coresight-etm4x: Controls pertaining to the context ID functions

Adding sysfs entries to access and configure specifics about the
context ID comparator functions.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
index 5c7391d4e33a08ae289c9d9956ea391899e9822b..f251b2c17f5b1e02e11092547e2eccb3f5114e86 100644 (file)
--- 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@linaro.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@linaro.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@linaro.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@linaro.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 308a48df4338156d859573f67de19fca59b10797..e94784fe68c4714373e1c24707cf35a0b22986cb 100644 (file)
--- 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,
 };