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

Jie Gan
2026-04-27T01:48:31Z

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.

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;
> };
>