ss_smp.

This includes remove TRCSSCRn from configurable item and
remove saving in etm4_disable_hw().

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 .../hwtracing/coresight/coresight-etm4x-cfg.c |  1 -
 .../coresight/coresight-etm4x-core.c          | 19 ++++++-------------
 .../coresight/coresight-etm4x-sysfs.c         |  7 ++-----
 drivers/hwtracing/coresight/coresight-etm4x.h |  7 ++++++-
 4 files changed, 14 insertions(+), 20 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
index c302072b293a..d14d7c8a23e5 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
@@ -86,7 +86,6 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
 		off_mask =  (offset & GENMASK(11, 5));
 		do {
 			CHECKREGIDX(TRCSSCCRn(0), ss_ctrl, idx, off_mask);
-			CHECKREGIDX(TRCSSCSRn(0), ss_status, idx, off_mask);
 			CHECKREGIDX(TRCSSPCICRn(0), ss_pe_cmp, idx, off_mask);
 		} while (0);
 	} else if ((offset >= TRCCIDCVRn(0)) && (offset <= TRCVMIDCVRn(7))) {
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index b2b092a76eb5..f55338a4989d 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -91,7 +91,7 @@ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
 	const struct etmv4_caps *caps = &drvdata->caps;
 
 	return (n < caps->nr_ss_cmp) && caps->nr_pe_cmp &&
-	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
+	       (caps->ss_cmp[n] & TRCSSCSRn_PC);
 }
 
 u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
@@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
 
 	for (i = 0; i < caps->nr_ss_cmp; i++) {
-		/* always clear status bit on restart if using single-shot */
-		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
-			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
 		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
-		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
+		/* always clear status and pending bits on restart if using single-shot */
+		etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));
 		if (etm4x_sspcicrn_present(drvdata, i))
 			etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
 	}
@@ -1055,12 +1053,6 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
 
 	etm4_disable_trace_unit(drvdata);
 
-	/* read the status of the single shot comparators */
-	for (i = 0; i < caps->nr_ss_cmp; i++) {
-		config->ss_status[i] =
-			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
-	}
-
 	/* read back the current counter values */
 	for (i = 0; i < caps->nr_cntr; i++) {
 		config->cntr_val[i] =
@@ -1503,8 +1495,9 @@ static void etm4_init_arch_data(void *info)
 	 */
 	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
 	for (i = 0; i < caps->nr_ss_cmp; i++) {
-		drvdata->config.ss_status[i] =
-			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+		caps->ss_cmp[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
+		caps->ss_cmp[i] &= (TRCSSCSRn_PC | TRCSSCSRn_DV |
+				    TRCSSCSRn_DA | TRCSSCSRn_INST);
 	}
 	/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
 	caps->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
index 8bd28e71d4c9..5e26c2ec8f7b 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
@@ -1829,8 +1829,6 @@ static ssize_t sshot_ctrl_store(struct device *dev,
 	raw_spin_lock(&drvdata->spinlock);
 	idx = config->ss_idx;
 	config->ss_ctrl[idx] = FIELD_PREP(TRCSSCCRn_SAC_ARC_RST_MASK, val);
-	/* must clear bit 31 in related status register on programming */
-	config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
 	raw_spin_unlock(&drvdata->spinlock);
 	return size;
 }
@@ -1841,10 +1839,11 @@ static ssize_t sshot_status_show(struct device *dev,
 {
 	unsigned long val;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etmv4_caps *caps = &drvdata->caps;
 	struct etmv4_config *config = &drvdata->config;
 
 	raw_spin_lock(&drvdata->spinlock);
-	val = config->ss_status[config->ss_idx];
+	val = caps->ss_cmp[config->ss_idx];
 	raw_spin_unlock(&drvdata->spinlock);
 	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
 }
@@ -1879,8 +1878,6 @@ static ssize_t sshot_pe_ctrl_store(struct device *dev,
 	raw_spin_lock(&drvdata->spinlock);
 	idx = config->ss_idx;
 	config->ss_pe_cmp[idx] = FIELD_PREP(TRCSSPCICRn_PC_MASK, val);
-	/* must clear bit 31 in related status register on programming */
-	config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
 	raw_spin_unlock(&drvdata->spinlock);
 	return size;
 }
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 8168676f2945..db56c4414873 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -213,6 +213,7 @@
 #define TRCACATRn_EXLEVEL_MASK			GENMASK(14, 8)
 
 #define TRCSSCSRn_STATUS			BIT(31)
+#define TRCSSCSRn_PENDING			BIT(30)
 #define TRCSSCCRn_SAC_ARC_RST_MASK		GENMASK(24, 0)
 
 #define TRCSSPCICRn_PC_MASK			GENMASK(7, 0)
@@ -729,6 +730,9 @@ static inline u32 etm4_res_sel_pair(u8 res_sel_idx)
 #define ETM_DEFAULT_ADDR_COMP		0
 
 #define TRCSSCSRn_PC			BIT(3)
+#define TRCSSCSRn_DV			BIT(2)
+#define TRCSSCSRn_DA			BIT(1)
+#define TRCSSCSRn_INST			BIT(0)
 
 /* PowerDown Control Register bits */
 #define TRCPDCR_PU			BIT(3)
@@ -861,6 +865,7 @@ enum etm_impdef_type {
  * @lpoverride:	If the implementation can support low-power state over.
  * @skip_power_up: Indicates if an implementation can skip powering up
  *		   the trace unit.
+ * @ss_cmp:	Indicates supported single-shot comparators.
  */
 struct etmv4_caps {
 	u8	nr_pe;
@@ -899,6 +904,7 @@ struct etmv4_caps {
 	bool	atbtrig : 1;
 	bool	lpoverride : 1;
 	bool	skip_power_up : 1;
+	u32	ss_cmp[ETM_MAX_SS_CMP];
 };
 
 /**
@@ -977,7 +983,6 @@ struct etmv4_config {
 	u32				res_ctrl[ETM_MAX_RES_SEL]; /* TRCRSCTLRn */
 	u8				ss_idx;
 	u32				ss_ctrl[ETM_MAX_SS_CMP];
-	u32				ss_status[ETM_MAX_SS_CMP];
 	u32				ss_pe_cmp[ETM_MAX_SS_CMP];
 	u8				addr_idx;
 	u64				addr_val[ETM_MAX_SINGLE_ADDR_CMP];
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

Re: [PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

[Jie Gan]

On 4/16/2026 12:55 AM, Yeoreum Yun wrote:
> The purpose of TRCSSCSRn register is to show status of
> the corresponding Single-shot Comparator Control and input supports.
> That means writable field's purpose for reset or restore from idle status
> not for configuration.
> 
> Therefore, exclude ss_status from drvdata->config, move it to etm4x_caps
> and rename it to ss_smp.
> 
> This includes remove TRCSSCRn from configurable item and
> remove saving in etm4_disable_hw().
> 
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> ---
>   .../hwtracing/coresight/coresight-etm4x-cfg.c |  1 -
>   .../coresight/coresight-etm4x-core.c          | 19 ++++++-------------
>   .../coresight/coresight-etm4x-sysfs.c         |  7 ++-----
>   drivers/hwtracing/coresight/coresight-etm4x.h |  7 ++++++-
>   4 files changed, 14 insertions(+), 20 deletions(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> index c302072b293a..d14d7c8a23e5 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> @@ -86,7 +86,6 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
>   		off_mask =  (offset & GENMASK(11, 5));
>   		do {
>   			CHECKREGIDX(TRCSSCCRn(0), ss_ctrl, idx, off_mask);
> -			CHECKREGIDX(TRCSSCSRn(0), ss_status, idx, off_mask);
>   			CHECKREGIDX(TRCSSPCICRn(0), ss_pe_cmp, idx, off_mask);
>   		} while (0);
>   	} else if ((offset >= TRCCIDCVRn(0)) && (offset <= TRCVMIDCVRn(7))) {
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index b2b092a76eb5..f55338a4989d 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -91,7 +91,7 @@ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
>   	const struct etmv4_caps *caps = &drvdata->caps;
>   
>   	return (n < caps->nr_ss_cmp) && caps->nr_pe_cmp &&
> -	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
> +	       (caps->ss_cmp[n] & TRCSSCSRn_PC);
>   }
>   
>   u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
> @@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>   		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
>   
>   	for (i = 0; i < caps->nr_ss_cmp; i++) {
> -		/* always clear status bit on restart if using single-shot */
> -		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
> -			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
>   		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
> -		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
> +		/* always clear status and pending bits on restart if using single-shot */
> +		etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));
>   		if (etm4x_sspcicrn_present(drvdata, i))
>   			etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
>   	}
> @@ -1055,12 +1053,6 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
>   
>   	etm4_disable_trace_unit(drvdata);
>   
> -	/* read the status of the single shot comparators */
> -	for (i = 0; i < caps->nr_ss_cmp; i++) {
> -		config->ss_status[i] =
> -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> -	}
> -
>   	/* read back the current counter values */
>   	for (i = 0; i < caps->nr_cntr; i++) {
>   		config->cntr_val[i] =
> @@ -1503,8 +1495,9 @@ static void etm4_init_arch_data(void *info)
>   	 */
>   	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
>   	for (i = 0; i < caps->nr_ss_cmp; i++) {
> -		drvdata->config.ss_status[i] =
> -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> +		caps->ss_cmp[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> +		caps->ss_cmp[i] &= (TRCSSCSRn_PC | TRCSSCSRn_DV |
> +				    TRCSSCSRn_DA | TRCSSCSRn_INST);

Just re-go through this patch and had a question here:

I’m not sure whether this new change should be documented in the ABI, 
given that the TRCSSCSRn_STATUS bit is masked. In my opinion, this 
change breaks the existing ABI description.

Description from the ABI document:

What:           /sys/bus/coresight/devices/etm<N>/sshot_status
Date:           December 2019
KernelVersion:  5.5
Contact:        Mathieu Poirier <mathieu.poirier@linaro.org>
Description:    (Read) Print the current value of the selected single
                 shot status register.

Thanks,
Jie

>   	}
>   	/* NUMCIDC, bits[27:24] number of Context ID comparators for tracing */
>   	caps->numcidc = FIELD_GET(TRCIDR4_NUMCIDC_MASK, etmidr4);
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index 8bd28e71d4c9..5e26c2ec8f7b 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -1829,8 +1829,6 @@ static ssize_t sshot_ctrl_store(struct device *dev,
>   	raw_spin_lock(&drvdata->spinlock);
>   	idx = config->ss_idx;
>   	config->ss_ctrl[idx] = FIELD_PREP(TRCSSCCRn_SAC_ARC_RST_MASK, val);
> -	/* must clear bit 31 in related status register on programming */
> -	config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
>   	raw_spin_unlock(&drvdata->spinlock);
>   	return size;
>   }
> @@ -1841,10 +1839,11 @@ static ssize_t sshot_status_show(struct device *dev,
>   {
>   	unsigned long val;
>   	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	const struct etmv4_caps *caps = &drvdata->caps;
>   	struct etmv4_config *config = &drvdata->config;
>   
>   	raw_spin_lock(&drvdata->spinlock);
> -	val = config->ss_status[config->ss_idx];
> +	val = caps->ss_cmp[config->ss_idx];
>   	raw_spin_unlock(&drvdata->spinlock);
>   	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
>   }
> @@ -1879,8 +1878,6 @@ static ssize_t sshot_pe_ctrl_store(struct device *dev,
>   	raw_spin_lock(&drvdata->spinlock);
>   	idx = config->ss_idx;
>   	config->ss_pe_cmp[idx] = FIELD_PREP(TRCSSPCICRn_PC_MASK, val);
> -	/* must clear bit 31 in related status register on programming */
> -	config->ss_status[idx] &= ~TRCSSCSRn_STATUS;
>   	raw_spin_unlock(&drvdata->spinlock);
>   	return size;
>   }
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index 8168676f2945..db56c4414873 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -213,6 +213,7 @@
>   #define TRCACATRn_EXLEVEL_MASK			GENMASK(14, 8)
>   
>   #define TRCSSCSRn_STATUS			BIT(31)
> +#define TRCSSCSRn_PENDING			BIT(30)
>   #define TRCSSCCRn_SAC_ARC_RST_MASK		GENMASK(24, 0)
>   
>   #define TRCSSPCICRn_PC_MASK			GENMASK(7, 0)
> @@ -729,6 +730,9 @@ static inline u32 etm4_res_sel_pair(u8 res_sel_idx)
>   #define ETM_DEFAULT_ADDR_COMP		0
>   
>   #define TRCSSCSRn_PC			BIT(3)
> +#define TRCSSCSRn_DV			BIT(2)
> +#define TRCSSCSRn_DA			BIT(1)
> +#define TRCSSCSRn_INST			BIT(0)
>   
>   /* PowerDown Control Register bits */
>   #define TRCPDCR_PU			BIT(3)
> @@ -861,6 +865,7 @@ enum etm_impdef_type {
>    * @lpoverride:	If the implementation can support low-power state over.
>    * @skip_power_up: Indicates if an implementation can skip powering up
>    *		   the trace unit.
> + * @ss_cmp:	Indicates supported single-shot comparators.
>    */
>   struct etmv4_caps {
>   	u8	nr_pe;
> @@ -899,6 +904,7 @@ struct etmv4_caps {
>   	bool	atbtrig : 1;
>   	bool	lpoverride : 1;
>   	bool	skip_power_up : 1;
> +	u32	ss_cmp[ETM_MAX_SS_CMP];
>   };
>   
>   /**
> @@ -977,7 +983,6 @@ struct etmv4_config {
>   	u32				res_ctrl[ETM_MAX_RES_SEL]; /* TRCRSCTLRn */
>   	u8				ss_idx;
>   	u32				ss_ctrl[ETM_MAX_SS_CMP];
> -	u32				ss_status[ETM_MAX_SS_CMP];
>   	u32				ss_pe_cmp[ETM_MAX_SS_CMP];
>   	u8				addr_idx;
>   	u64				addr_val[ETM_MAX_SINGLE_ADDR_CMP];

Re: [PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

[Yeoreum Yun]

Hi Jie,

>
>
> On 4/16/2026 12:55 AM, Yeoreum Yun wrote:
> > The purpose of TRCSSCSRn register is to show status of
> > the corresponding Single-shot Comparator Control and input supports.
> > That means writable field's purpose for reset or restore from idle status
> > not for configuration.
> >
> > Therefore, exclude ss_status from drvdata->config, move it to etm4x_caps
> > and rename it to ss_smp.
> >
> > This includes remove TRCSSCRn from configurable item and
> > remove saving in etm4_disable_hw().
> >
> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > ---
> >   .../hwtracing/coresight/coresight-etm4x-cfg.c |  1 -
> >   .../coresight/coresight-etm4x-core.c          | 19 ++++++-------------
> >   .../coresight/coresight-etm4x-sysfs.c         |  7 ++-----
> >   drivers/hwtracing/coresight/coresight-etm4x.h |  7 ++++++-
> >   4 files changed, 14 insertions(+), 20 deletions(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > index c302072b293a..d14d7c8a23e5 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
> > @@ -86,7 +86,6 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
> >   		off_mask =  (offset & GENMASK(11, 5));
> >   		do {
> >   			CHECKREGIDX(TRCSSCCRn(0), ss_ctrl, idx, off_mask);
> > -			CHECKREGIDX(TRCSSCSRn(0), ss_status, idx, off_mask);
> >   			CHECKREGIDX(TRCSSPCICRn(0), ss_pe_cmp, idx, off_mask);
> >   		} while (0);
> >   	} else if ((offset >= TRCCIDCVRn(0)) && (offset <= TRCVMIDCVRn(7))) {
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > index b2b092a76eb5..f55338a4989d 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > @@ -91,7 +91,7 @@ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
> >   	const struct etmv4_caps *caps = &drvdata->caps;
> >   	return (n < caps->nr_ss_cmp) && caps->nr_pe_cmp &&
> > -	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
> > +	       (caps->ss_cmp[n] & TRCSSCSRn_PC);
> >   }
> >   u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
> > @@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
> >   		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
> >   	for (i = 0; i < caps->nr_ss_cmp; i++) {
> > -		/* always clear status bit on restart if using single-shot */
> > -		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
> > -			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
> >   		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
> > -		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
> > +		/* always clear status and pending bits on restart if using single-shot */
> > +		etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));
> >   		if (etm4x_sspcicrn_present(drvdata, i))
> >   			etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
> >   	}
> > @@ -1055,12 +1053,6 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
> >   	etm4_disable_trace_unit(drvdata);
> > -	/* read the status of the single shot comparators */
> > -	for (i = 0; i < caps->nr_ss_cmp; i++) {
> > -		config->ss_status[i] =
> > -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> > -	}
> > -
> >   	/* read back the current counter values */
> >   	for (i = 0; i < caps->nr_cntr; i++) {
> >   		config->cntr_val[i] =
> > @@ -1503,8 +1495,9 @@ static void etm4_init_arch_data(void *info)
> >   	 */
> >   	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
> >   	for (i = 0; i < caps->nr_ss_cmp; i++) {
> > -		drvdata->config.ss_status[i] =
> > -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> > +		caps->ss_cmp[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
> > +		caps->ss_cmp[i] &= (TRCSSCSRn_PC | TRCSSCSRn_DV |
> > +				    TRCSSCSRn_DA | TRCSSCSRn_INST);
>
> Just re-go through this patch and had a question here:
>
> I’m not sure whether this new change should be documented in the ABI, given
> that the TRCSSCSRn_STATUS bit is masked. In my opinion, this change breaks
> the existing ABI description.
>
> Description from the ABI document:
>
> What:           /sys/bus/coresight/devices/etm<N>/sshot_status
> Date:           December 2019
> KernelVersion:  5.5
> Contact:        Mathieu Poirier <mathieu.poirier@linaro.org>
> Description:    (Read) Print the current value of the selected single
>                 shot status register.

But, as I mentioned another thread:
  - https://lore.kernel.org/all/ad5yV2FoNbGGLE6R@e129823.arm.com/

Till now, sysfs doesn't show the *current value* of the single shot
state since the config->ss_status is updated enabled/disabled sysfs
session. an I think once the session is disabled, other status bits
(currently STATUS and PENDING bits) don't have any meaning.

I think it's enough to change the doc's Description for this.

Any thought?

--
Sincerely,
Yeoreum Yun

Re: [PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

[Jie Gan]

On 4/16/2026 2:54 PM, Yeoreum Yun wrote:
> Hi Jie,
> 

Hi Yeoreum,

>>
>>
>> On 4/16/2026 12:55 AM, Yeoreum Yun wrote:
>>> The purpose of TRCSSCSRn register is to show status of
>>> the corresponding Single-shot Comparator Control and input supports.
>>> That means writable field's purpose for reset or restore from idle status
>>> not for configuration.
>>>
>>> Therefore, exclude ss_status from drvdata->config, move it to etm4x_caps
>>> and rename it to ss_smp.
>>>
>>> This includes remove TRCSSCRn from configurable item and
>>> remove saving in etm4_disable_hw().
>>>
>>> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
>>> ---
>>>    .../hwtracing/coresight/coresight-etm4x-cfg.c |  1 -
>>>    .../coresight/coresight-etm4x-core.c          | 19 ++++++-------------
>>>    .../coresight/coresight-etm4x-sysfs.c         |  7 ++-----
>>>    drivers/hwtracing/coresight/coresight-etm4x.h |  7 ++++++-
>>>    4 files changed, 14 insertions(+), 20 deletions(-)
>>>
>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
>>> index c302072b293a..d14d7c8a23e5 100644
>>> --- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
>>> @@ -86,7 +86,6 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
>>>    		off_mask =  (offset & GENMASK(11, 5));
>>>    		do {
>>>    			CHECKREGIDX(TRCSSCCRn(0), ss_ctrl, idx, off_mask);
>>> -			CHECKREGIDX(TRCSSCSRn(0), ss_status, idx, off_mask);
>>>    			CHECKREGIDX(TRCSSPCICRn(0), ss_pe_cmp, idx, off_mask);
>>>    		} while (0);
>>>    	} else if ((offset >= TRCCIDCVRn(0)) && (offset <= TRCVMIDCVRn(7))) {
>>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>> index b2b092a76eb5..f55338a4989d 100644
>>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>>> @@ -91,7 +91,7 @@ static bool etm4x_sspcicrn_present(struct etmv4_drvdata *drvdata, int n)
>>>    	const struct etmv4_caps *caps = &drvdata->caps;
>>>    	return (n < caps->nr_ss_cmp) && caps->nr_pe_cmp &&
>>> -	       (drvdata->config.ss_status[n] & TRCSSCSRn_PC);
>>> +	       (caps->ss_cmp[n] & TRCSSCSRn_PC);
>>>    }
>>>    u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
>>> @@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>>>    		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
>>>    	for (i = 0; i < caps->nr_ss_cmp; i++) {
>>> -		/* always clear status bit on restart if using single-shot */
>>> -		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
>>> -			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
>>>    		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
>>> -		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
>>> +		/* always clear status and pending bits on restart if using single-shot */
>>> +		etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));
>>>    		if (etm4x_sspcicrn_present(drvdata, i))
>>>    			etm4x_relaxed_write32(csa, config->ss_pe_cmp[i], TRCSSPCICRn(i));
>>>    	}
>>> @@ -1055,12 +1053,6 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
>>>    	etm4_disable_trace_unit(drvdata);
>>> -	/* read the status of the single shot comparators */
>>> -	for (i = 0; i < caps->nr_ss_cmp; i++) {
>>> -		config->ss_status[i] =
>>> -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
>>> -	}
>>> -
>>>    	/* read back the current counter values */
>>>    	for (i = 0; i < caps->nr_cntr; i++) {
>>>    		config->cntr_val[i] =
>>> @@ -1503,8 +1495,9 @@ static void etm4_init_arch_data(void *info)
>>>    	 */
>>>    	caps->nr_ss_cmp = FIELD_GET(TRCIDR4_NUMSSCC_MASK, etmidr4);
>>>    	for (i = 0; i < caps->nr_ss_cmp; i++) {
>>> -		drvdata->config.ss_status[i] =
>>> -			etm4x_relaxed_read32(csa, TRCSSCSRn(i));
>>> +		caps->ss_cmp[i] = etm4x_relaxed_read32(csa, TRCSSCSRn(i));
>>> +		caps->ss_cmp[i] &= (TRCSSCSRn_PC | TRCSSCSRn_DV |
>>> +				    TRCSSCSRn_DA | TRCSSCSRn_INST);
>>
>> Just re-go through this patch and had a question here:
>>
>> I’m not sure whether this new change should be documented in the ABI, given
>> that the TRCSSCSRn_STATUS bit is masked. In my opinion, this change breaks
>> the existing ABI description.
>>
>> Description from the ABI document:
>>
>> What:           /sys/bus/coresight/devices/etm<N>/sshot_status
>> Date:           December 2019
>> KernelVersion:  5.5
>> Contact:        Mathieu Poirier <mathieu.poirier@linaro.org>
>> Description:    (Read) Print the current value of the selected single
>>                  shot status register.
> 
> But, as I mentioned another thread:
>    - https://lore.kernel.org/all/ad5yV2FoNbGGLE6R@e129823.arm.com/
> 
> Till now, sysfs doesn't show the *current value* of the single shot
> state since the config->ss_status is updated enabled/disabled sysfs
> session. an I think once the session is disabled, other status bits
> (currently STATUS and PENDING bits) don't have any meaning.
> 
> I think it's enough to change the doc's Description for this.
> 
> Any thought?

Thanks for the info. I have missed this info, we are calling it 
'comparator' instead of 'status' by focusing on the capability bits.

Make sense to me.

Thanks,
Jie

> 
> --
> Sincerely,
> Yeoreum Yun

Re: [PATCH v5 04/12] coresight: etm4x: exclude ss_status from drvdata->config

[Leo Yan]

On Wed, Apr 15, 2026 at 05:55:20PM +0100, Yeoreum Yun wrote:

[...]

> @@ -573,11 +573,9 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>  		etm4x_relaxed_write32(csa, config->res_ctrl[i], TRCRSCTLRn(i));
>  
>  	for (i = 0; i < caps->nr_ss_cmp; i++) {
> -		/* always clear status bit on restart if using single-shot */
> -		if (config->ss_ctrl[i] || config->ss_pe_cmp[i])
> -			config->ss_status[i] &= ~TRCSSCSRn_STATUS;
>  		etm4x_relaxed_write32(csa, config->ss_ctrl[i], TRCSSCCRn(i));
> -		etm4x_relaxed_write32(csa, config->ss_status[i], TRCSSCSRn(i));
> +		/* always clear status and pending bits on restart if using single-shot */
> +		etm4x_relaxed_write32(csa, 0x0, TRCSSCSRn(i));

In Arm ARM, D24.4.60 TRCSSCSR<n>, bits[0..3] are RO.  I think it is
fine for directly clear the regiser with zero (means it will only
clear status / pending bits).

[...]

> @@ -1841,10 +1839,11 @@ static ssize_t sshot_status_show(struct device *dev,
>  {
>  	unsigned long val;
>  	struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
> +	const struct etmv4_caps *caps = &drvdata->caps;
>  	struct etmv4_config *config = &drvdata->config;
>  
>  	raw_spin_lock(&drvdata->spinlock);
> -	val = config->ss_status[config->ss_idx];
> +	val = caps->ss_cmp[config->ss_idx];
>  	raw_spin_unlock(&drvdata->spinlock);
>  	return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
>  }

This sysfs knob never can print out a realtime status for sshot, I am
fine for only printing caps->ss_cmp, this can avoid any misleading.

@Suzuki, @Mike, do you agree with the change above?

If maintainers agree with this, as Jie suggested, it is good to add a
comment in the code and update the document:

  Documentation/trace/coresight/coresight-etm4x-reference.rst

Thanks,
Leo

[PATCH v5 05/12] coresight: etm4x: remove redundant fields in etmv4_save_state

[Yeoreum Yun]

Some of fields are redundant in etmv4_save_state and never used:

    ss_status => trcsscsr
    seq_state => trcseqstr
    cntr_val => trccntvr
    vinst_ctrl => trcvictlr

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x.h | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index db56c4414873..cbd8890d166a 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -1047,11 +1047,6 @@ struct etmv4_save_state {
 
 	u32	trcclaimset;
 
-	u32	cntr_val[ETMv4_MAX_CNTR];
-	u32	seq_state;
-	u32	vinst_ctrl;
-	u32	ss_status[ETM_MAX_SS_CMP];
-
 	u32	trcpdcr;
 };
 
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Yeoreum Yun]

If etm4_enable_sysfs() fails in cscfg_csdev_enable_active_config(),
the trace ID may be leaked because it is not released.

To address this, call etm4_release_trace_id() when etm4_enable_sysfs()
fails in cscfg_csdev_enable_active_config().

Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index f55338a4989d..b199aebbdb60 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -920,8 +920,10 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
 	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
 	if (cfg_hash) {
 		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
-		if (ret)
+		if (ret) {
+			etm4_release_trace_id(drvdata);
 			return ret;
+		}
 	}
 
 	raw_spin_lock(&drvdata->spinlock);
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Leo Yan]

On Wed, Apr 15, 2026 at 05:55:22PM +0100, Yeoreum Yun wrote:
> If etm4_enable_sysfs() fails in cscfg_csdev_enable_active_config(),
> the trace ID may be leaked because it is not released.
> 
> To address this, call etm4_release_trace_id() when etm4_enable_sysfs()
> fails in cscfg_csdev_enable_active_config().
> 
> Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> ---
>  drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index f55338a4989d..b199aebbdb60 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -920,8 +920,10 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
>  	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
>  	if (cfg_hash) {
>  		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
> -		if (ret)
> +		if (ret) {
> +			etm4_release_trace_id(drvdata);
>  			return ret;
> +		}

LGTM:

Reviewed-by: Leo Yan <leo.yan@arm.com>

Just recording a bit thoughts.  As Suzuki mentioned, it would be better
to allocate trace IDs within a session.  We might consider maintaining
the trace ID map in the sink driver data, since the sink driver is
unique within a session so it is a central place to allocate trace ID.

We should use paired way for allocation and release. For example:

  coresight_enable_sysfs()
  {
      ...
      coresight_path_assign_trace_id(path);

  failed:
      coresight_path_unassign_trace_id(path);
  }

  coresight_disable_sysfs()
  {
      coresight_path_unassign_trace_id(path);
  }

But this requires broader refactoring.  E.g., the STM driver currently
allocates system trace IDs statically during probe, we might need to
consolidate for all modules to use dynamic allocation.

Thanks,
Leo

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Yeoreum Yun]

Hi Leo,
> On Wed, Apr 15, 2026 at 05:55:22PM +0100, Yeoreum Yun wrote:
> > If etm4_enable_sysfs() fails in cscfg_csdev_enable_active_config(),
> > the trace ID may be leaked because it is not released.
> >
> > To address this, call etm4_release_trace_id() when etm4_enable_sysfs()
> > fails in cscfg_csdev_enable_active_config().
> >
> > Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > ---
> >  drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 +++-
> >  1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > index f55338a4989d..b199aebbdb60 100644
> > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> > @@ -920,8 +920,10 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
> >  	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
> >  	if (cfg_hash) {
> >  		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
> > -		if (ret)
> > +		if (ret) {
> > +			etm4_release_trace_id(drvdata);
> >  			return ret;
> > +		}
>
> LGTM:
>
> Reviewed-by: Leo Yan <leo.yan@arm.com>

Thanks.

>
> Just recording a bit thoughts.  As Suzuki mentioned, it would be better
> to allocate trace IDs within a session.  We might consider maintaining
> the trace ID map in the sink driver data, since the sink driver is
> unique within a session so it is a central place to allocate trace ID.
>
> We should use paired way for allocation and release. For example:
>
>   coresight_enable_sysfs()
>   {
>       ...
>       coresight_path_assign_trace_id(path);
>
>   failed:
>       coresight_path_unassign_trace_id(path);
>   }
>
>   coresight_disable_sysfs()
>   {
>       coresight_path_unassign_trace_id(path);
>   }
>
> But this requires broader refactoring.  E.g., the STM driver currently
> allocates system trace IDs statically during probe, we might need to
> consolidate for all modules to use dynamic allocation.

So IIUC, Do we want to "map" per "session" and save this map information
in the "sink" driver? or just use "global" map but locate it in sink
driver?

I totally agree for above suggestion -- unsigned trace id
in the coresight_XXX function -- (but we need to add another callback
for this) but I think we don't need to sustain map per session
and it seems enough to use current storage for trace_id not move to
sink driver.

Anyway It would be better to refactorying wiht another patchset...

Thanks.

--
Sincerely,
Yeoreum Yun

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Leo Yan]

Hi Levi,

On Thu, Apr 16, 2026 at 06:06:41PM +0100, Yeoreum Yun wrote:

[...]

> > We should use paired way for allocation and release. For example:
> >
> >   coresight_enable_sysfs()
> >   {
> >       ...
> >       coresight_path_assign_trace_id(path);
> >
> >   failed:
> >       coresight_path_unassign_trace_id(path);
> >   }
> >
> >   coresight_disable_sysfs()
> >   {
> >       coresight_path_unassign_trace_id(path);
> >   }
> >
> > But this requires broader refactoring.  E.g., the STM driver currently
> > allocates system trace IDs statically during probe, we might need to
> > consolidate for all modules to use dynamic allocation.
> 
> So IIUC, Do we want to "map" per "session" and save this map information
> in the "sink" driver? or just use "global" map but locate it in sink
> driver?

I prefer to save map in the sink's driver data, this is more scalable
as the trace ID is allocated within a session rather than system wide.

> I totally agree for above suggestion -- unsigned trace id
> in the coresight_XXX function -- (but we need to add another callback
> for this) but I think we don't need to sustain map per session
> and it seems enough to use current storage for trace_id not move to
> sink driver.
> 
> Anyway It would be better to refactorying wiht another patchset...

Yeah, we can come back to these ideas when work on it.

Thanks,
Leo

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Jie Gan]

On 4/17/2026 12:55 AM, Leo Yan wrote:
> On Wed, Apr 15, 2026 at 05:55:22PM +0100, Yeoreum Yun wrote:
>> If etm4_enable_sysfs() fails in cscfg_csdev_enable_active_config(),
>> the trace ID may be leaked because it is not released.
>>
>> To address this, call etm4_release_trace_id() when etm4_enable_sysfs()
>> fails in cscfg_csdev_enable_active_config().
>>
>> Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
>> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
>> ---
>>   drivers/hwtracing/coresight/coresight-etm4x-core.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index f55338a4989d..b199aebbdb60 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -920,8 +920,10 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
>>   	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
>>   	if (cfg_hash) {
>>   		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
>> -		if (ret)
>> +		if (ret) {
>> +			etm4_release_trace_id(drvdata);
>>   			return ret;
>> +		}
> 
> LGTM:
> 
> Reviewed-by: Leo Yan <leo.yan@arm.com>
> 
> Just recording a bit thoughts.  As Suzuki mentioned, it would be better
> to allocate trace IDs within a session.  We might consider maintaining
> the trace ID map in the sink driver data, since the sink driver is
> unique within a session so it is a central place to allocate trace ID.
> 
> We should use paired way for allocation and release. For example:
> 
>    coresight_enable_sysfs()
>    {
>        ...
>        coresight_path_assign_trace_id(path);
> 
>    failed:
>        coresight_path_unassign_trace_id(path);
>    }
> 
>    coresight_disable_sysfs()
>    {
>        coresight_path_unassign_trace_id(path);
>    }
> 
> But this requires broader refactoring.  E.g., the STM driver currently
> allocates system trace IDs statically during probe, we might need to
> consolidate for all modules to use dynamic allocation.

Agree. That's making sense. Currently, the trace ID of some devices is 
allocated during probe, and never to be released. It's kind of waste of 
our trace ID resource if the device never to be enabled. But we still 
need support static trace ID allocation in parallel for the dummy 
sources and we should not break this logic in future refactor.

Thanks,
Jie

> 
> Thanks,
> Leo

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Leo Yan]

Hi Jie,

On Fri, Apr 17, 2026 at 09:01:17AM +0800, Jie Gan wrote:

[...]

> ... we still need support static trace ID allocation in parallel for
> the dummy sources and we should not break this logic in future refactor.

Just confirm what is the reason you need to use static trace ID for the
dummy sources?

I am wandering if we could use dev->devt as trace ID for dummy
devices.  Since the device's MAJOR number is non-zero and occupies the
upper bits (see MINORBITS), it is naturally separated from the hardware
trace ID range.  If so, we even don't need to bother ID alloc/release.

Thanks,
Leo

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Jie Gan]

On 4/17/2026 4:41 PM, Leo Yan wrote:
> Hi Jie,
> 

Hi Leo,

> On Fri, Apr 17, 2026 at 09:01:17AM +0800, Jie Gan wrote:
> 
> [...]
> 
>> ... we still need support static trace ID allocation in parallel for
>> the dummy sources and we should not break this logic in future refactor.
> 
> Just confirm what is the reason you need to use static trace ID for the
> dummy sources?
> 
> I am wandering if we could use dev->devt as trace ID for dummy
> devices.  Since the device's MAJOR number is non-zero and occupies the
> upper bits (see MINORBITS), it is naturally separated from the hardware
> trace ID range.  If so, we even don't need to bother ID alloc/release.
> 

The data frame is generated by the dummy source(static TPDM, or some 
other static devices, connected to a funnel or replicator, or TPDA 
device) automatically(contained pre-assigned trace ID) and the data 
trace is enabled by default. What we should do for the dummy source is 
enabling its connected port in driver for outputting the trace data to 
the connected device(funnel/TPDA/replicator etc...).

For this scenario, we cannot dynamic allocate trace ID for the dummy 
source device. Because it's pre-assigned during the hardware design.

Thanks,
Jie

> Thanks,
> Leo

Re: [PATCH v5 06/12] coresight: etm4x: fix leaked trace id

[Jie Gan]

On 4/17/2026 4:51 PM, Jie Gan wrote:
> 
> 
> On 4/17/2026 4:41 PM, Leo Yan wrote:
>> Hi Jie,
>>
> 
> Hi Leo,
> 
>> On Fri, Apr 17, 2026 at 09:01:17AM +0800, Jie Gan wrote:
>>
>> [...]
>>
>>> ... we still need support static trace ID allocation in parallel for
>>> the dummy sources and we should not break this logic in future refactor.
>>
>> Just confirm what is the reason you need to use static trace ID for the
>> dummy sources?
>>
>> I am wandering if we could use dev->devt as trace ID for dummy
>> devices.  Since the device's MAJOR number is non-zero and occupies the
>> upper bits (see MINORBITS), it is naturally separated from the hardware
>> trace ID range.  If so, we even don't need to bother ID alloc/release.
>>
> 
> The data frame is generated by the dummy source(static TPDM, or some 

I shouldnt take TPDM as example here, TPDM is a special source device 
and it's trace data will be re-constructed in it's connected TPDA device 
with TPDA's trace ID.

We have some other dummy sources designed for the CDSP/ADSP/MODEM 
subsystems... which cannot be directly accessed by the kernel.

Thanks,
Jie

> other static devices, connected to a funnel or replicator, or TPDA 
> device) automatically(contained pre-assigned trace ID) and the data 
> trace is enabled by default. What we should do for the dummy source is 
> enabling its connected port in driver for outputting the trace data to 
> the connected device(funnel/TPDA/replicator etc...).
> 
> For this scenario, we cannot dynamic allocate trace ID for the dummy 
> source device. Because it's pre-assigned during the hardware design.
> 
> Thanks,
> Jie
> 
>> Thanks,
>> Leo
> 

[PATCH v5 07/12] coresight: etm4x: fix inconsistencies with sysfs configuration

[Yeoreum Yun]

The current ETM4x configuration via sysfs can lead to
several inconsistencies:

  - If the configuration is modified via sysfs while a perf session is
    active, the running configuration may differ before a sched-out and
    after a subsequent sched-in.

  - If a perf session and a sysfs session enable tracing concurrently,
    the configuration from configfs may become corrupted.

  - There is a risk of corrupting drvdata->config if a perf session enables
    tracing while cscfg_csdev_disable_active_config() is being handled in
    etm4_disable_sysfs().

To resolve these issues, separate the configuration into:

  - active_config: the configuration applied to the current session
  - config: the configuration set via sysfs

Additionally:

  - Apply the configuration from configfs after taking the appropriate mode.

  - Since active_config and related fields are accessed only by the local CPU
    in etm4_enable/disable_sysfs_smp_call() (similar to perf enable/disable),
    remove the lock/unlock from the sysfs enable/disable path and
    startup/dying_cpu except when to access config fields.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 .../hwtracing/coresight/coresight-etm4x-cfg.c |   2 +-
 .../coresight/coresight-etm4x-core.c          | 107 ++++++++++--------
 drivers/hwtracing/coresight/coresight-etm4x.h |   2 +
 3 files changed, 63 insertions(+), 48 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
index d14d7c8a23e5..0553771d04e7 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-cfg.c
@@ -47,7 +47,7 @@ static int etm4_cfg_map_reg_offset(struct etmv4_drvdata *drvdata,
 				   struct cscfg_regval_csdev *reg_csdev, u32 offset)
 {
 	int err = -EINVAL, idx;
-	struct etmv4_config *drvcfg = &drvdata->config;
+	struct etmv4_config *drvcfg = &drvdata->active_config;
 	u32 off_mask;
 
 	if (((offset >= TRCEVENTCTL0R) && (offset <= TRCVIPCSSCTLR)) ||
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index b199aebbdb60..15aaf4a898e1 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -245,6 +245,10 @@ void etm4_release_trace_id(struct etmv4_drvdata *drvdata)
 
 struct etm4_enable_arg {
 	struct etmv4_drvdata *drvdata;
+	unsigned long cfg_hash;
+	int preset;
+	u8 trace_id;
+	struct etmv4_config config;
 	int rc;
 };
 
@@ -270,10 +274,11 @@ static void etm4x_prohibit_trace(struct etmv4_drvdata *drvdata)
 static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata)
 {
 	u64 trfcr = drvdata->trfcr;
+	struct etmv4_config *config = &drvdata->active_config;
 
-	if (drvdata->config.mode & ETM_MODE_EXCL_KERN)
+	if (config->mode & ETM_MODE_EXCL_KERN)
 		trfcr &= ~TRFCR_EL1_ExTRE;
-	if (drvdata->config.mode & ETM_MODE_EXCL_USER)
+	if (config->mode & ETM_MODE_EXCL_USER)
 		trfcr &= ~TRFCR_EL1_E0TRE;
 
 	return trfcr;
@@ -281,7 +286,7 @@ static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata)
 
 /*
  * etm4x_allow_trace - Allow CPU tracing in the respective ELs,
- * as configured by the drvdata->config.mode for the current
+ * as configured by the drvdata->active_config.mode for the current
  * session. Even though we have TRCVICTLR bits to filter the
  * trace in the ELs, it doesn't prevent the ETM from generating
  * a packet (e.g, TraceInfo) that might contain the addresses from
@@ -292,12 +297,13 @@ static u64 etm4x_get_kern_user_filter(struct etmv4_drvdata *drvdata)
 static void etm4x_allow_trace(struct etmv4_drvdata *drvdata)
 {
 	u64 trfcr, guest_trfcr;
+	struct etmv4_config *config = &drvdata->active_config;
 
 	/* If the CPU doesn't support FEAT_TRF, nothing to do */
 	if (!drvdata->trfcr)
 		return;
 
-	if (drvdata->config.mode & ETM_MODE_EXCL_HOST)
+	if (config->mode & ETM_MODE_EXCL_HOST)
 		trfcr = drvdata->trfcr & ~(TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE);
 	else
 		trfcr = etm4x_get_kern_user_filter(drvdata);
@@ -305,7 +311,7 @@ static void etm4x_allow_trace(struct etmv4_drvdata *drvdata)
 	write_trfcr(trfcr);
 
 	/* Set filters for guests and pass to KVM */
-	if (drvdata->config.mode & ETM_MODE_EXCL_GUEST)
+	if (config->mode & ETM_MODE_EXCL_GUEST)
 		guest_trfcr = drvdata->trfcr & ~(TRFCR_EL1_ExTRE | TRFCR_EL1_E0TRE);
 	else
 		guest_trfcr = etm4x_get_kern_user_filter(drvdata);
@@ -499,7 +505,7 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 {
 	int i, rc;
 	const struct etmv4_caps *caps = &drvdata->caps;
-	struct etmv4_config *config = &drvdata->config;
+	struct etmv4_config *config = &drvdata->active_config;
 	struct coresight_device *csdev = drvdata->csdev;
 	struct device *etm_dev = &csdev->dev;
 	struct csdev_access *csa = &csdev->access;
@@ -618,23 +624,45 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
 static void etm4_enable_sysfs_smp_call(void *info)
 {
 	struct etm4_enable_arg *arg = info;
+	struct etmv4_drvdata *drvdata;
 	struct coresight_device *csdev;
 
 	if (WARN_ON(!arg))
 		return;
 
-	csdev = arg->drvdata->csdev;
+	drvdata = arg->drvdata;
+	csdev = drvdata->csdev;
 	if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) {
 		/* Someone is already using the tracer */
 		arg->rc = -EBUSY;
 		return;
 	}
 
-	arg->rc = etm4_enable_hw(arg->drvdata);
+	drvdata->active_config = arg->config;
 
-	/* The tracer didn't start */
+	if (arg->cfg_hash) {
+		arg->rc = cscfg_csdev_enable_active_config(csdev,
+							   arg->cfg_hash,
+							   arg->preset);
+		if (arg->rc)
+			goto err;
+	}
+
+	drvdata->trcid = arg->trace_id;
+
+	/* Tracer will never be paused in sysfs mode */
+	drvdata->paused = false;
+
+	arg->rc = etm4_enable_hw(drvdata);
 	if (arg->rc)
-		coresight_set_mode(csdev, CS_MODE_DISABLED);
+		goto err;
+
+	drvdata->sticky_enable = true;
+
+	return;
+err:
+	/* The tracer didn't start */
+	coresight_set_mode(csdev, CS_MODE_DISABLED);
 }
 
 /*
@@ -672,7 +700,7 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata,
 	int ctridx;
 	int rselector;
 	const struct etmv4_caps *caps = &drvdata->caps;
-	struct etmv4_config *config = &drvdata->config;
+	struct etmv4_config *config = &drvdata->active_config;
 
 	/* No point in trying if we don't have at least one counter */
 	if (!caps->nr_cntr)
@@ -756,7 +784,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
 	int ret = 0;
 	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
 	const struct etmv4_caps *caps = &drvdata->caps;
-	struct etmv4_config *config = &drvdata->config;
+	struct etmv4_config *config = &drvdata->active_config;
 	struct perf_event_attr max_timestamp = {
 		.ATTR_CFG_FLD_timestamp_CFG = U64_MAX,
 	};
@@ -918,40 +946,29 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
 
 	/* enable any config activated by configfs */
 	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
-	if (cfg_hash) {
-		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
-		if (ret) {
-			etm4_release_trace_id(drvdata);
-			return ret;
-		}
-	}
-
-	raw_spin_lock(&drvdata->spinlock);
-
-	drvdata->trcid = path->trace_id;
-
-	/* Tracer will never be paused in sysfs mode */
-	drvdata->paused = false;
 
 	/*
 	 * Executing etm4_enable_hw on the cpu whose ETM is being enabled
 	 * ensures that register writes occur when cpu is powered.
 	 */
 	arg.drvdata = drvdata;
+	arg.cfg_hash = cfg_hash;
+	arg.preset = preset;
+	arg.trace_id = path->trace_id;
+
+	raw_spin_lock(&drvdata->spinlock);
+	arg.config = drvdata->config;
+	raw_spin_unlock(&drvdata->spinlock);
+
 	ret = smp_call_function_single(drvdata->cpu,
 				       etm4_enable_sysfs_smp_call, &arg, 1);
 	if (!ret)
 		ret = arg.rc;
 	if (!ret)
-		drvdata->sticky_enable = true;
-
-	if (ret)
+		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
+	else
 		etm4_release_trace_id(drvdata);
 
-	raw_spin_unlock(&drvdata->spinlock);
-
-	if (!ret)
-		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
 	return ret;
 }
 
@@ -1038,7 +1055,7 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
 {
 	u32 control;
 	const struct etmv4_caps *caps = &drvdata->caps;
-	struct etmv4_config *config = &drvdata->config;
+	struct etmv4_config *config = &drvdata->active_config;
 	struct coresight_device *csdev = drvdata->csdev;
 	struct csdev_access *csa = &csdev->access;
 	int i;
@@ -1074,6 +1091,8 @@ static void etm4_disable_sysfs_smp_call(void *info)
 
 	etm4_disable_hw(drvdata);
 
+	cscfg_csdev_disable_active_config(drvdata->csdev);
+
 	coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED);
 }
 
@@ -1124,7 +1143,6 @@ static void etm4_disable_sysfs(struct coresight_device *csdev)
 	 * DYING hotplug callback is serviced by the ETM driver.
 	 */
 	cpus_read_lock();
-	raw_spin_lock(&drvdata->spinlock);
 
 	/*
 	 * Executing etm4_disable_hw on the cpu whose ETM is being disabled
@@ -1133,10 +1151,6 @@ static void etm4_disable_sysfs(struct coresight_device *csdev)
 	smp_call_function_single(drvdata->cpu, etm4_disable_sysfs_smp_call,
 				 drvdata, 1);
 
-	raw_spin_unlock(&drvdata->spinlock);
-
-	cscfg_csdev_disable_active_config(csdev);
-
 	cpus_read_unlock();
 
 	/*
@@ -1379,6 +1393,7 @@ static void etm4_init_arch_data(void *info)
 	struct etm4_init_arg *init_arg = info;
 	struct etmv4_drvdata *drvdata;
 	struct etmv4_caps *caps;
+	struct etmv4_config *config;
 	struct csdev_access *csa;
 	struct device *dev = init_arg->dev;
 	int i;
@@ -1386,6 +1401,7 @@ static void etm4_init_arch_data(void *info)
 	drvdata = dev_get_drvdata(init_arg->dev);
 	caps = &drvdata->caps;
 	csa = init_arg->csa;
+	config = &drvdata->active_config;
 
 	/*
 	 * If we are unable to detect the access mechanism,
@@ -1446,7 +1462,7 @@ static void etm4_init_arch_data(void *info)
 
 	/* EXLEVEL_S, bits[19:16] Secure state instruction tracing */
 	caps->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3);
-	drvdata->config.s_ex_level = caps->s_ex_level;
+	config->s_ex_level = caps->s_ex_level;
 	/* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */
 	caps->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3);
 	/*
@@ -1692,7 +1708,7 @@ static void etm4_set_default(struct etmv4_config *config)
 static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type)
 {
 	int nr_comparator, index = 0;
-	struct etmv4_config *config = &drvdata->config;
+	struct etmv4_config *config = &drvdata->active_config;
 
 	/*
 	 * nr_addr_cmp holds the number of comparator _pair_, so time 2
@@ -1733,7 +1749,7 @@ static int etm4_set_event_filters(struct etmv4_drvdata *drvdata,
 {
 	int i, comparator, ret = 0;
 	u64 address;
-	struct etmv4_config *config = &drvdata->config;
+	struct etmv4_config *config = &drvdata->active_config;
 	struct etm_filters *filters = event->hw.addr_filters;
 
 	if (!filters)
@@ -1851,13 +1867,11 @@ static int etm4_starting_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu])
 		return 0;
 
-	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
 	if (!etmdrvdata[cpu]->os_unlock)
 		etm4_os_unlock(etmdrvdata[cpu]);
 
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
 		etm4_enable_hw(etmdrvdata[cpu]);
-	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }
 
@@ -1866,10 +1880,8 @@ static int etm4_dying_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu])
 		return 0;
 
-	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
 		etm4_disable_hw(etmdrvdata[cpu]);
-	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }
 
@@ -2255,7 +2267,8 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
 	if (!desc.name)
 		return -ENOMEM;
 
-	etm4_set_default(&drvdata->config);
+	etm4_set_default(&drvdata->active_config);
+	drvdata->config = drvdata->active_config;
 
 	pdata = coresight_get_platform_data(dev);
 	if (IS_ERR(pdata))
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index cbd8890d166a..9b50aaa368cf 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -1069,6 +1069,7 @@ struct etmv4_save_state {
  *		allows tracing at all ELs. We don't want to compute this
  *		at runtime, due to the additional setting of TRFCR_CX when
  *		in EL2. Otherwise, 0.
+ * @active_config:	structure holding current applied configuration parameters.
  * @config:	structure holding configuration parameters.
  * @save_state:	State to be preserved across power loss
  * @paused:	Indicates if the trace unit is paused.
@@ -1089,6 +1090,7 @@ struct etmv4_drvdata {
 	bool				os_unlock : 1;
 	bool				paused : 1;
 	u64				trfcr;
+	struct etmv4_config		active_config;
 	struct etmv4_config		config;
 	struct etmv4_save_state		*save_state;
 	DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX);
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

Re: [PATCH v5 07/12] coresight: etm4x: fix inconsistencies with sysfs configuration

[Jie Gan]

On 4/16/2026 12:55 AM, Yeoreum Yun wrote:
> The current ETM4x configuration via sysfs can lead to
> several inconsistencies:
> 
>    - If the configuration is modified via sysfs while a perf session is
>      active, the running configuration may differ before a sched-out and
>      after a subsequent sched-in.
> 
>    - If a perf session and a sysfs session enable tracing concurrently,
>      the configuration from configfs may become corrupted.
> 
>    - There is a risk of corrupting drvdata->config if a perf session enables
>      tracing while cscfg_csdev_disable_active_config() is being handled in
>      etm4_disable_sysfs().
> 
> To resolve these issues, separate the configuration into:
> 
>    - active_config: the configuration applied to the current session
>    - config: the configuration set via sysfs
> 
> Additionally:
> 
>    - Apply the configuration from configfs after taking the appropriate mode.
> 
>    - Since active_config and related fields are accessed only by the local CPU
>      in etm4_enable/disable_sysfs_smp_call() (similar to perf enable/disable),
>      remove the lock/unlock from the sysfs enable/disable path and
>      startup/dying_cpu except when to access config fields.
> 
> Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> ---

<...>

> @@ -618,23 +624,45 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
>   static void etm4_enable_sysfs_smp_call(void *info)
>   {
>   	struct etm4_enable_arg *arg = info;
> +	struct etmv4_drvdata *drvdata;
>   	struct coresight_device *csdev;
>   
>   	if (WARN_ON(!arg))
>   		return;
>   
> -	csdev = arg->drvdata->csdev;
> +	drvdata = arg->drvdata;
> +	csdev = drvdata->csdev;
>   	if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) {
>   		/* Someone is already using the tracer */
>   		arg->rc = -EBUSY;
>   		return;
>   	}
>   
> -	arg->rc = etm4_enable_hw(arg->drvdata);
> +	drvdata->active_config = arg->config;
>   
> -	/* The tracer didn't start */
> +	if (arg->cfg_hash) {
> +		arg->rc = cscfg_csdev_enable_active_config(csdev,
> +							   arg->cfg_hash,
> +							   arg->preset);
> +		if (arg->rc)
> +			goto err;
> +	}
> +
> +	drvdata->trcid = arg->trace_id;
> +
> +	/* Tracer will never be paused in sysfs mode */
> +	drvdata->paused = false;
> +
> +	arg->rc = etm4_enable_hw(drvdata);
>   	if (arg->rc)
> -		coresight_set_mode(csdev, CS_MODE_DISABLED);

needs disable the active config in error path:
cscfg_csdev_disable_active_config(drvdata->csdev);

Thanks,
Jie

> +		goto err;
> +
> +	drvdata->sticky_enable = true;
> +
> +	return;
> +err:
> +	/* The tracer didn't start */
> +	coresight_set_mode(csdev, CS_MODE_DISABLED);
>   }
>   
>   /*
> @@ -672,7 +700,7 @@ static int etm4_config_timestamp_event(struct etmv4_drvdata *drvdata,
>   	int ctridx;
>   	int rselector;
>   	const struct etmv4_caps *caps = &drvdata->caps;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   
>   	/* No point in trying if we don't have at least one counter */
>   	if (!caps->nr_cntr)
> @@ -756,7 +784,7 @@ static int etm4_parse_event_config(struct coresight_device *csdev,
>   	int ret = 0;
>   	struct etmv4_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
>   	const struct etmv4_caps *caps = &drvdata->caps;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct perf_event_attr max_timestamp = {
>   		.ATTR_CFG_FLD_timestamp_CFG = U64_MAX,
>   	};
> @@ -918,40 +946,29 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
>   
>   	/* enable any config activated by configfs */
>   	cscfg_config_sysfs_get_active_cfg(&cfg_hash, &preset);
> -	if (cfg_hash) {
> -		ret = cscfg_csdev_enable_active_config(csdev, cfg_hash, preset);
> -		if (ret) {
> -			etm4_release_trace_id(drvdata);
> -			return ret;
> -		}
> -	}
> -
> -	raw_spin_lock(&drvdata->spinlock);
> -
> -	drvdata->trcid = path->trace_id;
> -
> -	/* Tracer will never be paused in sysfs mode */
> -	drvdata->paused = false;
>   
>   	/*
>   	 * Executing etm4_enable_hw on the cpu whose ETM is being enabled
>   	 * ensures that register writes occur when cpu is powered.
>   	 */
>   	arg.drvdata = drvdata;
> +	arg.cfg_hash = cfg_hash;
> +	arg.preset = preset;
> +	arg.trace_id = path->trace_id;
> +
> +	raw_spin_lock(&drvdata->spinlock);
> +	arg.config = drvdata->config;
> +	raw_spin_unlock(&drvdata->spinlock);
> +
>   	ret = smp_call_function_single(drvdata->cpu,
>   				       etm4_enable_sysfs_smp_call, &arg, 1);
>   	if (!ret)
>   		ret = arg.rc;
>   	if (!ret)
> -		drvdata->sticky_enable = true;
> -
> -	if (ret)
> +		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
> +	else
>   		etm4_release_trace_id(drvdata);
>   
> -	raw_spin_unlock(&drvdata->spinlock);
> -
> -	if (!ret)
> -		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
>   	return ret;
>   }
>   
> @@ -1038,7 +1055,7 @@ static void etm4_disable_hw(struct etmv4_drvdata *drvdata)
>   {
>   	u32 control;
>   	const struct etmv4_caps *caps = &drvdata->caps;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct coresight_device *csdev = drvdata->csdev;
>   	struct csdev_access *csa = &csdev->access;
>   	int i;
> @@ -1074,6 +1091,8 @@ static void etm4_disable_sysfs_smp_call(void *info)
>   
>   	etm4_disable_hw(drvdata);
>   
> +	cscfg_csdev_disable_active_config(drvdata->csdev);
> +
>   	coresight_set_mode(drvdata->csdev, CS_MODE_DISABLED);
>   }
>   
> @@ -1124,7 +1143,6 @@ static void etm4_disable_sysfs(struct coresight_device *csdev)
>   	 * DYING hotplug callback is serviced by the ETM driver.
>   	 */
>   	cpus_read_lock();
> -	raw_spin_lock(&drvdata->spinlock);
>   
>   	/*
>   	 * Executing etm4_disable_hw on the cpu whose ETM is being disabled
> @@ -1133,10 +1151,6 @@ static void etm4_disable_sysfs(struct coresight_device *csdev)
>   	smp_call_function_single(drvdata->cpu, etm4_disable_sysfs_smp_call,
>   				 drvdata, 1);
>   
> -	raw_spin_unlock(&drvdata->spinlock);
> -
> -	cscfg_csdev_disable_active_config(csdev);
> -
>   	cpus_read_unlock();
>   
>   	/*
> @@ -1379,6 +1393,7 @@ static void etm4_init_arch_data(void *info)
>   	struct etm4_init_arg *init_arg = info;
>   	struct etmv4_drvdata *drvdata;
>   	struct etmv4_caps *caps;
> +	struct etmv4_config *config;
>   	struct csdev_access *csa;
>   	struct device *dev = init_arg->dev;
>   	int i;
> @@ -1386,6 +1401,7 @@ static void etm4_init_arch_data(void *info)
>   	drvdata = dev_get_drvdata(init_arg->dev);
>   	caps = &drvdata->caps;
>   	csa = init_arg->csa;
> +	config = &drvdata->active_config;
>   
>   	/*
>   	 * If we are unable to detect the access mechanism,
> @@ -1446,7 +1462,7 @@ static void etm4_init_arch_data(void *info)
>   
>   	/* EXLEVEL_S, bits[19:16] Secure state instruction tracing */
>   	caps->s_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_S_MASK, etmidr3);
> -	drvdata->config.s_ex_level = caps->s_ex_level;
> +	config->s_ex_level = caps->s_ex_level;
>   	/* EXLEVEL_NS, bits[23:20] Non-secure state instruction tracing */
>   	caps->ns_ex_level = FIELD_GET(TRCIDR3_EXLEVEL_NS_MASK, etmidr3);
>   	/*
> @@ -1692,7 +1708,7 @@ static void etm4_set_default(struct etmv4_config *config)
>   static int etm4_get_next_comparator(struct etmv4_drvdata *drvdata, u32 type)
>   {
>   	int nr_comparator, index = 0;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   
>   	/*
>   	 * nr_addr_cmp holds the number of comparator _pair_, so time 2
> @@ -1733,7 +1749,7 @@ static int etm4_set_event_filters(struct etmv4_drvdata *drvdata,
>   {
>   	int i, comparator, ret = 0;
>   	u64 address;
> -	struct etmv4_config *config = &drvdata->config;
> +	struct etmv4_config *config = &drvdata->active_config;
>   	struct etm_filters *filters = event->hw.addr_filters;
>   
>   	if (!filters)
> @@ -1851,13 +1867,11 @@ static int etm4_starting_cpu(unsigned int cpu)
>   	if (!etmdrvdata[cpu])
>   		return 0;
>   
> -	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
>   	if (!etmdrvdata[cpu]->os_unlock)
>   		etm4_os_unlock(etmdrvdata[cpu]);
>   
>   	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
>   		etm4_enable_hw(etmdrvdata[cpu]);
> -	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
>   	return 0;
>   }
>   
> @@ -1866,10 +1880,8 @@ static int etm4_dying_cpu(unsigned int cpu)
>   	if (!etmdrvdata[cpu])
>   		return 0;
>   
> -	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
>   	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
>   		etm4_disable_hw(etmdrvdata[cpu]);
> -	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
>   	return 0;
>   }
>   
> @@ -2255,7 +2267,8 @@ static int etm4_add_coresight_dev(struct etm4_init_arg *init_arg)
>   	if (!desc.name)
>   		return -ENOMEM;
>   
> -	etm4_set_default(&drvdata->config);
> +	etm4_set_default(&drvdata->active_config);
> +	drvdata->config = drvdata->active_config;
>   
>   	pdata = coresight_get_platform_data(dev);
>   	if (IS_ERR(pdata))
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
> index cbd8890d166a..9b50aaa368cf 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.h
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.h
> @@ -1069,6 +1069,7 @@ struct etmv4_save_state {
>    *		allows tracing at all ELs. We don't want to compute this
>    *		at runtime, due to the additional setting of TRFCR_CX when
>    *		in EL2. Otherwise, 0.
> + * @active_config:	structure holding current applied configuration parameters.
>    * @config:	structure holding configuration parameters.
>    * @save_state:	State to be preserved across power loss
>    * @paused:	Indicates if the trace unit is paused.
> @@ -1089,6 +1090,7 @@ struct etmv4_drvdata {
>   	bool				os_unlock : 1;
>   	bool				paused : 1;
>   	u64				trfcr;
> +	struct etmv4_config		active_config;
>   	struct etmv4_config		config;
>   	struct etmv4_save_state		*save_state;
>   	DECLARE_BITMAP(arch_features, ETM4_IMPDEF_FEATURE_MAX);

Re: [PATCH v5 07/12] coresight: etm4x: fix inconsistencies with sysfs configuration

[Yeoreum Yun]

Hi Jie,
>
>
> On 4/16/2026 12:55 AM, Yeoreum Yun wrote:
> > The current ETM4x configuration via sysfs can lead to
> > several inconsistencies:
> >
> >    - If the configuration is modified via sysfs while a perf session is
> >      active, the running configuration may differ before a sched-out and
> >      after a subsequent sched-in.
> >
> >    - If a perf session and a sysfs session enable tracing concurrently,
> >      the configuration from configfs may become corrupted.
> >
> >    - There is a risk of corrupting drvdata->config if a perf session enables
> >      tracing while cscfg_csdev_disable_active_config() is being handled in
> >      etm4_disable_sysfs().
> >
> > To resolve these issues, separate the configuration into:
> >
> >    - active_config: the configuration applied to the current session
> >    - config: the configuration set via sysfs
> >
> > Additionally:
> >
> >    - Apply the configuration from configfs after taking the appropriate mode.
> >
> >    - Since active_config and related fields are accessed only by the local CPU
> >      in etm4_enable/disable_sysfs_smp_call() (similar to perf enable/disable),
> >      remove the lock/unlock from the sysfs enable/disable path and
> >      startup/dying_cpu except when to access config fields.
> >
> > Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
> > ---
>
> <...>
>
> > @@ -618,23 +624,45 @@ static int etm4_enable_hw(struct etmv4_drvdata *drvdata)
> >   static void etm4_enable_sysfs_smp_call(void *info)
> >   {
> >   	struct etm4_enable_arg *arg = info;
> > +	struct etmv4_drvdata *drvdata;
> >   	struct coresight_device *csdev;
> >   	if (WARN_ON(!arg))
> >   		return;
> > -	csdev = arg->drvdata->csdev;
> > +	drvdata = arg->drvdata;
> > +	csdev = drvdata->csdev;
> >   	if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) {
> >   		/* Someone is already using the tracer */
> >   		arg->rc = -EBUSY;
> >   		return;
> >   	}
> > -	arg->rc = etm4_enable_hw(arg->drvdata);
> > +	drvdata->active_config = arg->config;
> > -	/* The tracer didn't start */
> > +	if (arg->cfg_hash) {
> > +		arg->rc = cscfg_csdev_enable_active_config(csdev,
> > +							   arg->cfg_hash,
> > +							   arg->preset);
> > +		if (arg->rc)
> > +			goto err;
> > +	}
> > +
> > +	drvdata->trcid = arg->trace_id;
> > +
> > +	/* Tracer will never be paused in sysfs mode */
> > +	drvdata->paused = false;
> > +
> > +	arg->rc = etm4_enable_hw(drvdata);
> >   	if (arg->rc)
> > -		coresight_set_mode(csdev, CS_MODE_DISABLED);
>
> needs disable the active config in error path:
> cscfg_csdev_disable_active_config(drvdata->csdev);

You're right. I missed it. Thanks!

[...]

--
Sincerely,
Yeoreum Yun

[PATCH v5 08/12] coresight: etm4x: remove redundant call etm4_enable_hw() with hotplug

[Yeoreum Yun]

The cpu_online_mask is set at the CPUHP_BRINGUP_CPU step.
In other words, if etm4_enable_sysfs() is called between
CPUHP_BRINGUP_CPU and CPUHP_AP_ARM_CORESIGHT_STARTING,
etm4_enable_hw() may be invoked in etm4_enable_sysfs_smp_call()
and then executed again in etm4_starting_cpu().

To remove this redundant call, take the hotplug lock before executing
etm4_enable_sysfs_smp_call().

Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm4x-core.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 15aaf4a898e1..2ce6b08f7f54 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -960,8 +960,20 @@ static int etm4_enable_sysfs(struct coresight_device *csdev, struct coresight_pa
 	arg.config = drvdata->config;
 	raw_spin_unlock(&drvdata->spinlock);
 
+	/*
+	 * Take the hotplug lock to prevent redundant calls to etm4_enable_hw().
+	 *
+	 * The cpu_online_mask is set at the CPUHP_BRINGUP_CPU step.
+	 * In other words, if etm4_enable_sysfs() is called between
+	 * CPUHP_BRINGUP_CPU and CPUHP_AP_ARM_CORESIGHT_STARTING,
+	 * etm4_enable_hw() may be invoked in etm4_enable_sysfs_smp_call()
+	 * and then executed again in etm4_starting_cpu().
+	 */
+	cpus_read_lock();
 	ret = smp_call_function_single(drvdata->cpu,
 				       etm4_enable_sysfs_smp_call, &arg, 1);
+	cpus_read_unlock();
+
 	if (!ret)
 		ret = arg.rc;
 	if (!ret)
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 09/12] coresight: etm3x: change drvdata->spinlock type to raw_spin_lock_t

[Yeoreum Yun]

etm_starting_cpu()/etm_dying_cpu() are called in not sleepable context.
This poses an issue in PREEMPT_RT kernel where spinlock_t is sleepable.

To address this, change etm3's drvdata->spinlock type to raw_spin_lock_t.
This will be good to align with etm4x.

Reviewed-by: Jie Gan <jie.gan@oss.qualcomm.com>
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm.h   |   2 +-
 .../coresight/coresight-etm3x-core.c          |  18 +--
 .../coresight/coresight-etm3x-sysfs.c         | 130 +++++++++---------
 3 files changed, 75 insertions(+), 75 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index 1d753cca2943..40f20daded4f 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -232,7 +232,7 @@ struct etm_drvdata {
 	struct csdev_access		csa;
 	struct clk			*atclk;
 	struct coresight_device		*csdev;
-	spinlock_t			spinlock;
+	raw_spinlock_t			spinlock;
 	int				cpu;
 	int				port_size;
 	u8				arch;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index a547a6d2e0bd..4a702b515733 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -511,7 +511,7 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat
 	struct etm_enable_arg arg = { };
 	int ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 
 	drvdata->traceid = path->trace_id;
 
@@ -534,7 +534,7 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat
 	if (ret)
 		etm_release_trace_id(drvdata);
 
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	if (!ret)
 		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
@@ -634,7 +634,7 @@ static void etm_disable_sysfs(struct coresight_device *csdev)
 	 * DYING hotplug callback is serviced by the ETM driver.
 	 */
 	cpus_read_lock();
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 
 	/*
 	 * Executing etm_disable_hw on the cpu whose ETM is being disabled
@@ -643,7 +643,7 @@ static void etm_disable_sysfs(struct coresight_device *csdev)
 	smp_call_function_single(drvdata->cpu, etm_disable_sysfs_smp_call,
 				 drvdata, 1);
 
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 	cpus_read_unlock();
 
 	/*
@@ -709,7 +709,7 @@ static int etm_starting_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu])
 		return 0;
 
-	spin_lock(&etmdrvdata[cpu]->spinlock);
+	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
 	if (!etmdrvdata[cpu]->os_unlock) {
 		etm_os_unlock(etmdrvdata[cpu]);
 		etmdrvdata[cpu]->os_unlock = true;
@@ -717,7 +717,7 @@ static int etm_starting_cpu(unsigned int cpu)
 
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
 		etm_enable_hw(etmdrvdata[cpu]);
-	spin_unlock(&etmdrvdata[cpu]->spinlock);
+	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }
 
@@ -726,10 +726,10 @@ static int etm_dying_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu])
 		return 0;
 
-	spin_lock(&etmdrvdata[cpu]->spinlock);
+	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
 		etm_disable_hw(etmdrvdata[cpu]);
-	spin_unlock(&etmdrvdata[cpu]->spinlock);
+	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }
 
@@ -856,7 +856,7 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 
 	desc.access = drvdata->csa = CSDEV_ACCESS_IOMEM(base);
 
-	spin_lock_init(&drvdata->spinlock);
+	raw_spin_lock_init(&drvdata->spinlock);
 
 	drvdata->atclk = devm_clk_get_optional_enabled(dev, "atclk");
 	if (IS_ERR(drvdata->atclk))
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
index 762109307b86..42b12c33516b 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
@@ -49,13 +49,13 @@ static ssize_t etmsr_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 
 	pm_runtime_get_sync(dev->parent);
-	spin_lock_irqsave(&drvdata->spinlock, flags);
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
 	CS_UNLOCK(drvdata->csa.base);
 
 	val = etm_readl(drvdata, ETMSR);
 
 	CS_LOCK(drvdata->csa.base);
-	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 	pm_runtime_put(dev->parent);
 
 	return sprintf(buf, "%#lx\n", val);
@@ -76,7 +76,7 @@ static ssize_t reset_store(struct device *dev,
 		return ret;
 
 	if (val) {
-		spin_lock(&drvdata->spinlock);
+		raw_spin_lock(&drvdata->spinlock);
 		memset(config, 0, sizeof(struct etm_config));
 		config->mode = ETM_MODE_EXCLUDE;
 		config->trigger_event = ETM_DEFAULT_EVENT_VAL;
@@ -86,7 +86,7 @@ static ssize_t reset_store(struct device *dev,
 
 		etm_set_default(config);
 		etm_release_trace_id(drvdata);
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 	}
 
 	return size;
@@ -117,7 +117,7 @@ static ssize_t mode_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->mode = val & ETM_MODE_ALL;
 
 	if (config->mode & ETM_MODE_EXCLUDE)
@@ -168,12 +168,12 @@ static ssize_t mode_store(struct device *dev,
 	if (config->mode & (ETM_MODE_EXCL_KERN | ETM_MODE_EXCL_USER))
 		etm_config_trace_mode(config);
 
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 
 err_unlock:
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 	return ret;
 }
 static DEVICE_ATTR_RW(mode);
@@ -299,9 +299,9 @@ static ssize_t addr_idx_store(struct device *dev,
 	 * Use spinlock to ensure index doesn't change while it gets
 	 * dereferenced multiple times within a spinlock block elsewhere.
 	 */
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->addr_idx = val;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -315,16 +315,16 @@ static ssize_t addr_single_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (!(config->addr_type[idx] == ETM_ADDR_TYPE_NONE ||
 	      config->addr_type[idx] == ETM_ADDR_TYPE_SINGLE)) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EINVAL;
 	}
 
 	val = config->addr_val[idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -343,17 +343,17 @@ static ssize_t addr_single_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (!(config->addr_type[idx] == ETM_ADDR_TYPE_NONE ||
 	      config->addr_type[idx] == ETM_ADDR_TYPE_SINGLE)) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EINVAL;
 	}
 
 	config->addr_val[idx] = val;
 	config->addr_type[idx] = ETM_ADDR_TYPE_SINGLE;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -367,23 +367,23 @@ static ssize_t addr_range_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (idx % 2 != 0) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 	if (!((config->addr_type[idx] == ETM_ADDR_TYPE_NONE &&
 	       config->addr_type[idx + 1] == ETM_ADDR_TYPE_NONE) ||
 	      (config->addr_type[idx] == ETM_ADDR_TYPE_RANGE &&
 	       config->addr_type[idx + 1] == ETM_ADDR_TYPE_RANGE))) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 
 	val1 = config->addr_val[idx];
 	val2 = config->addr_val[idx + 1];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx %#lx\n", val1, val2);
 }
@@ -403,17 +403,17 @@ static ssize_t addr_range_store(struct device *dev,
 	if (val1 > val2)
 		return -EINVAL;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (idx % 2 != 0) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 	if (!((config->addr_type[idx] == ETM_ADDR_TYPE_NONE &&
 	       config->addr_type[idx + 1] == ETM_ADDR_TYPE_NONE) ||
 	      (config->addr_type[idx] == ETM_ADDR_TYPE_RANGE &&
 	       config->addr_type[idx + 1] == ETM_ADDR_TYPE_RANGE))) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 
@@ -422,7 +422,7 @@ static ssize_t addr_range_store(struct device *dev,
 	config->addr_val[idx + 1] = val2;
 	config->addr_type[idx + 1] = ETM_ADDR_TYPE_RANGE;
 	config->enable_ctrl1 |= (1 << (idx/2));
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -436,16 +436,16 @@ static ssize_t addr_start_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (!(config->addr_type[idx] == ETM_ADDR_TYPE_NONE ||
 	      config->addr_type[idx] == ETM_ADDR_TYPE_START)) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 
 	val = config->addr_val[idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -464,11 +464,11 @@ static ssize_t addr_start_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (!(config->addr_type[idx] == ETM_ADDR_TYPE_NONE ||
 	      config->addr_type[idx] == ETM_ADDR_TYPE_START)) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 
@@ -476,7 +476,7 @@ static ssize_t addr_start_store(struct device *dev,
 	config->addr_type[idx] = ETM_ADDR_TYPE_START;
 	config->startstop_ctrl |= (1 << idx);
 	config->enable_ctrl1 |= ETMTECR1_START_STOP;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -490,16 +490,16 @@ static ssize_t addr_stop_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (!(config->addr_type[idx] == ETM_ADDR_TYPE_NONE ||
 	      config->addr_type[idx] == ETM_ADDR_TYPE_STOP)) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 
 	val = config->addr_val[idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -518,11 +518,11 @@ static ssize_t addr_stop_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	idx = config->addr_idx;
 	if (!(config->addr_type[idx] == ETM_ADDR_TYPE_NONE ||
 	      config->addr_type[idx] == ETM_ADDR_TYPE_STOP)) {
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return -EPERM;
 	}
 
@@ -530,7 +530,7 @@ static ssize_t addr_stop_store(struct device *dev,
 	config->addr_type[idx] = ETM_ADDR_TYPE_STOP;
 	config->startstop_ctrl |= (1 << (idx + 16));
 	config->enable_ctrl1 |= ETMTECR1_START_STOP;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -543,9 +543,9 @@ static ssize_t addr_acctype_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	val = config->addr_acctype[config->addr_idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -563,9 +563,9 @@ static ssize_t addr_acctype_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->addr_acctype[config->addr_idx] = val;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -601,9 +601,9 @@ static ssize_t cntr_idx_store(struct device *dev,
 	 * Use spinlock to ensure index doesn't change while it gets
 	 * dereferenced multiple times within a spinlock block elsewhere.
 	 */
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->cntr_idx = val;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -616,9 +616,9 @@ static ssize_t cntr_rld_val_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	val = config->cntr_rld_val[config->cntr_idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -636,9 +636,9 @@ static ssize_t cntr_rld_val_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->cntr_rld_val[config->cntr_idx] = val;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -651,9 +651,9 @@ static ssize_t cntr_event_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	val = config->cntr_event[config->cntr_idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -671,9 +671,9 @@ static ssize_t cntr_event_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->cntr_event[config->cntr_idx] = val & ETM_EVENT_MASK;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -686,9 +686,9 @@ static ssize_t cntr_rld_event_show(struct device *dev,
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 	struct etm_config *config = &drvdata->config;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	val = config->cntr_rld_event[config->cntr_idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -706,9 +706,9 @@ static ssize_t cntr_rld_event_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->cntr_rld_event[config->cntr_idx] = val & ETM_EVENT_MASK;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -723,11 +723,11 @@ static ssize_t cntr_val_show(struct device *dev,
 	struct etm_config *config = &drvdata->config;
 
 	if (!coresight_get_mode(drvdata->csdev)) {
-		spin_lock(&drvdata->spinlock);
+		raw_spin_lock(&drvdata->spinlock);
 		for (i = 0; i < drvdata->nr_cntr; i++)
 			ret += sprintf(buf, "counter %d: %x\n",
 				       i, config->cntr_val[i]);
-		spin_unlock(&drvdata->spinlock);
+		raw_spin_unlock(&drvdata->spinlock);
 		return ret;
 	}
 
@@ -752,9 +752,9 @@ static ssize_t cntr_val_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->cntr_val[config->cntr_idx] = val;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -947,13 +947,13 @@ static ssize_t seq_curr_state_show(struct device *dev,
 	}
 
 	pm_runtime_get_sync(dev->parent);
-	spin_lock_irqsave(&drvdata->spinlock, flags);
+	raw_spin_lock_irqsave(&drvdata->spinlock, flags);
 
 	CS_UNLOCK(drvdata->csa.base);
 	val = (etm_readl(drvdata, ETMSQR) & ETM_SQR_MASK);
 	CS_LOCK(drvdata->csa.base);
 
-	spin_unlock_irqrestore(&drvdata->spinlock, flags);
+	raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
 	pm_runtime_put(dev->parent);
 out:
 	return sprintf(buf, "%#lx\n", val);
@@ -1012,9 +1012,9 @@ static ssize_t ctxid_idx_store(struct device *dev,
 	 * Use spinlock to ensure index doesn't change while it gets
 	 * dereferenced multiple times within a spinlock block elsewhere.
 	 */
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->ctxid_idx = val;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
@@ -1034,9 +1034,9 @@ static ssize_t ctxid_pid_show(struct device *dev,
 	if (task_active_pid_ns(current) != &init_pid_ns)
 		return -EINVAL;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	val = config->ctxid_pid[config->ctxid_idx];
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return sprintf(buf, "%#lx\n", val);
 }
@@ -1066,9 +1066,9 @@ static ssize_t ctxid_pid_store(struct device *dev,
 	if (ret)
 		return ret;
 
-	spin_lock(&drvdata->spinlock);
+	raw_spin_lock(&drvdata->spinlock);
 	config->ctxid_pid[config->ctxid_idx] = pid;
-	spin_unlock(&drvdata->spinlock);
+	raw_spin_unlock(&drvdata->spinlock);
 
 	return size;
 }
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 10/12] coresight: etm3x: introduce struct etm_caps

[Yeoreum Yun]

Introduce struct etm_caps to describe ETMv3 capabilities
and move capabilities information into it.

Since drvdata->etmccr and drvdata->etmccer are used to check
whether it supports fifofull logic and timestamping,
remove etmccr and etmccer field from drvdata and add relevant fields
in etm_caps structure.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm.h   | 42 ++++++++++++-------
 .../coresight/coresight-etm3x-core.c          | 39 ++++++++++-------
 .../coresight/coresight-etm3x-sysfs.c         | 29 ++++++++-----
 3 files changed, 67 insertions(+), 43 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index 40f20daded4f..932bec82fb47 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -140,6 +140,30 @@
 				 ETM_ADD_COMP_0		|	\
 				 ETM_EVENT_NOT_A)
 
+/**
+ * struct etm_caps - specifics ETM capabilities
+ * @port_size:	port size as reported by ETMCR bit 4-6 and 21.
+ * @nr_addr_cmp:Number of pairs of address comparators as found in ETMCCR.
+ * @nr_cntr:	Number of counters as found in ETMCCR bit 13-15.
+ * @nr_ext_inp:	Number of external input as found in ETMCCR bit 17-19.
+ * @nr_ext_out:	Number of external output as found in ETMCCR bit 20-22.
+ * @nr_ctxid_cmp: Number of contextID comparators as found in ETMCCR bit 24-25.
+ * @fifofull:	FIFOFULL logic is present.
+ * @timestamp:	Timestamping is implemented.
+ * @retstack:	Return stack is implemented.
+ */
+struct etm_caps {
+	int	port_size;
+	u8	nr_addr_cmp;
+	u8	nr_cntr;
+	u8	nr_ext_inp;
+	u8	nr_ext_out;
+	u8	nr_ctxid_cmp;
+	bool	fifofull : 1;
+	bool	timestamp : 1;
+	bool	retstack : 1;
+};
+
 /**
  * struct etm_config - configuration information related to an ETM
  * @mode:	controls various modes supported by this ETM/PTM.
@@ -212,19 +236,12 @@ struct etm_config {
  * @csdev:	component vitals needed by the framework.
  * @spinlock:	only one at a time pls.
  * @cpu:	the cpu this component is affined to.
- * @port_size:	port size as reported by ETMCR bit 4-6 and 21.
  * @arch:	ETM/PTM version number.
+ * @caps:	ETM capabilities.
  * @use_cpu14:	true if management registers need to be accessed via CP14.
  * @sticky_enable: true if ETM base configuration has been done.
  * @boot_enable:true if we should start tracing at boot time.
  * @os_unlock:	true if access to management registers is allowed.
- * @nr_addr_cmp:Number of pairs of address comparators as found in ETMCCR.
- * @nr_cntr:	Number of counters as found in ETMCCR bit 13-15.
- * @nr_ext_inp:	Number of external input as found in ETMCCR bit 17-19.
- * @nr_ext_out:	Number of external output as found in ETMCCR bit 20-22.
- * @nr_ctxid_cmp: Number of contextID comparators as found in ETMCCR bit 24-25.
- * @etmccr:	value of register ETMCCR.
- * @etmccer:	value of register ETMCCER.
  * @traceid:	value of the current ID for this component.
  * @config:	structure holding configuration parameters.
  */
@@ -234,19 +251,12 @@ struct etm_drvdata {
 	struct coresight_device		*csdev;
 	raw_spinlock_t			spinlock;
 	int				cpu;
-	int				port_size;
 	u8				arch;
+	struct etm_caps			caps;
 	bool				use_cp14;
 	bool				sticky_enable;
 	bool				boot_enable;
 	bool				os_unlock;
-	u8				nr_addr_cmp;
-	u8				nr_cntr;
-	u8				nr_ext_inp;
-	u8				nr_ext_out;
-	u8				nr_ctxid_cmp;
-	u32				etmccr;
-	u32				etmccer;
 	u32				traceid;
 	struct etm_config		config;
 };
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 4a702b515733..e42ca346da91 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -308,6 +308,7 @@ void etm_config_trace_mode(struct etm_config *config)
 static int etm_parse_event_config(struct etm_drvdata *drvdata,
 				  struct perf_event *event)
 {
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 	struct perf_event_attr *attr = &event->attr;
 	u8 ts_level;
@@ -356,8 +357,7 @@ static int etm_parse_event_config(struct etm_drvdata *drvdata,
 	 * has ret stack) on the same SoC. So only enable when it can be honored
 	 * - trace will still continue normally otherwise.
 	 */
-	if (ATTR_CFG_GET_FLD(attr, retstack) &&
-	    (drvdata->etmccer & ETMCCER_RETSTACK))
+	if (ATTR_CFG_GET_FLD(attr, retstack) && (caps->retstack))
 		config->ctrl |= ETMCR_RETURN_STACK;
 
 	return 0;
@@ -367,6 +367,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 {
 	int i, rc;
 	u32 etmcr;
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 	struct coresight_device *csdev = drvdata->csdev;
 
@@ -388,7 +389,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 	etmcr = etm_readl(drvdata, ETMCR);
 	/* Clear setting from a previous run if need be */
 	etmcr &= ~ETM3X_SUPPORTED_OPTIONS;
-	etmcr |= drvdata->port_size;
+	etmcr |= caps->port_size;
 	etmcr |= ETMCR_ETM_EN;
 	etm_writel(drvdata, config->ctrl | etmcr, ETMCR);
 	etm_writel(drvdata, config->trigger_event, ETMTRIGGER);
@@ -396,11 +397,11 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 	etm_writel(drvdata, config->enable_event, ETMTEEVR);
 	etm_writel(drvdata, config->enable_ctrl1, ETMTECR1);
 	etm_writel(drvdata, config->fifofull_level, ETMFFLR);
-	for (i = 0; i < drvdata->nr_addr_cmp; i++) {
+	for (i = 0; i < caps->nr_addr_cmp; i++) {
 		etm_writel(drvdata, config->addr_val[i], ETMACVRn(i));
 		etm_writel(drvdata, config->addr_acctype[i], ETMACTRn(i));
 	}
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		etm_writel(drvdata, config->cntr_rld_val[i], ETMCNTRLDVRn(i));
 		etm_writel(drvdata, config->cntr_event[i], ETMCNTENRn(i));
 		etm_writel(drvdata, config->cntr_rld_event[i],
@@ -414,9 +415,9 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 	etm_writel(drvdata, config->seq_32_event, ETMSQ32EVR);
 	etm_writel(drvdata, config->seq_13_event, ETMSQ13EVR);
 	etm_writel(drvdata, config->seq_curr_state, ETMSQR);
-	for (i = 0; i < drvdata->nr_ext_out; i++)
+	for (i = 0; i < caps->nr_ext_out; i++)
 		etm_writel(drvdata, ETM_DEFAULT_EVENT_VAL, ETMEXTOUTEVRn(i));
-	for (i = 0; i < drvdata->nr_ctxid_cmp; i++)
+	for (i = 0; i < caps->nr_ctxid_cmp; i++)
 		etm_writel(drvdata, config->ctxid_pid[i], ETMCIDCVRn(i));
 	etm_writel(drvdata, config->ctxid_mask, ETMCIDCMR);
 	etm_writel(drvdata, config->sync_freq, ETMSYNCFR);
@@ -563,6 +564,7 @@ static int etm_enable(struct coresight_device *csdev, struct perf_event *event,
 static void etm_disable_hw(struct etm_drvdata *drvdata)
 {
 	int i;
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 	struct coresight_device *csdev = drvdata->csdev;
 
@@ -572,7 +574,7 @@ static void etm_disable_hw(struct etm_drvdata *drvdata)
 	/* Read back sequencer and counters for post trace analysis */
 	config->seq_curr_state = (etm_readl(drvdata, ETMSQR) & ETM_SQR_MASK);
 
-	for (i = 0; i < drvdata->nr_cntr; i++)
+	for (i = 0; i < caps->nr_cntr; i++)
 		config->cntr_val[i] = etm_readl(drvdata, ETMCNTVRn(i));
 
 	etm_set_pwrdwn(drvdata);
@@ -754,7 +756,9 @@ static void etm_init_arch_data(void *info)
 {
 	u32 etmidr;
 	u32 etmccr;
+	u32 etmccer;
 	struct etm_drvdata *drvdata = info;
+	struct etm_caps *caps = &drvdata->caps;
 
 	/* Make sure all registers are accessible */
 	etm_os_unlock(drvdata);
@@ -779,16 +783,19 @@ static void etm_init_arch_data(void *info)
 	/* Find all capabilities */
 	etmidr = etm_readl(drvdata, ETMIDR);
 	drvdata->arch = BMVAL(etmidr, 4, 11);
-	drvdata->port_size = etm_readl(drvdata, ETMCR) & PORT_SIZE_MASK;
+	caps->port_size = etm_readl(drvdata, ETMCR) & PORT_SIZE_MASK;
+
+	etmccer = etm_readl(drvdata, ETMCCER);
+	caps->timestamp = !!(etmccer & ETMCCER_TIMESTAMP);
+	caps->retstack = !!(etmccer & ETMCCER_RETSTACK);
 
-	drvdata->etmccer = etm_readl(drvdata, ETMCCER);
 	etmccr = etm_readl(drvdata, ETMCCR);
-	drvdata->etmccr = etmccr;
-	drvdata->nr_addr_cmp = BMVAL(etmccr, 0, 3) * 2;
-	drvdata->nr_cntr = BMVAL(etmccr, 13, 15);
-	drvdata->nr_ext_inp = BMVAL(etmccr, 17, 19);
-	drvdata->nr_ext_out = BMVAL(etmccr, 20, 22);
-	drvdata->nr_ctxid_cmp = BMVAL(etmccr, 24, 25);
+	caps->fifofull = !!(etmccr & ETMCCR_FIFOFULL);
+	caps->nr_addr_cmp = BMVAL(etmccr, 0, 3) * 2;
+	caps->nr_cntr = BMVAL(etmccr, 13, 15);
+	caps->nr_ext_inp = BMVAL(etmccr, 17, 19);
+	caps->nr_ext_out = BMVAL(etmccr, 20, 22);
+	caps->nr_ctxid_cmp = BMVAL(etmccr, 24, 25);
 
 	coresight_clear_self_claim_tag_unlocked(&drvdata->csa);
 	etm_set_pwrdwn(drvdata);
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
index 42b12c33516b..f7330d830e21 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
@@ -15,8 +15,9 @@ static ssize_t nr_addr_cmp_show(struct device *dev,
 {
 	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_addr_cmp;
+	val = caps->nr_addr_cmp;
 	return sprintf(buf, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_addr_cmp);
@@ -25,8 +26,9 @@ static ssize_t nr_cntr_show(struct device *dev,
 			    struct device_attribute *attr, char *buf)
 {	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 
-	val = drvdata->nr_cntr;
+	val = caps->nr_cntr;
 	return sprintf(buf, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_cntr);
@@ -37,7 +39,7 @@ static ssize_t nr_ctxid_cmp_show(struct device *dev,
 	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
 
-	val = drvdata->nr_ctxid_cmp;
+	val = drvdata->caps.nr_ctxid_cmp;
 	return sprintf(buf, "%#lx\n", val);
 }
 static DEVICE_ATTR_RO(nr_ctxid_cmp);
@@ -80,7 +82,7 @@ static ssize_t reset_store(struct device *dev,
 		memset(config, 0, sizeof(struct etm_config));
 		config->mode = ETM_MODE_EXCLUDE;
 		config->trigger_event = ETM_DEFAULT_EVENT_VAL;
-		for (i = 0; i < drvdata->nr_addr_cmp; i++) {
+		for (i = 0; i < drvdata->caps.nr_addr_cmp; i++) {
 			config->addr_type[i] = ETM_ADDR_TYPE_NONE;
 		}
 
@@ -111,6 +113,7 @@ static ssize_t mode_store(struct device *dev,
 	int ret;
 	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 
 	ret = kstrtoul(buf, 16, &val);
@@ -131,7 +134,7 @@ static ssize_t mode_store(struct device *dev,
 		config->ctrl &= ~ETMCR_CYC_ACC;
 
 	if (config->mode & ETM_MODE_STALL) {
-		if (!(drvdata->etmccr & ETMCCR_FIFOFULL)) {
+		if (!caps->fifofull) {
 			dev_warn(dev, "stall mode not supported\n");
 			ret = -EINVAL;
 			goto err_unlock;
@@ -141,7 +144,7 @@ static ssize_t mode_store(struct device *dev,
 		config->ctrl &= ~ETMCR_STALL_MODE;
 
 	if (config->mode & ETM_MODE_TIMESTAMP) {
-		if (!(drvdata->etmccer & ETMCCER_TIMESTAMP)) {
+		if (!caps->timestamp) {
 			dev_warn(dev, "timestamp not supported\n");
 			ret = -EINVAL;
 			goto err_unlock;
@@ -286,13 +289,14 @@ static ssize_t addr_idx_store(struct device *dev,
 	int ret;
 	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 
 	ret = kstrtoul(buf, 16, &val);
 	if (ret)
 		return ret;
 
-	if (val >= drvdata->nr_addr_cmp)
+	if (val >= caps->nr_addr_cmp)
 		return -EINVAL;
 
 	/*
@@ -589,13 +593,14 @@ static ssize_t cntr_idx_store(struct device *dev,
 	int ret;
 	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 
 	ret = kstrtoul(buf, 16, &val);
 	if (ret)
 		return ret;
 
-	if (val >= drvdata->nr_cntr)
+	if (val >= caps->nr_cntr)
 		return -EINVAL;
 	/*
 	 * Use spinlock to ensure index doesn't change while it gets
@@ -720,18 +725,19 @@ static ssize_t cntr_val_show(struct device *dev,
 	int i, ret = 0;
 	u32 val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 
 	if (!coresight_get_mode(drvdata->csdev)) {
 		raw_spin_lock(&drvdata->spinlock);
-		for (i = 0; i < drvdata->nr_cntr; i++)
+		for (i = 0; i < caps->nr_cntr; i++)
 			ret += sprintf(buf, "counter %d: %x\n",
 				       i, config->cntr_val[i]);
 		raw_spin_unlock(&drvdata->spinlock);
 		return ret;
 	}
 
-	for (i = 0; i < drvdata->nr_cntr; i++) {
+	for (i = 0; i < caps->nr_cntr; i++) {
 		val = etm_readl(drvdata, ETMCNTVRn(i));
 		ret += sprintf(buf, "counter %d: %x\n", i, val);
 	}
@@ -999,13 +1005,14 @@ static ssize_t ctxid_idx_store(struct device *dev,
 	int ret;
 	unsigned long val;
 	struct etm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+	const struct etm_caps *caps = &drvdata->caps;
 	struct etm_config *config = &drvdata->config;
 
 	ret = kstrtoul(buf, 16, &val);
 	if (ret)
 		return ret;
 
-	if (val >= drvdata->nr_ctxid_cmp)
+	if (val >= caps->nr_ctxid_cmp)
 		return -EINVAL;
 
 	/*
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 11/12] coresight: etm3x: fix inconsistencies with sysfs configuration

[Yeoreum Yun]

The current ETM3x configuration via sysfs can lead to the following
inconsistencies:

  - If a configuration is modified via sysfs while a perf session is
    active, the running configuration may differ between before
    a sched-out and after a subsequent sched-in.

To resolve these issues, separate the configuration into:

  - active_config: the configuration applied to the current session
  - config: the configuration set via sysfs

Additionally:

  - Since active_config and related fields are accessed only by the local CPU
    in etm_enable/disable_sysfs_smp_call() (similar to perf enable/disable),
    remove the lock/unlock from the sysfs enable/disable path and
    starting/dying_cpu path except when to access config fields only.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 drivers/hwtracing/coresight/coresight-etm.h   |  2 +
 .../coresight/coresight-etm3x-core.c          | 49 ++++++++++---------
 2 files changed, 27 insertions(+), 24 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index 932bec82fb47..01f1a7f2559c 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -243,6 +243,7 @@ struct etm_config {
  * @boot_enable:true if we should start tracing at boot time.
  * @os_unlock:	true if access to management registers is allowed.
  * @traceid:	value of the current ID for this component.
+ * @active_config:	structure holding current running configuration parameters.
  * @config:	structure holding configuration parameters.
  */
 struct etm_drvdata {
@@ -258,6 +259,7 @@ struct etm_drvdata {
 	bool				boot_enable;
 	bool				os_unlock;
 	u32				traceid;
+	struct etm_config		active_config;
 	struct etm_config		config;
 };
 
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index e42ca346da91..706a4c7a40df 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -309,7 +309,7 @@ static int etm_parse_event_config(struct etm_drvdata *drvdata,
 				  struct perf_event *event)
 {
 	const struct etm_caps *caps = &drvdata->caps;
-	struct etm_config *config = &drvdata->config;
+	struct etm_config *config = &drvdata->active_config;
 	struct perf_event_attr *attr = &event->attr;
 	u8 ts_level;
 
@@ -368,7 +368,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 	int i, rc;
 	u32 etmcr;
 	const struct etm_caps *caps = &drvdata->caps;
-	struct etm_config *config = &drvdata->config;
+	struct etm_config *config = &drvdata->active_config;
 	struct coresight_device *csdev = drvdata->csdev;
 
 	CS_UNLOCK(drvdata->csa.base);
@@ -442,29 +442,38 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
 
 struct etm_enable_arg {
 	struct etm_drvdata *drvdata;
+	u32 traceid;
+	struct etm_config config;
 	int rc;
 };
 
 static void etm_enable_sysfs_smp_call(void *info)
 {
 	struct etm_enable_arg *arg = info;
+	struct etm_drvdata *drvdata;
 	struct coresight_device *csdev;
 
 	if (WARN_ON(!arg))
 		return;
 
-	csdev = arg->drvdata->csdev;
+	drvdata = arg->drvdata;
+	csdev = drvdata->csdev;
 	if (!coresight_take_mode(csdev, CS_MODE_SYSFS)) {
 		/* Someone is already using the tracer */
 		arg->rc = -EBUSY;
 		return;
 	}
 
+	drvdata->active_config = arg->config;
+	drvdata->traceid = arg->traceid;
+
 	arg->rc = etm_enable_hw(arg->drvdata);
 
 	/* The tracer didn't start */
 	if (arg->rc)
 		coresight_set_mode(csdev, CS_MODE_DISABLED);
+	else
+		drvdata->sticky_enable = true;
 }
 
 static int etm_cpu_id(struct coresight_device *csdev)
@@ -512,9 +521,6 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat
 	struct etm_enable_arg arg = { };
 	int ret;
 
-	raw_spin_lock(&drvdata->spinlock);
-
-	drvdata->traceid = path->trace_id;
 
 	/*
 	 * Configure the ETM only if the CPU is online.  If it isn't online
@@ -522,23 +528,25 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat
 	 */
 	if (cpu_online(drvdata->cpu)) {
 		arg.drvdata = drvdata;
+		arg.traceid = path->trace_id;
+
+		raw_spin_lock(&drvdata->spinlock);
+		arg.config = drvdata->config;
+		raw_spin_unlock(&drvdata->spinlock);
+
 		ret = smp_call_function_single(drvdata->cpu,
 					       etm_enable_sysfs_smp_call, &arg, 1);
 		if (!ret)
 			ret = arg.rc;
-		if (!ret)
-			drvdata->sticky_enable = true;
 	} else {
 		ret = -ENODEV;
 	}
 
-	if (ret)
-		etm_release_trace_id(drvdata);
-
-	raw_spin_unlock(&drvdata->spinlock);
-
 	if (!ret)
 		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
+	else
+		etm_release_trace_id(drvdata);
+
 	return ret;
 }
 
@@ -565,7 +573,7 @@ static void etm_disable_hw(struct etm_drvdata *drvdata)
 {
 	int i;
 	const struct etm_caps *caps = &drvdata->caps;
-	struct etm_config *config = &drvdata->config;
+	struct etm_config *config = &drvdata->active_config;
 	struct coresight_device *csdev = drvdata->csdev;
 
 	CS_UNLOCK(drvdata->csa.base);
@@ -636,7 +644,6 @@ static void etm_disable_sysfs(struct coresight_device *csdev)
 	 * DYING hotplug callback is serviced by the ETM driver.
 	 */
 	cpus_read_lock();
-	raw_spin_lock(&drvdata->spinlock);
 
 	/*
 	 * Executing etm_disable_hw on the cpu whose ETM is being disabled
@@ -645,7 +652,6 @@ static void etm_disable_sysfs(struct coresight_device *csdev)
 	smp_call_function_single(drvdata->cpu, etm_disable_sysfs_smp_call,
 				 drvdata, 1);
 
-	raw_spin_unlock(&drvdata->spinlock);
 	cpus_read_unlock();
 
 	/*
@@ -711,15 +717,11 @@ static int etm_starting_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu])
 		return 0;
 
-	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
-	if (!etmdrvdata[cpu]->os_unlock) {
+	if (!etmdrvdata[cpu]->os_unlock)
 		etm_os_unlock(etmdrvdata[cpu]);
-		etmdrvdata[cpu]->os_unlock = true;
-	}
 
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
 		etm_enable_hw(etmdrvdata[cpu]);
-	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }
 
@@ -728,10 +730,8 @@ static int etm_dying_cpu(unsigned int cpu)
 	if (!etmdrvdata[cpu])
 		return 0;
 
-	raw_spin_lock(&etmdrvdata[cpu]->spinlock);
 	if (coresight_get_mode(etmdrvdata[cpu]->csdev))
 		etm_disable_hw(etmdrvdata[cpu]);
-	raw_spin_unlock(&etmdrvdata[cpu]->spinlock);
 	return 0;
 }
 
@@ -884,7 +884,8 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
 	if (etm_arch_supported(drvdata->arch) == false)
 		return -EINVAL;
 
-	etm_set_default(&drvdata->config);
+	etm_set_default(&drvdata->active_config);
+	drvdata->config = drvdata->active_config;
 
 	pdata = coresight_get_platform_data(dev);
 	if (IS_ERR(pdata))
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

[PATCH v5 12/12] coresight: etm3x: remove redundant call etm_enable_hw() with hotplug

[Yeoreum Yun]

The cpu_online_mask is set at the CPUHP_BRINGUP_CPU step.
In other words, if etm4_enable_sysfs() is called between
CPUHP_BRINGUP_CPU and CPUHP_AP_ARM_CORESIGHT_STARTING,
etm_enable_hw() may be invoked in etm_enable_sysfs_smp_call()
and then executed again in etm_starting_cpu().

To remove this redundant call, take the hotplug lock before executing
etm_enable_sysfs_smp_call().

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
---
 .../coresight/coresight-etm3x-core.c          | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 706a4c7a40df..8bf7ae276096 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -521,26 +521,26 @@ static int etm_enable_sysfs(struct coresight_device *csdev, struct coresight_pat
 	struct etm_enable_arg arg = { };
 	int ret;
 
+	arg.drvdata = drvdata;
+	arg.traceid = path->trace_id;
+
+	raw_spin_lock(&drvdata->spinlock);
+	arg.config = drvdata->config;
+	raw_spin_unlock(&drvdata->spinlock);
 
 	/*
 	 * Configure the ETM only if the CPU is online.  If it isn't online
 	 * hw configuration will take place on the local CPU during bring up.
 	 */
-	if (cpu_online(drvdata->cpu)) {
-		arg.drvdata = drvdata;
-		arg.traceid = path->trace_id;
-
-		raw_spin_lock(&drvdata->spinlock);
-		arg.config = drvdata->config;
-		raw_spin_unlock(&drvdata->spinlock);
-
+	cpus_read_lock();
 		ret = smp_call_function_single(drvdata->cpu,
 					       etm_enable_sysfs_smp_call, &arg, 1);
-		if (!ret)
-			ret = arg.rc;
-	} else {
+	cpus_read_unlock();
+
+	if (!ret)
+		ret = arg.rc;
+	else
 		ret = -ENODEV;
-	}
 
 	if (!ret)
 		dev_dbg(&csdev->dev, "ETM tracing enabled\n");
-- 
LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}