| Message ID | 20210513232701.411773-1-rajatja@google.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v4,1/2] driver core: Move the "removable" attribute from USB to core | expand |
On Thu, May 13, 2021 at 04:27:00PM -0700, Rajat Jain wrote: > Move the "removable" attribute from USB to core in order to allow it to be > supported by other subsystem / buses. Individual buses that want to support > this attribute can populate the removable property of the device while > enumerating it with the 3 possible values - > - "unknown" > - "fixed" > - "removable" > Leaving the field unchanged (i.e. "not supported") would mean that the > attribute would not show up in sysfs for that device. The UAPI (location, > symantics etc) for the attribute remains unchanged. > > Signed-off-by: Rajat Jain <rajatja@google.com> > --- > v4: - instead of devicce_type->supports_removable, add 1 more value in > device_removable_enum > - documentation update. > - Remove "Acked-by" and "Reviewed-by" tags from previous versions. > v3: - Minor commit log / comments updated. > - use sysfs_emit() > - Rename local variable name (state -> loc) > - change supports_removable flag from bool to bitfield. > v2: Add documentation This looks good to me, I have no further objection to it at all, nice cleanups. I can take this in my driver-core tree, so that other busses can use it (and can create a tag to pull from if needed), or I can also take the PCI patch (patch 2/2 here), if Bjorn gives his reviewed-by: for it. Are there other busses besides PCI that you want to enable this soon (i.e. before 5.14-rc1)? thanks, greg k-h
On Thu, May 13, 2021 at 04:27:00PM -0700, Rajat Jain wrote: > Move the "removable" attribute from USB to core in order to allow it to be > supported by other subsystem / buses. Individual buses that want to support > this attribute can populate the removable property of the device while > enumerating it with the 3 possible values - > - "unknown" > - "fixed" > - "removable" > Leaving the field unchanged (i.e. "not supported") would mean that the > attribute would not show up in sysfs for that device. The UAPI (location, > symantics etc) for the attribute remains unchanged. Looks nice! Maybe the mini usage guide here could be a little more explicit, e.g., Move the "removable" attribute from USB to the device core so it can be used by other subsystems / buses. By default, devices do not have a "removable" attribute in sysfs. If a subsystem or bus driver wants to support a "removable" attribute, it should call device_set_removable() before calling device_register() or device_add(), e.g., device_set_removable(dev, DEVICE_REMOVABLE); device_register(dev); The possible values and the resulting sysfs attribute contents are: DEVICE_REMOVABLE_UNKNOWN -> "unknown" DEVICE_REMOVABLE -> "removable" DEVICE_FIXED -> "fixed" Convert the USB "removable" attribute to use this new device core functionality. There should be no user-visible change in the location or semantics of attribute for USB devices. > Signed-off-by: Rajat Jain <rajatja@google.com> Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> Minor comment below, reviewed-by applies whether or not you do anything. > --- > v4: - instead of devicce_type->supports_removable, add 1 more value in > device_removable_enum > - documentation update. > - Remove "Acked-by" and "Reviewed-by" tags from previous versions. > v3: - Minor commit log / comments updated. > - use sysfs_emit() > - Rename local variable name (state -> loc) > - change supports_removable flag from bool to bitfield. > v2: Add documentation > > Documentation/ABI/testing/sysfs-bus-usb | 11 ------ > .../ABI/testing/sysfs-devices-removable | 17 +++++++++ > drivers/base/core.c | 28 ++++++++++++++ > drivers/usb/core/hub.c | 13 ++++--- > drivers/usb/core/sysfs.c | 24 ------------ > include/linux/device.h | 37 +++++++++++++++++++ > include/linux/usb.h | 7 ---- > 7 files changed, 89 insertions(+), 48 deletions(-) > create mode 100644 Documentation/ABI/testing/sysfs-devices-removable > > diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb > index bf2c1968525f..73eb23bc1f34 100644 > --- a/Documentation/ABI/testing/sysfs-bus-usb > +++ b/Documentation/ABI/testing/sysfs-bus-usb > @@ -154,17 +154,6 @@ Description: > files hold a string value (enable or disable) indicating whether > or not USB3 hardware LPM U1 or U2 is enabled for the device. > > -What: /sys/bus/usb/devices/.../removable > -Date: February 2012 > -Contact: Matthew Garrett <mjg@redhat.com> > -Description: > - Some information about whether a given USB device is > - physically fixed to the platform can be inferred from a > - combination of hub descriptor bits and platform-specific data > - such as ACPI. This file will read either "removable" or > - "fixed" if the information is available, and "unknown" > - otherwise. > - > What: /sys/bus/usb/devices/.../ltm_capable > Date: July 2012 > Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com> > diff --git a/Documentation/ABI/testing/sysfs-devices-removable b/Documentation/ABI/testing/sysfs-devices-removable > new file mode 100644 > index 000000000000..acf7766e800b > --- /dev/null > +++ b/Documentation/ABI/testing/sysfs-devices-removable > @@ -0,0 +1,17 @@ > +What: /sys/devices/.../removable > +Date: May 2021 > +Contact: Rajat Jain <rajatxjain@gmail.com> > +Description: > + Information about whether a given device can be removed from the > + platform by the user. This is determined by its subsystem in a > + bus / platform-specific way. This attribute is only present for > + devices that can support determining such information: > + > + "removable": device can be removed from the platform by the user > + "fixed": device is fixed to the platform / cannot be removed > + by the user. > + "unknown": The information is unavailable / cannot be deduced. > + > + Currently this is only supported by USB (which infers the > + information from a combination of hub descriptor bits and > + platform-specific data such as ACPI). > diff --git a/drivers/base/core.c b/drivers/base/core.c > index 4a8bf8cda52b..ae3d6a4a79fb 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -2404,6 +2404,25 @@ static ssize_t online_store(struct device *dev, struct device_attribute *attr, > } > static DEVICE_ATTR_RW(online); > > +static ssize_t removable_show(struct device *dev, struct device_attribute *attr, > + char *buf) > +{ > + const char *loc; > + > + switch (dev->removable) { > + case DEVICE_REMOVABLE: > + loc = "removable"; > + break; > + case DEVICE_FIXED: > + loc = "fixed"; > + break; > + default: > + loc = "unknown"; > + } > + return sysfs_emit(buf, "%s\n", loc); > +} > +static DEVICE_ATTR_RO(removable); > + > int device_add_groups(struct device *dev, const struct attribute_group **groups) > { > return sysfs_create_groups(&dev->kobj, groups); > @@ -2581,8 +2600,16 @@ static int device_add_attrs(struct device *dev) > goto err_remove_dev_online; > } > > + if (dev_removable_is_valid(dev)) { > + error = device_create_file(dev, &dev_attr_removable); > + if (error) > + goto err_remove_dev_waiting_for_supplier; > + } > + > return 0; > > + err_remove_dev_waiting_for_supplier: > + device_remove_file(dev, &dev_attr_waiting_for_supplier); > err_remove_dev_online: > device_remove_file(dev, &dev_attr_online); > err_remove_dev_groups: > @@ -2602,6 +2629,7 @@ static void device_remove_attrs(struct device *dev) > struct class *class = dev->class; > const struct device_type *type = dev->type; > > + device_remove_file(dev, &dev_attr_removable); > device_remove_file(dev, &dev_attr_waiting_for_supplier); > device_remove_file(dev, &dev_attr_online); > device_remove_groups(dev, dev->groups); > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > index b2bc4b7c4289..366cb7ef3b72 100644 > --- a/drivers/usb/core/hub.c > +++ b/drivers/usb/core/hub.c > @@ -2432,6 +2432,8 @@ static void set_usb_port_removable(struct usb_device *udev) > u16 wHubCharacteristics; > bool removable = true; > > + dev_set_removable(&udev->dev, DEVICE_REMOVABLE_UNKNOWN); > + > if (!hdev) > return; > > @@ -2443,11 +2445,11 @@ static void set_usb_port_removable(struct usb_device *udev) > */ > switch (hub->ports[udev->portnum - 1]->connect_type) { > case USB_PORT_CONNECT_TYPE_HOT_PLUG: > - udev->removable = USB_DEVICE_REMOVABLE; > + dev_set_removable(&udev->dev, DEVICE_REMOVABLE); > return; > case USB_PORT_CONNECT_TYPE_HARD_WIRED: > case USB_PORT_NOT_USED: > - udev->removable = USB_DEVICE_FIXED; > + dev_set_removable(&udev->dev, DEVICE_FIXED); > return; > default: > break; > @@ -2472,9 +2474,9 @@ static void set_usb_port_removable(struct usb_device *udev) > } > > if (removable) > - udev->removable = USB_DEVICE_REMOVABLE; > + dev_set_removable(&udev->dev, DEVICE_REMOVABLE); > else > - udev->removable = USB_DEVICE_FIXED; > + dev_set_removable(&udev->dev, DEVICE_FIXED); > > } > > @@ -2546,8 +2548,7 @@ int usb_new_device(struct usb_device *udev) > device_enable_async_suspend(&udev->dev); > > /* check whether the hub or firmware marks this port as non-removable */ > - if (udev->parent) > - set_usb_port_removable(udev); > + set_usb_port_removable(udev); > > /* Register the device. The device driver is responsible > * for configuring the device and invoking the add-device > diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c > index 5a168ba9fc51..fa2e49d432ff 100644 > --- a/drivers/usb/core/sysfs.c > +++ b/drivers/usb/core/sysfs.c > @@ -301,29 +301,6 @@ static ssize_t urbnum_show(struct device *dev, struct device_attribute *attr, > } > static DEVICE_ATTR_RO(urbnum); > > -static ssize_t removable_show(struct device *dev, struct device_attribute *attr, > - char *buf) > -{ > - struct usb_device *udev; > - char *state; > - > - udev = to_usb_device(dev); > - > - switch (udev->removable) { > - case USB_DEVICE_REMOVABLE: > - state = "removable"; > - break; > - case USB_DEVICE_FIXED: > - state = "fixed"; > - break; > - default: > - state = "unknown"; > - } > - > - return sprintf(buf, "%s\n", state); > -} > -static DEVICE_ATTR_RO(removable); > - > static ssize_t ltm_capable_show(struct device *dev, > struct device_attribute *attr, char *buf) > { > @@ -828,7 +805,6 @@ static struct attribute *dev_attrs[] = { > &dev_attr_avoid_reset_quirk.attr, > &dev_attr_authorized.attr, > &dev_attr_remove.attr, > - &dev_attr_removable.attr, > &dev_attr_ltm_capable.attr, > #ifdef CONFIG_OF > &dev_attr_devspec.attr, > diff --git a/include/linux/device.h b/include/linux/device.h > index 38a2071cf776..e3a4749694b7 100644 > --- a/include/linux/device.h > +++ b/include/linux/device.h > @@ -350,6 +350,22 @@ enum dl_dev_state { > DL_DEV_UNBINDING, > }; > > +/** > + * enum device_removable - Whether the device is removable. The criteria for a > + * device to be classified as removable is determined by its subsystem or bus. > + * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this > + * device (default). > + * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown. > + * @DEVICE_FIXED: Device is not removable by the user. > + * @DEVICE_REMOVABLE: Device is removable by the user. > + */ > +enum device_removable { > + DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */ > + DEVICE_REMOVABLE_UNKNOWN, > + DEVICE_FIXED, > + DEVICE_REMOVABLE, > +}; > + > /** > * struct dev_links_info - Device data related to device links. > * @suppliers: List of links to supplier devices. > @@ -431,6 +447,9 @@ struct dev_links_info { > * device (i.e. the bus driver that discovered the device). > * @iommu_group: IOMMU group the device belongs to. > * @iommu: Per device generic IOMMU runtime data > + * @removable: Whether the device can be removed from the system. This > + * should be set by the subsystem / bus driver that discovered > + * the device. > * > * @offline_disabled: If set, the device is permanently online. > * @offline: Set after successful invocation of bus type's .offline(). > @@ -544,6 +563,8 @@ struct device { > struct iommu_group *iommu_group; > struct dev_iommu *iommu; > > + enum device_removable removable; > + > bool offline_disabled:1; > bool offline:1; > bool of_node_reused:1; > @@ -782,6 +803,22 @@ static inline bool dev_has_sync_state(struct device *dev) > return false; > } > > +static inline void dev_set_removable(struct device *dev, > + enum device_removable removable) > +{ > + dev->removable = removable; > +} > + > +static inline bool dev_is_removable(struct device *dev) > +{ > + return dev && dev->removable == DEVICE_REMOVABLE; > +} > + > +static inline bool dev_removable_is_valid(struct device *dev) > +{ > + return dev && dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED; I probably wouldn't check for "dev" being non-NULL in these two functions unless you have a use case that requires it. > +} > + > /* > * High level routines for use by the bus drivers > */ > diff --git a/include/linux/usb.h b/include/linux/usb.h > index eaae24217e8a..b9bd664f44a1 100644 > --- a/include/linux/usb.h > +++ b/include/linux/usb.h > @@ -473,12 +473,6 @@ struct usb_dev_state; > > struct usb_tt; > > -enum usb_device_removable { > - USB_DEVICE_REMOVABLE_UNKNOWN = 0, > - USB_DEVICE_REMOVABLE, > - USB_DEVICE_FIXED, > -}; > - > enum usb_port_connect_type { > USB_PORT_CONNECT_TYPE_UNKNOWN = 0, > USB_PORT_CONNECT_TYPE_HOT_PLUG, > @@ -703,7 +697,6 @@ struct usb_device { > #endif > struct wusb_dev *wusb_dev; > int slot_id; > - enum usb_device_removable removable; > struct usb2_lpm_parameters l1_params; > struct usb3_lpm_parameters u1_params; > struct usb3_lpm_parameters u2_params; > -- > 2.31.1.751.gd2f1c929bd-goog >
On Fri, May 21, 2021 at 1:54 PM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Thu, May 13, 2021 at 04:27:00PM -0700, Rajat Jain wrote: > > Move the "removable" attribute from USB to core in order to allow it to be > > supported by other subsystem / buses. Individual buses that want to support > > this attribute can populate the removable property of the device while > > enumerating it with the 3 possible values - > > - "unknown" > > - "fixed" > > - "removable" > > Leaving the field unchanged (i.e. "not supported") would mean that the > > attribute would not show up in sysfs for that device. The UAPI (location, > > symantics etc) for the attribute remains unchanged. > > Looks nice! > > Maybe the mini usage guide here could be a little more explicit, e.g., > > Move the "removable" attribute from USB to the device core so it can > be used by other subsystems / buses. > > By default, devices do not have a "removable" attribute in sysfs. > > If a subsystem or bus driver wants to support a "removable" > attribute, it should call device_set_removable() before calling > device_register() or device_add(), e.g., > > device_set_removable(dev, DEVICE_REMOVABLE); > device_register(dev); > > The possible values and the resulting sysfs attribute contents are: > > DEVICE_REMOVABLE_UNKNOWN -> "unknown" > DEVICE_REMOVABLE -> "removable" > DEVICE_FIXED -> "fixed" > > Convert the USB "removable" attribute to use this new device core > functionality. There should be no user-visible change in the > location or semantics of attribute for USB devices. > > > Signed-off-by: Rajat Jain <rajatja@google.com> > > Reviewed-by: Bjorn Helgaas <bhelgaas@google.com> > > Minor comment below, reviewed-by applies whether or not you do > anything. Thanks Bjorn for your review, I took care of both the comments and updated the commit log. > > > --- > > v4: - instead of devicce_type->supports_removable, add 1 more value in > > device_removable_enum > > - documentation update. > > - Remove "Acked-by" and "Reviewed-by" tags from previous versions. > > v3: - Minor commit log / comments updated. > > - use sysfs_emit() > > - Rename local variable name (state -> loc) > > - change supports_removable flag from bool to bitfield. > > v2: Add documentation > > > > Documentation/ABI/testing/sysfs-bus-usb | 11 ------ > > .../ABI/testing/sysfs-devices-removable | 17 +++++++++ > > drivers/base/core.c | 28 ++++++++++++++ > > drivers/usb/core/hub.c | 13 ++++--- > > drivers/usb/core/sysfs.c | 24 ------------ > > include/linux/device.h | 37 +++++++++++++++++++ > > include/linux/usb.h | 7 ---- > > 7 files changed, 89 insertions(+), 48 deletions(-) > > create mode 100644 Documentation/ABI/testing/sysfs-devices-removable > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb > > index bf2c1968525f..73eb23bc1f34 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-usb > > +++ b/Documentation/ABI/testing/sysfs-bus-usb > > @@ -154,17 +154,6 @@ Description: > > files hold a string value (enable or disable) indicating whether > > or not USB3 hardware LPM U1 or U2 is enabled for the device. > > > > -What: /sys/bus/usb/devices/.../removable > > -Date: February 2012 > > -Contact: Matthew Garrett <mjg@redhat.com> > > -Description: > > - Some information about whether a given USB device is > > - physically fixed to the platform can be inferred from a > > - combination of hub descriptor bits and platform-specific data > > - such as ACPI. This file will read either "removable" or > > - "fixed" if the information is available, and "unknown" > > - otherwise. > > - > > What: /sys/bus/usb/devices/.../ltm_capable > > Date: July 2012 > > Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com> > > diff --git a/Documentation/ABI/testing/sysfs-devices-removable b/Documentation/ABI/testing/sysfs-devices-removable > > new file mode 100644 > > index 000000000000..acf7766e800b > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-devices-removable > > @@ -0,0 +1,17 @@ > > +What: /sys/devices/.../removable > > +Date: May 2021 > > +Contact: Rajat Jain <rajatxjain@gmail.com> > > +Description: > > + Information about whether a given device can be removed from the > > + platform by the user. This is determined by its subsystem in a > > + bus / platform-specific way. This attribute is only present for > > + devices that can support determining such information: > > + > > + "removable": device can be removed from the platform by the user > > + "fixed": device is fixed to the platform / cannot be removed > > + by the user. > > + "unknown": The information is unavailable / cannot be deduced. > > + > > + Currently this is only supported by USB (which infers the > > + information from a combination of hub descriptor bits and > > + platform-specific data such as ACPI). > > diff --git a/drivers/base/core.c b/drivers/base/core.c > > index 4a8bf8cda52b..ae3d6a4a79fb 100644 > > --- a/drivers/base/core.c > > +++ b/drivers/base/core.c > > @@ -2404,6 +2404,25 @@ static ssize_t online_store(struct device *dev, struct device_attribute *attr, > > } > > static DEVICE_ATTR_RW(online); > > > > +static ssize_t removable_show(struct device *dev, struct device_attribute *attr, > > + char *buf) > > +{ > > + const char *loc; > > + > > + switch (dev->removable) { > > + case DEVICE_REMOVABLE: > > + loc = "removable"; > > + break; > > + case DEVICE_FIXED: > > + loc = "fixed"; > > + break; > > + default: > > + loc = "unknown"; > > + } > > + return sysfs_emit(buf, "%s\n", loc); > > +} > > +static DEVICE_ATTR_RO(removable); > > + > > int device_add_groups(struct device *dev, const struct attribute_group **groups) > > { > > return sysfs_create_groups(&dev->kobj, groups); > > @@ -2581,8 +2600,16 @@ static int device_add_attrs(struct device *dev) > > goto err_remove_dev_online; > > } > > > > + if (dev_removable_is_valid(dev)) { > > + error = device_create_file(dev, &dev_attr_removable); > > + if (error) > > + goto err_remove_dev_waiting_for_supplier; > > + } > > + > > return 0; > > > > + err_remove_dev_waiting_for_supplier: > > + device_remove_file(dev, &dev_attr_waiting_for_supplier); > > err_remove_dev_online: > > device_remove_file(dev, &dev_attr_online); > > err_remove_dev_groups: > > @@ -2602,6 +2629,7 @@ static void device_remove_attrs(struct device *dev) > > struct class *class = dev->class; > > const struct device_type *type = dev->type; > > > > + device_remove_file(dev, &dev_attr_removable); > > device_remove_file(dev, &dev_attr_waiting_for_supplier); > > device_remove_file(dev, &dev_attr_online); > > device_remove_groups(dev, dev->groups); > > diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c > > index b2bc4b7c4289..366cb7ef3b72 100644 > > --- a/drivers/usb/core/hub.c > > +++ b/drivers/usb/core/hub.c > > @@ -2432,6 +2432,8 @@ static void set_usb_port_removable(struct usb_device *udev) > > u16 wHubCharacteristics; > > bool removable = true; > > > > + dev_set_removable(&udev->dev, DEVICE_REMOVABLE_UNKNOWN); > > + > > if (!hdev) > > return; > > > > @@ -2443,11 +2445,11 @@ static void set_usb_port_removable(struct usb_device *udev) > > */ > > switch (hub->ports[udev->portnum - 1]->connect_type) { > > case USB_PORT_CONNECT_TYPE_HOT_PLUG: > > - udev->removable = USB_DEVICE_REMOVABLE; > > + dev_set_removable(&udev->dev, DEVICE_REMOVABLE); > > return; > > case USB_PORT_CONNECT_TYPE_HARD_WIRED: > > case USB_PORT_NOT_USED: > > - udev->removable = USB_DEVICE_FIXED; > > + dev_set_removable(&udev->dev, DEVICE_FIXED); > > return; > > default: > > break; > > @@ -2472,9 +2474,9 @@ static void set_usb_port_removable(struct usb_device *udev) > > } > > > > if (removable) > > - udev->removable = USB_DEVICE_REMOVABLE; > > + dev_set_removable(&udev->dev, DEVICE_REMOVABLE); > > else > > - udev->removable = USB_DEVICE_FIXED; > > + dev_set_removable(&udev->dev, DEVICE_FIXED); > > > > } > > > > @@ -2546,8 +2548,7 @@ int usb_new_device(struct usb_device *udev) > > device_enable_async_suspend(&udev->dev); > > > > /* check whether the hub or firmware marks this port as non-removable */ > > - if (udev->parent) > > - set_usb_port_removable(udev); > > + set_usb_port_removable(udev); > > > > /* Register the device. The device driver is responsible > > * for configuring the device and invoking the add-device > > diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c > > index 5a168ba9fc51..fa2e49d432ff 100644 > > --- a/drivers/usb/core/sysfs.c > > +++ b/drivers/usb/core/sysfs.c > > @@ -301,29 +301,6 @@ static ssize_t urbnum_show(struct device *dev, struct device_attribute *attr, > > } > > static DEVICE_ATTR_RO(urbnum); > > > > -static ssize_t removable_show(struct device *dev, struct device_attribute *attr, > > - char *buf) > > -{ > > - struct usb_device *udev; > > - char *state; > > - > > - udev = to_usb_device(dev); > > - > > - switch (udev->removable) { > > - case USB_DEVICE_REMOVABLE: > > - state = "removable"; > > - break; > > - case USB_DEVICE_FIXED: > > - state = "fixed"; > > - break; > > - default: > > - state = "unknown"; > > - } > > - > > - return sprintf(buf, "%s\n", state); > > -} > > -static DEVICE_ATTR_RO(removable); > > - > > static ssize_t ltm_capable_show(struct device *dev, > > struct device_attribute *attr, char *buf) > > { > > @@ -828,7 +805,6 @@ static struct attribute *dev_attrs[] = { > > &dev_attr_avoid_reset_quirk.attr, > > &dev_attr_authorized.attr, > > &dev_attr_remove.attr, > > - &dev_attr_removable.attr, > > &dev_attr_ltm_capable.attr, > > #ifdef CONFIG_OF > > &dev_attr_devspec.attr, > > diff --git a/include/linux/device.h b/include/linux/device.h > > index 38a2071cf776..e3a4749694b7 100644 > > --- a/include/linux/device.h > > +++ b/include/linux/device.h > > @@ -350,6 +350,22 @@ enum dl_dev_state { > > DL_DEV_UNBINDING, > > }; > > > > +/** > > + * enum device_removable - Whether the device is removable. The criteria for a > > + * device to be classified as removable is determined by its subsystem or bus. > > + * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this > > + * device (default). > > + * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown. > > + * @DEVICE_FIXED: Device is not removable by the user. > > + * @DEVICE_REMOVABLE: Device is removable by the user. > > + */ > > +enum device_removable { > > + DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */ > > + DEVICE_REMOVABLE_UNKNOWN, > > + DEVICE_FIXED, > > + DEVICE_REMOVABLE, > > +}; > > + > > /** > > * struct dev_links_info - Device data related to device links. > > * @suppliers: List of links to supplier devices. > > @@ -431,6 +447,9 @@ struct dev_links_info { > > * device (i.e. the bus driver that discovered the device). > > * @iommu_group: IOMMU group the device belongs to. > > * @iommu: Per device generic IOMMU runtime data > > + * @removable: Whether the device can be removed from the system. This > > + * should be set by the subsystem / bus driver that discovered > > + * the device. > > * > > * @offline_disabled: If set, the device is permanently online. > > * @offline: Set after successful invocation of bus type's .offline(). > > @@ -544,6 +563,8 @@ struct device { > > struct iommu_group *iommu_group; > > struct dev_iommu *iommu; > > > > + enum device_removable removable; > > + > > bool offline_disabled:1; > > bool offline:1; > > bool of_node_reused:1; > > @@ -782,6 +803,22 @@ static inline bool dev_has_sync_state(struct device *dev) > > return false; > > } > > > > +static inline void dev_set_removable(struct device *dev, > > + enum device_removable removable) > > +{ > > + dev->removable = removable; > > +} > > + > > +static inline bool dev_is_removable(struct device *dev) > > +{ > > + return dev && dev->removable == DEVICE_REMOVABLE; > > +} > > + > > +static inline bool dev_removable_is_valid(struct device *dev) > > +{ > > + return dev && dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED; > > I probably wouldn't check for "dev" being non-NULL in these two > functions unless you have a use case that requires it. Done, I removed the check and submitted the v5 here: https://lore.kernel.org/patchwork/patch/1435682/ Thanks, Rajat > > > +} > > + > > /* > > * High level routines for use by the bus drivers > > */ > > diff --git a/include/linux/usb.h b/include/linux/usb.h > > index eaae24217e8a..b9bd664f44a1 100644 > > --- a/include/linux/usb.h > > +++ b/include/linux/usb.h > > @@ -473,12 +473,6 @@ struct usb_dev_state; > > > > struct usb_tt; > > > > -enum usb_device_removable { > > - USB_DEVICE_REMOVABLE_UNKNOWN = 0, > > - USB_DEVICE_REMOVABLE, > > - USB_DEVICE_FIXED, > > -}; > > - > > enum usb_port_connect_type { > > USB_PORT_CONNECT_TYPE_UNKNOWN = 0, > > USB_PORT_CONNECT_TYPE_HOT_PLUG, > > @@ -703,7 +697,6 @@ struct usb_device { > > #endif > > struct wusb_dev *wusb_dev; > > int slot_id; > > - enum usb_device_removable removable; > > struct usb2_lpm_parameters l1_params; > > struct usb3_lpm_parameters u1_params; > > struct usb3_lpm_parameters u2_params; > > -- > > 2.31.1.751.gd2f1c929bd-goog > >
diff --git a/Documentation/ABI/testing/sysfs-bus-usb b/Documentation/ABI/testing/sysfs-bus-usb index bf2c1968525f..73eb23bc1f34 100644 --- a/Documentation/ABI/testing/sysfs-bus-usb +++ b/Documentation/ABI/testing/sysfs-bus-usb @@ -154,17 +154,6 @@ Description: files hold a string value (enable or disable) indicating whether or not USB3 hardware LPM U1 or U2 is enabled for the device. -What: /sys/bus/usb/devices/.../removable -Date: February 2012 -Contact: Matthew Garrett <mjg@redhat.com> -Description: - Some information about whether a given USB device is - physically fixed to the platform can be inferred from a - combination of hub descriptor bits and platform-specific data - such as ACPI. This file will read either "removable" or - "fixed" if the information is available, and "unknown" - otherwise. - What: /sys/bus/usb/devices/.../ltm_capable Date: July 2012 Contact: Sarah Sharp <sarah.a.sharp@linux.intel.com> diff --git a/Documentation/ABI/testing/sysfs-devices-removable b/Documentation/ABI/testing/sysfs-devices-removable new file mode 100644 index 000000000000..acf7766e800b --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-removable @@ -0,0 +1,17 @@ +What: /sys/devices/.../removable +Date: May 2021 +Contact: Rajat Jain <rajatxjain@gmail.com> +Description: + Information about whether a given device can be removed from the + platform by the user. This is determined by its subsystem in a + bus / platform-specific way. This attribute is only present for + devices that can support determining such information: + + "removable": device can be removed from the platform by the user + "fixed": device is fixed to the platform / cannot be removed + by the user. + "unknown": The information is unavailable / cannot be deduced. + + Currently this is only supported by USB (which infers the + information from a combination of hub descriptor bits and + platform-specific data such as ACPI). diff --git a/drivers/base/core.c b/drivers/base/core.c index 4a8bf8cda52b..ae3d6a4a79fb 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2404,6 +2404,25 @@ static ssize_t online_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RW(online); +static ssize_t removable_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + const char *loc; + + switch (dev->removable) { + case DEVICE_REMOVABLE: + loc = "removable"; + break; + case DEVICE_FIXED: + loc = "fixed"; + break; + default: + loc = "unknown"; + } + return sysfs_emit(buf, "%s\n", loc); +} +static DEVICE_ATTR_RO(removable); + int device_add_groups(struct device *dev, const struct attribute_group **groups) { return sysfs_create_groups(&dev->kobj, groups); @@ -2581,8 +2600,16 @@ static int device_add_attrs(struct device *dev) goto err_remove_dev_online; } + if (dev_removable_is_valid(dev)) { + error = device_create_file(dev, &dev_attr_removable); + if (error) + goto err_remove_dev_waiting_for_supplier; + } + return 0; + err_remove_dev_waiting_for_supplier: + device_remove_file(dev, &dev_attr_waiting_for_supplier); err_remove_dev_online: device_remove_file(dev, &dev_attr_online); err_remove_dev_groups: @@ -2602,6 +2629,7 @@ static void device_remove_attrs(struct device *dev) struct class *class = dev->class; const struct device_type *type = dev->type; + device_remove_file(dev, &dev_attr_removable); device_remove_file(dev, &dev_attr_waiting_for_supplier); device_remove_file(dev, &dev_attr_online); device_remove_groups(dev, dev->groups); diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index b2bc4b7c4289..366cb7ef3b72 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -2432,6 +2432,8 @@ static void set_usb_port_removable(struct usb_device *udev) u16 wHubCharacteristics; bool removable = true; + dev_set_removable(&udev->dev, DEVICE_REMOVABLE_UNKNOWN); + if (!hdev) return; @@ -2443,11 +2445,11 @@ static void set_usb_port_removable(struct usb_device *udev) */ switch (hub->ports[udev->portnum - 1]->connect_type) { case USB_PORT_CONNECT_TYPE_HOT_PLUG: - udev->removable = USB_DEVICE_REMOVABLE; + dev_set_removable(&udev->dev, DEVICE_REMOVABLE); return; case USB_PORT_CONNECT_TYPE_HARD_WIRED: case USB_PORT_NOT_USED: - udev->removable = USB_DEVICE_FIXED; + dev_set_removable(&udev->dev, DEVICE_FIXED); return; default: break; @@ -2472,9 +2474,9 @@ static void set_usb_port_removable(struct usb_device *udev) } if (removable) - udev->removable = USB_DEVICE_REMOVABLE; + dev_set_removable(&udev->dev, DEVICE_REMOVABLE); else - udev->removable = USB_DEVICE_FIXED; + dev_set_removable(&udev->dev, DEVICE_FIXED); } @@ -2546,8 +2548,7 @@ int usb_new_device(struct usb_device *udev) device_enable_async_suspend(&udev->dev); /* check whether the hub or firmware marks this port as non-removable */ - if (udev->parent) - set_usb_port_removable(udev); + set_usb_port_removable(udev); /* Register the device. The device driver is responsible * for configuring the device and invoking the add-device diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c index 5a168ba9fc51..fa2e49d432ff 100644 --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -301,29 +301,6 @@ static ssize_t urbnum_show(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_RO(urbnum); -static ssize_t removable_show(struct device *dev, struct device_attribute *attr, - char *buf) -{ - struct usb_device *udev; - char *state; - - udev = to_usb_device(dev); - - switch (udev->removable) { - case USB_DEVICE_REMOVABLE: - state = "removable"; - break; - case USB_DEVICE_FIXED: - state = "fixed"; - break; - default: - state = "unknown"; - } - - return sprintf(buf, "%s\n", state); -} -static DEVICE_ATTR_RO(removable); - static ssize_t ltm_capable_show(struct device *dev, struct device_attribute *attr, char *buf) { @@ -828,7 +805,6 @@ static struct attribute *dev_attrs[] = { &dev_attr_avoid_reset_quirk.attr, &dev_attr_authorized.attr, &dev_attr_remove.attr, - &dev_attr_removable.attr, &dev_attr_ltm_capable.attr, #ifdef CONFIG_OF &dev_attr_devspec.attr, diff --git a/include/linux/device.h b/include/linux/device.h index 38a2071cf776..e3a4749694b7 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -350,6 +350,22 @@ enum dl_dev_state { DL_DEV_UNBINDING, }; +/** + * enum device_removable - Whether the device is removable. The criteria for a + * device to be classified as removable is determined by its subsystem or bus. + * @DEVICE_REMOVABLE_NOT_SUPPORTED: This attribute is not supported for this + * device (default). + * @DEVICE_REMOVABLE_UNKNOWN: Device location is Unknown. + * @DEVICE_FIXED: Device is not removable by the user. + * @DEVICE_REMOVABLE: Device is removable by the user. + */ +enum device_removable { + DEVICE_REMOVABLE_NOT_SUPPORTED = 0, /* must be 0 */ + DEVICE_REMOVABLE_UNKNOWN, + DEVICE_FIXED, + DEVICE_REMOVABLE, +}; + /** * struct dev_links_info - Device data related to device links. * @suppliers: List of links to supplier devices. @@ -431,6 +447,9 @@ struct dev_links_info { * device (i.e. the bus driver that discovered the device). * @iommu_group: IOMMU group the device belongs to. * @iommu: Per device generic IOMMU runtime data + * @removable: Whether the device can be removed from the system. This + * should be set by the subsystem / bus driver that discovered + * the device. * * @offline_disabled: If set, the device is permanently online. * @offline: Set after successful invocation of bus type's .offline(). @@ -544,6 +563,8 @@ struct device { struct iommu_group *iommu_group; struct dev_iommu *iommu; + enum device_removable removable; + bool offline_disabled:1; bool offline:1; bool of_node_reused:1; @@ -782,6 +803,22 @@ static inline bool dev_has_sync_state(struct device *dev) return false; } +static inline void dev_set_removable(struct device *dev, + enum device_removable removable) +{ + dev->removable = removable; +} + +static inline bool dev_is_removable(struct device *dev) +{ + return dev && dev->removable == DEVICE_REMOVABLE; +} + +static inline bool dev_removable_is_valid(struct device *dev) +{ + return dev && dev->removable != DEVICE_REMOVABLE_NOT_SUPPORTED; +} + /* * High level routines for use by the bus drivers */ diff --git a/include/linux/usb.h b/include/linux/usb.h index eaae24217e8a..b9bd664f44a1 100644 --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -473,12 +473,6 @@ struct usb_dev_state; struct usb_tt; -enum usb_device_removable { - USB_DEVICE_REMOVABLE_UNKNOWN = 0, - USB_DEVICE_REMOVABLE, - USB_DEVICE_FIXED, -}; - enum usb_port_connect_type { USB_PORT_CONNECT_TYPE_UNKNOWN = 0, USB_PORT_CONNECT_TYPE_HOT_PLUG, @@ -703,7 +697,6 @@ struct usb_device { #endif struct wusb_dev *wusb_dev; int slot_id; - enum usb_device_removable removable; struct usb2_lpm_parameters l1_params; struct usb3_lpm_parameters u1_params; struct usb3_lpm_parameters u2_params;
Move the "removable" attribute from USB to core in order to allow it to be supported by other subsystem / buses. Individual buses that want to support this attribute can populate the removable property of the device while enumerating it with the 3 possible values - - "unknown" - "fixed" - "removable" Leaving the field unchanged (i.e. "not supported") would mean that the attribute would not show up in sysfs for that device. The UAPI (location, symantics etc) for the attribute remains unchanged. Signed-off-by: Rajat Jain <rajatja@google.com> --- v4: - instead of devicce_type->supports_removable, add 1 more value in device_removable_enum - documentation update. - Remove "Acked-by" and "Reviewed-by" tags from previous versions. v3: - Minor commit log / comments updated. - use sysfs_emit() - Rename local variable name (state -> loc) - change supports_removable flag from bool to bitfield. v2: Add documentation Documentation/ABI/testing/sysfs-bus-usb | 11 ------ .../ABI/testing/sysfs-devices-removable | 17 +++++++++ drivers/base/core.c | 28 ++++++++++++++ drivers/usb/core/hub.c | 13 ++++--- drivers/usb/core/sysfs.c | 24 ------------ include/linux/device.h | 37 +++++++++++++++++++ include/linux/usb.h | 7 ---- 7 files changed, 89 insertions(+), 48 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-devices-removable