diff options
Diffstat (limited to 'drivers/hwtracing/coresight/coresight-etm4x-sysfs.c')
| -rw-r--r-- | drivers/hwtracing/coresight/coresight-etm4x-sysfs.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c index ddbfeb24fc3f..e8fdda45ffca 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c @@ -2370,6 +2370,56 @@ static ssize_t coresight_etm4x_reg_show(struct device *dev, return scnprintf(buf, PAGE_SIZE, "0x%x\n", val); } +static inline bool +etm4x_register_implemented(struct etmv4_drvdata *drvdata, u32 offset) +{ + switch (offset) { + ETM4x_SYSREG_LIST_CASES + /* + * Registers accessible via system instructions are always + * implemented. + */ + return true; + ETM4x_MMAP_LIST_CASES + /* + * Registers accessible only via memory-mapped registers + * must not be accessed via system instructions. + * We cannot access the drvdata->csdev here, as this + * function is called during the device creation, via + * coresight_register() and the csdev is not initialized + * until that is done. So rely on the drvdata->base to + * detect if we have a memory mapped access. + */ + return !!drvdata->base; + } + + return false; +} + +/* + * Hide the ETM4x registers that may not be available on the + * hardware. + * There are certain management registers unavailable via system + * instructions. Make those sysfs attributes hidden on such + * systems. + */ +static umode_t +coresight_etm4x_attr_reg_implemented(struct kobject *kobj, + struct attribute *attr, int unused) +{ + struct device *dev = kobj_to_dev(kobj); + struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent); + struct device_attribute *d_attr; + u32 offset; + + d_attr = container_of(attr, struct device_attribute, attr); + offset = coresight_etm4x_attr_to_offset(d_attr); + + if (etm4x_register_implemented(drvdata, offset)) + return attr->mode; + return 0; +} + #define coresight_etm4x_reg(name, offset) \ &((struct dev_ext_attribute[]) { \ { \ @@ -2417,6 +2467,7 @@ static const struct attribute_group coresight_etmv4_group = { }; static const struct attribute_group coresight_etmv4_mgmt_group = { + .is_visible = coresight_etm4x_attr_reg_implemented, .attrs = coresight_etmv4_mgmt_attrs, .name = "mgmt", }; |