| Message ID | 20210303095250.1360007-2-schnelle@linux.ibm.com |
|---|---|
| State | New |
| Headers | show |
| Series | s390/pci: expose a PCI device's UID as its index | expand |
Hi Niklas, [...] > +static ssize_t index_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); > + u32 index = ~0; > + > + if (zpci_unique_uid) > + index = zdev->uid; > + > + return sprintf(buf, "%u\n", index); [...] Would it be possible to use the new sysfs_emit() rather than sprintf() even though the zpci_attr macro and still use mio_enabled_show() still would use sprintf(). What do you think? See https://www.kernel.org/doc/html/latest/filesystems/sysfs.html for the changes in the internal API. Krzysztof
On 3/7/21 9:46 PM, Krzysztof Wilczyński wrote: > Hi Niklas, > > [...] >> +static ssize_t index_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); >> + u32 index = ~0; >> + >> + if (zpci_unique_uid) >> + index = zdev->uid; >> + >> + return sprintf(buf, "%u\n", index); > [...] > > Would it be possible to use the new sysfs_emit() rather than sprintf() > even though the zpci_attr macro and still use mio_enabled_show() still > would use sprintf(). What do you think? > > See https://www.kernel.org/doc/html/latest/filesystems/sysfs.html for > the changes in the internal API. > > Krzysztof > Of course that makes sense and thanks for pointing me to this API! @Viktor, may I carry your R-b over? I'll also update the other attributes in a clean up patch. Thanks, Niklas
On 3/8/21 8:02 AM, Niklas Schnelle wrote: > > > On 3/7/21 9:46 PM, Krzysztof Wilczyński wrote: >> Hi Niklas, >> >> [...] >>> +static ssize_t index_show(struct device *dev, >>> + struct device_attribute *attr, char *buf) >>> +{ >>> + struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); >>> + u32 index = ~0; >>> + >>> + if (zpci_unique_uid) >>> + index = zdev->uid; >>> + >>> + return sprintf(buf, "%u\n", index); >> [...] >> >> Would it be possible to use the new sysfs_emit() rather than sprintf() >> even though the zpci_attr macro and still use mio_enabled_show() still >> would use sprintf(). What do you think? >> >> See https://www.kernel.org/doc/html/latest/filesystems/sysfs.html for >> the changes in the internal API. >> >> Krzysztof >> > > Of course that makes sense and thanks for pointing me to this API! > @Viktor, may I carry your R-b over? > Sure, please go ahead. > I'll also update the other attributes in a clean up patch. > > Thanks, > Niklas >
diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index 25c9c39770c6..1241b6d11a52 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -195,10 +195,13 @@ What: /sys/bus/pci/devices/.../index Date: July 2010 Contact: Narendra K <narendra_k@dell.com>, linux-bugs@dell.com Description: - Reading this attribute will provide the firmware - given instance (SMBIOS type 41 device type instance) of the - PCI device. The attribute will be created only if the firmware - has given an instance number to the PCI device. + Reading this attribute will provide the firmware given instance + number of the PCI device. Depending on the platform this can + be for example the SMBIOS type 41 device type instance or the + user-defined ID (UID) on s390. The attribute will be created + only if the firmware has given an instance number to the PCI + device and that number is guaranteed to uniquely identify the + device in the system. Users: Userspace applications interested in knowing the firmware assigned device type instance of the PCI diff --git a/arch/s390/pci/pci_sysfs.c b/arch/s390/pci/pci_sysfs.c index 5c028bee91b9..30f48e8a1156 100644 --- a/arch/s390/pci/pci_sysfs.c +++ b/arch/s390/pci/pci_sysfs.c @@ -131,6 +131,38 @@ static ssize_t report_error_write(struct file *filp, struct kobject *kobj, } static BIN_ATTR(report_error, S_IWUSR, NULL, report_error_write, PAGE_SIZE); +#ifndef CONFIG_DMI +/* analogous to smbios index */ +static ssize_t index_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); + u32 index = ~0; + + if (zpci_unique_uid) + index = zdev->uid; + + return sprintf(buf, "%u\n", index); +} +static DEVICE_ATTR_RO(index); + +static umode_t zpci_unique_uids(struct kobject *kobj, + struct attribute *attr, int n) +{ + return zpci_unique_uid ? attr->mode : 0; +} + +static struct attribute *zpci_ident_attrs[] = { + &dev_attr_index.attr, + NULL, +}; + +static struct attribute_group zpci_ident_attr_group = { + .attrs = zpci_ident_attrs, + .is_visible = zpci_unique_uids, +}; +#endif + static struct bin_attribute *zpci_bin_attrs[] = { &bin_attr_util_string, &bin_attr_report_error, @@ -150,6 +182,7 @@ static struct attribute *zpci_dev_attrs[] = { &dev_attr_mio_enabled.attr, NULL, }; + static struct attribute_group zpci_attr_group = { .attrs = zpci_dev_attrs, .bin_attrs = zpci_bin_attrs, @@ -170,5 +203,8 @@ static struct attribute_group pfip_attr_group = { const struct attribute_group *zpci_attr_groups[] = { &zpci_attr_group, &pfip_attr_group, +#ifndef CONFIG_DMI + &zpci_ident_attr_group, +#endif NULL, };