On 13/03/2026 09:02, Jie Gan wrote:
Introduce functions for creating and inserting or removing the etr_buf_node to/from the etr_buf_list.
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.
Reviewed-by: Mike Leach mike.leach@linaro.org Signed-off-by: Jie Gan jie.gan@oss.qualcomm.com
drivers/hwtracing/coresight/coresight-tmc-core.c | 1 + drivers/hwtracing/coresight/coresight-tmc-etr.c | 108 +++++++++++++++++++++++ drivers/hwtracing/coresight/coresight-tmc.h | 17 ++++ 3 files changed, 126 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c index c89fe996af23..bac3278ef4dd 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-core.c +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c @@ -835,6 +835,7 @@ static int __tmc_probe(struct device *dev, struct resource *res) idr_init(&drvdata->idr); mutex_init(&drvdata->idr_mutex); dev_list = "tmc_etr";
INIT_LIST_HEAD(&drvdata->etr_buf_list);diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 4dc1defe27a5..fdf23e1c932f 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -1918,6 +1918,114 @@ const struct coresight_ops tmc_etr_cs_ops = { .panic_ops = &tmc_etr_sync_ops, }; +/**
- tmc_clean_etr_buf_list - clean the etr_buf_list.
- @drvdata: driver data of the TMC device.
- Remove unused buffers from @drvdata->etr_buf_list and free them.
- */
+void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata) +{
- struct etr_buf_node *nd, *next;
- unsigned long flags;
- lockdep_assert_held(&drvdata->spinlock);
- list_for_each_entry_safe(nd, next, &drvdata->etr_buf_list, link) {
if (nd->sysfs_buf == drvdata->sysfs_buf) {if (coresight_get_mode(drvdata->csdev) != CS_MODE_DISABLED) {/** Dont free the sysfs_buf, just remove it from list.* drvdata->sysfs_buf will hold the buffer and free it later.*/nd->sysfs_buf = NULL;list_del(&nd->link);kfree(nd);continue;}}/* Free allocated buffers which are not utilized by ETR */raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
This is dangerous ! Restoring the irqflags to an uninitialised value from a different function thant where it was locked. Please clean this up
Suzuki
tmc_etr_free_sysfs_buf(nd->sysfs_buf);raw_spin_lock_irqsave(&drvdata->spinlock, flags);drvdata->sysfs_buf = NULL;nd->sysfs_buf = NULL;list_del(&nd->link);kfree(nd);- }
+} +EXPORT_SYMBOL_GPL(tmc_clean_etr_buf_list);
+/**
- tmc_create_etr_buf_list - create a list to manage the etr_buf_node.
- @drvdata: driver data of the TMC device.
- @num_nodes: number of nodes want to create with the list.
- Return 0 upon success and return the error number if fail.
- */
+int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes) +{
- struct etr_buf_node *new_node;
- struct etr_buf *sysfs_buf;
- unsigned long flags;
- int i = 0, ret = 0;
- lockdep_assert_held(&drvdata->spinlock);
- /* We dont need a list if there is only one node */
- if (num_nodes < 2)
return -EINVAL;- /* We expect that sysfs_buf in drvdata has already been allocated. */
- if (drvdata->sysfs_buf) {
raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);/* Directly insert the allocated sysfs_buf into the list first */new_node = kzalloc_obj(*new_node, GFP_KERNEL);if (IS_ERR(new_node))return PTR_ERR(new_node);raw_spin_lock_irqsave(&drvdata->spinlock, flags);new_node->sysfs_buf = drvdata->sysfs_buf;new_node->is_free = false;list_add(&new_node->link, &drvdata->etr_buf_list);i++;- }
- raw_spin_unlock_irqrestore(&drvdata->spinlock, flags);
- while (i < num_nodes) {
new_node = kzalloc_obj(*new_node, GFP_KERNEL);if (IS_ERR(new_node)) {ret = PTR_ERR(new_node);break;}sysfs_buf = tmc_alloc_etr_buf(drvdata, drvdata->size, 0, cpu_to_node(0), NULL);if (IS_ERR(sysfs_buf)) {kfree(new_node);ret = PTR_ERR(sysfs_buf);break;}/* We dont have a available sysfs_buf in drvdata, setup one */if (!drvdata->sysfs_buf) {drvdata->sysfs_buf = sysfs_buf;new_node->is_free = false;} elsenew_node->is_free = true;new_node->sysfs_buf = sysfs_buf;list_add(&new_node->link, &drvdata->etr_buf_list);i++;- }
- /* Clean the list if there is an error */
- if (ret)
tmc_clean_etr_buf_list(drvdata);- raw_spin_lock_irqsave(&drvdata->spinlock, flags);
- return ret;
+} +EXPORT_SYMBOL_GPL(tmc_create_etr_buf_list);
- int tmc_read_prepare_etr(struct tmc_drvdata *drvdata) { int ret = 0;
diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h index 319a354ede9f..81237944b986 100644 --- a/drivers/hwtracing/coresight/coresight-tmc.h +++ b/drivers/hwtracing/coresight/coresight-tmc.h @@ -208,6 +208,19 @@ struct tmc_resrv_buf { s64 len; }; +/**
- @sysfs_buf: Allocated sysfs_buf.
- @is_free: Indicates whether the buffer is free to choose.
- @pos: Position of the buffer.
- @link: list_head of the node.
- */
+struct etr_buf_node {
- struct etr_buf *sysfs_buf;
- bool is_free;
- loff_t pos;
- struct list_head link;
+};
- /**
- struct tmc_drvdata - specifics associated to an TMC component
- @atclk: optional clock for the core parts of the TMC.
@@ -245,6 +258,7 @@ struct tmc_resrv_buf {
(after crash) by default.- @crash_mdata: Reserved memory for storing tmc crash metadata.
Used by ETR/ETF.
*/ struct tmc_drvdata { struct clk *atclk;
- @etr_buf_list: List that is used to manage allocated etr_buf.
@@ -275,6 +289,7 @@ 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_operations { @@ -447,5 +462,7 @@ struct etr_buf *tmc_etr_get_buffer(struct coresight_device *csdev, enum cs_mode mode, struct coresight_path *path); extern const struct attribute_group coresight_etr_group; +void tmc_clean_etr_buf_list(struct tmc_drvdata *drvdata); +int tmc_create_etr_buf_list(struct tmc_drvdata *drvdata, int num_nodes); #endif