Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 2.4
 *
 * Copyright (C) 2013, 2014 Linaro Ltd.
 */
 
#include <linux/efi.h>
#include <linux/init.h>
 
#include <asm/efi.h>
 
/*
 * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be
 * executable, everything else can be mapped with the XN bits
 * set. Also take the new (optional) RO/XP bits into account.
 */
static __init pteval_t create_mapping_protection(efi_memory_desc_t *md)
{
<------>u64 attr = md->attribute;
<------>u32 type = md->type;
 
<------>if (type == EFI_MEMORY_MAPPED_IO)
<------><------>return PROT_DEVICE_nGnRE;
 
<------>if (WARN_ONCE(!PAGE_ALIGNED(md->phys_addr),
<------><------>      "UEFI Runtime regions are not aligned to 64 KB -- buggy firmware?"))
<------><------>/*
<------><------> * If the region is not aligned to the page size of the OS, we
<------><------> * can not use strict permissions, since that would also affect
<------><------> * the mapping attributes of the adjacent regions.
<------><------> */
<------><------>return pgprot_val(PAGE_KERNEL_EXEC);
 
<------>/* R-- */
<------>if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) ==
<------>    (EFI_MEMORY_XP | EFI_MEMORY_RO))
<------><------>return pgprot_val(PAGE_KERNEL_RO);
 
<------>/* R-X */
<------>if (attr & EFI_MEMORY_RO)
<------><------>return pgprot_val(PAGE_KERNEL_ROX);
 
<------>/* RW- */
<------>if (((attr & (EFI_MEMORY_RP | EFI_MEMORY_WP | EFI_MEMORY_XP)) ==
<------>     EFI_MEMORY_XP) ||
<------>    type != EFI_RUNTIME_SERVICES_CODE)
<------><------>return pgprot_val(PAGE_KERNEL);
 
<------>/* RWX */
<------>return pgprot_val(PAGE_KERNEL_EXEC);
}
 
/* we will fill this structure from the stub, so don't put it in .bss */
struct screen_info screen_info __section(".data");
 
int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md)
{
<------>pteval_t prot_val = create_mapping_protection(md);
<------>bool page_mappings_only = (md->type == EFI_RUNTIME_SERVICES_CODE ||
<------><------><------><------>   md->type == EFI_RUNTIME_SERVICES_DATA);
 
<------>if (!PAGE_ALIGNED(md->phys_addr) ||
<------>    !PAGE_ALIGNED(md->num_pages << EFI_PAGE_SHIFT)) {
<------><------>/*
<------><------> * If the end address of this region is not aligned to page
<------><------> * size, the mapping is rounded up, and may end up sharing a
<------><------> * page frame with the next UEFI memory region. If we create
<------><------> * a block entry now, we may need to split it again when mapping
<------><------> * the next region, and support for that is going to be removed
<------><------> * from the MMU routines. So avoid block mappings altogether in
<------><------> * that case.
<------><------> */
<------><------>page_mappings_only = true;
<------>}
 
<------>create_pgd_mapping(mm, md->phys_addr, md->virt_addr,
<------><------><------>   md->num_pages << EFI_PAGE_SHIFT,
<------><------><------>   __pgprot(prot_val | PTE_NG), page_mappings_only);
<------>return 0;
}
 
static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data)
{
<------>efi_memory_desc_t *md = data;
<------>pte_t pte = READ_ONCE(*ptep);
 
<------>if (md->attribute & EFI_MEMORY_RO)
<------><------>pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
<------>if (md->attribute & EFI_MEMORY_XP)
<------><------>pte = set_pte_bit(pte, __pgprot(PTE_PXN));
<------>set_pte(ptep, pte);
<------>return 0;
}
 
int __init efi_set_mapping_permissions(struct mm_struct *mm,
<------><------><------><------>       efi_memory_desc_t *md)
{
<------>BUG_ON(md->type != EFI_RUNTIME_SERVICES_CODE &&
<------>       md->type != EFI_RUNTIME_SERVICES_DATA);
 
<------>/*
<------> * Calling apply_to_page_range() is only safe on regions that are
<------> * guaranteed to be mapped down to pages. Since we are only called
<------> * for regions that have been mapped using efi_create_mapping() above
<------> * (and this is checked by the generic Memory Attributes table parsing
<------> * routines), there is no need to check that again here.
<------> */
<------>return apply_to_page_range(mm, md->virt_addr,
<------><------><------><------>   md->num_pages << EFI_PAGE_SHIFT,
<------><------><------><------>   set_permissions, md);
}
 
/*
 * UpdateCapsule() depends on the system being shutdown via
 * ResetSystem().
 */
bool efi_poweroff_required(void)
{
<------>return efi_enabled(EFI_RUNTIME_SERVICES);
}
 
asmlinkage efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f)
{
<------>pr_err_ratelimited(FW_BUG "register x18 corrupted by EFI %s\n", f);
<------>return s;
}