57fdb89aeb
Unlike on 32-bit ARM, where we need to pass the stub's version of struct screen_info to the kernel proper via a configuration table, on 64-bit ARM it simply involves making the core kernel's copy of struct screen_info visible to the stub by exposing an __efistub_ alias for it. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Jones <pjones@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1461614832-17633-21-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar <mingo@kernel.org>
94 lines
2.4 KiB
C
94 lines
2.4 KiB
C
/*
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* Extensible Firmware Interface
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*
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* Based on Extensible Firmware Interface Specification version 2.4
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*
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* Copyright (C) 2013, 2014 Linaro Ltd.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/dmi.h>
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#include <linux/efi.h>
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#include <linux/init.h>
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#include <asm/efi.h>
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/*
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* Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
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* executable, everything else can be mapped with the XN bits
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* set. Also take the new (optional) RO/XP bits into account.
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*/
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static __init pteval_t create_mapping_protection(efi_memory_desc_t *md)
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{
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u64 attr = md->attribute;
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u32 type = md->type;
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if (type == EFI_MEMORY_MAPPED_IO)
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return PROT_DEVICE_nGnRE;
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if (WARN_ONCE(!PAGE_ALIGNED(md->phys_addr),
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"UEFI Runtime regions are not aligned to 64 KB -- buggy firmware?"))
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/*
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* If the region is not aligned to the page size of the OS, we
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* can not use strict permissions, since that would also affect
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* the mapping attributes of the adjacent regions.
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*/
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return pgprot_val(PAGE_KERNEL_EXEC);
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/* R-- */
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if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) ==
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(EFI_MEMORY_XP | EFI_MEMORY_RO))
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return pgprot_val(PAGE_KERNEL_RO);
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/* R-X */
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if (attr & EFI_MEMORY_RO)
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return pgprot_val(PAGE_KERNEL_ROX);
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/* RW- */
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if (attr & EFI_MEMORY_XP || type != EFI_RUNTIME_SERVICES_CODE)
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return pgprot_val(PAGE_KERNEL);
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/* RWX */
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return pgprot_val(PAGE_KERNEL_EXEC);
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}
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/* we will fill this structure from the stub, so don't put it in .bss */
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struct screen_info screen_info __section(.data);
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int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
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{
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pteval_t prot_val = create_mapping_protection(md);
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create_pgd_mapping(mm, md->phys_addr, md->virt_addr,
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md->num_pages << EFI_PAGE_SHIFT,
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__pgprot(prot_val | PTE_NG));
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return 0;
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}
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static int __init arm64_dmi_init(void)
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{
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/*
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* On arm64, DMI depends on UEFI, and dmi_scan_machine() needs to
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* be called early because dmi_id_init(), which is an arch_initcall
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* itself, depends on dmi_scan_machine() having been called already.
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*/
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dmi_scan_machine();
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if (dmi_available)
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dmi_set_dump_stack_arch_desc();
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return 0;
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}
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core_initcall(arm64_dmi_init);
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/*
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* UpdateCapsule() depends on the system being shutdown via
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* ResetSystem().
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*/
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bool efi_poweroff_required(void)
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{
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return efi_enabled(EFI_RUNTIME_SERVICES);
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}
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