The byte-cntr read function always reads trace data from the deactivated
and filled buffer which is already synced. The read function will fail
when the ETR cannot find a available buffer to receive trace data.
The read function terminates when the path is disabled or interrupted by a
signal.
Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
---
.../hwtracing/coresight/coresight-tmc-core.c | 31 ++++++-
.../hwtracing/coresight/coresight-tmc-etr.c | 90 +++++++++++++++++++
drivers/hwtracing/coresight/coresight-tmc.h | 3 +
3 files changed, 120 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index 354faeeddbb2..3ab25adc4e4d 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -318,14 +318,18 @@ static int tmc_open(struct inode *inode, struct file *file)
return 0;
}
-static ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata, loff_t pos, size_t len,
- char **bufpp)
+static ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata,
+ struct ctcu_byte_cntr *byte_cntr_data,
+ loff_t pos, size_t len, char **bufpp)
{
switch (drvdata->config_type) {
case TMC_CONFIG_TYPE_ETB:
case TMC_CONFIG_TYPE_ETF:
return tmc_etb_get_sysfs_trace(drvdata, pos, len, bufpp);
case TMC_CONFIG_TYPE_ETR:
+ if (byte_cntr_data && byte_cntr_data->thresh_val)
+ return tmc_byte_cntr_get_data(drvdata, byte_cntr_data, len, bufpp);
+
return tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
}
@@ -339,7 +343,21 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
ssize_t actual;
struct tmc_drvdata *drvdata = container_of(file->private_data,
struct tmc_drvdata, miscdev);
- actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp);
+ struct coresight_device *helper = coresight_get_helper(drvdata->csdev,
+ CORESIGHT_DEV_SUBTYPE_HELPER_CTCU);
+ struct ctcu_byte_cntr *byte_cntr_data = NULL;
+ struct ctcu_drvdata *ctcu_drvdata = NULL;
+ int port;
+
+ if (helper) {
+ port = coresight_get_port_helper(drvdata->csdev, helper);
+ if (port >= 0) {
+ ctcu_drvdata = dev_get_drvdata(helper->dev.parent);
+ byte_cntr_data = &ctcu_drvdata->byte_cntr_data[port];
+ }
+ }
+
+ actual = tmc_get_sysfs_trace(drvdata, byte_cntr_data, *ppos, len, &bufp);
if (actual <= 0)
return 0;
@@ -349,7 +367,12 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
return -EFAULT;
}
- *ppos += actual;
+ if (byte_cntr_data && byte_cntr_data->thresh_val) {
+ byte_cntr_data->total_size += actual;
+ drvdata->reading_node->pos += actual;
+ } else
+ *ppos += actual;
+
dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual);
return actual;
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
index 3e3e1b5e78ca..174411e76047 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
@@ -1163,6 +1163,10 @@ ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
ssize_t actual = len;
struct etr_buf *etr_buf = drvdata->sysfs_buf;
+ /* Reading the buffer from the buf_node if it exists*/
+ if (drvdata->reading_node)
+ etr_buf = drvdata->reading_node->sysfs_buf;
+
if (pos + actual > etr_buf->len)
actual = etr_buf->len - pos;
if (actual <= 0)
@@ -1339,6 +1343,92 @@ static bool tmc_byte_cntr_switch_buffer(struct tmc_drvdata *drvdata,
return found_free_buf;
}
+/*
+ * tmc_byte_cntr_get_data() - reads data from the deactivated and filled buffer.
+ * The byte-cntr reading work reads data from the deactivated and filled buffer.
+ * The read operation waits for a buffer to become available, either filled or
+ * upon timeout, and then reads trace data from the synced buffer.
+ */
+ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *drvdata,
+ struct ctcu_byte_cntr *byte_cntr_data,
+ size_t len, char **bufpp)
+{
+ size_t thresh_val = byte_cntr_data->thresh_val;
+ atomic_t *irq_cnt = &byte_cntr_data->irq_cnt;
+ struct etr_buf *sysfs_buf = drvdata->sysfs_buf;
+ struct device *dev = &drvdata->csdev->dev;
+ struct etr_buf_node *nd, *next;
+ ssize_t size = sysfs_buf->size;
+ ssize_t actual;
+ loff_t pos;
+ int ret;
+
+wait_buffer:
+ if (!byte_cntr_data->reading_buf) {
+ ret = wait_event_interruptible_timeout(byte_cntr_data->wq,
+ ((atomic_read(irq_cnt) + 1) * thresh_val >= size) ||
+ !byte_cntr_data->enable,
+ BYTE_CNTR_TIMEOUT);
+ if (ret < 0)
+ return ret;
+ /*
+ * The current etr_buf is almost full or timeout is triggered,
+ * so switch the buffer and mark the switched buffer as reading.
+ */
+ if (byte_cntr_data->enable) {
+ if (!tmc_byte_cntr_switch_buffer(drvdata, byte_cntr_data)) {
+ dev_err(dev, "Switch buffer failed for byte-cntr\n");
+ return -EINVAL;
+ }
+
+ byte_cntr_data->reading_buf = true;
+ } else {
+ if (!drvdata->reading_node) {
+ list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, node) {
+ if (nd->sysfs_buf == sysfs_buf) {
+ nd->pos = 0;
+ drvdata->reading_node = nd;
+ break;
+ }
+ }
+ }
+
+ pos = drvdata->reading_node->pos;
+ actual = tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
+ if (actual > 0)
+ return actual;
+
+ drvdata->reading_node = NULL;
+
+ /* Exit byte-cntr reading */
+ return -EINVAL;
+ }
+ }
+
+ /* Check the status of current etr_buf*/
+ if ((atomic_read(irq_cnt) + 1) * thresh_val >= size)
+ /*
+ * Unlikely to find a free buffer to switch, so just disable
+ * the ETR for a while.
+ */
+ if (!tmc_byte_cntr_switch_buffer(drvdata, byte_cntr_data))
+ dev_info(dev, "No available buffer to store data, disable ETR\n");
+
+ pos = drvdata->reading_node->pos;
+ actual = tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
+ if (actual == 0) {
+ /* Reading work for marked buffer has finished, reset flags */
+ drvdata->reading_node->reading = false;
+ byte_cntr_data->reading_buf = false;
+ drvdata->reading_node = NULL;
+
+ /* Nothing in the buffer, wait for next buffer to be filled */
+ goto wait_buffer;
+ }
+
+ return actual;
+}
+
static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
{
int ret = 0;
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 1dbba0bc50a3..4136ec5ecaf7 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -364,6 +364,9 @@ int tmc_read_prepare_byte_cntr(struct tmc_drvdata *drvdata,
struct ctcu_byte_cntr *byte_cntr_data);
int tmc_read_unprepare_byte_cntr(struct tmc_drvdata *drvdata,
struct ctcu_byte_cntr *byte_cntr_data);
+ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *drvdata,
+ struct ctcu_byte_cntr *byte_cntr_data,
+ size_t len, char **bufpp);
#define TMC_REG_PAIR(name, lo_off, hi_off) \
static inline u64 \
--
2.34.1Hi,
On Mon, 14 Jul 2025 at 07:32, Jie Gan <jie.gan@oss.qualcomm.com> wrote:
>
> The byte-cntr read function always reads trace data from the deactivated
> and filled buffer which is already synced. The read function will fail
> when the ETR cannot find a available buffer to receive trace data.
>
> The read function terminates when the path is disabled or interrupted by a
> signal.
>
> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
> ---
> .../hwtracing/coresight/coresight-tmc-core.c | 31 ++++++-
> .../hwtracing/coresight/coresight-tmc-etr.c | 90 +++++++++++++++++++
> drivers/hwtracing/coresight/coresight-tmc.h | 3 +
> 3 files changed, 120 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
> index 354faeeddbb2..3ab25adc4e4d 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
> @@ -318,14 +318,18 @@ static int tmc_open(struct inode *inode, struct file *file)
> return 0;
> }
>
> -static ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata, loff_t pos, size_t len,
> - char **bufpp)
> +static ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata,
> + struct ctcu_byte_cntr *byte_cntr_data,
> + loff_t pos, size_t len, char **bufpp)
Don't change "core" functionalilty to add in bytecntr parameters.
Use helper functions to have a pattern such as:
if (bytecntr_active())
call_byte_cntr_fn()
else
call_standard_fn()
> {
> switch (drvdata->config_type) {
> case TMC_CONFIG_TYPE_ETB:
> case TMC_CONFIG_TYPE_ETF:
> return tmc_etb_get_sysfs_trace(drvdata, pos, len, bufpp);
> case TMC_CONFIG_TYPE_ETR:
> + if (byte_cntr_data && byte_cntr_data->thresh_val)
> + return tmc_byte_cntr_get_data(drvdata, byte_cntr_data, len, bufpp);
> +
> return tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
> }
>
> @@ -339,7 +343,21 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
> ssize_t actual;
> struct tmc_drvdata *drvdata = container_of(file->private_data,
> struct tmc_drvdata, miscdev);
> - actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp);
> + struct coresight_device *helper = coresight_get_helper(drvdata->csdev,
> + CORESIGHT_DEV_SUBTYPE_HELPER_CTCU);
> + struct ctcu_byte_cntr *byte_cntr_data = NULL;
> + struct ctcu_drvdata *ctcu_drvdata = NULL;
> + int port;
> +
> + if (helper) {
> + port = coresight_get_port_helper(drvdata->csdev, helper);
> + if (port >= 0) {
> + ctcu_drvdata = dev_get_drvdata(helper->dev.parent);
> + byte_cntr_data = &ctcu_drvdata->byte_cntr_data[port];
> + }
> + }
> +
> + actual = tmc_get_sysfs_trace(drvdata, byte_cntr_data, *ppos, len, &bufp);
> if (actual <= 0)
> return 0;
>
> @@ -349,7 +367,12 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
> return -EFAULT;
> }
>
> - *ppos += actual;
> + if (byte_cntr_data && byte_cntr_data->thresh_val) {
> + byte_cntr_data->total_size += actual;
> + drvdata->reading_node->pos += actual;
> + } else
> + *ppos += actual;
> +
> dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual);
>
> return actual;
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> index 3e3e1b5e78ca..174411e76047 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
> @@ -1163,6 +1163,10 @@ ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
> ssize_t actual = len;
> struct etr_buf *etr_buf = drvdata->sysfs_buf;
>
> + /* Reading the buffer from the buf_node if it exists*/
> + if (drvdata->reading_node)
> + etr_buf = drvdata->reading_node->sysfs_buf;
> +
> if (pos + actual > etr_buf->len)
> actual = etr_buf->len - pos;
> if (actual <= 0)
> @@ -1339,6 +1343,92 @@ static bool tmc_byte_cntr_switch_buffer(struct tmc_drvdata *drvdata,
> return found_free_buf;
> }
>
> +/*
> + * tmc_byte_cntr_get_data() - reads data from the deactivated and filled buffer.
> + * The byte-cntr reading work reads data from the deactivated and filled buffer.
> + * The read operation waits for a buffer to become available, either filled or
> + * upon timeout, and then reads trace data from the synced buffer.
> + */
This entire function should be moved to one of the byte-cntr source files.
> +ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *drvdata,
> + struct ctcu_byte_cntr *byte_cntr_data,
> + size_t len, char **bufpp)
> +{
> + size_t thresh_val = byte_cntr_data->thresh_val;
> + atomic_t *irq_cnt = &byte_cntr_data->irq_cnt;
> + struct etr_buf *sysfs_buf = drvdata->sysfs_buf;
> + struct device *dev = &drvdata->csdev->dev;
> + struct etr_buf_node *nd, *next;
> + ssize_t size = sysfs_buf->size;
> + ssize_t actual;
> + loff_t pos;
> + int ret;
> +
> +wait_buffer:
> + if (!byte_cntr_data->reading_buf) {
> + ret = wait_event_interruptible_timeout(byte_cntr_data->wq,
> + ((atomic_read(irq_cnt) + 1) * thresh_val >= size) ||
> + !byte_cntr_data->enable,
> + BYTE_CNTR_TIMEOUT);
> + if (ret < 0)
> + return ret;
> + /*
> + * The current etr_buf is almost full or timeout is triggered,
> + * so switch the buffer and mark the switched buffer as reading.
> + */
> + if (byte_cntr_data->enable) {
> + if (!tmc_byte_cntr_switch_buffer(drvdata, byte_cntr_data)) {
> + dev_err(dev, "Switch buffer failed for byte-cntr\n");
> + return -EINVAL;
> + }
> +
> + byte_cntr_data->reading_buf = true;
> + } else {
> + if (!drvdata->reading_node) {
> + list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, node) {
> + if (nd->sysfs_buf == sysfs_buf) {
> + nd->pos = 0;
> + drvdata->reading_node = nd;
> + break;
> + }
> + }
> + }
> +
> + pos = drvdata->reading_node->pos;
> + actual = tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
> + if (actual > 0)
> + return actual;
> +
> + drvdata->reading_node = NULL;
> +
> + /* Exit byte-cntr reading */
> + return -EINVAL;
> + }
> + }
> +
> + /* Check the status of current etr_buf*/
> + if ((atomic_read(irq_cnt) + 1) * thresh_val >= size)
> + /*
> + * Unlikely to find a free buffer to switch, so just disable
> + * the ETR for a while.
> + */
> + if (!tmc_byte_cntr_switch_buffer(drvdata, byte_cntr_data))
> + dev_info(dev, "No available buffer to store data, disable ETR\n");
> +
> + pos = drvdata->reading_node->pos;
> + actual = tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
> + if (actual == 0) {
> + /* Reading work for marked buffer has finished, reset flags */
> + drvdata->reading_node->reading = false;
> + byte_cntr_data->reading_buf = false;
> + drvdata->reading_node = NULL;
> +
> + /* Nothing in the buffer, wait for next buffer to be filled */
> + goto wait_buffer;
> + }
> +
> + return actual;
> +}
> +
> static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
> {
> int ret = 0;
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 1dbba0bc50a3..4136ec5ecaf7 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -364,6 +364,9 @@ int tmc_read_prepare_byte_cntr(struct tmc_drvdata *drvdata,
> struct ctcu_byte_cntr *byte_cntr_data);
> int tmc_read_unprepare_byte_cntr(struct tmc_drvdata *drvdata,
> struct ctcu_byte_cntr *byte_cntr_data);
Declare this in a byte_cntr header file, not here.
> +ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *drvdata,
> + struct ctcu_byte_cntr *byte_cntr_data,
> + size_t len, char **bufpp);
>
> #define TMC_REG_PAIR(name, lo_off, hi_off) \
> static inline u64 \
> --
> 2.34.1
>
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
On 7/22/2025 11:01 PM, Mike Leach wrote:
> Hi,
>
> On Mon, 14 Jul 2025 at 07:32, Jie Gan <jie.gan@oss.qualcomm.com> wrote:
>>
>> The byte-cntr read function always reads trace data from the deactivated
>> and filled buffer which is already synced. The read function will fail
>> when the ETR cannot find a available buffer to receive trace data.
>>
>> The read function terminates when the path is disabled or interrupted by a
>> signal.
>>
>> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
>> ---
>> .../hwtracing/coresight/coresight-tmc-core.c | 31 ++++++-
>> .../hwtracing/coresight/coresight-tmc-etr.c | 90 +++++++++++++++++++
>> drivers/hwtracing/coresight/coresight-tmc.h | 3 +
>> 3 files changed, 120 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
>> index 354faeeddbb2..3ab25adc4e4d 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
>> @@ -318,14 +318,18 @@ static int tmc_open(struct inode *inode, struct file *file)
>> return 0;
>> }
>>
>> -static ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata, loff_t pos, size_t len,
>> - char **bufpp)
>> +static ssize_t tmc_get_sysfs_trace(struct tmc_drvdata *drvdata,
>> + struct ctcu_byte_cntr *byte_cntr_data,
>> + loff_t pos, size_t len, char **bufpp)
>
> Don't change "core" functionalilty to add in bytecntr parameters.
>
> Use helper functions to have a pattern such as:
>
> if (bytecntr_active())
> call_byte_cntr_fn()
> else
> call_standard_fn()
got it. Will fix in next version.
Thanks,
Jie
>
>> {
>> switch (drvdata->config_type) {
>> case TMC_CONFIG_TYPE_ETB:
>> case TMC_CONFIG_TYPE_ETF:
>> return tmc_etb_get_sysfs_trace(drvdata, pos, len, bufpp);
>> case TMC_CONFIG_TYPE_ETR:
>> + if (byte_cntr_data && byte_cntr_data->thresh_val)
>> + return tmc_byte_cntr_get_data(drvdata, byte_cntr_data, len, bufpp);
>> +
>> return tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
>> }
>>
>> @@ -339,7 +343,21 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
>> ssize_t actual;
>> struct tmc_drvdata *drvdata = container_of(file->private_data,
>> struct tmc_drvdata, miscdev);
>> - actual = tmc_get_sysfs_trace(drvdata, *ppos, len, &bufp);
>> + struct coresight_device *helper = coresight_get_helper(drvdata->csdev,
>> + CORESIGHT_DEV_SUBTYPE_HELPER_CTCU);
>> + struct ctcu_byte_cntr *byte_cntr_data = NULL;
>> + struct ctcu_drvdata *ctcu_drvdata = NULL;
>> + int port;
>> +
>> + if (helper) {
>> + port = coresight_get_port_helper(drvdata->csdev, helper);
>> + if (port >= 0) {
>> + ctcu_drvdata = dev_get_drvdata(helper->dev.parent);
>> + byte_cntr_data = &ctcu_drvdata->byte_cntr_data[port];
>> + }
>> + }
>> +
>> + actual = tmc_get_sysfs_trace(drvdata, byte_cntr_data, *ppos, len, &bufp);
>> if (actual <= 0)
>> return 0;
>>
>> @@ -349,7 +367,12 @@ static ssize_t tmc_read(struct file *file, char __user *data, size_t len,
>> return -EFAULT;
>> }
>>
>> - *ppos += actual;
>> + if (byte_cntr_data && byte_cntr_data->thresh_val) {
>> + byte_cntr_data->total_size += actual;
>> + drvdata->reading_node->pos += actual;
>> + } else
>> + *ppos += actual;
>> +
>> dev_dbg(&drvdata->csdev->dev, "%zu bytes copied\n", actual);
>>
>> return actual;
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c
>> index 3e3e1b5e78ca..174411e76047 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c
>> +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c
>> @@ -1163,6 +1163,10 @@ ssize_t tmc_etr_get_sysfs_trace(struct tmc_drvdata *drvdata,
>> ssize_t actual = len;
>> struct etr_buf *etr_buf = drvdata->sysfs_buf;
>>
>> + /* Reading the buffer from the buf_node if it exists*/
>> + if (drvdata->reading_node)
>> + etr_buf = drvdata->reading_node->sysfs_buf;
>> +
>> if (pos + actual > etr_buf->len)
>> actual = etr_buf->len - pos;
>> if (actual <= 0)
>> @@ -1339,6 +1343,92 @@ static bool tmc_byte_cntr_switch_buffer(struct tmc_drvdata *drvdata,
>> return found_free_buf;
>> }
>>
>> +/*
>> + * tmc_byte_cntr_get_data() - reads data from the deactivated and filled buffer.
>> + * The byte-cntr reading work reads data from the deactivated and filled buffer.
>> + * The read operation waits for a buffer to become available, either filled or
>> + * upon timeout, and then reads trace data from the synced buffer.
>> + */
>
> This entire function should be moved to one of the byte-cntr source files.
>
>> +ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *drvdata,
>> + struct ctcu_byte_cntr *byte_cntr_data,
>> + size_t len, char **bufpp)
>> +{
>> + size_t thresh_val = byte_cntr_data->thresh_val;
>> + atomic_t *irq_cnt = &byte_cntr_data->irq_cnt;
>> + struct etr_buf *sysfs_buf = drvdata->sysfs_buf;
>> + struct device *dev = &drvdata->csdev->dev;
>> + struct etr_buf_node *nd, *next;
>> + ssize_t size = sysfs_buf->size;
>> + ssize_t actual;
>> + loff_t pos;
>> + int ret;
>> +
>> +wait_buffer:
>> + if (!byte_cntr_data->reading_buf) {
>> + ret = wait_event_interruptible_timeout(byte_cntr_data->wq,
>> + ((atomic_read(irq_cnt) + 1) * thresh_val >= size) ||
>> + !byte_cntr_data->enable,
>> + BYTE_CNTR_TIMEOUT);
>> + if (ret < 0)
>> + return ret;
>> + /*
>> + * The current etr_buf is almost full or timeout is triggered,
>> + * so switch the buffer and mark the switched buffer as reading.
>> + */
>> + if (byte_cntr_data->enable) {
>> + if (!tmc_byte_cntr_switch_buffer(drvdata, byte_cntr_data)) {
>> + dev_err(dev, "Switch buffer failed for byte-cntr\n");
>> + return -EINVAL;
>> + }
>> +
>> + byte_cntr_data->reading_buf = true;
>> + } else {
>> + if (!drvdata->reading_node) {
>> + list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, node) {
>> + if (nd->sysfs_buf == sysfs_buf) {
>> + nd->pos = 0;
>> + drvdata->reading_node = nd;
>> + break;
>> + }
>> + }
>> + }
>> +
>> + pos = drvdata->reading_node->pos;
>> + actual = tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
>> + if (actual > 0)
>> + return actual;
>> +
>> + drvdata->reading_node = NULL;
>> +
>> + /* Exit byte-cntr reading */
>> + return -EINVAL;
>> + }
>> + }
>> +
>> + /* Check the status of current etr_buf*/
>> + if ((atomic_read(irq_cnt) + 1) * thresh_val >= size)
>> + /*
>> + * Unlikely to find a free buffer to switch, so just disable
>> + * the ETR for a while.
>> + */
>> + if (!tmc_byte_cntr_switch_buffer(drvdata, byte_cntr_data))
>> + dev_info(dev, "No available buffer to store data, disable ETR\n");
>> +
>> + pos = drvdata->reading_node->pos;
>> + actual = tmc_etr_get_sysfs_trace(drvdata, pos, len, bufpp);
>> + if (actual == 0) {
>> + /* Reading work for marked buffer has finished, reset flags */
>> + drvdata->reading_node->reading = false;
>> + byte_cntr_data->reading_buf = false;
>> + drvdata->reading_node = NULL;
>> +
>> + /* Nothing in the buffer, wait for next buffer to be filled */
>> + goto wait_buffer;
>> + }
>> +
>> + return actual;
>> +}
>> +
>> static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev)
>> {
>> int ret = 0;
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
>> index 1dbba0bc50a3..4136ec5ecaf7 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc.h
>> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
>> @@ -364,6 +364,9 @@ int tmc_read_prepare_byte_cntr(struct tmc_drvdata *drvdata,
>> struct ctcu_byte_cntr *byte_cntr_data);
>> int tmc_read_unprepare_byte_cntr(struct tmc_drvdata *drvdata,
>> struct ctcu_byte_cntr *byte_cntr_data);
>
> Declare this in a byte_cntr header file, not here.
I will add it to,for example, ctcu_byte_cntr_read_ops->read.
So I think I dont need define it in any header file in future.
Will remove it.
Thanks,
Jie
>
>> +ssize_t tmc_byte_cntr_get_data(struct tmc_drvdata *drvdata,
>> + struct ctcu_byte_cntr *byte_cntr_data,
>> + size_t len, char **bufpp);
>>
>> #define TMC_REG_PAIR(name, lo_off, hi_off) \
>> static inline u64 \
>> --
>> 2.34.1
>>
>
>
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