Re: [PATCH v7 04/13] coresight-tpda: Add DSB dataset support

From: Suzuki K Poulose
Date: Fri Aug 04 2023 - 11:02:34 EST


On 25/07/2023 08:15, Tao Zhang wrote:
Read the DSB element size from the device tree. Set the register
bit that controls the DSB element size of the corresponding port.

Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
drivers/hwtracing/coresight/coresight-tpda.c | 96 +++++++++++++++++++++++++---
drivers/hwtracing/coresight/coresight-tpda.h | 4 ++
2 files changed, 90 insertions(+), 10 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index 8d2b9d2..7c71342 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -21,6 +21,58 @@
DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");
+/* Search and read element data size from the TPDM node in

minor nit:

/*
* Search ...

+ * the devicetree. Each input port of TPDA is connected to
+ * a TPDM. Different TPDM supports different types of dataset,
+ * and some may support more than one type of dataset.
+ * Parameter "inport" is used to pass in the input port number
+ * of TPDA, and it is set to 0 in the recursize call.

+ * Parameter "parent" is used to pass in the original call.

Please remove references to the past and describe "match_inport"

+ */
+static int tpda_set_element_size(struct tpda_drvdata *drvdata,
+ struct coresight_device *csdev, int inport, bool match_inport)

May be we could switch the order of the parameters:

match_inport, int port

Or even inport < 0, implies, port wont be matched.

i.e.,

tpda_set_element_size(drvdata, child, inport)

+{
+ static int nr_inport;
+ int i;
+ static bool tpdm_found;
+ struct coresight_device *in_csdev;
+
+ if (inport > (TPDA_MAX_INPORTS - 1))
+ return -EINVAL;
+
+ if (match_inport) {
+ nr_inport = inport;
+ tpdm_found = false;
+ }

Could we not avoid the static variables and this dance by making the function return the dsb_size ? See further down.


+
+ for (i = 0; i < csdev->pdata->nr_inconns; i++) {
+ in_csdev = csdev->pdata->in_conns[i]->src_dev;
+ if (!in_csdev)
+ break;
continue ?
+
+ if (match_inport)
+ if (csdev->pdata->in_conns[i]->dest_port != inport)
+ continue;
+
+ if ((in_csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
+ (in_csdev->subtype.source_subtype
+ == CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM)) {

Please provide a helper :

static bool coresight_device_is_tpdm(csdev) {
return
(csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
(in_csdev->subtype.source_subtype ==
CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM);
}



+ of_property_read_u8(in_csdev->dev.parent->of_node,
+ "qcom,dsb-element-size", &drvdata->dsb_esize[nr_inport]);



+ if (!tpdm_found)
+ tpdm_found = true;
+ else
+ dev_warn(drvdata->dev,
+ "More than one TPDM is mapped to the TPDA input port %d.\n",
+ nr_inport);
+ continue;
+ }
+ tpda_set_element_size(drvdata, in_csdev, 0, false);
+ }
+

/*
* Read the DSB element size from the TPDM device
* Returns
* the size read from the firmware if available.
* 0 - Otherwise, with a Warning once.
*/
static int tpdm_read_dsb_element_size(struct coresight_device *csdev)
{
int rc, size = 0;

rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
"qcom,dsb-element-size", &size);
if (rc)
dev_warn_once(&in->dev, "Failed to read TPDM DSB Element size: %d\n",
rc);
return size;
}

static int tpda_get_element_size(struct coresight_device *csdev,
int inport)
{
int dsb_size = -ENOENT;

for (i = 0; i < csdev->pdata->nr_inconns; i++) {
in = csdev->pdata->in_conns[i]->src_dev;
if (!in)
continue;
if (coresight_device_is_tpdm(in)) {
/* Ignore the TPDMs that do not match port */
if (inport > 0 &&
(csdev->pdata->in_conns[i]->dest_port !=
inport))
continue;
size = tpdm_read_dsb_element_size(csdev);
} else {
/* Recurse down the path */
size = tpda_set_element_size(in, -1);
}

if (size < 0)
return size;
/* We have found a size, save it. */
if (dsb_size < 0) {
dsb_size = size;
} else {
/* We have duplicate TPDMs */
return -EEXIST;
}
}
return dsb_size;
}




+ return 0;
+}
+
/* Settings pre enabling port control register */
static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
{
@@ -32,26 +84,43 @@ static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
writel_relaxed(val, drvdata->base + TPDA_CR);
}
-static void tpda_enable_port(struct tpda_drvdata *drvdata, int port)
+static int tpda_enable_port(struct tpda_drvdata *drvdata, int port)
{
u32 val;
val = readl_relaxed(drvdata->base + TPDA_Pn_CR(port));
+ /*
+ * Configure aggregator port n DSB data set element size
+ * Set the bit to 0 if the size is 32
+ * Set the bit to 1 if the size is 64
+ */
+ if (drvdata->dsb_esize[port] == 32)
+ val &= ~TPDA_Pn_CR_DSBSIZE;
+ else if (drvdata->dsb_esize[port] == 64)
+ val |= TPDA_Pn_CR_DSBSIZE;

Couldn't this be detected via tpda_get_element_size()? see below.

+ else
+ return -EINVAL;
+
/* Enable the port */
val |= TPDA_Pn_CR_ENA;
writel_relaxed(val, drvdata->base + TPDA_Pn_CR(port));
+
+ return 0;
}
-static void __tpda_enable(struct tpda_drvdata *drvdata, int port)
+static int __tpda_enable(struct tpda_drvdata *drvdata, int port)
{
+ int ret;
+
CS_UNLOCK(drvdata->base);
if (!drvdata->csdev->enable)
tpda_enable_pre_port(drvdata);
- tpda_enable_port(drvdata, port);
-
+ ret = tpda_enable_port(drvdata, port);
CS_LOCK(drvdata->base);
+
+ return ret;
}
static int tpda_enable(struct coresight_device *csdev,
@@ -59,16 +128,23 @@ static int tpda_enable(struct coresight_device *csdev,
struct coresight_connection *out)
{
struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ int ret;
+
+ ret = tpda_set_element_size(drvdata, csdev, in->dest_port, true);

size = tpda_get_element_size(csdev, in->dest_port);
switch (size) {
case 32:
case 64:
break;
case -EEXIST:
dev_warn_once("Detected multiple TPDMs on port %d", ..)
fallthrough;
default:
return size;
}

drvdata->dsb_esize[in->dest_port] = size;

Suzuki



+ if (ret)
+ return ret;
spin_lock(&drvdata->spinlock);
- if (atomic_read(&in->dest_refcnt) == 0)
- __tpda_enable(drvdata, in->dest_port);
+ if (atomic_read(&in->dest_refcnt) == 0) {
+ ret = __tpda_enable(drvdata, in->dest_port);
+ if (!ret) {
+ atomic_inc(&in->dest_refcnt);
+ dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
+ }
+ }
- atomic_inc(&in->dest_refcnt);
spin_unlock(&drvdata->spinlock);
-
- dev_dbg(drvdata->dev, "TPDA inport %d enabled.\n", in->dest_port);
- return 0;
+ return ret;
}
static void __tpda_disable(struct tpda_drvdata *drvdata, int port)
diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/hwtracing/coresight/coresight-tpda.h
index 0399678..12a1472 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.h
+++ b/drivers/hwtracing/coresight/coresight-tpda.h
@@ -10,6 +10,8 @@
#define TPDA_Pn_CR(n) (0x004 + (n * 4))
/* Aggregator port enable bit */
#define TPDA_Pn_CR_ENA BIT(0)
+/* Aggregator port DSB data set element size bit */
+#define TPDA_Pn_CR_DSBSIZE BIT(8)
#define TPDA_MAX_INPORTS 32
@@ -23,6 +25,7 @@
* @csdev: component vitals needed by the framework.
* @spinlock: lock for the drvdata value.
* @enable: enable status of the component.
+ * @dsb_esize: DSB element size for each inport, it must be 32 or 64.
*/
struct tpda_drvdata {
void __iomem *base;
@@ -30,6 +33,7 @@ struct tpda_drvdata {
struct coresight_device *csdev;
spinlock_t spinlock;
u8 atid;
+ u8 dsb_esize[TPDA_MAX_INPORTS];
};
#endif /* _CORESIGHT_CORESIGHT_TPDA_H */