From 6423d2951087231706246f81851067f7f0593d4a Mon Sep 17 00:00:00 2001 From: Won Chung Date: Mon, 14 Mar 2022 19:54:58 +0000 Subject: driver core: Add sysfs support for physical location of a device When ACPI table includes _PLD fields for a device, create a new directory (physical_location) in sysfs to share _PLD fields. Currently without PLD information, when there are multiple of same devices, it is hard to distinguish which device corresponds to which physical device at which location. For example, when there are two Type C connectors, it is hard to find out which connector corresponds to the Type C port on the left panel versus the Type C port on the right panel. With PLD information provided, we can determine which specific device at which location is doing what. _PLD output includes much more fields, but only generic fields are added and exposed to sysfs, so that non-ACPI devices can also support it in the future. The minimal generic fields needed for locating a device are the following. - panel - vertical_position - horizontal_position - dock - lid Signed-off-by: Won Chung Link: https://lore.kernel.org/r/20220314195458.271430-1-wonchung@google.com Signed-off-by: Greg Kroah-Hartman --- include/linux/device.h | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 93459724dcde..766fbea6ca83 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -386,6 +386,75 @@ struct dev_msi_info { #endif }; +/** + * enum device_physical_location_panel - Describes which panel surface of the + * system's housing the device connection point resides on. + * @DEVICE_PANEL_TOP: Device connection point is on the top panel. + * @DEVICE_PANEL_BOTTOM: Device connection point is on the bottom panel. + * @DEVICE_PANEL_LEFT: Device connection point is on the left panel. + * @DEVICE_PANEL_RIGHT: Device connection point is on the right panel. + * @DEVICE_PANEL_FRONT: Device connection point is on the front panel. + * @DEVICE_PANEL_BACK: Device connection point is on the back panel. + * @DEVICE_PANEL_UNKNOWN: The panel with device connection point is unknown. + */ +enum device_physical_location_panel { + DEVICE_PANEL_TOP, + DEVICE_PANEL_BOTTOM, + DEVICE_PANEL_LEFT, + DEVICE_PANEL_RIGHT, + DEVICE_PANEL_FRONT, + DEVICE_PANEL_BACK, + DEVICE_PANEL_UNKNOWN, +}; + +/** + * enum device_physical_location_vertical_position - Describes vertical + * position of the device connection point on the panel surface. + * @DEVICE_VERT_POS_UPPER: Device connection point is at upper part of panel. + * @DEVICE_VERT_POS_CENTER: Device connection point is at center part of panel. + * @DEVICE_VERT_POS_LOWER: Device connection point is at lower part of panel. + */ +enum device_physical_location_vertical_position { + DEVICE_VERT_POS_UPPER, + DEVICE_VERT_POS_CENTER, + DEVICE_VERT_POS_LOWER, +}; + +/** + * enum device_physical_location_horizontal_position - Describes horizontal + * position of the device connection point on the panel surface. + * @DEVICE_HORI_POS_LEFT: Device connection point is at left part of panel. + * @DEVICE_HORI_POS_CENTER: Device connection point is at center part of panel. + * @DEVICE_HORI_POS_RIGHT: Device connection point is at right part of panel. + */ +enum device_physical_location_horizontal_position { + DEVICE_HORI_POS_LEFT, + DEVICE_HORI_POS_CENTER, + DEVICE_HORI_POS_RIGHT, +}; + +/** + * struct device_physical_location - Device data related to physical location + * of the device connection point. + * @panel: Panel surface of the system's housing that the device connection + * point resides on. + * @vertical_position: Vertical position of the device connection point within + * the panel. + * @horizontal_position: Horizontal position of the device connection point + * within the panel. + * @dock: Set if the device connection point resides in a docking station or + * port replicator. + * @lid: Set if this device connection point resides on the lid of laptop + * system. + */ +struct device_physical_location { + enum device_physical_location_panel panel; + enum device_physical_location_vertical_position vertical_position; + enum device_physical_location_horizontal_position horizontal_position; + bool dock; + bool lid; +}; + /** * struct device - The basic device structure * @parent: The device's "parent" device, the device to which it is attached. @@ -453,6 +522,8 @@ struct dev_msi_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 + * @physical_location: Describes physical location of the device connection + * point in the system housing. * @removable: Whether the device can be removed from the system. This * should be set by the subsystem / bus driver that discovered * the device. @@ -567,6 +638,8 @@ struct device { struct iommu_group *iommu_group; struct dev_iommu *iommu; + struct device_physical_location *physical_location; + enum device_removable removable; bool offline_disabled:1; -- cgit v1.2.3 From d864b8ea6468cf1dce614a58eec92a23d8e07fec Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 26 Apr 2022 12:22:44 -0700 Subject: cxl/acpi: Add root device lockdep validation The CXL "root" device, ACPI0017, is an attach point for coordinating platform level CXL resources and is the parent device for a CXL port topology tree. As such it has distinct locking rules relative to other CXL subsystem objects, but because it is an ACPI device the lock class is established well before it is given to the cxl_acpi driver. However, the lockdep API does support changing the lock class "live" for situations like this. Add a device_lock_set_class() helper that a driver can use in ->probe() to set a custom lock class, and device_lock_reset_class() to return to the default "no validate" class before the custom lock class key goes out of scope after ->remove(). Note the helpers are all macros to support dead code elimination in the CONFIG_PROVE_LOCKING=n case, however device_set_lock_class() still needs #ifdef CONFIG_PROVE_LOCKING since lockdep_match_class() explicitly does not have a helper in the CONFIG_PROVE_LOCKING=n case (see comment in lockdep.h). The lockdep API needs 2 small tweaks to prevent "unused" warnings for the @key argument to lock_set_class(), and a new lock_set_novalidate_class() is added to supplement lockdep_set_novalidate_class() in the cases where the lock class is converted while the lock is held. Suggested-by: Peter Zijlstra Cc: "Rafael J. Wysocki" Cc: Ingo Molnar Cc: Will Deacon Cc: Waiman Long Cc: Boqun Feng Cc: Alison Schofield Cc: Vishal Verma Cc: Ben Widawsky Cc: Jonathan Cameron Reviewed-by: Greg Kroah-Hartman Reviewed-by: Ira Weiny Link: https://lore.kernel.org/r/165100081305.1528964.11138612430659737238.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams --- include/linux/device.h | 43 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 93459724dcde..833b0b3b0193 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -850,6 +850,49 @@ static inline bool device_supports_offline(struct device *dev) return dev->bus && dev->bus->offline && dev->bus->online; } +#define __device_lock_set_class(dev, name, key) \ +do { \ + struct device *__d2 __maybe_unused = dev; \ + lock_set_class(&__d2->mutex.dep_map, name, key, 0, _THIS_IP_); \ +} while (0) + +/** + * device_lock_set_class - Specify a temporary lock class while a device + * is attached to a driver + * @dev: device to modify + * @key: lock class key data + * + * This must be called with the device_lock() already held, for example + * from driver ->probe(). Take care to only override the default + * lockdep_no_validate class. + */ +#ifdef CONFIG_LOCKDEP +#define device_lock_set_class(dev, key) \ +do { \ + struct device *__d = dev; \ + dev_WARN_ONCE(__d, !lockdep_match_class(&__d->mutex, \ + &__lockdep_no_validate__), \ + "overriding existing custom lock class\n"); \ + __device_lock_set_class(__d, #key, key); \ +} while (0) +#else +#define device_lock_set_class(dev, key) __device_lock_set_class(dev, #key, key) +#endif + +/** + * device_lock_reset_class - Return a device to the default lockdep novalidate state + * @dev: device to modify + * + * This must be called with the device_lock() already held, for example + * from driver ->remove(). + */ +#define device_lock_reset_class(dev) \ +do { \ + struct device *__d __maybe_unused = dev; \ + lock_set_novalidate_class(&__d->mutex.dep_map, "&dev->mutex", \ + _THIS_IP_); \ +} while (0) + void lock_device_hotplug(void); void unlock_device_hotplug(void); int lock_device_hotplug_sysfs(void); -- cgit v1.2.3 From fd3abd2cafa46955846d731b9a6ded2c19ab73d8 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 21 Apr 2022 08:33:45 -0700 Subject: device-core: Kill the lockdep_mutex Per Peter [1], the lockdep API has native support for all the use cases lockdep_mutex was attempting to enable. Now that all lockdep_mutex users have been converted to those APIs, drop this lock. Link: https://lore.kernel.org/r/Ylf0dewci8myLvoW@hirez.programming.kicks-ass.net [1] Cc: Greg Kroah-Hartman Cc: "Rafael J. Wysocki" Suggested-by: Peter Zijlstra Reviewed-by: Ira Weiny Acked-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/165055522548.3745911.14298368286915484086.stgit@dwillia2-desk3.amr.corp.intel.com Signed-off-by: Dan Williams --- include/linux/device.h | 5 ----- 1 file changed, 5 deletions(-) (limited to 'include/linux/device.h') diff --git a/include/linux/device.h b/include/linux/device.h index 833b0b3b0193..073f1b0126ac 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -400,8 +400,6 @@ struct dev_msi_info { * This identifies the device type and carries type-specific * information. * @mutex: Mutex to synchronize calls to its driver. - * @lockdep_mutex: An optional debug lock that a subsystem can use as a - * peer lock to gain localized lockdep coverage of the device_lock. * @bus: Type of bus device is on. * @driver: Which driver has allocated this * @platform_data: Platform data specific to the device. @@ -499,9 +497,6 @@ struct device { core doesn't touch it */ void *driver_data; /* Driver data, set and get with dev_set_drvdata/dev_get_drvdata */ -#ifdef CONFIG_PROVE_LOCKING - struct mutex lockdep_mutex; -#endif struct mutex mutex; /* mutex to synchronize calls to * its driver. */ -- cgit v1.2.3