This can be left behind from a crashed kernel after a kexec so clear it
when probing each device. Similarly to
coresight_disclaim_device_unlocked(), only clear it if it's already set
to avoid races with an external debugger.
We need a csdev_access struct in etm_init_arch_data() so just replace
the iomem pointer with a full csdev_access struct. This means all usages
need to be updated to go through csa->base.
Signed-off-by: James Clark <james.clark@linaro.org>
---
drivers/hwtracing/coresight/coresight-catu.c | 1 +
drivers/hwtracing/coresight/coresight-core.c | 48 +++++++++++++++----
.../hwtracing/coresight/coresight-cti-core.c | 2 +
drivers/hwtracing/coresight/coresight-etb10.c | 2 +
drivers/hwtracing/coresight/coresight-etm.h | 6 +--
.../coresight/coresight-etm3x-core.c | 28 +++++------
.../coresight/coresight-etm3x-sysfs.c | 8 ++--
.../coresight/coresight-etm4x-core.c | 2 +
.../hwtracing/coresight/coresight-funnel.c | 2 +
.../coresight/coresight-replicator.c | 1 +
.../hwtracing/coresight/coresight-tmc-core.c | 1 +
include/linux/coresight.h | 3 ++
12 files changed, 73 insertions(+), 31 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
index d9259c0b6e64..575c2d247a90 100644
--- a/drivers/hwtracing/coresight/coresight-catu.c
+++ b/drivers/hwtracing/coresight/coresight-catu.c
@@ -558,6 +558,7 @@ static int __catu_probe(struct device *dev, struct resource *res)
catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
catu_desc.ops = &catu_ops;
+ coresight_reset_claim(&catu_desc.access);
drvdata->csdev = coresight_register(&catu_desc);
if (IS_ERR(drvdata->csdev))
ret = PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
index 7fe5d5d432c4..97f33ffad05e 100644
--- a/drivers/hwtracing/coresight/coresight-core.c
+++ b/drivers/hwtracing/coresight/coresight-core.c
@@ -212,20 +212,48 @@ int coresight_claim_device(struct coresight_device *csdev)
EXPORT_SYMBOL_GPL(coresight_claim_device);
/*
- * coresight_disclaim_device_unlocked : Clear the claim tag for the device.
+ * Clear the claim tag for the device.
+ * Returns an error if the device wasn't already claimed.
+ */
+int coresight_reset_claim(struct csdev_access *csa)
+{
+ int ret;
+
+ CS_UNLOCK(csa->base);
+ ret = coresight_reset_claim_unlocked(csa);
+ CS_LOCK(csa->base);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(coresight_reset_claim);
+
+/*
+ * Clear the claim tag for the device. Called with CS_UNLOCKed for the component.
+ * Returns an error if the device wasn't already claimed.
+ */
+int coresight_reset_claim_unlocked(struct csdev_access *csa)
+{
+ if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED) {
+ coresight_clear_self_claim_tag(csa);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(coresight_reset_claim_unlocked);
+
+/*
+ * coresight_disclaim_device_unlocked : Clear the claim tag for the device
+ * and warn if the device wasn't already claimed.
* Called with CS_UNLOCKed for the component.
*/
void coresight_disclaim_device_unlocked(struct csdev_access *csa)
{
- if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
- coresight_clear_self_claim_tag(csa);
- else
- /*
- * The external agent may have not honoured our claim
- * and has manipulated it. Or something else has seriously
- * gone wrong in our driver.
- */
- WARN_ON_ONCE(1);
+ /*
+ * Warn if the external agent hasn't honoured our claim
+ * and has manipulated it. Or something else has seriously
+ * gone wrong in our driver.
+ */
+ WARN_ON_ONCE(coresight_reset_claim_unlocked(csa));
}
EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index 073f67a41af9..389a72362f0c 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -931,6 +931,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
cti_desc.ops = &cti_ops;
cti_desc.groups = drvdata->ctidev.con_groups;
cti_desc.dev = dev;
+
+ coresight_reset_claim(&cti_desc.access);
drvdata->csdev = coresight_register(&cti_desc);
if (IS_ERR(drvdata->csdev)) {
ret = PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
index d8bc3e776c88..b598b2c0c9bb 100644
--- a/drivers/hwtracing/coresight/coresight-etb10.c
+++ b/drivers/hwtracing/coresight/coresight-etb10.c
@@ -772,6 +772,8 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
desc.pdata = pdata;
desc.dev = dev;
desc.groups = coresight_etb_groups;
+
+ coresight_reset_claim(&desc.access);
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev))
return PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
index e02c3ea972c9..a89736309c27 100644
--- a/drivers/hwtracing/coresight/coresight-etm.h
+++ b/drivers/hwtracing/coresight/coresight-etm.h
@@ -229,7 +229,7 @@ struct etm_config {
* @config: structure holding configuration parameters.
*/
struct etm_drvdata {
- void __iomem *base;
+ struct csdev_access csa;
struct clk *atclk;
struct coresight_device *csdev;
spinlock_t spinlock;
@@ -260,7 +260,7 @@ static inline void etm_writel(struct etm_drvdata *drvdata,
"invalid CP14 access to ETM reg: %#x", off);
}
} else {
- writel_relaxed(val, drvdata->base + off);
+ writel_relaxed(val, drvdata->csa.base + off);
}
}
@@ -274,7 +274,7 @@ static inline unsigned int etm_readl(struct etm_drvdata *drvdata, u32 off)
"invalid CP14 access to ETM reg: %#x", off);
}
} else {
- val = readl_relaxed(drvdata->base + off);
+ val = readl_relaxed(drvdata->csa.base + off);
}
return val;
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
index 509f53b69e42..0b010683b883 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
@@ -86,9 +86,9 @@ static void etm_set_pwrup(struct etm_drvdata *drvdata)
{
u32 etmpdcr;
- etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
+ etmpdcr = readl_relaxed(drvdata->csa.base + ETMPDCR);
etmpdcr |= ETMPDCR_PWD_UP;
- writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
+ writel_relaxed(etmpdcr, drvdata->csa.base + ETMPDCR);
/* Ensure pwrup completes before subsequent cp14 accesses */
mb();
isb();
@@ -101,9 +101,9 @@ static void etm_clr_pwrup(struct etm_drvdata *drvdata)
/* Ensure pending cp14 accesses complete before clearing pwrup */
mb();
isb();
- etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
+ etmpdcr = readl_relaxed(drvdata->csa.base + ETMPDCR);
etmpdcr &= ~ETMPDCR_PWD_UP;
- writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
+ writel_relaxed(etmpdcr, drvdata->csa.base + ETMPDCR);
}
/**
@@ -365,7 +365,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
struct etm_config *config = &drvdata->config;
struct coresight_device *csdev = drvdata->csdev;
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(drvdata->csa.base);
rc = coresight_claim_device_unlocked(csdev);
if (rc)
@@ -427,7 +427,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
etm_clr_prog(drvdata);
done:
- CS_LOCK(drvdata->base);
+ CS_LOCK(drvdata->csa.base);
dev_dbg(&drvdata->csdev->dev, "cpu: %d enable smp call done: %d\n",
drvdata->cpu, rc);
@@ -589,7 +589,7 @@ static void etm_disable_hw(void *info)
struct etm_config *config = &drvdata->config;
struct coresight_device *csdev = drvdata->csdev;
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(drvdata->csa.base);
etm_set_prog(drvdata);
/* Read back sequencer and counters for post trace analysis */
@@ -601,7 +601,7 @@ static void etm_disable_hw(void *info)
etm_set_pwrdwn(drvdata);
coresight_disclaim_device_unlocked(&csdev->access);
- CS_LOCK(drvdata->base);
+ CS_LOCK(drvdata->csa.base);
dev_dbg(&drvdata->csdev->dev,
"cpu: %d disable smp call done\n", drvdata->cpu);
@@ -614,7 +614,7 @@ static void etm_disable_perf(struct coresight_device *csdev)
if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
return;
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(drvdata->csa.base);
/* Setting the prog bit disables tracing immediately */
etm_set_prog(drvdata);
@@ -626,7 +626,7 @@ static void etm_disable_perf(struct coresight_device *csdev)
etm_set_pwrdwn(drvdata);
coresight_disclaim_device_unlocked(&csdev->access);
- CS_LOCK(drvdata->base);
+ CS_LOCK(drvdata->csa.base);
/*
* perf will release trace ids when _free_aux()
@@ -772,7 +772,7 @@ static void etm_init_arch_data(void *info)
/* Make sure all registers are accessible */
etm_os_unlock(drvdata);
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(drvdata->csa.base);
/* First dummy read */
(void)etm_readl(drvdata, ETMPDSR);
@@ -803,9 +803,10 @@ static void etm_init_arch_data(void *info)
drvdata->nr_ext_out = BMVAL(etmccr, 20, 22);
drvdata->nr_ctxid_cmp = BMVAL(etmccr, 24, 25);
+ coresight_reset_claim_unlocked(&drvdata->csa);
etm_set_pwrdwn(drvdata);
etm_clr_pwrup(drvdata);
- CS_LOCK(drvdata->base);
+ CS_LOCK(drvdata->csa.base);
}
static int __init etm_hp_setup(void)
@@ -866,8 +867,7 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
if (IS_ERR(base))
return PTR_ERR(base);
- drvdata->base = base;
- desc.access = CSDEV_ACCESS_IOMEM(base);
+ desc.access = drvdata->csa = CSDEV_ACCESS_IOMEM(base);
spin_lock_init(&drvdata->spinlock);
diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
index 68c644be9813..af566b62785c 100644
--- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
@@ -50,11 +50,11 @@ static ssize_t etmsr_show(struct device *dev,
pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(drvdata->csa.base);
val = etm_readl(drvdata, ETMSR);
- CS_LOCK(drvdata->base);
+ CS_LOCK(drvdata->csa.base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
pm_runtime_put(dev->parent);
@@ -949,9 +949,9 @@ static ssize_t seq_curr_state_show(struct device *dev,
pm_runtime_get_sync(dev->parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
- CS_UNLOCK(drvdata->base);
+ CS_UNLOCK(drvdata->csa.base);
val = (etm_readl(drvdata, ETMSQR) & ETM_SQR_MASK);
- CS_LOCK(drvdata->base);
+ CS_LOCK(drvdata->csa.base);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
pm_runtime_put(dev->parent);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 45b30a4b3eba..3609bb74c4ec 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -1337,6 +1337,8 @@ static void etm4_init_arch_data(void *info)
drvdata->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);
+
+ coresight_reset_claim_unlocked(csa);
etm4_cs_lock(drvdata, csa);
cpu_detect_trace_filtering(drvdata);
}
diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
index e986922d555b..be2a47636ef3 100644
--- a/drivers/hwtracing/coresight/coresight-funnel.c
+++ b/drivers/hwtracing/coresight/coresight-funnel.c
@@ -255,6 +255,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
drvdata->base = base;
desc.groups = coresight_funnel_groups;
desc.access = CSDEV_ACCESS_IOMEM(base);
+ coresight_reset_claim(&desc.access);
}
dev_set_drvdata(dev, drvdata);
@@ -272,6 +273,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
desc.ops = &funnel_cs_ops;
desc.pdata = pdata;
desc.dev = dev;
+
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev)) {
ret = PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
index 5d42a9a8c460..679a36effbe8 100644
--- a/drivers/hwtracing/coresight/coresight-replicator.c
+++ b/drivers/hwtracing/coresight/coresight-replicator.c
@@ -284,6 +284,7 @@ static int replicator_probe(struct device *dev, struct resource *res)
desc.pdata = dev->platform_data;
desc.dev = dev;
+ coresight_reset_claim(&desc.access);
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev)) {
ret = PTR_ERR(drvdata->csdev);
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index e9876252a789..5ac4e3c706ac 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -558,6 +558,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
dev->platform_data = pdata;
desc.pdata = pdata;
+ coresight_reset_claim(&desc.access);
drvdata->csdev = coresight_register(&desc);
if (IS_ERR(drvdata->csdev)) {
ret = PTR_ERR(drvdata->csdev);
diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 937931d107e0..11808aee9d1d 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -655,6 +655,9 @@ extern int coresight_claim_device_unlocked(struct coresight_device *csdev);
extern void coresight_disclaim_device(struct csdev_access *csa);
extern void coresight_disclaim_device_unlocked(struct csdev_access *csa);
+int coresight_reset_claim_unlocked(struct csdev_access *csa);
+int coresight_reset_claim(struct csdev_access *csa);
+
extern char *coresight_alloc_device_name(struct coresight_dev_list *devs,
struct device *dev);
--
2.34.1On Tue, Feb 11, 2025 at 10:39:41AM +0000, James Clark wrote:
>
> This can be left behind from a crashed kernel after a kexec so clear it
> when probing each device. Similarly to
> coresight_disclaim_device_unlocked(), only clear it if it's already set
> to avoid races with an external debugger.
>
> We need a csdev_access struct in etm_init_arch_data() so just replace
> the iomem pointer with a full csdev_access struct. This means all usages
> need to be updated to go through csa->base.
>
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-catu.c | 1 +
> drivers/hwtracing/coresight/coresight-core.c | 48 +++++++++++++++----
> .../hwtracing/coresight/coresight-cti-core.c | 2 +
> drivers/hwtracing/coresight/coresight-etb10.c | 2 +
> drivers/hwtracing/coresight/coresight-etm.h | 6 +--
> .../coresight/coresight-etm3x-core.c | 28 +++++------
> .../coresight/coresight-etm3x-sysfs.c | 8 ++--
> .../coresight/coresight-etm4x-core.c | 2 +
> .../hwtracing/coresight/coresight-funnel.c | 2 +
> .../coresight/coresight-replicator.c | 1 +
> .../hwtracing/coresight/coresight-tmc-core.c | 1 +
> include/linux/coresight.h | 3 ++
> 12 files changed, 73 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
> index d9259c0b6e64..575c2d247a90 100644
> --- a/drivers/hwtracing/coresight/coresight-catu.c
> +++ b/drivers/hwtracing/coresight/coresight-catu.c
> @@ -558,6 +558,7 @@ static int __catu_probe(struct device *dev, struct resource *res)
> catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
> catu_desc.ops = &catu_ops;
>
> + coresight_reset_claim(&catu_desc.access);
> drvdata->csdev = coresight_register(&catu_desc);
> if (IS_ERR(drvdata->csdev))
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 7fe5d5d432c4..97f33ffad05e 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -212,20 +212,48 @@ int coresight_claim_device(struct coresight_device *csdev)
> EXPORT_SYMBOL_GPL(coresight_claim_device);
>
> /*
> - * coresight_disclaim_device_unlocked : Clear the claim tag for the device.
> + * Clear the claim tag for the device.
> + * Returns an error if the device wasn't already claimed.
> + */
> +int coresight_reset_claim(struct csdev_access *csa)
> +{
> + int ret;
> +
> + CS_UNLOCK(csa->base);
> + ret = coresight_reset_claim_unlocked(csa);
> + CS_LOCK(csa->base);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(coresight_reset_claim);
Maybe my question is overlapping with Mike's comment.
Callers never check the return values from coresight_reset_claim(). I am
wandering if coresight_reset_claim() can directly call
coresight_clear_self_claim_tag() for _trying_ to clear self-host tag in
probe phase. Any self claim tag issues will be deferred to detect until
enable the component.
For consistent, we might rename coresight_reset_claim() to
coresight_reset_self_claim_tag(), which acquires CS lock and clear
self claim tag.
> +/*
> + * Clear the claim tag for the device. Called with CS_UNLOCKed for the component.
> + * Returns an error if the device wasn't already claimed.
> + */
> +int coresight_reset_claim_unlocked(struct csdev_access *csa)
> +{
> + if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED) {
> + coresight_clear_self_claim_tag(csa);
> + return 0;
> + }
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(coresight_reset_claim_unlocked);
> +
> +/*
> + * coresight_disclaim_device_unlocked : Clear the claim tag for the device
> + * and warn if the device wasn't already claimed.
> * Called with CS_UNLOCKed for the component.
> */
> void coresight_disclaim_device_unlocked(struct csdev_access *csa)
> {
> - if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
> - coresight_clear_self_claim_tag(csa);
> - else
> - /*
> - * The external agent may have not honoured our claim
> - * and has manipulated it. Or something else has seriously
> - * gone wrong in our driver.
> - */
> - WARN_ON_ONCE(1);
> + /*
> + * Warn if the external agent hasn't honoured our claim
> + * and has manipulated it. Or something else has seriously
> + * gone wrong in our driver.
> + */
> + WARN_ON_ONCE(coresight_reset_claim_unlocked(csa));
> }
> EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
> index 073f67a41af9..389a72362f0c 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
> @@ -931,6 +931,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
> cti_desc.ops = &cti_ops;
> cti_desc.groups = drvdata->ctidev.con_groups;
> cti_desc.dev = dev;
> +
> + coresight_reset_claim(&cti_desc.access);
> drvdata->csdev = coresight_register(&cti_desc);
> if (IS_ERR(drvdata->csdev)) {
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index d8bc3e776c88..b598b2c0c9bb 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -772,6 +772,8 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
> desc.pdata = pdata;
> desc.dev = dev;
> desc.groups = coresight_etb_groups;
> +
> + coresight_reset_claim(&desc.access);
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev))
> return PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
> index e02c3ea972c9..a89736309c27 100644
> --- a/drivers/hwtracing/coresight/coresight-etm.h
> +++ b/drivers/hwtracing/coresight/coresight-etm.h
> @@ -229,7 +229,7 @@ struct etm_config {
> * @config: structure holding configuration parameters.
> */
> struct etm_drvdata {
> - void __iomem *base;
> + struct csdev_access csa;
I would like to extract the change for using `csdev_access` in the
ETMv3 driver into a new patch, which is irrelevant to reset self claim
tags and would significantly reduce the complexity in this patch.
Thanks,
Leo
On 13/03/2025 4:04 pm, Leo Yan wrote:
> On Tue, Feb 11, 2025 at 10:39:41AM +0000, James Clark wrote:
>>
>> This can be left behind from a crashed kernel after a kexec so clear it
>> when probing each device. Similarly to
>> coresight_disclaim_device_unlocked(), only clear it if it's already set
>> to avoid races with an external debugger.
>>
>> We need a csdev_access struct in etm_init_arch_data() so just replace
>> the iomem pointer with a full csdev_access struct. This means all usages
>> need to be updated to go through csa->base.
>>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> ---
>> drivers/hwtracing/coresight/coresight-catu.c | 1 +
>> drivers/hwtracing/coresight/coresight-core.c | 48 +++++++++++++++----
>> .../hwtracing/coresight/coresight-cti-core.c | 2 +
>> drivers/hwtracing/coresight/coresight-etb10.c | 2 +
>> drivers/hwtracing/coresight/coresight-etm.h | 6 +--
>> .../coresight/coresight-etm3x-core.c | 28 +++++------
>> .../coresight/coresight-etm3x-sysfs.c | 8 ++--
>> .../coresight/coresight-etm4x-core.c | 2 +
>> .../hwtracing/coresight/coresight-funnel.c | 2 +
>> .../coresight/coresight-replicator.c | 1 +
>> .../hwtracing/coresight/coresight-tmc-core.c | 1 +
>> include/linux/coresight.h | 3 ++
>> 12 files changed, 73 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
>> index d9259c0b6e64..575c2d247a90 100644
>> --- a/drivers/hwtracing/coresight/coresight-catu.c
>> +++ b/drivers/hwtracing/coresight/coresight-catu.c
>> @@ -558,6 +558,7 @@ static int __catu_probe(struct device *dev, struct resource *res)
>> catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
>> catu_desc.ops = &catu_ops;
>>
>> + coresight_reset_claim(&catu_desc.access);
>> drvdata->csdev = coresight_register(&catu_desc);
>> if (IS_ERR(drvdata->csdev))
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
>> index 7fe5d5d432c4..97f33ffad05e 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -212,20 +212,48 @@ int coresight_claim_device(struct coresight_device *csdev)
>> EXPORT_SYMBOL_GPL(coresight_claim_device);
>>
>> /*
>> - * coresight_disclaim_device_unlocked : Clear the claim tag for the device.
>> + * Clear the claim tag for the device.
>> + * Returns an error if the device wasn't already claimed.
>> + */
>> +int coresight_reset_claim(struct csdev_access *csa)
>> +{
>> + int ret;
>> +
>> + CS_UNLOCK(csa->base);
>> + ret = coresight_reset_claim_unlocked(csa);
>> + CS_LOCK(csa->base);
>> + return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(coresight_reset_claim);
>
> Maybe my question is overlapping with Mike's comment.
>
> Callers never check the return values from coresight_reset_claim(). I am
I can remove the return value if it's confusing. The thought process was
probably that it could be useful somewhere in the future, and
coresight_reset_claim_unlocked() returns something anyway so might as
well pass it up.
> wandering if coresight_reset_claim() can directly call
> coresight_clear_self_claim_tag() for _trying_ to clear self-host tag in
> probe phase. Any self claim tag issues will be deferred to detect until
> enable the component.
>
Maybe, the spec does a read before setting which I assumed should be
done for clearing as well. As in to not touch anything if it's in use
externally. It doesn't specifically describe any clearing sequence, but
if we assume it's ok to blindly clear self hosted flag even when it's in
use then yes we can directly call coresight_clear_self_claim_tag().
This doesn't change anything about deferring errors though,
coresight_reset_claim() doesn't warn early either.
> For consistent, we might rename coresight_reset_claim() to
> coresight_reset_self_claim_tag(), which acquires CS lock and clear
> self claim tag.
>
>> +/*
>> + * Clear the claim tag for the device. Called with CS_UNLOCKed for the component.
>> + * Returns an error if the device wasn't already claimed.
>> + */
>> +int coresight_reset_claim_unlocked(struct csdev_access *csa)
>> +{
>> + if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED) {
>> + coresight_clear_self_claim_tag(csa);
>> + return 0;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +EXPORT_SYMBOL_GPL(coresight_reset_claim_unlocked);
>> +
>> +/*
>> + * coresight_disclaim_device_unlocked : Clear the claim tag for the device
>> + * and warn if the device wasn't already claimed.
>> * Called with CS_UNLOCKed for the component.
>> */
>> void coresight_disclaim_device_unlocked(struct csdev_access *csa)
>> {
>> - if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
>> - coresight_clear_self_claim_tag(csa);
>> - else
>> - /*
>> - * The external agent may have not honoured our claim
>> - * and has manipulated it. Or something else has seriously
>> - * gone wrong in our driver.
>> - */
>> - WARN_ON_ONCE(1);
>> + /*
>> + * Warn if the external agent hasn't honoured our claim
>> + * and has manipulated it. Or something else has seriously
>> + * gone wrong in our driver.
>> + */
>> + WARN_ON_ONCE(coresight_reset_claim_unlocked(csa));
>> }
>> EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
>> index 073f67a41af9..389a72362f0c 100644
>> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
>> @@ -931,6 +931,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
>> cti_desc.ops = &cti_ops;
>> cti_desc.groups = drvdata->ctidev.con_groups;
>> cti_desc.dev = dev;
>> +
>> + coresight_reset_claim(&cti_desc.access);
>> drvdata->csdev = coresight_register(&cti_desc);
>> if (IS_ERR(drvdata->csdev)) {
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
>> index d8bc3e776c88..b598b2c0c9bb 100644
>> --- a/drivers/hwtracing/coresight/coresight-etb10.c
>> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
>> @@ -772,6 +772,8 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
>> desc.pdata = pdata;
>> desc.dev = dev;
>> desc.groups = coresight_etb_groups;
>> +
>> + coresight_reset_claim(&desc.access);
>> drvdata->csdev = coresight_register(&desc);
>> if (IS_ERR(drvdata->csdev))
>> return PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
>> index e02c3ea972c9..a89736309c27 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm.h
>> +++ b/drivers/hwtracing/coresight/coresight-etm.h
>> @@ -229,7 +229,7 @@ struct etm_config {
>> * @config: structure holding configuration parameters.
>> */
>> struct etm_drvdata {
>> - void __iomem *base;
>> + struct csdev_access csa;
>
> I would like to extract the change for using `csdev_access` in the
> ETMv3 driver into a new patch, which is irrelevant to reset self claim
> tags and would significantly reduce the complexity in this patch.
>
Will do, good point.
> Thanks,
> Leo
On Mon, Mar 17, 2025 at 03:05:41PM +0000, James Clark wrote:
[...]
> > > /*
> > > - * coresight_disclaim_device_unlocked : Clear the claim tag for the device.
> > > + * Clear the claim tag for the device.
> > > + * Returns an error if the device wasn't already claimed.
> > > + */
> > > +int coresight_reset_claim(struct csdev_access *csa)
> > > +{
> > > + int ret;
> > > +
> > > + CS_UNLOCK(csa->base);
> > > + ret = coresight_reset_claim_unlocked(csa);
> > > + CS_LOCK(csa->base);
> > > + return ret;
> > > +}
> > > +EXPORT_SYMBOL_GPL(coresight_reset_claim);
> >
> > Maybe my question is overlapping with Mike's comment.
> >
> > Callers never check the return values from coresight_reset_claim(). I am
>
> I can remove the return value if it's confusing. The thought process was
> probably that it could be useful somewhere in the future, and
> coresight_reset_claim_unlocked() returns something anyway so might as well
> pass it up.
>
> > wandering if coresight_reset_claim() can directly call
> > coresight_clear_self_claim_tag() for _trying_ to clear self-host tag in
> > probe phase. Any self claim tag issues will be deferred to detect until
> > enable the component.
> >
>
> Maybe, the spec does a read before setting which I assumed should be done
> for clearing as well.
If you mean PSCI doc, the flow for claiming tag is a handshake between
self-host software and external debugger, this is why a read is
required.
For a cleaning up, it is not about syncing with external debugger. And
writing bit 0 to TRCCLAIMCLR will not impact external debugger. So I
don't think a read prior to cleaning self claim tag is needed.
> As in to not touch anything if it's in use externally.
> It doesn't specifically describe any clearing sequence, but if we assume
> it's ok to blindly clear self hosted flag even when it's in use then yes we
> can directly call coresight_clear_self_claim_tag().
As a result, directly calling coresight_clear_self_claim_tag() works
for me.
Thanks,
Leo
Hi James,
On Tue, 11 Feb 2025 at 10:40, James Clark <james.clark@linaro.org> wrote:
>
> This can be left behind from a crashed kernel after a kexec so clear it
> when probing each device. Similarly to
> coresight_disclaim_device_unlocked(), only clear it if it's already set
> to avoid races with an external debugger.
>
> We need a csdev_access struct in etm_init_arch_data() so just replace
> the iomem pointer with a full csdev_access struct. This means all usages
> need to be updated to go through csa->base.
>
> Signed-off-by: James Clark <james.clark@linaro.org>
> ---
> drivers/hwtracing/coresight/coresight-catu.c | 1 +
> drivers/hwtracing/coresight/coresight-core.c | 48 +++++++++++++++----
> .../hwtracing/coresight/coresight-cti-core.c | 2 +
> drivers/hwtracing/coresight/coresight-etb10.c | 2 +
> drivers/hwtracing/coresight/coresight-etm.h | 6 +--
> .../coresight/coresight-etm3x-core.c | 28 +++++------
> .../coresight/coresight-etm3x-sysfs.c | 8 ++--
> .../coresight/coresight-etm4x-core.c | 2 +
> .../hwtracing/coresight/coresight-funnel.c | 2 +
> .../coresight/coresight-replicator.c | 1 +
> .../hwtracing/coresight/coresight-tmc-core.c | 1 +
> include/linux/coresight.h | 3 ++
> 12 files changed, 73 insertions(+), 31 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
> index d9259c0b6e64..575c2d247a90 100644
> --- a/drivers/hwtracing/coresight/coresight-catu.c
> +++ b/drivers/hwtracing/coresight/coresight-catu.c
> @@ -558,6 +558,7 @@ static int __catu_probe(struct device *dev, struct resource *res)
> catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
> catu_desc.ops = &catu_ops;
>
> + coresight_reset_claim(&catu_desc.access);
> drvdata->csdev = coresight_register(&catu_desc);
> if (IS_ERR(drvdata->csdev))
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 7fe5d5d432c4..97f33ffad05e 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -212,20 +212,48 @@ int coresight_claim_device(struct coresight_device *csdev)
> EXPORT_SYMBOL_GPL(coresight_claim_device);
>
> /*
> - * coresight_disclaim_device_unlocked : Clear the claim tag for the device.
> + * Clear the claim tag for the device.
> + * Returns an error if the device wasn't already claimed.
> + */
> +int coresight_reset_claim(struct csdev_access *csa)
Given the iusue being fixed - i.e. previous sessions having residual
claims - and the fact that this funtion is only ever called from
device initialisation as far as I can tell,
would this be better to be called coresight_init_claim() and return /
log an error only if the device _was_ actually claimed.
As it stands it seems to return an error if the device was not claimed
- which on initialisation is the correct state!
Since the retrun code is ignored by all of the callees, the rerun
could be dropped and a warning issued withing this function if the
claim needed clearing.
> +{
> + int ret;
> +
> + CS_UNLOCK(csa->base);
> + ret = coresight_reset_claim_unlocked(csa);
> + CS_LOCK(csa->base);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(coresight_reset_claim);
> +
> +/*
> + * Clear the claim tag for the device. Called with CS_UNLOCKed for the component.
> + * Returns an error if the device wasn't already claimed.
> + */
> +int coresight_reset_claim_unlocked(struct csdev_access *csa)
Given the comment and the function - this could be named
"coresight_clear_claim_unlocked()"
Regards
Mike
> +{
> + if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED) {
> + coresight_clear_self_claim_tag(csa);
> + return 0;
> + }
> +
> + return -EINVAL;
> +}
> +EXPORT_SYMBOL_GPL(coresight_reset_claim_unlocked);
> +
> +/*
> + * coresight_disclaim_device_unlocked : Clear the claim tag for the device
> + * and warn if the device wasn't already claimed.
> * Called with CS_UNLOCKed for the component.
> */
> void coresight_disclaim_device_unlocked(struct csdev_access *csa)
> {
> - if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
> - coresight_clear_self_claim_tag(csa);
> - else
> - /*
> - * The external agent may have not honoured our claim
> - * and has manipulated it. Or something else has seriously
> - * gone wrong in our driver.
> - */
> - WARN_ON_ONCE(1);
> + /*
> + * Warn if the external agent hasn't honoured our claim
> + * and has manipulated it. Or something else has seriously
> + * gone wrong in our driver.
> + */
> + WARN_ON_ONCE(coresight_reset_claim_unlocked(csa));
> }
> EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
>
> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
> index 073f67a41af9..389a72362f0c 100644
> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
> @@ -931,6 +931,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
> cti_desc.ops = &cti_ops;
> cti_desc.groups = drvdata->ctidev.con_groups;
> cti_desc.dev = dev;
> +
> + coresight_reset_claim(&cti_desc.access);
> drvdata->csdev = coresight_register(&cti_desc);
> if (IS_ERR(drvdata->csdev)) {
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
> index d8bc3e776c88..b598b2c0c9bb 100644
> --- a/drivers/hwtracing/coresight/coresight-etb10.c
> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
> @@ -772,6 +772,8 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
> desc.pdata = pdata;
> desc.dev = dev;
> desc.groups = coresight_etb_groups;
> +
> + coresight_reset_claim(&desc.access);
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev))
> return PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
> index e02c3ea972c9..a89736309c27 100644
> --- a/drivers/hwtracing/coresight/coresight-etm.h
> +++ b/drivers/hwtracing/coresight/coresight-etm.h
> @@ -229,7 +229,7 @@ struct etm_config {
> * @config: structure holding configuration parameters.
> */
> struct etm_drvdata {
> - void __iomem *base;
> + struct csdev_access csa;
> struct clk *atclk;
> struct coresight_device *csdev;
> spinlock_t spinlock;
> @@ -260,7 +260,7 @@ static inline void etm_writel(struct etm_drvdata *drvdata,
> "invalid CP14 access to ETM reg: %#x", off);
> }
> } else {
> - writel_relaxed(val, drvdata->base + off);
> + writel_relaxed(val, drvdata->csa.base + off);
> }
> }
>
> @@ -274,7 +274,7 @@ static inline unsigned int etm_readl(struct etm_drvdata *drvdata, u32 off)
> "invalid CP14 access to ETM reg: %#x", off);
> }
> } else {
> - val = readl_relaxed(drvdata->base + off);
> + val = readl_relaxed(drvdata->csa.base + off);
> }
>
> return val;
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> index 509f53b69e42..0b010683b883 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> @@ -86,9 +86,9 @@ static void etm_set_pwrup(struct etm_drvdata *drvdata)
> {
> u32 etmpdcr;
>
> - etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
> + etmpdcr = readl_relaxed(drvdata->csa.base + ETMPDCR);
> etmpdcr |= ETMPDCR_PWD_UP;
> - writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
> + writel_relaxed(etmpdcr, drvdata->csa.base + ETMPDCR);
> /* Ensure pwrup completes before subsequent cp14 accesses */
> mb();
> isb();
> @@ -101,9 +101,9 @@ static void etm_clr_pwrup(struct etm_drvdata *drvdata)
> /* Ensure pending cp14 accesses complete before clearing pwrup */
> mb();
> isb();
> - etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
> + etmpdcr = readl_relaxed(drvdata->csa.base + ETMPDCR);
> etmpdcr &= ~ETMPDCR_PWD_UP;
> - writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
> + writel_relaxed(etmpdcr, drvdata->csa.base + ETMPDCR);
> }
>
> /**
> @@ -365,7 +365,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
> struct etm_config *config = &drvdata->config;
> struct coresight_device *csdev = drvdata->csdev;
>
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(drvdata->csa.base);
>
> rc = coresight_claim_device_unlocked(csdev);
> if (rc)
> @@ -427,7 +427,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
> etm_clr_prog(drvdata);
>
> done:
> - CS_LOCK(drvdata->base);
> + CS_LOCK(drvdata->csa.base);
>
> dev_dbg(&drvdata->csdev->dev, "cpu: %d enable smp call done: %d\n",
> drvdata->cpu, rc);
> @@ -589,7 +589,7 @@ static void etm_disable_hw(void *info)
> struct etm_config *config = &drvdata->config;
> struct coresight_device *csdev = drvdata->csdev;
>
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(drvdata->csa.base);
> etm_set_prog(drvdata);
>
> /* Read back sequencer and counters for post trace analysis */
> @@ -601,7 +601,7 @@ static void etm_disable_hw(void *info)
> etm_set_pwrdwn(drvdata);
> coresight_disclaim_device_unlocked(&csdev->access);
>
> - CS_LOCK(drvdata->base);
> + CS_LOCK(drvdata->csa.base);
>
> dev_dbg(&drvdata->csdev->dev,
> "cpu: %d disable smp call done\n", drvdata->cpu);
> @@ -614,7 +614,7 @@ static void etm_disable_perf(struct coresight_device *csdev)
> if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
> return;
>
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(drvdata->csa.base);
>
> /* Setting the prog bit disables tracing immediately */
> etm_set_prog(drvdata);
> @@ -626,7 +626,7 @@ static void etm_disable_perf(struct coresight_device *csdev)
> etm_set_pwrdwn(drvdata);
> coresight_disclaim_device_unlocked(&csdev->access);
>
> - CS_LOCK(drvdata->base);
> + CS_LOCK(drvdata->csa.base);
>
> /*
> * perf will release trace ids when _free_aux()
> @@ -772,7 +772,7 @@ static void etm_init_arch_data(void *info)
> /* Make sure all registers are accessible */
> etm_os_unlock(drvdata);
>
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(drvdata->csa.base);
>
> /* First dummy read */
> (void)etm_readl(drvdata, ETMPDSR);
> @@ -803,9 +803,10 @@ static void etm_init_arch_data(void *info)
> drvdata->nr_ext_out = BMVAL(etmccr, 20, 22);
> drvdata->nr_ctxid_cmp = BMVAL(etmccr, 24, 25);
>
> + coresight_reset_claim_unlocked(&drvdata->csa);
> etm_set_pwrdwn(drvdata);
> etm_clr_pwrup(drvdata);
> - CS_LOCK(drvdata->base);
> + CS_LOCK(drvdata->csa.base);
> }
>
> static int __init etm_hp_setup(void)
> @@ -866,8 +867,7 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
> if (IS_ERR(base))
> return PTR_ERR(base);
>
> - drvdata->base = base;
> - desc.access = CSDEV_ACCESS_IOMEM(base);
> + desc.access = drvdata->csa = CSDEV_ACCESS_IOMEM(base);
>
> spin_lock_init(&drvdata->spinlock);
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
> index 68c644be9813..af566b62785c 100644
> --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
> @@ -50,11 +50,11 @@ static ssize_t etmsr_show(struct device *dev,
>
> pm_runtime_get_sync(dev->parent);
> spin_lock_irqsave(&drvdata->spinlock, flags);
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(drvdata->csa.base);
>
> val = etm_readl(drvdata, ETMSR);
>
> - CS_LOCK(drvdata->base);
> + CS_LOCK(drvdata->csa.base);
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> pm_runtime_put(dev->parent);
>
> @@ -949,9 +949,9 @@ static ssize_t seq_curr_state_show(struct device *dev,
> pm_runtime_get_sync(dev->parent);
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> - CS_UNLOCK(drvdata->base);
> + CS_UNLOCK(drvdata->csa.base);
> val = (etm_readl(drvdata, ETMSQR) & ETM_SQR_MASK);
> - CS_LOCK(drvdata->base);
> + CS_LOCK(drvdata->csa.base);
>
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> pm_runtime_put(dev->parent);
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 45b30a4b3eba..3609bb74c4ec 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -1337,6 +1337,8 @@ static void etm4_init_arch_data(void *info)
> drvdata->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);
> +
> + coresight_reset_claim_unlocked(csa);
> etm4_cs_lock(drvdata, csa);
> cpu_detect_trace_filtering(drvdata);
> }
> diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
> index e986922d555b..be2a47636ef3 100644
> --- a/drivers/hwtracing/coresight/coresight-funnel.c
> +++ b/drivers/hwtracing/coresight/coresight-funnel.c
> @@ -255,6 +255,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
> drvdata->base = base;
> desc.groups = coresight_funnel_groups;
> desc.access = CSDEV_ACCESS_IOMEM(base);
> + coresight_reset_claim(&desc.access);
> }
>
> dev_set_drvdata(dev, drvdata);
> @@ -272,6 +273,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
> desc.ops = &funnel_cs_ops;
> desc.pdata = pdata;
> desc.dev = dev;
> +
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev)) {
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
> index 5d42a9a8c460..679a36effbe8 100644
> --- a/drivers/hwtracing/coresight/coresight-replicator.c
> +++ b/drivers/hwtracing/coresight/coresight-replicator.c
> @@ -284,6 +284,7 @@ static int replicator_probe(struct device *dev, struct resource *res)
> desc.pdata = dev->platform_data;
> desc.dev = dev;
>
> + coresight_reset_claim(&desc.access);
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev)) {
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
> index e9876252a789..5ac4e3c706ac 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
> @@ -558,6 +558,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
> dev->platform_data = pdata;
> desc.pdata = pdata;
>
> + coresight_reset_claim(&desc.access);
> drvdata->csdev = coresight_register(&desc);
> if (IS_ERR(drvdata->csdev)) {
> ret = PTR_ERR(drvdata->csdev);
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index 937931d107e0..11808aee9d1d 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -655,6 +655,9 @@ extern int coresight_claim_device_unlocked(struct coresight_device *csdev);
>
> extern void coresight_disclaim_device(struct csdev_access *csa);
> extern void coresight_disclaim_device_unlocked(struct csdev_access *csa);
> +int coresight_reset_claim_unlocked(struct csdev_access *csa);
> +int coresight_reset_claim(struct csdev_access *csa);
> +
> extern char *coresight_alloc_device_name(struct coresight_dev_list *devs,
> struct device *dev);
>
> --
> 2.34.1
>
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
On 12/02/2025 6:24 pm, Mike Leach wrote:
> Hi James,
>
> On Tue, 11 Feb 2025 at 10:40, James Clark <james.clark@linaro.org> wrote:
>>
>> This can be left behind from a crashed kernel after a kexec so clear it
>> when probing each device. Similarly to
>> coresight_disclaim_device_unlocked(), only clear it if it's already set
>> to avoid races with an external debugger.
>>
>> We need a csdev_access struct in etm_init_arch_data() so just replace
>> the iomem pointer with a full csdev_access struct. This means all usages
>> need to be updated to go through csa->base.
>>
>> Signed-off-by: James Clark <james.clark@linaro.org>
>> ---
>> drivers/hwtracing/coresight/coresight-catu.c | 1 +
>> drivers/hwtracing/coresight/coresight-core.c | 48 +++++++++++++++----
>> .../hwtracing/coresight/coresight-cti-core.c | 2 +
>> drivers/hwtracing/coresight/coresight-etb10.c | 2 +
>> drivers/hwtracing/coresight/coresight-etm.h | 6 +--
>> .../coresight/coresight-etm3x-core.c | 28 +++++------
>> .../coresight/coresight-etm3x-sysfs.c | 8 ++--
>> .../coresight/coresight-etm4x-core.c | 2 +
>> .../hwtracing/coresight/coresight-funnel.c | 2 +
>> .../coresight/coresight-replicator.c | 1 +
>> .../hwtracing/coresight/coresight-tmc-core.c | 1 +
>> include/linux/coresight.h | 3 ++
>> 12 files changed, 73 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-catu.c b/drivers/hwtracing/coresight/coresight-catu.c
>> index d9259c0b6e64..575c2d247a90 100644
>> --- a/drivers/hwtracing/coresight/coresight-catu.c
>> +++ b/drivers/hwtracing/coresight/coresight-catu.c
>> @@ -558,6 +558,7 @@ static int __catu_probe(struct device *dev, struct resource *res)
>> catu_desc.subtype.helper_subtype = CORESIGHT_DEV_SUBTYPE_HELPER_CATU;
>> catu_desc.ops = &catu_ops;
>>
>> + coresight_reset_claim(&catu_desc.access);
>> drvdata->csdev = coresight_register(&catu_desc);
>> if (IS_ERR(drvdata->csdev))
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
>> index 7fe5d5d432c4..97f33ffad05e 100644
>> --- a/drivers/hwtracing/coresight/coresight-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-core.c
>> @@ -212,20 +212,48 @@ int coresight_claim_device(struct coresight_device *csdev)
>> EXPORT_SYMBOL_GPL(coresight_claim_device);
>>
>> /*
>> - * coresight_disclaim_device_unlocked : Clear the claim tag for the device.
>> + * Clear the claim tag for the device.
>> + * Returns an error if the device wasn't already claimed.
>> + */
>> +int coresight_reset_claim(struct csdev_access *csa)
>
> Given the iusue being fixed - i.e. previous sessions having residual
> claims - and the fact that this funtion is only ever called from
> device initialisation as far as I can tell,
> would this be better to be called coresight_init_claim() and return /
> log an error only if the device _was_ actually claimed.
>
> As it stands it seems to return an error if the device was not claimed
> - which on initialisation is the correct state!
>
> Since the retrun code is ignored by all of the callees, the rerun
> could be dropped and a warning issued withing this function if the
> claim needed clearing.
>
This is only to reuse code with coresight_disclaim_device_unlocked()
which does use the return code. I can drop the return code from here but
then we'd have to have two functions that do the same thing. One used on
probe and the other used on disable.
>> +{
>> + int ret;
>> +
>> + CS_UNLOCK(csa->base);
>> + ret = coresight_reset_claim_unlocked(csa);
>> + CS_LOCK(csa->base);
>> + return ret;
>> +}
>> +EXPORT_SYMBOL_GPL(coresight_reset_claim);
>> +
>> +/*
>> + * Clear the claim tag for the device. Called with CS_UNLOCKed for the component.
>> + * Returns an error if the device wasn't already claimed.
>> + */
>> +int coresight_reset_claim_unlocked(struct csdev_access *csa)
>
> Given the comment and the function - this could be named
> "coresight_clear_claim_unlocked()"
>
I suppose we could rename it. It might cause some confusion with
coresight_clear_self_claim_tag() though. I deliberately picked 'reset'
because of when it was used on probe. Whereas 'clearing' is some
existing function that only clears a bit without any extra logic. That
kind of leaves it structured like this:
clear: lowest level, only mechanical clear of the bit
reset: clear if set, no warning
disclaim: clear if set, warn if not set
>
> Regards
>
> Mike
>
>> +{
>> + if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED) {
>> + coresight_clear_self_claim_tag(csa);
>> + return 0;
>> + }
>> +
>> + return -EINVAL;
>> +}
>> +EXPORT_SYMBOL_GPL(coresight_reset_claim_unlocked);
>> +
>> +/*
>> + * coresight_disclaim_device_unlocked : Clear the claim tag for the device
>> + * and warn if the device wasn't already claimed.
>> * Called with CS_UNLOCKed for the component.
>> */
>> void coresight_disclaim_device_unlocked(struct csdev_access *csa)
>> {
>> - if (coresight_read_claim_tags(csa) == CORESIGHT_CLAIM_SELF_HOSTED)
>> - coresight_clear_self_claim_tag(csa);
>> - else
>> - /*
>> - * The external agent may have not honoured our claim
>> - * and has manipulated it. Or something else has seriously
>> - * gone wrong in our driver.
>> - */
>> - WARN_ON_ONCE(1);
>> + /*
>> + * Warn if the external agent hasn't honoured our claim
>> + * and has manipulated it. Or something else has seriously
>> + * gone wrong in our driver.
>> + */
>> + WARN_ON_ONCE(coresight_reset_claim_unlocked(csa));
>> }
>> EXPORT_SYMBOL_GPL(coresight_disclaim_device_unlocked);
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
>> index 073f67a41af9..389a72362f0c 100644
>> --- a/drivers/hwtracing/coresight/coresight-cti-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-cti-core.c
>> @@ -931,6 +931,8 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
>> cti_desc.ops = &cti_ops;
>> cti_desc.groups = drvdata->ctidev.con_groups;
>> cti_desc.dev = dev;
>> +
>> + coresight_reset_claim(&cti_desc.access);
>> drvdata->csdev = coresight_register(&cti_desc);
>> if (IS_ERR(drvdata->csdev)) {
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-etb10.c b/drivers/hwtracing/coresight/coresight-etb10.c
>> index d8bc3e776c88..b598b2c0c9bb 100644
>> --- a/drivers/hwtracing/coresight/coresight-etb10.c
>> +++ b/drivers/hwtracing/coresight/coresight-etb10.c
>> @@ -772,6 +772,8 @@ static int etb_probe(struct amba_device *adev, const struct amba_id *id)
>> desc.pdata = pdata;
>> desc.dev = dev;
>> desc.groups = coresight_etb_groups;
>> +
>> + coresight_reset_claim(&desc.access);
>> drvdata->csdev = coresight_register(&desc);
>> if (IS_ERR(drvdata->csdev))
>> return PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-etm.h b/drivers/hwtracing/coresight/coresight-etm.h
>> index e02c3ea972c9..a89736309c27 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm.h
>> +++ b/drivers/hwtracing/coresight/coresight-etm.h
>> @@ -229,7 +229,7 @@ struct etm_config {
>> * @config: structure holding configuration parameters.
>> */
>> struct etm_drvdata {
>> - void __iomem *base;
>> + struct csdev_access csa;
>> struct clk *atclk;
>> struct coresight_device *csdev;
>> spinlock_t spinlock;
>> @@ -260,7 +260,7 @@ static inline void etm_writel(struct etm_drvdata *drvdata,
>> "invalid CP14 access to ETM reg: %#x", off);
>> }
>> } else {
>> - writel_relaxed(val, drvdata->base + off);
>> + writel_relaxed(val, drvdata->csa.base + off);
>> }
>> }
>>
>> @@ -274,7 +274,7 @@ static inline unsigned int etm_readl(struct etm_drvdata *drvdata, u32 off)
>> "invalid CP14 access to ETM reg: %#x", off);
>> }
>> } else {
>> - val = readl_relaxed(drvdata->base + off);
>> + val = readl_relaxed(drvdata->csa.base + off);
>> }
>>
>> return val;
>> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-core.c b/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> index 509f53b69e42..0b010683b883 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
>> @@ -86,9 +86,9 @@ static void etm_set_pwrup(struct etm_drvdata *drvdata)
>> {
>> u32 etmpdcr;
>>
>> - etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
>> + etmpdcr = readl_relaxed(drvdata->csa.base + ETMPDCR);
>> etmpdcr |= ETMPDCR_PWD_UP;
>> - writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
>> + writel_relaxed(etmpdcr, drvdata->csa.base + ETMPDCR);
>> /* Ensure pwrup completes before subsequent cp14 accesses */
>> mb();
>> isb();
>> @@ -101,9 +101,9 @@ static void etm_clr_pwrup(struct etm_drvdata *drvdata)
>> /* Ensure pending cp14 accesses complete before clearing pwrup */
>> mb();
>> isb();
>> - etmpdcr = readl_relaxed(drvdata->base + ETMPDCR);
>> + etmpdcr = readl_relaxed(drvdata->csa.base + ETMPDCR);
>> etmpdcr &= ~ETMPDCR_PWD_UP;
>> - writel_relaxed(etmpdcr, drvdata->base + ETMPDCR);
>> + writel_relaxed(etmpdcr, drvdata->csa.base + ETMPDCR);
>> }
>>
>> /**
>> @@ -365,7 +365,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
>> struct etm_config *config = &drvdata->config;
>> struct coresight_device *csdev = drvdata->csdev;
>>
>> - CS_UNLOCK(drvdata->base);
>> + CS_UNLOCK(drvdata->csa.base);
>>
>> rc = coresight_claim_device_unlocked(csdev);
>> if (rc)
>> @@ -427,7 +427,7 @@ static int etm_enable_hw(struct etm_drvdata *drvdata)
>> etm_clr_prog(drvdata);
>>
>> done:
>> - CS_LOCK(drvdata->base);
>> + CS_LOCK(drvdata->csa.base);
>>
>> dev_dbg(&drvdata->csdev->dev, "cpu: %d enable smp call done: %d\n",
>> drvdata->cpu, rc);
>> @@ -589,7 +589,7 @@ static void etm_disable_hw(void *info)
>> struct etm_config *config = &drvdata->config;
>> struct coresight_device *csdev = drvdata->csdev;
>>
>> - CS_UNLOCK(drvdata->base);
>> + CS_UNLOCK(drvdata->csa.base);
>> etm_set_prog(drvdata);
>>
>> /* Read back sequencer and counters for post trace analysis */
>> @@ -601,7 +601,7 @@ static void etm_disable_hw(void *info)
>> etm_set_pwrdwn(drvdata);
>> coresight_disclaim_device_unlocked(&csdev->access);
>>
>> - CS_LOCK(drvdata->base);
>> + CS_LOCK(drvdata->csa.base);
>>
>> dev_dbg(&drvdata->csdev->dev,
>> "cpu: %d disable smp call done\n", drvdata->cpu);
>> @@ -614,7 +614,7 @@ static void etm_disable_perf(struct coresight_device *csdev)
>> if (WARN_ON_ONCE(drvdata->cpu != smp_processor_id()))
>> return;
>>
>> - CS_UNLOCK(drvdata->base);
>> + CS_UNLOCK(drvdata->csa.base);
>>
>> /* Setting the prog bit disables tracing immediately */
>> etm_set_prog(drvdata);
>> @@ -626,7 +626,7 @@ static void etm_disable_perf(struct coresight_device *csdev)
>> etm_set_pwrdwn(drvdata);
>> coresight_disclaim_device_unlocked(&csdev->access);
>>
>> - CS_LOCK(drvdata->base);
>> + CS_LOCK(drvdata->csa.base);
>>
>> /*
>> * perf will release trace ids when _free_aux()
>> @@ -772,7 +772,7 @@ static void etm_init_arch_data(void *info)
>> /* Make sure all registers are accessible */
>> etm_os_unlock(drvdata);
>>
>> - CS_UNLOCK(drvdata->base);
>> + CS_UNLOCK(drvdata->csa.base);
>>
>> /* First dummy read */
>> (void)etm_readl(drvdata, ETMPDSR);
>> @@ -803,9 +803,10 @@ static void etm_init_arch_data(void *info)
>> drvdata->nr_ext_out = BMVAL(etmccr, 20, 22);
>> drvdata->nr_ctxid_cmp = BMVAL(etmccr, 24, 25);
>>
>> + coresight_reset_claim_unlocked(&drvdata->csa);
>> etm_set_pwrdwn(drvdata);
>> etm_clr_pwrup(drvdata);
>> - CS_LOCK(drvdata->base);
>> + CS_LOCK(drvdata->csa.base);
>> }
>>
>> static int __init etm_hp_setup(void)
>> @@ -866,8 +867,7 @@ static int etm_probe(struct amba_device *adev, const struct amba_id *id)
>> if (IS_ERR(base))
>> return PTR_ERR(base);
>>
>> - drvdata->base = base;
>> - desc.access = CSDEV_ACCESS_IOMEM(base);
>> + desc.access = drvdata->csa = CSDEV_ACCESS_IOMEM(base);
>>
>> spin_lock_init(&drvdata->spinlock);
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
>> index 68c644be9813..af566b62785c 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm3x-sysfs.c
>> @@ -50,11 +50,11 @@ static ssize_t etmsr_show(struct device *dev,
>>
>> pm_runtime_get_sync(dev->parent);
>> spin_lock_irqsave(&drvdata->spinlock, flags);
>> - CS_UNLOCK(drvdata->base);
>> + CS_UNLOCK(drvdata->csa.base);
>>
>> val = etm_readl(drvdata, ETMSR);
>>
>> - CS_LOCK(drvdata->base);
>> + CS_LOCK(drvdata->csa.base);
>> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>> pm_runtime_put(dev->parent);
>>
>> @@ -949,9 +949,9 @@ static ssize_t seq_curr_state_show(struct device *dev,
>> pm_runtime_get_sync(dev->parent);
>> spin_lock_irqsave(&drvdata->spinlock, flags);
>>
>> - CS_UNLOCK(drvdata->base);
>> + CS_UNLOCK(drvdata->csa.base);
>> val = (etm_readl(drvdata, ETMSQR) & ETM_SQR_MASK);
>> - CS_LOCK(drvdata->base);
>> + CS_LOCK(drvdata->csa.base);
>>
>> spin_unlock_irqrestore(&drvdata->spinlock, flags);
>> pm_runtime_put(dev->parent);
>> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> index 45b30a4b3eba..3609bb74c4ec 100644
>> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
>> @@ -1337,6 +1337,8 @@ static void etm4_init_arch_data(void *info)
>> drvdata->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);
>> +
>> + coresight_reset_claim_unlocked(csa);
>> etm4_cs_lock(drvdata, csa);
>> cpu_detect_trace_filtering(drvdata);
>> }
>> diff --git a/drivers/hwtracing/coresight/coresight-funnel.c b/drivers/hwtracing/coresight/coresight-funnel.c
>> index e986922d555b..be2a47636ef3 100644
>> --- a/drivers/hwtracing/coresight/coresight-funnel.c
>> +++ b/drivers/hwtracing/coresight/coresight-funnel.c
>> @@ -255,6 +255,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
>> drvdata->base = base;
>> desc.groups = coresight_funnel_groups;
>> desc.access = CSDEV_ACCESS_IOMEM(base);
>> + coresight_reset_claim(&desc.access);
>> }
>>
>> dev_set_drvdata(dev, drvdata);
>> @@ -272,6 +273,7 @@ static int funnel_probe(struct device *dev, struct resource *res)
>> desc.ops = &funnel_cs_ops;
>> desc.pdata = pdata;
>> desc.dev = dev;
>> +
>> drvdata->csdev = coresight_register(&desc);
>> if (IS_ERR(drvdata->csdev)) {
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-replicator.c b/drivers/hwtracing/coresight/coresight-replicator.c
>> index 5d42a9a8c460..679a36effbe8 100644
>> --- a/drivers/hwtracing/coresight/coresight-replicator.c
>> +++ b/drivers/hwtracing/coresight/coresight-replicator.c
>> @@ -284,6 +284,7 @@ static int replicator_probe(struct device *dev, struct resource *res)
>> desc.pdata = dev->platform_data;
>> desc.dev = dev;
>>
>> + coresight_reset_claim(&desc.access);
>> drvdata->csdev = coresight_register(&desc);
>> if (IS_ERR(drvdata->csdev)) {
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
>> index e9876252a789..5ac4e3c706ac 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
>> @@ -558,6 +558,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
>> dev->platform_data = pdata;
>> desc.pdata = pdata;
>>
>> + coresight_reset_claim(&desc.access);
>> drvdata->csdev = coresight_register(&desc);
>> if (IS_ERR(drvdata->csdev)) {
>> ret = PTR_ERR(drvdata->csdev);
>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
>> index 937931d107e0..11808aee9d1d 100644
>> --- a/include/linux/coresight.h
>> +++ b/include/linux/coresight.h
>> @@ -655,6 +655,9 @@ extern int coresight_claim_device_unlocked(struct coresight_device *csdev);
>>
>> extern void coresight_disclaim_device(struct csdev_access *csa);
>> extern void coresight_disclaim_device_unlocked(struct csdev_access *csa);
>> +int coresight_reset_claim_unlocked(struct csdev_access *csa);
>> +int coresight_reset_claim(struct csdev_access *csa);
>> +
>> extern char *coresight_alloc_device_name(struct coresight_dev_list *devs,
>> struct device *dev);
>>
>> --
>> 2.34.1
>>
>
>
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