/* * xen-acpi-pad.c - Xen pad interface * * Copyright (c) 2012, Intel Corporation. * Author: Liu, Jinsong * * This program is free software; you can redistribute it and/or modify it * under the terms and conditions of the GNU General Public License, * version 2, as published by the Free Software Foundation. * * This program is distributed in the hope it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #define ACPI_PROCESSOR_AGGREGATOR_CLASS "acpi_pad" #define ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME "Processor Aggregator" #define ACPI_PROCESSOR_AGGREGATOR_NOTIFY 0x80 static DEFINE_MUTEX(xen_cpu_lock); static int xen_acpi_pad_idle_cpus(unsigned int idle_nums) { struct xen_platform_op op; op.cmd = XENPF_core_parking; op.u.core_parking.type = XEN_CORE_PARKING_SET; op.u.core_parking.idle_nums = idle_nums; return HYPERVISOR_platform_op(&op); } static int xen_acpi_pad_idle_cpus_num(void) { struct xen_platform_op op; op.cmd = XENPF_core_parking; op.u.core_parking.type = XEN_CORE_PARKING_GET; return HYPERVISOR_platform_op(&op) ?: op.u.core_parking.idle_nums; } /* * Query firmware how many CPUs should be idle * return -1 on failure */ static int acpi_pad_pur(acpi_handle handle) { struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL}; union acpi_object *package; int num = -1; if (ACPI_FAILURE(acpi_evaluate_object(handle, "_PUR", NULL, &buffer))) return num; if (!buffer.length || !buffer.pointer) return num; package = buffer.pointer; if (package->type == ACPI_TYPE_PACKAGE && package->package.count == 2 && package->package.elements[0].integer.value == 1) /* rev 1 */ num = package->package.elements[1].integer.value; kfree(buffer.pointer); return num; } static void acpi_pad_handle_notify(acpi_handle handle) { int idle_nums; struct acpi_buffer param = { .length = 4, .pointer = (void *)&idle_nums, }; mutex_lock(&xen_cpu_lock); idle_nums = acpi_pad_pur(handle); if (idle_nums < 0) { mutex_unlock(&xen_cpu_lock); return; } idle_nums = xen_acpi_pad_idle_cpus(idle_nums) ?: xen_acpi_pad_idle_cpus_num(); if (idle_nums >= 0) acpi_evaluate_ost(handle, ACPI_PROCESSOR_AGGREGATOR_NOTIFY, 0, ¶m); mutex_unlock(&xen_cpu_lock); } static void acpi_pad_notify(acpi_handle handle, u32 event, void *data) { switch (event) { case ACPI_PROCESSOR_AGGREGATOR_NOTIFY: acpi_pad_handle_notify(handle); break; default: pr_warn("Unsupported event [0x%x]\n", event); break; } } static int acpi_pad_add(struct acpi_device *device) { acpi_status status; strcpy(acpi_device_name(device), ACPI_PROCESSOR_AGGREGATOR_DEVICE_NAME); strcpy(acpi_device_class(device), ACPI_PROCESSOR_AGGREGATOR_CLASS); status = acpi_install_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, acpi_pad_notify, device); if (ACPI_FAILURE(status)) return -ENODEV; return 0; } static int acpi_pad_remove(struct acpi_device *device) { mutex_lock(&xen_cpu_lock); xen_acpi_pad_idle_cpus(0); mutex_unlock(&xen_cpu_lock); acpi_remove_notify_handler(device->handle, ACPI_DEVICE_NOTIFY, acpi_pad_notify); return 0; } static const struct acpi_device_id pad_device_ids[] = { {"ACPI000C", 0}, {"", 0}, }; static struct acpi_driver acpi_pad_driver = { .name = "processor_aggregator", .class = ACPI_PROCESSOR_AGGREGATOR_CLASS, .ids = pad_device_ids, .ops = { .add = acpi_pad_add, .remove = acpi_pad_remove, }, }; static int __init xen_acpi_pad_init(void) { /* Only DOM0 is responsible for Xen acpi pad */ if (!xen_initial_domain()) return -ENODEV; /* Only Xen4.2 or later support Xen acpi pad */ if (!xen_running_on_version_or_later(4, 2)) return -ENODEV; return acpi_bus_register_driver(&acpi_pad_driver); } subsys_initcall(xen_acpi_pad_init); ' onchange='this.form.submit();'>mode:
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 /drivers/usb/musb/tusb6010.c
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 'drivers/usb/musb/tusb6010.c')