// SPDX-License-Identifier: GPL-2.0 /* * x86_64 specific EFI support functions * Based on Extensible Firmware Interface Specification version 1.0 * * Copyright (C) 2005-2008 Intel Co. * Fenghua Yu <[email protected]> * Bibo Mao <[email protected]> * Chandramouli Narayanan <[email protected]> * Huang Ying <[email protected]> * * Code to convert EFI to E820 map has been implemented in elilo bootloader * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table * is setup appropriately for EFI runtime code. * - mouli 06/14/2007. * */ #define pr_fmt(fmt) … #include <linux/kernel.h> #include <linux/init.h> #include <linux/mm.h> #include <linux/types.h> #include <linux/spinlock.h> #include <linux/memblock.h> #include <linux/ioport.h> #include <linux/mc146818rtc.h> #include <linux/efi.h> #include <linux/export.h> #include <linux/uaccess.h> #include <linux/io.h> #include <linux/reboot.h> #include <linux/slab.h> #include <linux/ucs2_string.h> #include <linux/cc_platform.h> #include <linux/sched/task.h> #include <asm/setup.h> #include <asm/page.h> #include <asm/e820/api.h> #include <asm/tlbflush.h> #include <asm/proto.h> #include <asm/efi.h> #include <asm/cacheflush.h> #include <asm/fixmap.h> #include <asm/realmode.h> #include <asm/time.h> #include <asm/pgalloc.h> #include <asm/sev.h> /* * We allocate runtime services regions top-down, starting from -4G, i.e. * 0xffff_ffff_0000_0000 and limit EFI VA mapping space to 64G. */ static u64 efi_va = …; static struct mm_struct *efi_prev_mm; /* * We need our own copy of the higher levels of the page tables * because we want to avoid inserting EFI region mappings (EFI_VA_END * to EFI_VA_START) into the standard kernel page tables. Everything * else can be shared, see efi_sync_low_kernel_mappings(). * * We don't want the pgd on the pgd_list and cannot use pgd_alloc() for the * allocation. */ int __init efi_alloc_page_tables(void) { … } /* * Add low kernel mappings for passing arguments to EFI functions. */ void efi_sync_low_kernel_mappings(void) { … } /* * Wrapper for slow_virt_to_phys() that handles NULL addresses. */ static inline phys_addr_t virt_to_phys_or_null_size(void *va, unsigned long size) { … } #define virt_to_phys_or_null(addr) … int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages) { … } static void __init __map_region(efi_memory_desc_t *md, u64 va) { … } void __init efi_map_region(efi_memory_desc_t *md) { … } /* * kexec kernel will use efi_map_region_fixed to map efi runtime memory ranges. * md->virt_addr is the original virtual address which had been mapped in kexec * 1st kernel. */ void __init efi_map_region_fixed(efi_memory_desc_t *md) { … } void __init parse_efi_setup(u64 phys_addr, u32 data_len) { … } static int __init efi_update_mappings(efi_memory_desc_t *md, unsigned long pf) { … } bool efi_disable_ibt_for_runtime __ro_after_init = …; static int __init efi_update_mem_attr(struct mm_struct *mm, efi_memory_desc_t *md, bool has_ibt) { … } void __init efi_runtime_update_mappings(void) { … } void __init efi_dump_pagetable(void) { … } /* * Makes the calling thread switch to/from efi_mm context. Can be used * in a kernel thread and user context. Preemption needs to remain disabled * while the EFI-mm is borrowed. mmgrab()/mmdrop() is not used because the mm * can not change under us. * It should be ensured that there are no concurrent calls to this function. */ static void efi_enter_mm(void) { … } static void efi_leave_mm(void) { … } void arch_efi_call_virt_setup(void) { … } void arch_efi_call_virt_teardown(void) { … } static DEFINE_SPINLOCK(efi_runtime_lock); /* * DS and ES contain user values. We need to save them. * The 32-bit EFI code needs a valid DS, ES, and SS. There's no * need to save the old SS: __KERNEL_DS is always acceptable. */ #define __efi_thunk(func, ...) … /* * Switch to the EFI page tables early so that we can access the 1:1 * runtime services mappings which are not mapped in any other page * tables. * * Also, disable interrupts because the IDT points to 64-bit handlers, * which aren't going to function correctly when we switch to 32-bit. */ #define efi_thunk(func...) … static efi_status_t __init __no_sanitize_address efi_thunk_set_virtual_address_map(unsigned long memory_map_size, unsigned long descriptor_size, u32 descriptor_version, efi_memory_desc_t *virtual_map) { … } static efi_status_t efi_thunk_get_time(efi_time_t *tm, efi_time_cap_t *tc) { … } static efi_status_t efi_thunk_set_time(efi_time_t *tm) { … } static efi_status_t efi_thunk_get_wakeup_time(efi_bool_t *enabled, efi_bool_t *pending, efi_time_t *tm) { … } static efi_status_t efi_thunk_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm) { … } static unsigned long efi_name_size(efi_char16_t *name) { … } static efi_status_t efi_thunk_get_variable(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, unsigned long *data_size, void *data) { … } static efi_status_t efi_thunk_set_variable(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data) { … } static efi_status_t efi_thunk_set_variable_nonblocking(efi_char16_t *name, efi_guid_t *vendor, u32 attr, unsigned long data_size, void *data) { … } static efi_status_t efi_thunk_get_next_variable(unsigned long *name_size, efi_char16_t *name, efi_guid_t *vendor) { … } static efi_status_t efi_thunk_get_next_high_mono_count(u32 *count) { … } static void efi_thunk_reset_system(int reset_type, efi_status_t status, unsigned long data_size, efi_char16_t *data) { … } static efi_status_t efi_thunk_update_capsule(efi_capsule_header_t **capsules, unsigned long count, unsigned long sg_list) { … } static efi_status_t efi_thunk_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { … } static efi_status_t efi_thunk_query_variable_info_nonblocking(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { … } static efi_status_t efi_thunk_query_capsule_caps(efi_capsule_header_t **capsules, unsigned long count, u64 *max_size, int *reset_type) { … } void __init efi_thunk_runtime_setup(void) { … } efi_status_t __init __no_sanitize_address efi_set_virtual_address_map(unsigned long memory_map_size, unsigned long descriptor_size, u32 descriptor_version, efi_memory_desc_t *virtual_map, unsigned long systab_phys) { … }
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