user/sven/linux.git/include/linux/device.h, branch v4.19.209

PCI/MSI: Protect msi_desc::masked for multi-MSI

2021-08-26T12:36:41Z

commit 77e89afc25f30abd56e76a809ee2884d7c1b63ce upstream. Multi-MSI uses a single MSI descriptor and there is a single mask register when the device supports per vector masking. To avoid reading back the mask register the value is cached in the MSI descriptor and updates are done by clearing and setting bits in the cache and writing it to the device. But nothing protects msi_desc::masked and the mask register from being modified concurrently on two different CPUs for two different Linux interrupts which belong to the same multi-MSI descriptor. Add a lock to struct device and protect any operation on the mask and the mask register with it. This makes the update of msi_desc::masked unconditional, but there is no place which requires a modification of the hardware register without updating the masked cache. msi_mask_irq() is now an empty wrapper which will be cleaned up in follow up changes. The problem goes way back to the initial support of multi-MSI, but picking the commit which introduced the mask cache is a valid cut off point (2.6.30). Fixes: f2440d9acbe8 ("PCI MSI: Refactor interrupt masking code") Signed-off-by: Thomas Gleixner Tested-by: Marc Zyngier Reviewed-by: Marc Zyngier Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210729222542.726833414@linutronix.de Signed-off-by: Greg Kroah-Hartman

driver core: Remove device link creation limitation

2020-03-20T10:55:58Z

commit 515db266a9dace92b0cbaed9a6044dd5304b8ca9 upstream. If device_link_add() is called for a consumer/supplier pair with an existing device link between them and the existing link's type is not in agreement with the flags passed to that function by its caller, NULL will be returned. That is seriously inconvenient, because it forces the callers of device_link_add() to worry about what others may or may not do even if that is not relevant to them for any other reasons. It turns out, however, that this limitation can be made go away relatively easily. The underlying observation is that if DL_FLAG_STATELESS has been passed to device_link_add() in flags for the given consumer/supplier pair at least once, calling either device_link_del() or device_link_remove() to release the link returned by it should work, but there are no other requirements associated with that flag. In turn, if at least one of the callers of device_link_add() for the given consumer/supplier pair has not passed DL_FLAG_STATELESS to it in flags, the driver core should track the status of the link and act on it as appropriate (ie. the link should be treated as "managed"). This means that DL_FLAG_STATELESS needs to be set for managed device links and it should be valid to call device_link_del() or device_link_remove() to drop references to them in certain sutiations. To allow that to happen, introduce a new (internal) device link flag called DL_FLAG_MANAGED and make device_link_add() set it automatically whenever DL_FLAG_STATELESS is not passed to it. Also make it take additional references to existing device links that were previously stateless (that is, with DL_FLAG_STATELESS set and DL_FLAG_MANAGED unset) and will need to be managed going forward and initialize their status (which has been DL_STATE_NONE so far). Accordingly, when a managed device link is dropped automatically by the driver core, make it clear DL_FLAG_MANAGED, reset the link's status back to DL_STATE_NONE and drop the reference to it associated with DL_FLAG_MANAGED instead of just deleting it right away (to allow it to stay around in case it still needs to be released explicitly by someone). With that, since setting DL_FLAG_STATELESS doesn't mean that the device link in question is not managed any more, replace all of the status-tracking checks against DL_FLAG_STATELESS with analogous checks against DL_FLAG_MANAGED and update the documentation to reflect these changes. While at it, make device_link_add() reject flags that it does not recognize, including DL_FLAG_MANAGED. Signed-off-by: Rafael J. Wysocki Reviewed-by: Saravana Kannan Tested-by: Marek Szyprowski Review-by: Saravana Kannan Link: https://lore.kernel.org/r/2305283.AStDPdUUnE@kreacher Signed-off-by: Saravana Kannan Signed-off-by: Greg Kroah-Hartman

driver core: Add device link flag DL_FLAG_AUTOPROBE_CONSUMER

2020-03-20T10:55:58Z

commit e7dd40105aac9ba051e44ad711123bc53a5e4c71 upstream. Add a new device link flag, DL_FLAG_AUTOPROBE_CONSUMER, to request the driver core to probe for a consumer driver automatically after binding a driver to the supplier device on a persistent managed device link. As unbinding the supplier driver on a managed device link causes the consumer driver to be detached from its device automatically, this flag provides a complementary mechanism which is needed to address some "composite device" use cases. Signed-off-by: Rafael J. Wysocki Signed-off-by: Saravana Kannan Signed-off-by: Greg Kroah-Hartman

devres: allow const resource arguments

2020-01-27T13:51:00Z

[ Upstream commit 9dea44c91469512d346e638694c22c30a5273992 ] devm_ioremap_resource() does not currently take 'const' arguments, which results in a warning from the first driver trying to do it anyway: drivers/gpio/gpio-amd-fch.c: In function 'amd_fch_gpio_probe': drivers/gpio/gpio-amd-fch.c:171:49: error: passing argument 2 of 'devm_ioremap_resource' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers] priv->base = devm_ioremap_resource(&pdev->dev, &amd_fch_gpio_iores); ^~~~~~~~~~~~~~~~~~~ Change the prototype to allow it, as there is no real reason not to. Fixes: 9bb2e0452508 ("gpio: amd: Make resource struct const") Signed-off-by: Arnd Bergmann Link: https://lore.kernel.org/r/20190628150049.1108048-1-arnd@arndb.de Acked-by: Greg Kroah-Hartman Reviwed-By: Enrico Weigelt Signed-off-by: Linus Walleij Signed-off-by: Sasha Levin

driver core: Fix PM-runtime for links added during consumer probe

2020-01-27T13:50:26Z

[ Upstream commit 36003d4cf57ca431fb3f94d317bcca426a2394d6 ] Commit 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance") introduced a regression that causes suppliers to be suspended prematurely for device links added during consumer driver probe if the initial PM-runtime status of the consumer is "suspended" and the consumer is resumed after adding the link and before pm_runtime_put_suppliers() is called. In that case, pm_runtime_put_suppliers() will drop the rpm_active refcount for the link by one and (since rpm_active is equal to two after the preceding consumer resume) the supplier's PM-runtime usage counter will be decremented, which may cause the supplier to suspend even though the consumer's PM-runtime status is "active". For this reason, partially revert commit 4c06c4e6cf63 as the problem it tried to fix needs to be addressed somewhat differently, and change pm_runtime_get_suppliers() and pm_runtime_put_suppliers() so that the latter only drops rpm_active references acquired by the former. [This requires adding a new field to struct device_link, but I coulnd't find a cleaner way to address the issue that would work in all cases.] This causes pm_runtime_put_suppliers() to effectively ignore device links added during consumer probe, so device_link_add() doesn't need to worry about ensuring that suppliers will remain active after pm_runtime_put_suppliers() for links created with DL_FLAG_RPM_ACTIVE set and it only needs to bump up rpm_active by one for those links, so pm_runtime_active_link() is not necessary any more. Fixes: 4c06c4e6cf63 ("driver core: Fix possible supplier PM-usage counter imbalance") Reported-by: Jon Hunter Tested-by: Jon Hunter Tested-by: Ulf Hansson Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Tested-by: Thierry Reding Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

driver core: Fix handling of runtime PM flags in device_link_add()

2020-01-27T13:50:17Z

[ Upstream commit e2f3cd831a280fc226118d9369bf3f77aab58c56 ] After commit ead18c23c263 ("driver core: Introduce device links reference counting"), if there is a link between the given supplier and the given consumer already, device_link_add() will refcount it and return it unconditionally without updating its flags. It is possible, however, that the second (or any subsequent) caller of device_link_add() for the same consumer-supplier pair will pass DL_FLAG_PM_RUNTIME, possibly along with DL_FLAG_RPM_ACTIVE, in flags to it and the existing link may not behave as expected then. First, if DL_FLAG_PM_RUNTIME is not set in the existing link's flags at all, it needs to be set like during the original initialization of the link. Second, if DL_FLAG_RPM_ACTIVE is passed to device_link_add() in flags (in addition to DL_FLAG_PM_RUNTIME), the existing link should to be updated to reflect the "active" runtime PM configuration of the consumer-supplier pair and extra care must be taken here to avoid possible destructive races with runtime PM of the consumer. To that end, redefine the rpm_active field in struct device_link as a refcount, initialize it to 1 and make rpm_resume() (for the consumer) and device_link_add() increment it whenever they acquire a runtime PM reference on the supplier device. Accordingly, make rpm_suspend() (for the consumer) and pm_runtime_clean_up_links() decrement it and drop runtime PM references to the supplier device in a loop until rpm_active becones 1 again. Fixes: ead18c23c263 ("driver core: Introduce device links reference counting") Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

drivers/base: Introduce kill_device()

2019-08-09T15:52:28Z

commit 00289cd87676e14913d2d8492d1ce05c4baafdae upstream. The libnvdimm subsystem arranges for devices to be destroyed as a result of a sysfs operation. Since device_unregister() cannot be called from an actively running sysfs attribute of the same device libnvdimm arranges for device_unregister() to be performed in an out-of-line async context. The driver core maintains a 'dead' state for coordinating its own racing async registration / de-registration requests. Rather than add local 'dead' state tracking infrastructure to libnvdimm device objects, export the existing state tracking via a new kill_device() helper. The kill_device() helper simply marks the device as dead, i.e. that it is on its way to device_del(), or returns that the device was already dead. This can be used in advance of calling device_unregister() for subsystems like libnvdimm that might need to handle multiple user threads racing to delete a device. This refactoring does not change any behavior, but it is a pre-requisite for follow-on fixes and therefore marked for -stable. Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Fixes: 4d88a97aa9e8 ("libnvdimm, nvdimm: dimm driver and base libnvdimm device-driver...") Cc: Tested-by: Jane Chu Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/156341207332.292348.14959761496009347574.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams Signed-off-by: Sasha Levin

drivers: base: Helpers for adding device connection descriptions

2019-04-03T04:26:30Z

commit cd7753d371388e712e3ee52b693459f9b71aaac2 upstream. Introducing helpers for adding and removing multiple device connection descriptions at once. Acked-by: Hans de Goede Tested-by: Hans de Goede Signed-off-by: Heikki Krogerus Signed-off-by: Greg Kroah-Hartman

Merge tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

2018-08-18T18:44:53Z

Pull driver core updates from Greg KH: "Here are all of the driver core and related patches for 4.19-rc1. Nothing huge here, just a number of small cleanups and the ability to now stop the deferred probing after init happens. All of these have been in linux-next for a while with only a merge issue reported" * tag 'driver-core-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits) base: core: Remove WARN_ON from link dependencies check drivers/base: stop new probing during shutdown drivers: core: Remove glue dirs from sysfs earlier driver core: remove unnecessary function extern declare sysfs.h: fix non-kernel-doc comment PM / Domains: Stop deferring probe at the end of initcall iommu: Remove IOMMU_OF_DECLARE iommu: Stop deferring probe at end of initcalls pinctrl: Support stopping deferred probe after initcalls dt-bindings: pinctrl: add a 'pinctrl-use-default' property driver core: allow stopping deferred probe after init driver core: add a debugfs entry to show deferred devices sysfs: Fix internal_create_group() for named group updates base: fix order of OF initialization linux/device.h: fix kernel-doc notation warning Documentation: update firmware loader fallback reference kobject: Replace strncpy with memcpy drivers: base: cacheinfo: use OF property_read_u32 instead of get_property,read_number kernfs: Replace strncpy with memcpy device: Add #define dev_fmt similar to #define pr_fmt ...

Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2018-08-18T18:04:51Z

Pull char/misc driver updates from Greg KH: "Here is the bit set of char/misc drivers for 4.19-rc1 There is a lot here, much more than normal, seems like everyone is writing new driver subsystems these days... Anyway, major things here are: - new FSI driver subsystem, yet-another-powerpc low-level hardware bus - gnss, finally an in-kernel GPS subsystem to try to tame all of the crazy out-of-tree drivers that have been floating around for years, combined with some really hacky userspace implementations. This is only for GNSS receivers, but you have to start somewhere, and this is great to see. Other than that, there are new slimbus drivers, new coresight drivers, new fpga drivers, and loads of DT bindings for all of these and existing drivers. All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits) android: binder: Rate-limit debug and userspace triggered err msgs fsi: sbefifo: Bump max command length fsi: scom: Fix NULL dereference misc: mic: SCIF Fix scif_get_new_port() error handling misc: cxl: changed asterisk position genwqe: card_base: Use true and false for boolean values misc: eeprom: assignment outside the if statement uio: potential double frees if __uio_register_device() fails eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency misc: ti-st: Fix memory leak in the error path of probe() android: binder: Show extra_buffers_size in trace firmware: vpd: Fix section enabled flag on vpd_section_destroy platform: goldfish: Retire pdev_bus goldfish: Use dedicated macros instead of manual bit shifting goldfish: Add missing includes to goldfish.h mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux dt-bindings: mux: add adi,adgs1408 Drivers: hv: vmbus: Cleanup synic memory free path Drivers: hv: vmbus: Remove use of slow_virt_to_phys() Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind() ...