Re: [PATCH v7 09/13] coresight-tpdm: Add nodes for dsb edge control

From: Suzuki K Poulose
Date: Mon Aug 07 2023 - 05:24:23 EST


On 25/07/2023 08:15, Tao Zhang wrote:
Add the nodes to set value for DSB edge control and DSB edge
control mask. Each DSB subunit TPDM has maximum of n(n<16) EDCR
resgisters to configure edge control. DSB edge detection control
00: Rising edge detection
01: Falling edge detection
10: Rising and falling edge detection (toggle detection)
And each DSB subunit TPDM has maximum of m(m<8) ECDMR registers to
configure mask. Eight 32 bit registers providing DSB interface
edge detection mask control.

Add the nodes to configure DSB edge control and DSB edge control
mask. Each DSB subunit TPDM maximum of 256 edge detections can be
configured. The index and value sysfs files need to be paired and
written to order. The index sysfs file is to set the index number
of the edge detection which needs to be configured. And the value
sysfs file is to set the control or mask for the edge detection.
DSB edge detection control should be set as the following values.
00: Rising edge detection
01: Falling edge detection
10: Rising and falling edge detection (toggle detection)
And DSB edge mask should be set as 0 or 1.
Each DSB subunit TPDM has maximum of n(n<16) EDCR resgisters to
configure edge control. And each DSB subunit TPDM has maximum of
m(m<8) ECDMR registers to configure mask.

Signed-off-by: Tao Zhang <quic_taozha@xxxxxxxxxxx>
---
.../ABI/testing/sysfs-bus-coresight-devices-tpdm | 39 +++++
drivers/hwtracing/coresight/coresight-tpdm.c | 158 ++++++++++++++++++++-
drivers/hwtracing/coresight/coresight-tpdm.h | 30 +++-
3 files changed, 223 insertions(+), 4 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
index 2a82cd0..a4550c5 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-tpdm
@@ -60,3 +60,42 @@ Description:
Bit[3] : Set to 0 for low performance mode.
Set to 1 for high performance mode.
Bit[4:8] : Select byte lane for high performance mode.
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge_ctrl_idx
+Date: March 2023
+KernelVersion 6.5
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Read/Write the index number of the edge detection for the DSB
+ subunit TPDM. Since there are at most 256 edge detections, this
+ value ranges from 0 to 255.
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge_ctrl_val
+Date: March 2023
+KernelVersion 6.5
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Read a set of the edge control registers of the DSB in TPDM.
+ Write a data to control the edge detection corresponding to
+ the index number. Before writing data to this sysfs file,
+ "dsb_edge_ctrl_idx" should be written first to configure the
+ index number of the edge detection which needs to be controlled.
+
+ Accepts only one of the following values.
+ 0 - Rising edge detection
+ 1 - Falling edge detection
+ 2 - Rising and falling edge detection (toggle detection)
+
+
+What: /sys/bus/coresight/devices/<tpdm-name>/dsb_edge_ctrl_mask
+Date: March 2023
+KernelVersion 6.5
+Contact: Jinlong Mao (QUIC) <quic_jinlmao@xxxxxxxxxxx>, Tao Zhang (QUIC) <quic_taozha@xxxxxxxxxxx>
+Description:
+ Read a set of the edge control mask registers of the DSB in TPDM.
+ Write a data to mask the edge detection corresponding to the index
+ number. Before writing data to this sysfs file, "dsb_edge_ctrl_idx"
+ should be written first to configure the index number of the edge
+ detection which needs to be masked.
+
+ Accepts only one of the 2 values - 0 or 1.
\ No newline at end of file
diff --git a/drivers/hwtracing/coresight/coresight-tpdm.c b/drivers/hwtracing/coresight/coresight-tpdm.c
index c38760b..98fd6ab 100644
--- a/drivers/hwtracing/coresight/coresight-tpdm.c
+++ b/drivers/hwtracing/coresight/coresight-tpdm.c
@@ -71,7 +71,14 @@ static void set_dsb_perf_mode(struct tpdm_drvdata *drvdata, u32 *val)
static void tpdm_enable_dsb(struct tpdm_drvdata *drvdata)
{
- u32 val;
+ u32 val, i;
+
+ for (i = 0; i < TPDM_DSB_MAX_EDCR; i++)
+ writel_relaxed(drvdata->dsb->edge_ctrl[i],
+ drvdata->base + TPDM_DSB_EDCR(i));
+ for (i = 0; i < TPDM_DSB_MAX_EDCMR; i++)
+ writel_relaxed(drvdata->dsb->edge_ctrl_mask[i],
+ drvdata->base + TPDM_DSB_EDCMR(i));
val = readl_relaxed(drvdata->base + TPDM_DSB_TIER);
/* Set trigger timestamp */
@@ -302,6 +309,152 @@ static ssize_t dsb_mode_store(struct device *dev,
}
static DEVICE_ATTR_RW(dsb_mode);
+static ssize_t dsb_edge_ctrl_idx_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ return sysfs_emit(buf, "%u\n",
+ (unsigned int)drvdata->dsb->edge_ctrl_idx);
+}
+
+/*
+ * The EDCR registers can include up to 16 32-bit registers, and each
+ * one can be configured to control up to 16 edge detections(2 bits
+ * control one edge detection). So a total 256 edge detections can be
+ * configured. This function provides a way to set the index number of
+ * the edge detection which needs to be configured.
+ */
+static ssize_t dsb_edge_ctrl_idx_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val;
+
+ if ((kstrtoul(buf, 0, &val)) || (val >= TPDM_DSB_MAX_LINES))
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ drvdata->dsb->edge_ctrl_idx = val;
+ spin_unlock(&drvdata->spinlock);
+
+ return size;
+}
+static DEVICE_ATTR_RW(dsb_edge_ctrl_idx);
+
+static ssize_t dsb_edge_ctrl_val_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ ssize_t size = 0;
+ unsigned long bytes;
+ int i;
+
+ spin_lock(&drvdata->spinlock);
+ for (i = 0; i < TPDM_DSB_MAX_EDCR; i++) {
+ bytes = sysfs_emit_at(buf, size,
+ "Val:0x%x\n", drvdata->dsb->edge_ctrl[i]);
+ if (bytes <= 0)
+ break;
+ size += bytes;
+ }
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+
+/*
+ * This function is used to control the edge detection according
+ * to the index number that has been set.
+ * "edge_ctrl" should be one of the following values.
+ * 0 - Rising edge detection
+ * 1 - Falling edge detection
+ * 2 - Rising and falling edge detection (toggle detection)
+ */
+static ssize_t dsb_edge_ctrl_val_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val, mask, edge_ctrl;
+ int reg;
+
+ if ((kstrtoul(buf, 0, &edge_ctrl)) || (edge_ctrl > 0x2))
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ /*
+ * There are 2 bit per DSB Edge Control line.
+ * Thus we have 16 lines in a 32bit word.
+ */
+ reg = EDCR_TO_WORD_IDX(drvdata->dsb->edge_ctrl_idx);
+ mask = EDCR_TO_WORD_MASK(drvdata->dsb->edge_ctrl_idx);
+ val = drvdata->dsb->edge_ctrl[reg];
+ val &= ~EDCR_TO_WORD_MASK(drvdata->dsb->edge_ctrl_idx);
+ val |= EDCR_TO_WORD_VAL(edge_ctrl, drvdata->dsb->edge_ctrl_idx);
+ drvdata->dsb->edge_ctrl[reg] = val;
+ spin_unlock(&drvdata->spinlock);
+
+ return size;
+}
+static DEVICE_ATTR_RW(dsb_edge_ctrl_val);
+
+static ssize_t dsb_edge_ctrl_mask_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ ssize_t size = 0;
+ unsigned long bytes;
+ int i;
+
+ spin_lock(&drvdata->spinlock);
+ for (i = 0; i < TPDM_DSB_MAX_EDCMR; i++) {
+ bytes = sysfs_emit_at(buf, size,
+ "Val:0x%x\n", drvdata->dsb->edge_ctrl_mask[i]);
+ if (bytes <= 0)
+ break;
+ size += bytes;
+ }
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+
+static ssize_t dsb_edge_ctrl_mask_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t size)
+{
+ struct tpdm_drvdata *drvdata = dev_get_drvdata(dev->parent);
+ unsigned long val;
+ u32 set;
+ int reg;
+
+ if ((kstrtoul(buf, 0, &val)) || (val & ~1UL))
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ /*
+ * There is 1 bit per DSB Edge Control Mark line.
+ * Thus we have 32 lines in a 32bit word.
+ */
+ reg = EDCMR_TO_WORD_IDX(drvdata->dsb->edge_ctrl_idx);
+ set = drvdata->dsb->edge_ctrl_mask[reg];
+ if (val)
+ set |= BIT(EDCMR_TO_WORD_SHIFT(drvdata->dsb->edge_ctrl_idx));
+ else
+ set &= ~BIT(EDCMR_TO_WORD_SHIFT(drvdata->dsb->edge_ctrl_idx));
+ drvdata->dsb->edge_ctrl_mask[reg] = set;


drivers/hwtracing/coresight/coresight-tpdm.c: In function ‘dsb_edge_ctrl_mask_store’:
drivers/hwtracing/coresight/coresight-tpdm.c:449:2: error: this ‘else’ clause does not guard... [-Werror=misleading-indentation]
else
^~~~
drivers/hwtracing/coresight/coresight-tpdm.c:451:3: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the ‘else’
drvdata->dsb->edge_ctrl_mask[reg] = set;
^~~~~~~
cc1: all warnings being treated as errors
make[4]: *** [scripts/Makefile.build:243: drivers/hwtracing/coresight/coresight-tpdm.o] Error 1
make[3]: *** [scripts/Makefile.build:480: drivers/hwtracing/coresight] Error 2
make[2]: *** [scripts/Makefile.build:480: drivers] Error 2
make[1]: *** [/ssd/src/LINUX-CORESIGHT/Makefile:2032: .] Error 2
make: *** [Makefile:234: __sub-make] Error 2

Suzuki