/* * All the USB notify logic * * (C) Copyright 2005 Greg Kroah-Hartman * * notifier functions originally based on those in kernel/sys.c * but fixed up to not be so broken. * * Released under the GPLv2 only. * SPDX-License-Identifier: GPL-2.0 */ #include #include #include #include #include #include "usb.h" static BLOCKING_NOTIFIER_HEAD(usb_notifier_list); /** * usb_register_notify - register a notifier callback whenever a usb change happens * @nb: pointer to the notifier block for the callback events. * * These changes are either USB devices or busses being added or removed. */ void usb_register_notify(struct notifier_block *nb) { blocking_notifier_chain_register(&usb_notifier_list, nb); } EXPORT_SYMBOL_GPL(usb_register_notify); /** * usb_unregister_notify - unregister a notifier callback * @nb: pointer to the notifier block for the callback events. * * usb_register_notify() must have been previously called for this function * to work properly. */ void usb_unregister_notify(struct notifier_block *nb) { blocking_notifier_chain_unregister(&usb_notifier_list, nb); } EXPORT_SYMBOL_GPL(usb_unregister_notify); void usb_notify_add_device(struct usb_device *udev) { blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_ADD, udev); } void usb_notify_remove_device(struct usb_device *udev) { /* Protect against simultaneous usbfs open */ mutex_lock(&usbfs_mutex); blocking_notifier_call_chain(&usb_notifier_list, USB_DEVICE_REMOVE, udev); mutex_unlock(&usbfs_mutex); } void usb_notify_add_bus(struct usb_bus *ubus) { blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_ADD, ubus); } void usb_notify_remove_bus(struct usb_bus *ubus) { blocking_notifier_call_chain(&usb_notifier_list, USB_BUS_REMOVE, ubus); } ove'>logtreecommitdiff
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authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-02-01 17:45:02 +0000
committerIngo Molnar <mingo@kernel.org>2017-02-01 21:17:49 +0100
commitc8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch)
treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /sound/pci/ali5451/Makefile
parentbf29bddf0417a4783da3b24e8c9e017ac649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'sound/pci/ali5451/Makefile')