Re: [PATCH v8 04/13] coresight-tpda: Add DSB dataset support

From: Suzuki K Poulose
Date: Thu Aug 31 2023 - 11:51:26 EST


On 22/08/2023 06:26, 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 | 126 ++++++++++++++++++++++++---
drivers/hwtracing/coresight/coresight-tpda.h | 2 +
2 files changed, 118 insertions(+), 10 deletions(-)

diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
index 8d2b9d2..0f21cd1 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -21,6 +21,80 @@
DEFINE_CORESIGHT_DEVLIST(tpda_devs, "tpda");
+static bool coresight_device_is_tpdm(struct coresight_device *csdev)
+{
+ return (csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
+ (csdev->subtype.source_subtype ==

minor nit: Please align

return (csdev->type == CORESIGHT_DEV_TYPE_SOURCE) &&
(csdev->subtype.source_subtype ==
+ CORESIGHT_DEV_SUBTYPE_SOURCE_TPDM);


+}
+
+/*
+ * Read the DSB element size from the TPDM device
+ * Returns
+ * The dsb element size read from the devicetree if available.
+ * 0 - Otherwise, with a warning once.
+ */
+static int tpdm_read_dsb_element_size(struct coresight_device *csdev)
+{
+ int rc = 0;
+ u8 size = 0;
+
+ rc = fwnode_property_read_u8(dev_fwnode(csdev->dev.parent),
+ "qcom,dsb-element-size", &size);
+ if (rc)
+ dev_warn_once(&csdev->dev,
+ "Failed to read TPDM DSB Element size: %d\n", rc);
+
+ return size;
+}
+
+/*
+ * Search and read element data size from the TPDM node in
+ * 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 -1 in the recursize call.
+ */
+static int tpda_get_element_size(struct coresight_device *csdev,
+ int inport)

nit: Again, please align.

static int tpda_get_element_size(struct coresight_device *csdev,
int inport)
{


+{
+ int dsb_size = -ENOENT;
+ int i, size;
+ struct coresight_device *in;
+
+ for (i = 0; i < csdev->pdata->nr_inconns; i++) {
+ in = csdev->pdata->in_conns[i]->src_dev;
+ if (!in)
+ continue;
+
+ /* Ignore the paths that do not match port */
+ if (inport > 0 &&
+ (csdev->pdata->in_conns[i]->dest_port != inport))

Align please :

if (inport > 0 &&
(csdev->pdata->in_conns[i]->dest_port != inport))

+ continue;
+
+ if (coresight_device_is_tpdm(in)) {
+ size = tpdm_read_dsb_element_size(in);
+ } else {
+ /* Recurse down the path */
+ size = tpda_get_element_size(in, -1);
+ }
+
+ if (size < 0)
+ return size;
+
+ if (dsb_size < 0) {
+ /* Found a size, save it. */
+ dsb_size = size;
+ } else {
+ /* Found duplicate TPDMs */
+ return -EEXIST;
+ }
+ }
+
+ return dsb_size;
+}
+
/* Settings pre enabling port control register */
static void tpda_enable_pre_port(struct tpda_drvdata *drvdata)
{
@@ -32,26 +106,55 @@ 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;
+ int size;
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
+ */
+ size = tpda_get_element_size(drvdata->csdev, port);
+ switch (size) {
+ case 32:
+ val &= ~TPDA_Pn_CR_DSBSIZE;
+ break;
+ case 64:
+ val |= TPDA_Pn_CR_DSBSIZE;
+ break;
+ case 0:
+ return -EEXIST;
+ case -EEXIST:
+ dev_warn_once(&drvdata->csdev->dev,
+ "Detected multiple TPDMs on port %d", -EEXIST);
+ return -EEXIST;
+ default:
+ 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 +162,19 @@ static int tpda_enable(struct coresight_device *csdev,
struct coresight_connection *out)
{
struct tpda_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
+ int ret;

As reported by the build robot, please initialise this to 0.

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..b3b38fd 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

Rest looks fine to me.

Suzuki