Add a list to store allocated etr_buf.
The byte-cntr functionality requires two etr_buf to receive trace data.
The active etr_buf collects the trace data from source device, while the
byte-cntr reading function accesses the deactivated etr_buf after is
has been filled and synced, transferring data to the userspace.
Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
---
.../hwtracing/coresight/coresight-tmc-core.c | 1 +
drivers/hwtracing/coresight/coresight-tmc.h | 19 +++++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
index be964656be93..4d249af93097 100644
--- a/drivers/hwtracing/coresight/coresight-tmc-core.c
+++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
@@ -830,6 +830,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
idr_init(&drvdata->idr);
mutex_init(&drvdata->idr_mutex);
dev_list = &etr_devs;
+ INIT_LIST_HEAD(&drvdata->etr_buf_list);
break;
case TMC_CONFIG_TYPE_ETF:
desc.groups = coresight_etf_groups;
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
index 6541a27a018e..52ee5f8efe8c 100644
--- a/drivers/hwtracing/coresight/coresight-tmc.h
+++ b/drivers/hwtracing/coresight/coresight-tmc.h
@@ -208,6 +208,21 @@ struct tmc_resrv_buf {
s64 len;
};
+/**
+ * @sysfs_buf: Allocated sysfs_buf.
+ * @is_free: Indicates whether the buffer is free to choose.
+ * @reading: Indicates whether the buffer is reading.
+ * @pos: Position of the buffer.
+ * @node: Node in etr_buf_list.
+ */
+struct etr_buf_node {
+ struct etr_buf *sysfs_buf;
+ bool is_free;
+ bool reading;
+ loff_t pos;
+ struct list_head node;
+};
+
/**
* struct tmc_drvdata - specifics associated to an TMC component
* @pclk: APB clock if present, otherwise NULL
@@ -242,6 +257,8 @@ struct tmc_resrv_buf {
* (after crash) by default.
* @crash_mdata: Reserved memory for storing tmc crash metadata.
* Used by ETR/ETF.
+ * @etr_buf_list: List that is used to manage allocated etr_buf.
+ * @reading_node: Available buffer for byte-cntr reading.
*/
struct tmc_drvdata {
struct clk *pclk;
@@ -271,6 +288,8 @@ struct tmc_drvdata {
struct etr_buf *perf_buf;
struct tmc_resrv_buf resrv_buf;
struct tmc_resrv_buf crash_mdata;
+ struct list_head etr_buf_list;
+ struct etr_buf_node *reading_node;
};
struct etr_buf_operations {
--
2.34.1Hi
On Fri, 25 Jul 2025 at 11:08, Jie Gan <jie.gan@oss.qualcomm.com> wrote:
>
> Add a list to store allocated etr_buf.
>
> The byte-cntr functionality requires two etr_buf to receive trace data.
> The active etr_buf collects the trace data from source device, while the
> byte-cntr reading function accesses the deactivated etr_buf after is
> has been filled and synced, transferring data to the userspace.
>
> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
> ---
> .../hwtracing/coresight/coresight-tmc-core.c | 1 +
> drivers/hwtracing/coresight/coresight-tmc.h | 19 +++++++++++++++++++
> 2 files changed, 20 insertions(+)
>
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
> index be964656be93..4d249af93097 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
> @@ -830,6 +830,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
> idr_init(&drvdata->idr);
> mutex_init(&drvdata->idr_mutex);
> dev_list = &etr_devs;
> + INIT_LIST_HEAD(&drvdata->etr_buf_list);
> break;
> case TMC_CONFIG_TYPE_ETF:
> desc.groups = coresight_etf_groups;
> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
> index 6541a27a018e..52ee5f8efe8c 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc.h
> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
> @@ -208,6 +208,21 @@ struct tmc_resrv_buf {
> s64 len;
> };
>
> +/**
> + * @sysfs_buf: Allocated sysfs_buf.
> + * @is_free: Indicates whether the buffer is free to choose.
> + * @reading: Indicates whether the buffer is reading.
> + * @pos: Position of the buffer.
> + * @node: Node in etr_buf_list.
> + */
> +struct etr_buf_node {
> + struct etr_buf *sysfs_buf;
> + bool is_free;
> + bool reading;
> + loff_t pos;
> + struct list_head node;
> +};
> +
> /**
> * struct tmc_drvdata - specifics associated to an TMC component
> * @pclk: APB clock if present, otherwise NULL
> @@ -242,6 +257,8 @@ struct tmc_resrv_buf {
> * (after crash) by default.
> * @crash_mdata: Reserved memory for storing tmc crash metadata.
> * Used by ETR/ETF.
> + * @etr_buf_list: List that is used to manage allocated etr_buf.
> + * @reading_node: Available buffer for byte-cntr reading.
> */
> struct tmc_drvdata {
> struct clk *pclk;
> @@ -271,6 +288,8 @@ struct tmc_drvdata {
> struct etr_buf *perf_buf;
> struct tmc_resrv_buf resrv_buf;
> struct tmc_resrv_buf crash_mdata;
> + struct list_head etr_buf_list;
> + struct etr_buf_node *reading_node;
Potential simplification:-
do you need both reading_node here and reading in the etr_buf_node?
reading_node handles the logic for which buffer is being read, while
is_free handles the empty/full logic - reading seems unneeded?
> };
>
> struct etr_buf_operations {
> --
> 2.34.1
>
regards
Mike
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
On 8/5/2025 6:15 PM, Mike Leach wrote:
> Hi
>
> On Fri, 25 Jul 2025 at 11:08, Jie Gan <jie.gan@oss.qualcomm.com> wrote:
>>
>> Add a list to store allocated etr_buf.
>>
>> The byte-cntr functionality requires two etr_buf to receive trace data.
>> The active etr_buf collects the trace data from source device, while the
>> byte-cntr reading function accesses the deactivated etr_buf after is
>> has been filled and synced, transferring data to the userspace.
>>
>> Signed-off-by: Jie Gan <jie.gan@oss.qualcomm.com>
>> ---
>> .../hwtracing/coresight/coresight-tmc-core.c | 1 +
>> drivers/hwtracing/coresight/coresight-tmc.h | 19 +++++++++++++++++++
>> 2 files changed, 20 insertions(+)
>>
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c
>> index be964656be93..4d249af93097 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc-core.c
>> +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c
>> @@ -830,6 +830,7 @@ static int __tmc_probe(struct device *dev, struct resource *res)
>> idr_init(&drvdata->idr);
>> mutex_init(&drvdata->idr_mutex);
>> dev_list = &etr_devs;
>> + INIT_LIST_HEAD(&drvdata->etr_buf_list);
>> break;
>> case TMC_CONFIG_TYPE_ETF:
>> desc.groups = coresight_etf_groups;
>> diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h
>> index 6541a27a018e..52ee5f8efe8c 100644
>> --- a/drivers/hwtracing/coresight/coresight-tmc.h
>> +++ b/drivers/hwtracing/coresight/coresight-tmc.h
>> @@ -208,6 +208,21 @@ struct tmc_resrv_buf {
>> s64 len;
>> };
>>
>> +/**
>> + * @sysfs_buf: Allocated sysfs_buf.
>> + * @is_free: Indicates whether the buffer is free to choose.
>> + * @reading: Indicates whether the buffer is reading.
>> + * @pos: Position of the buffer.
>> + * @node: Node in etr_buf_list.
>> + */
>> +struct etr_buf_node {
>> + struct etr_buf *sysfs_buf;
>> + bool is_free;
>> + bool reading;
>> + loff_t pos;
>> + struct list_head node;
>> +};
>> +
>> /**
>> * struct tmc_drvdata - specifics associated to an TMC component
>> * @pclk: APB clock if present, otherwise NULL
>> @@ -242,6 +257,8 @@ struct tmc_resrv_buf {
>> * (after crash) by default.
>> * @crash_mdata: Reserved memory for storing tmc crash metadata.
>> * Used by ETR/ETF.
>> + * @etr_buf_list: List that is used to manage allocated etr_buf.
>> + * @reading_node: Available buffer for byte-cntr reading.
>> */
>> struct tmc_drvdata {
>> struct clk *pclk;
>> @@ -271,6 +288,8 @@ struct tmc_drvdata {
>> struct etr_buf *perf_buf;
>> struct tmc_resrv_buf resrv_buf;
>> struct tmc_resrv_buf crash_mdata;
>> + struct list_head etr_buf_list;
>> + struct etr_buf_node *reading_node;
>
> Potential simplification:-
> do you need both reading_node here and reading in the etr_buf_node?
> reading_node handles the logic for which buffer is being read, while
> is_free handles the empty/full logic - reading seems unneeded?
Yes, you are right. I checked the usage of reading. It can be replaced
by reading_node in switch function.
I will simplify this patch in next version.
Thanks,
Jie
>
>> };
>>
>> struct etr_buf_operations {
>> --
>> 2.34.1
>>
>
> regards
>
> Mike
>
© 2016 - 2026 Red Hat, Inc.