Re: [PATCH v8 1/4] coresight: cti: Convert trigger usage fields to dynamic bitmaps and arrays

[Jie Gan <jie.gan@oss.qualcomm.com>]

On 4/27/2026 9:48 AM, Jie Gan wrote:
> 
> 
> On 4/26/2026 5:44 PM, 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.
>>
>> Signed-off-by: Yingchao Deng <yingchao.deng@oss.qualcomm.com>
>> ---
>>   drivers/hwtracing/coresight/coresight-cti-core.c   | 59 ++++++++++++ 
>> +++++-----
>>   .../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, 76 insertions(+), 35 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/ 
>> drivers/hwtracing/coresight/coresight-cti-core.c
>> index 2f4c9362709a..4e7d12bd2d3e 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 +181,26 @@ 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 +209,7 @@ 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 +240,10 @@ 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 +254,8 @@ 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;
>>       tc = devm_kzalloc(dev, sizeof(struct cti_trig_con), GFP_KERNEL);
>>       if (!tc)
>> @@ -242,12 +267,20 @@ 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 +296,6 @@ 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 +306,8 @@ 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 +320,6 @@ 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 +329,16 @@ 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 +716,9 @@ 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 4eff96f48594..557debbc8ca4 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);
>> @@ -316,23 +316,33 @@ 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;
>> +    }
>> +
>>       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);
> 
> The error may be silently ignored when a memory allocation error 
> occured. I think it's better to add a log print to tell user what happened.

My fault here, please ignore this comment.
This error will be handled by probe fail process.

Thanks,
Jie


> 
> Thanks,
> Jie
> 
>> +    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;
>>   };
>>
>