void __init efi_runtime_update_mappings(void)
{
efi_memory_desc_t *md;
if (efi_enabled(EFI_OLD_MEMMAP)) {
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
return;
}
/*
* Use the EFI Memory Attribute Table for mapping permissions if it
* exists, since it is intended to supersede EFI_PROPERTIES_TABLE.
*/
if (efi_enabled(EFI_MEM_ATTR)) {
efi_memattr_apply_permissions(NULL, efi_update_mem_attr);
return;
}
/*
* EFI_MEMORY_ATTRIBUTES_TABLE is intended to replace
* EFI_PROPERTIES_TABLE. So, use EFI_PROPERTIES_TABLE to update
* permissions only if EFI_MEMORY_ATTRIBUTES_TABLE is not
* published by the firmware. Even if we find a buggy implementation of
* EFI_MEMORY_ATTRIBUTES_TABLE, don't fall back to
* EFI_PROPERTIES_TABLE, because of the same reason.
*/
if (!efi_enabled(EFI_NX_PE_DATA))
return;
for_each_efi_memory_desc(md) {
unsigned long pf = 0;
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (!(md->attribute & EFI_MEMORY_WB))
pf |= _PAGE_PCD;
if ((md->attribute & EFI_MEMORY_XP) ||
(md->type == EFI_RUNTIME_SERVICES_DATA))
pf |= _PAGE_NX;
if (!(md->attribute & EFI_MEMORY_RO) &&
(md->type != EFI_RUNTIME_SERVICES_CODE))
pf |= _PAGE_RW;
if (sev_active())
pf |= _PAGE_ENC;
efi_update_mappings(md, pf);
}
}
static bool __init efi_virtmap_init(void)
{
efi_memory_desc_t *md;
bool systab_found;
efi_mm.pgd = pgd_alloc(&efi_mm);
init_new_context(NULL, &efi_mm);
systab_found = false;
for_each_efi_memory_desc(md) {
phys_addr_t phys = md->phys_addr;
int ret;
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (md->virt_addr == 0)
return false;
ret = efi_create_mapping(&efi_mm, md);
if (!ret) {
pr_info(" EFI remap %pa => %p\n",
&phys, (void *)(unsigned long)md->virt_addr);
} else {
pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
&phys, ret);
return false;
}
/*
* If this entry covers the address of the UEFI system table,
* calculate and record its virtual address.
*/
if (efi_system_table >= phys &&
efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) {
efi.systab = (void *)(unsigned long)(efi_system_table -
phys + md->virt_addr);
systab_found = true;
}
}
if (!systab_found) {
pr_err("No virtual mapping found for the UEFI System Table\n");
return false;
}
if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
return false;
return true;
}
