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Message-Id: <1431534861-24986-11-git-send-email-mathieu.poirier@linaro.org>
Date: Wed, 13 May 2015 10:34:18 -0600
From: Mathieu Poirier <mathieu.poirier@...aro.org>
To: gregkh@...uxfoundation.org
Cc: linux-arm-kernel@...ts.infradead.org, linux-api@...r.kernel.org,
linux-kernel@...r.kernel.org, kaixu.xia@...aro.org,
zhang.chunyan@...aro.org, mathieu.poirier@...aro.org
Subject: [PATCH v4 10/13] coresight-etm4x: Controls pertaining to the context ID functions
From: Pratik Patel <pratikp@...eaurora.org>
Adding sysfs entries to access and configure specifics about the
context ID comparator functions.
Signed-off-by: Pratik Patel <pratikp@...eaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@...aro.org>
---
.../ABI/testing/sysfs-bus-coresight-devices-etm4x | 19 +++
drivers/hwtracing/coresight/coresight-etm4x.c | 187 +++++++++++++++++++++
2 files changed, 206 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
index 5c7391d4e33a..f251b2c17f5b 100644
--- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
+++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
@@ -242,3 +242,22 @@ Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@...aro.org>
Description: (RW) Controls the selection of the resources in the trace unit.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/ctxid_idx
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@...aro.org>
+Description: (RW) Select which context ID comparator to work with.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/ctxid_val
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@...aro.org>
+Description: (RW) Get/Set the context ID comparator value to trigger on.
+
+What: /sys/bus/coresight/devices/<memory_map>.etm/ctxid_masks
+Date: April 2015
+KernelVersion: 4.01
+Contact: Mathieu Poirier <mathieu.poirier@...aro.org>
+Description: (RW) Mask for all 8 context ID comparator value
+ registers (if implemented).
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
index 308a48df4338..e94784fe68c4 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x.c
@@ -1780,6 +1780,190 @@ static ssize_t res_ctrl_store(struct device *dev,
}
static DEVICE_ATTR_RW(res_ctrl);
+static ssize_t ctxid_idx_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ val = drvdata->ctxid_idx;
+ return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t ctxid_idx_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ if (kstrtoul(buf, 16, &val))
+ return -EINVAL;
+ if (val >= drvdata->numcidc)
+ return -EINVAL;
+
+ /*
+ * Use spinlock to ensure index doesn't change while it gets
+ * dereferenced multiple times within a spinlock block elsewhere.
+ */
+ spin_lock(&drvdata->spinlock);
+ drvdata->ctxid_idx = val;
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(ctxid_idx);
+
+static ssize_t ctxid_val_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->ctxid_idx;
+ val = (unsigned long)drvdata->ctxid_val[idx];
+ spin_unlock(&drvdata->spinlock);
+ return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
+}
+
+static ssize_t ctxid_val_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ u8 idx;
+ unsigned long val;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ /*
+ * only implemented when ctxid tracing is enabled, i.e. at least one
+ * ctxid comparator is implemented and ctxid is greater than 0 bits
+ * in length
+ */
+ if (!drvdata->ctxid_size || !drvdata->numcidc)
+ return -EINVAL;
+ if (kstrtoul(buf, 16, &val))
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ idx = drvdata->ctxid_idx;
+ drvdata->ctxid_val[idx] = (u64)val;
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(ctxid_val);
+
+static ssize_t ctxid_masks_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ unsigned long val1, val2;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ spin_lock(&drvdata->spinlock);
+ val1 = drvdata->ctxid_mask0;
+ val2 = drvdata->ctxid_mask1;
+ spin_unlock(&drvdata->spinlock);
+ return scnprintf(buf, PAGE_SIZE, "%#lx %#lx\n", val1, val2);
+}
+
+static ssize_t ctxid_masks_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t size)
+{
+ u8 i, j, maskbyte;
+ unsigned long val1, val2, mask;
+ struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
+
+ /*
+ * only implemented when ctxid tracing is enabled, i.e. at least one
+ * ctxid comparator is implemented and ctxid is greater than 0 bits
+ * in length
+ */
+ if (!drvdata->ctxid_size || !drvdata->numcidc)
+ return -EINVAL;
+ if (sscanf(buf, "%lx %lx", &val1, &val2) != 2)
+ return -EINVAL;
+
+ spin_lock(&drvdata->spinlock);
+ /*
+ * each byte[0..3] controls mask value applied to ctxid
+ * comparator[0..3]
+ */
+ switch (drvdata->numcidc) {
+ case 0x1:
+ /* COMP0, bits[7:0] */
+ drvdata->ctxid_mask0 = val1 & 0xFF;
+ break;
+ case 0x2:
+ /* COMP1, bits[15:8] */
+ drvdata->ctxid_mask0 = val1 & 0xFFFF;
+ break;
+ case 0x3:
+ /* COMP2, bits[23:16] */
+ drvdata->ctxid_mask0 = val1 & 0xFFFFFF;
+ break;
+ case 0x4:
+ /* COMP3, bits[31:24] */
+ drvdata->ctxid_mask0 = val1;
+ break;
+ case 0x5:
+ /* COMP4, bits[7:0] */
+ drvdata->ctxid_mask0 = val1;
+ drvdata->ctxid_mask1 = val2 & 0xFF;
+ break;
+ case 0x6:
+ /* COMP5, bits[15:8] */
+ drvdata->ctxid_mask0 = val1;
+ drvdata->ctxid_mask1 = val2 & 0xFFFF;
+ break;
+ case 0x7:
+ /* COMP6, bits[23:16] */
+ drvdata->ctxid_mask0 = val1;
+ drvdata->ctxid_mask1 = val2 & 0xFFFFFF;
+ break;
+ case 0x8:
+ /* COMP7, bits[31:24] */
+ drvdata->ctxid_mask0 = val1;
+ drvdata->ctxid_mask1 = val2;
+ break;
+ default:
+ break;
+ }
+ /*
+ * If software sets a mask bit to 1, it must program relevant byte
+ * of ctxid comparator value 0x0, otherwise behavior is unpredictable.
+ * For example, if bit[3] of ctxid_mask0 is 1, we must clear bits[31:24]
+ * of ctxid comparator0 value (corresponding to byte 0) register.
+ */
+ mask = drvdata->ctxid_mask0;
+ for (i = 0; i < drvdata->numcidc; i++) {
+ /* mask value of corresponding ctxid comparator */
+ maskbyte = mask & ETMv4_EVENT_MASK;
+ /*
+ * each bit corresponds to a byte of respective ctxid comparator
+ * value register
+ */
+ for (j = 0; j < 8; j++) {
+ if (maskbyte & 1)
+ drvdata->ctxid_val[i] &= ~(0xFF << (j * 8));
+ maskbyte >>= 1;
+ }
+ /* Select the next ctxid comparator mask value */
+ if (i == 3)
+ /* ctxid comparators[4-7] */
+ mask = drvdata->ctxid_mask1;
+ else
+ mask >>= 0x8;
+ }
+
+ spin_unlock(&drvdata->spinlock);
+ return size;
+}
+static DEVICE_ATTR_RW(ctxid_masks);
+
static ssize_t cpu_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -1832,6 +2016,9 @@ static struct attribute *coresight_etmv4_attrs[] = {
&dev_attr_cntr_ctrl.attr,
&dev_attr_res_idx.attr,
&dev_attr_res_ctrl.attr,
+ &dev_attr_ctxid_idx.attr,
+ &dev_attr_ctxid_val.attr,
+ &dev_attr_ctxid_masks.attr,
&dev_attr_cpu.attr,
NULL,
};
--
1.9.1
--
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