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0c5ed61adb
Not only can EfiResetSystem() be used to reboot, it can also be used to power down machines. By and large, this functionality doesn't work very well across the range of EFI machines in the wild, so it should definitely only be used as a last resort. In an ideal world, this wouldn't be needed at all. Unfortunately, we're starting to see machines where EFI is the *only* reliable way to power down, and nothing else, not PCI, not ACPI, works. efi_poweroff_required() should be implemented on a per-architecture basis, since exactly when we should be using EFI runtime services is a platform-specific decision. There's no analogue for reboot because each architecture handles reboot very differently - the x86 code in particular is pretty complex. Patches to enable this for specific classes of hardware will be submitted separately. Tested-by: Mark Salter <msalter@redhat.com> Signed-off-by: Matt Fleming <matt.fleming@intel.com>
49 lines
904 B
C
49 lines
904 B
C
/*
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* Copyright (C) 2014 Intel Corporation; author Matt Fleming
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* Copyright (c) 2014 Red Hat, Inc., Mark Salter <msalter@redhat.com>
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*/
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#include <linux/efi.h>
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#include <linux/reboot.h>
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void efi_reboot(enum reboot_mode reboot_mode, const char *__unused)
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{
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int efi_mode;
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if (!efi_enabled(EFI_RUNTIME_SERVICES))
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return;
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switch (reboot_mode) {
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case REBOOT_WARM:
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case REBOOT_SOFT:
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efi_mode = EFI_RESET_WARM;
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break;
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default:
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efi_mode = EFI_RESET_COLD;
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break;
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}
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efi.reset_system(efi_mode, EFI_SUCCESS, 0, NULL);
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}
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bool __weak efi_poweroff_required(void)
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{
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return false;
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}
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static void efi_power_off(void)
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{
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efi.reset_system(EFI_RESET_SHUTDOWN, EFI_SUCCESS, 0, NULL);
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}
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static int __init efi_shutdown_init(void)
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{
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if (!efi_enabled(EFI_RUNTIME_SERVICES))
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return -ENODEV;
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if (efi_poweroff_required())
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pm_power_off = efi_power_off;
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return 0;
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}
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late_initcall(efi_shutdown_init);
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