From 40d8ebf0715f86b0231927a80bbc068869cc5ef1 Mon Sep 17 00:00:00 2001 From: Pratik Patel Date: Wed, 13 May 2015 10:34:19 -0600 Subject: [PATCH] coresight-etm4x: Controls pertaining to the VM ID functions Adding sysfs entries to access and configure specifics about the virtual machine ID comparator functions. Signed-off-by: Pratik Patel Signed-off-by: Mathieu Poirier Signed-off-by: Greg Kroah-Hartman --- .../testing/sysfs-bus-coresight-devices-etm4x | 20 ++ drivers/hwtracing/coresight/coresight-etm4x.c | 178 ++++++++++++++++++ 2 files changed, 198 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x index f251b2c17f5b..648f28ded226 100644 --- a/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x +++ b/Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x @@ -261,3 +261,23 @@ KernelVersion: 4.01 Contact: Mathieu Poirier Description: (RW) Mask for all 8 context ID comparator value registers (if implemented). + +What: /sys/bus/coresight/devices/.etm/vmid_idx +Date: April 2015 +KernelVersion: 4.01 +Contact: Mathieu Poirier +Description: (RW) Select which virtual machine ID comparator to work with. + +What: /sys/bus/coresight/devices/.etm/vmid_val +Date: April 2015 +KernelVersion: 4.01 +Contact: Mathieu Poirier +Description: (RW) Get/Set the virtual machine ID comparator value to + trigger on. + +What: /sys/bus/coresight/devices/.etm/vmid_masks +Date: April 2015 +KernelVersion: 4.01 +Contact: Mathieu Poirier +Description: (RW) Mask for all 8 virtual machine ID comparator value + registers (if implemented). diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index e94784fe68c4..02ee6fc97ddf 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -1964,6 +1964,181 @@ static ssize_t ctxid_masks_store(struct device *dev, } static DEVICE_ATTR_RW(ctxid_masks); +static ssize_t vmid_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->vmid_idx; + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val); +} + +static ssize_t vmid_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->numvmidc) + 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->vmid_idx = val; + spin_unlock(&drvdata->spinlock); + return size; +} +static DEVICE_ATTR_RW(vmid_idx); + +static ssize_t vmid_val_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + unsigned long val; + struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); + + val = (unsigned long)drvdata->vmid_val[drvdata->vmid_idx]; + return scnprintf(buf, PAGE_SIZE, "%#lx\n", val); +} + +static ssize_t vmid_val_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); + + /* + * only implemented when vmid tracing is enabled, i.e. at least one + * vmid comparator is implemented and at least 8 bit vmid size + */ + if (!drvdata->vmid_size || !drvdata->numvmidc) + return -EINVAL; + if (kstrtoul(buf, 16, &val)) + return -EINVAL; + + spin_lock(&drvdata->spinlock); + drvdata->vmid_val[drvdata->vmid_idx] = (u64)val; + spin_unlock(&drvdata->spinlock); + return size; +} +static DEVICE_ATTR_RW(vmid_val); + +static ssize_t vmid_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->vmid_mask0; + val2 = drvdata->vmid_mask1; + spin_unlock(&drvdata->spinlock); + return scnprintf(buf, PAGE_SIZE, "%#lx %#lx\n", val1, val2); +} + +static ssize_t vmid_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 vmid tracing is enabled, i.e. at least one + * vmid comparator is implemented and at least 8 bit vmid size + */ + if (!drvdata->vmid_size || !drvdata->numvmidc) + 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 vmid + * comparator[0..3] + */ + switch (drvdata->numvmidc) { + case 0x1: + /* COMP0, bits[7:0] */ + drvdata->vmid_mask0 = val1 & 0xFF; + break; + case 0x2: + /* COMP1, bits[15:8] */ + drvdata->vmid_mask0 = val1 & 0xFFFF; + break; + case 0x3: + /* COMP2, bits[23:16] */ + drvdata->vmid_mask0 = val1 & 0xFFFFFF; + break; + case 0x4: + /* COMP3, bits[31:24] */ + drvdata->vmid_mask0 = val1; + break; + case 0x5: + /* COMP4, bits[7:0] */ + drvdata->vmid_mask0 = val1; + drvdata->vmid_mask1 = val2 & 0xFF; + break; + case 0x6: + /* COMP5, bits[15:8] */ + drvdata->vmid_mask0 = val1; + drvdata->vmid_mask1 = val2 & 0xFFFF; + break; + case 0x7: + /* COMP6, bits[23:16] */ + drvdata->vmid_mask0 = val1; + drvdata->vmid_mask1 = val2 & 0xFFFFFF; + break; + case 0x8: + /* COMP7, bits[31:24] */ + drvdata->vmid_mask0 = val1; + drvdata->vmid_mask1 = val2; + break; + default: + break; + } + + /* + * If software sets a mask bit to 1, it must program relevant byte + * of vmid comparator value 0x0, otherwise behavior is unpredictable. + * For example, if bit[3] of vmid_mask0 is 1, we must clear bits[31:24] + * of vmid comparator0 value (corresponding to byte 0) register. + */ + mask = drvdata->vmid_mask0; + for (i = 0; i < drvdata->numvmidc; i++) { + /* mask value of corresponding vmid comparator */ + maskbyte = mask & ETMv4_EVENT_MASK; + /* + * each bit corresponds to a byte of respective vmid comparator + * value register + */ + for (j = 0; j < 8; j++) { + if (maskbyte & 1) + drvdata->vmid_val[i] &= ~(0xFF << (j * 8)); + maskbyte >>= 1; + } + /* Select the next vmid comparator mask value */ + if (i == 3) + /* vmid comparators[4-7] */ + mask = drvdata->vmid_mask1; + else + mask >>= 0x8; + } + spin_unlock(&drvdata->spinlock); + return size; +} +static DEVICE_ATTR_RW(vmid_masks); + static ssize_t cpu_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -2019,6 +2194,9 @@ static struct attribute *coresight_etmv4_attrs[] = { &dev_attr_ctxid_idx.attr, &dev_attr_ctxid_val.attr, &dev_attr_ctxid_masks.attr, + &dev_attr_vmid_idx.attr, + &dev_attr_vmid_val.attr, + &dev_attr_vmid_masks.attr, &dev_attr_cpu.attr, NULL, }; -- 2.20.1