Re: [PATCH v10 1/5] coresight: cti: Convert trigger usage fields to dynamic - CoreSight

11 Sep 2026

Reviewed-by: Mike Leach mike.leach@arm.com
On 6/15/26 13:32, Yingchao Deng wrote:
...
Replace the fixed-size u32 fields in the cti_config and cti_trig_grp
structure with dynamically allocated bitmaps and arrays. This allows
memory to be allocated based on the actual number of triggers during probe
time, reducing memory footprint and improving scalability for platforms
with varying trigger counts.
Also add a bounds check in cti_allocate_trig_con() to ensure the caller
does not pass in/out signal counts larger than nr_trig_max.
Reviewed-by: Leo Yan leo.yan@arm.com
Signed-off-by: Yingchao Deng yingchao.deng@oss.qualcomm.com

drivers/hwtracing/coresight/coresight-cti-core.c   | 70 +++++++++++++++++-----
  .../hwtracing/coresight/coresight-cti-platform.c   | 26 +++++---
  drivers/hwtracing/coresight/coresight-cti-sysfs.c  | 14 ++---
  drivers/hwtracing/coresight/coresight-cti.h        | 12 ++--
  4 files changed, 87 insertions(+), 35 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c
index b2c9a4db13b4..572798ab504c 100644
--- a/drivers/hwtracing/coresight/coresight-cti-core.c
+++ b/drivers/hwtracing/coresight/coresight-cti-core.c
@@ -161,8 +161,8 @@ void cti_write_intack(struct device *dev, u32 ackval)
  /* DEVID[19:16] - number of CTM channels */
  #define CTI_DEVID_CTMCHANNELS(devid_val) ((int) BMVAL(devid_val, 16, 19))
  
-static void cti_set_default_config(struct device *dev,

		   struct cti_drvdata *drvdata)



+static int cti_set_default_config(struct device *dev,

		  struct cti_drvdata *drvdata)

{
struct cti_config *config = &drvdata->config;
u32 devid;

@@ -181,6 +181,31 @@ static void cti_set_default_config(struct device *dev,
   	config->nr_trig_max = CTIINOUTEN_MAX;
   }

config->trig_in_use = devm_bitmap_zalloc(dev, config->nr_trig_max,
				 GFP_KERNEL);


if (!config->trig_in_use)
return -ENOMEM;



config->trig_out_use = devm_bitmap_zalloc(dev, config->nr_trig_max,
				  GFP_KERNEL);


if (!config->trig_out_use)
return -ENOMEM;



config->trig_out_filter = devm_bitmap_zalloc(dev, config->nr_trig_max,
				     GFP_KERNEL);


if (!config->trig_out_filter)
return -ENOMEM;



config->ctiinen = devm_kcalloc(dev, config->nr_trig_max, sizeof(u32),
		       GFP_KERNEL);


if (!config->ctiinen)
return -ENOMEM;



config->ctiouten = devm_kcalloc(dev, config->nr_trig_max, sizeof(u32),
			GFP_KERNEL);


if (!config->ctiouten)
return -ENOMEM;


config->nr_ctm_channels = CTI_DEVID_CTMCHANNELS(devid);

/* Most regs default to 0 as zalloc'ed except...*/
@@ -189,6 +214,7 @@ static void cti_set_default_config(struct device *dev,
   config->enable_req_count = 0;
  
   config->asicctl_impl = !!FIELD_GET(GENMASK(4, 0), devid);

return 0;
}

/*
@@ -219,8 +245,10 @@ int cti_add_connection_entry(struct device *dev, struct cti_drvdata *drvdata,
   cti_dev->nr_trig_con++;
  
   /* add connection usage bit info to overall info */

drvdata->config.trig_in_use |= tc->con_in->used_mask;
drvdata->config.trig_out_use |= tc->con_out->used_mask;


bitmap_or(drvdata->config.trig_in_use, drvdata->config.trig_in_use,
  tc->con_in->used_mask, drvdata->config.nr_trig_max);


bitmap_or(drvdata->config.trig_out_use, drvdata->config.trig_out_use,
  tc->con_out->used_mask, drvdata->config.nr_trig_max);



return 0;
  }
@@ -231,6 +259,14 @@ struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
  {
   struct cti_trig_con *tc = NULL;
   struct cti_trig_grp *in = NULL, *out = NULL;

struct cti_drvdata *drvdata = dev_get_drvdata(dev);
int n_trigs = drvdata->config.nr_trig_max;

if (in_sigs > n_trigs || out_sigs > n_trigs) {
dev_err(dev, "trigger signal is out of range: in=%d out=%d nr_max=%d\n",


	in_sigs, out_sigs, n_trigs);


return NULL;


}

tc = devm_kzalloc(dev, sizeof(struct cti_trig_con), GFP_KERNEL);
   if (!tc)
@@ -242,12 +278,20 @@ struct cti_trig_con *cti_allocate_trig_con(struct device *dev, int in_sigs,
   if (!in)
   	return NULL;

in->used_mask = devm_bitmap_zalloc(dev, n_trigs, GFP_KERNEL);
if (!in->used_mask)
return NULL;


out = devm_kzalloc(dev,
  	   offsetof(struct cti_trig_grp, sig_types[out_sigs]),
  	   GFP_KERNEL);
 if (!out)
  return NULL;


out->used_mask = devm_bitmap_zalloc(dev, n_trigs, GFP_KERNEL);
if (!out->used_mask)
return NULL;


tc->con_in = in;
 tc->con_out = out;
 tc->con_in->nr_sigs = in_sigs;

@@ -263,7 +307,6 @@ int cti_add_default_connection(struct device *dev, struct cti_drvdata *drvdata)
  {
   int ret = 0;
   int n_trigs = drvdata->config.nr_trig_max;

u32 n_trig_mask = GENMASK(n_trigs - 1, 0);
struct cti_trig_con *tc = NULL;

/*
@@ -274,8 +317,8 @@ int cti_add_default_connection(struct device *dev, struct cti_drvdata *drvdata)
   if (!tc)
   	return -ENOMEM;

tc->con_in->used_mask = n_trig_mask;
tc->con_out->used_mask = n_trig_mask;


bitmap_fill(tc->con_in->used_mask, n_trigs);
bitmap_fill(tc->con_out->used_mask, n_trigs);
ret = cti_add_connection_entry(dev, drvdata, tc, NULL, "default");
return ret;
}

@@ -288,7 +331,6 @@ int cti_channel_trig_op(struct device *dev, enum cti_chan_op op,
  {
   struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
   struct cti_config *config = &drvdata->config;

u32 trig_bitmask;
u32 chan_bitmask;
u32 reg_value;
int reg_offset;

@@ -298,18 +340,16 @@ int cti_channel_trig_op(struct device *dev, enum cti_chan_op op,
      (trigger_idx >= config->nr_trig_max))
   	return -EINVAL;

trig_bitmask = BIT(trigger_idx);
/* ensure registered triggers and not out filtered */
 if (direction == CTI_TRIG_IN)	{
if (!(trig_bitmask & config->trig_in_use))




if (!(test_bit(trigger_idx, config->trig_in_use)))
return -EINVAL;

} else {


if (!(trig_bitmask & config->trig_out_use))




if (!(test_bit(trigger_idx, config->trig_out_use)))
return -EINVAL;



if ((config->trig_filter_enable) &&

    (config->trig_out_filter & trig_bitmask))




    test_bit(trigger_idx, config->trig_out_filter))
return -EINVAL;

}

@@ -687,7 +727,9 @@ static int cti_probe(struct amba_device *adev, const struct amba_id *id)
   raw_spin_lock_init(&drvdata->spinlock);
  
   /* initialise CTI driver config values */

cti_set_default_config(dev, drvdata);


ret = cti_set_default_config(dev, drvdata);
if (ret)
return ret;



pdata = coresight_cti_get_platform_data(dev);
   if (IS_ERR(pdata)) {
diff --git a/drivers/hwtracing/coresight/coresight-cti-platform.c b/drivers/hwtracing/coresight/coresight-cti-platform.c
index d6d5388705c3..ba5a7e4b6bff 100644
--- a/drivers/hwtracing/coresight/coresight-cti-platform.c
+++ b/drivers/hwtracing/coresight/coresight-cti-platform.c
@@ -136,8 +136,8 @@ static int cti_plat_create_v8_etm_connection(struct device *dev,
   	goto create_v8_etm_out;
  
   /* build connection data */

tc->con_in->used_mask = 0xF0; /* sigs <4,5,6,7> */
tc->con_out->used_mask = 0xF0; /* sigs <4,5,6,7> */


bitmap_set(tc->con_in->used_mask, 4, 4); /* sigs <4,5,6,7> */
bitmap_set(tc->con_out->used_mask, 4, 4); /* sigs <4,5,6,7> */

/*
    * The EXTOUT type signals from the ETM are connected to a set of input
@@ -194,10 +194,10 @@ static int cti_plat_create_v8_connections(struct device *dev,
   	goto of_create_v8_out;
  
   /* Set the v8 PE CTI connection data */

tc->con_in->used_mask = 0x3; /* sigs <0 1> */


bitmap_set(tc->con_in->used_mask, 0, 2); /* sigs <0 1> */
tc->con_in->sig_types[0] = PE_DBGTRIGGER;
tc->con_in->sig_types[1] = PE_PMUIRQ;


tc->con_out->used_mask = 0x7; /* sigs <0 1 2 > */


bitmap_set(tc->con_out->used_mask, 0, 3); /* sigs <0 1 2 > */
tc->con_out->sig_types[0] = PE_EDBGREQ;
tc->con_out->sig_types[1] = PE_DBGRESTART;
tc->con_out->sig_types[2] = PE_CTIIRQ;

@@ -213,7 +213,7 @@ static int cti_plat_create_v8_connections(struct device *dev,
   	goto of_create_v8_out;
  
   /* filter pe_edbgreq - PE trigout sig <0> */

drvdata->config.trig_out_filter |= 0x1;


set_bit(0, drvdata->config.trig_out_filter);

of_create_v8_out:
   return ret;
@@ -257,7 +257,7 @@ static int cti_plat_read_trig_group(struct cti_trig_grp *tgrp,
   if (!err) {
   	/* set the signal usage mask */
   	for (idx = 0; idx < tgrp->nr_sigs; idx++)

	tgrp->used_mask |= BIT(values[idx]);




	set_bit(values[idx], tgrp->used_mask);

}

kfree(values);
@@ -316,24 +316,34 @@ static int cti_plat_process_filter_sigs(struct cti_drvdata *drvdata,
  {
   struct cti_trig_grp *tg = NULL;
   int err = 0, nr_filter_sigs;

int nr_trigs = drvdata->config.nr_trig_max;

nr_filter_sigs = cti_plat_count_sig_elements(fwnode,
   					     CTI_DT_FILTER_OUT_SIGS);
   if (nr_filter_sigs == 0)
   	return 0;

if (nr_filter_sigs > drvdata->config.nr_trig_max)


if (nr_filter_sigs > nr_trigs)
return -EINVAL;

tg = kzalloc_obj(*tg);
   if (!tg)
   	return -ENOMEM;

tg->used_mask = bitmap_zalloc(nr_trigs, GFP_KERNEL);
if (!tg->used_mask) {
kfree(tg);


return -ENOMEM;


}
tg->nr_sigs = nr_filter_sigs;
 err = cti_plat_read_trig_group(tg, fwnode, CTI_DT_FILTER_OUT_SIGS);
 if (!err)


drvdata->config.trig_out_filter |= tg->used_mask;




bitmap_or(drvdata->config.trig_out_filter,


	  drvdata->config.trig_out_filter,


	  tg->used_mask, nr_trigs);




bitmap_free(tg->used_mask);
kfree(tg);
return err;
}

diff --git a/drivers/hwtracing/coresight/coresight-cti-sysfs.c b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
index 3fe2c916d228..2bbfa405cb6b 100644
--- a/drivers/hwtracing/coresight/coresight-cti-sysfs.c
+++ b/drivers/hwtracing/coresight/coresight-cti-sysfs.c
@@ -719,12 +719,12 @@ static ssize_t trigout_filtered_show(struct device *dev,
   struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
   struct cti_config *cfg = &drvdata->config;
   int nr_trig_max = cfg->nr_trig_max;

unsigned long mask = cfg->trig_out_filter;


unsigned long *mask = cfg->trig_out_filter;


if (mask == 0)


if (bitmap_empty(mask, nr_trig_max))
return 0;


return sysfs_emit(buf, "%*pbl\n", nr_trig_max, &mask);


return sysfs_emit(buf, "%*pbl\n", nr_trig_max, mask);
}
static DEVICE_ATTR_RO(trigout_filtered);

@@ -931,9 +931,9 @@ static ssize_t trigin_sig_show(struct device *dev,
   struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
   struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
   struct cti_config *cfg = &drvdata->config;

unsigned long mask = con->con_in->used_mask;


unsigned long *mask = con->con_in->used_mask;


return sysfs_emit(buf, "%*pbl\n", cfg->nr_trig_max, &mask);


return sysfs_emit(buf, "%*pbl\n", cfg->nr_trig_max, mask);
}

static ssize_t trigout_sig_show(struct device *dev,
@@ -945,9 +945,9 @@ static ssize_t trigout_sig_show(struct device *dev,
   struct cti_trig_con *con = (struct cti_trig_con *)ext_attr->var;
   struct cti_drvdata *drvdata = dev_get_drvdata(dev->parent);
   struct cti_config *cfg = &drvdata->config;

unsigned long mask = con->con_out->used_mask;


unsigned long *mask = con->con_out->used_mask;


return sysfs_emit(buf, "%*pbl\n", cfg->nr_trig_max, &mask);


return sysfs_emit(buf, "%*pbl\n", cfg->nr_trig_max, mask);
}

/* convert a sig type id to a name */
diff --git a/drivers/hwtracing/coresight/coresight-cti.h b/drivers/hwtracing/coresight/coresight-cti.h
index c5f9e79fabc6..ef079fc18b72 100644
--- a/drivers/hwtracing/coresight/coresight-cti.h
+++ b/drivers/hwtracing/coresight/coresight-cti.h
@@ -68,7 +68,7 @@ struct fwnode_handle;
   */
  struct cti_trig_grp {
   int nr_sigs;

u32 used_mask;


unsigned long *used_mask;
int sig_types[];
};

@@ -145,17 +145,17 @@ struct cti_config {
   int enable_req_count;
  
   /* registered triggers and filtering */

u32 trig_in_use;
u32 trig_out_use;
u32 trig_out_filter;


unsigned long *trig_in_use;
unsigned long *trig_out_use;
unsigned long *trig_out_filter;
bool trig_filter_enable;
u8 xtrig_rchan_sel;

/* cti cross trig programmable regs */
   u32 ctiappset;
   u8 ctiinout_sel;

u32 ctiinen[CTIINOUTEN_MAX];
u32 ctiouten[CTIINOUTEN_MAX];


u32 *ctiinen;
u32 *ctiouten;
u32 ctigate;
u32 asicctl;
};


    