On 8/27/2025 5:17 PM, James Clark wrote:
On 27/08/2025 5:20 am, Jie Gan wrote:
From: Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>
Setting bit i in the TPDA_FLUSH_CR register initiates a flush request
for port i, forcing the data to synchronize and be transmitted to the
sink device.
Signed-off-by: Tao Zhang <tao.zhang@xxxxxxxxxxxxxxxx>
Co-developed-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
Signed-off-by: Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
---
.../testing/sysfs-bus-coresight-devices-tpda | 7 ++++
drivers/hwtracing/coresight/coresight-tpda.c | 42 +++++++++++++++++++
drivers/hwtracing/coresight/coresight-tpda.h | 2 +
3 files changed, 51 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-
tpda b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
index fb651aebeb31..2cf2dcfc13c8 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpda
@@ -41,3 +41,10 @@ Contact: Jinlong Mao
<jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang <tao.zhang@xxxxxx
Description:
(RW) Configure the CMB/MCMB channel mode for all enabled ports.
Value 0 means raw channel mapping mode. Value 1 means
channel pair marking mode.
+
+What: /sys/bus/coresight/devices/<tpda-name>/port_flush_req
+Date: August 2025
+KernelVersion: 6.17
+Contact: Jinlong Mao <jinlong.mao@xxxxxxxxxxxxxxxx>, Tao Zhang
<tao.zhang@xxxxxxxxxxxxxxxx>, Jie Gan <jie.gan@xxxxxxxxxxxxxxxx>
+Description:
+ (RW) Configure the bit i to requests a flush operation of
port i on the TPDA.
diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/
hwtracing/coresight/coresight-tpda.c
index 430f76c559f2..8b1fe128881d 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.c
+++ b/drivers/hwtracing/coresight/coresight-tpda.c
@@ -487,6 +487,47 @@ static ssize_t cmbchan_mode_store(struct device
*dev,
}
static DEVICE_ATTR_RW(cmbchan_mode);
+static ssize_t port_flush_req_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val;
+
+ if (!drvdata->csdev->refcnt)
+ return -EINVAL;
+
+ guard(spinlock)(&drvdata->spinlock);
+ CS_UNLOCK(drvdata->base);
+ val = readl_relaxed(drvdata->base + TPDA_FLUSH_CR);
+ CS_LOCK(drvdata->base);
+ return sysfs_emit(buf, "%lx\n", val);
Still missing the 0x prefix
Will re-check rest of the codes and add prefix. Sorry I missed it during
the review process.
+}
+
+static ssize_t port_flush_req_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct tpda_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val;
+
+ if (kstrtoul(buf, 0, &val))
+ return -EINVAL;
+
+ if (!drvdata->csdev->refcnt || !val)
+ return -EINVAL;
+
+ val |= FIELD_PREP(TPDA_MAX_INPORTS_MASK, val);
Using FIELD_PREP() now that it's the full width of the register makes
less sense. Especially when there is no corresponding FIELD_FIT() check,
which is fine because everything always fits. But if you didn't know
the mask was the full width you'd wonder if the check is missing.
I would just write val directly to TPDA_FLUSH_CR so it's simpler.
It should also have been val = FIELD_PREP(...)
Yeah, it should have been val = FIELD_PREP(...) here... sorry for the
mistake here..
I was thinking the unsigned long here could be 64 or 32 bits and we only
need the value of the lower 32 bits. So that's why I am using val =
FIELD_PREP(...) here. We shouldn't write a value greater than UINT32_MAX
to the register.
Thanks,
Jie
+ guard(spinlock)(&drvdata->spinlock);
+ CS_UNLOCK(drvdata->base);
+ writel_relaxed(val, drvdata->base + TPDA_FLUSH_CR);
+ CS_LOCK(drvdata->base);
+
+ return size;
+}
+static DEVICE_ATTR_RW(port_flush_req);
+
static struct attribute *tpda_attrs[] = {
&dev_attr_trig_async_enable.attr,
&dev_attr_trig_flag_ts_enable.attr,
@@ -494,6 +535,7 @@ static struct attribute *tpda_attrs[] = {
&dev_attr_freq_ts_enable.attr,
&dev_attr_global_flush_req.attr,
&dev_attr_cmbchan_mode.attr,
+ &dev_attr_port_flush_req.attr,
NULL,
};
diff --git a/drivers/hwtracing/coresight/coresight-tpda.h b/drivers/
hwtracing/coresight/coresight-tpda.h
index 8e1b66115ad1..56d3ad293e46 100644
--- a/drivers/hwtracing/coresight/coresight-tpda.h
+++ b/drivers/hwtracing/coresight/coresight-tpda.h
@@ -10,6 +10,7 @@
#define TPDA_Pn_CR(n) (0x004 + (n * 4))
#define TPDA_FPID_CR (0x084)
#define TPDA_SYNCR (0x08C)
+#define TPDA_FLUSH_CR (0x090)
/* Cross trigger FREQ packets timestamp bit */
#define TPDA_CR_FREQTS BIT(2)
@@ -35,6 +36,7 @@
#define TPDA_SYNCR_MAX_COUNTER_VAL (0xFFF)
#define TPDA_MAX_INPORTS 32
+#define TPDA_MAX_INPORTS_MASK GENMASK(31, 0)
/* Bits 6 ~ 12 is for atid value */
#define TPDA_CR_ATID GENMASK(12, 6)
