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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 <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pratik Patel 2015-05-13 10:34:19 -06:00 committed by Greg Kroah-Hartman
parent 4a584be1d0
commit 40d8ebf071
2 changed files with 198 additions and 0 deletions
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20
Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
View File

@ -261,3 +261,23 @@ KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Mask for all 8 context ID comparator value
registers (if implemented).
What: /sys/bus/coresight/devices/<memory_map>.etm/vmid_idx
Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Select which virtual machine ID comparator to work with.
What: /sys/bus/coresight/devices/<memory_map>.etm/vmid_val
Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Get/Set the virtual machine ID comparator value to
trigger on.
What: /sys/bus/coresight/devices/<memory_map>.etm/vmid_masks
Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Mask for all 8 virtual machine ID comparator value
registers (if implemented).

178
drivers/hwtracing/coresight/coresight-etm4x.c
View File

@ -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,
};