ubuntu-linux-kernel/arch/x86/platform/efi/efi_32.c

103 lines
2.4 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 1.0
*
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
* Copyright (C) 1999-2002 Hewlett-Packard Co.
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
*
* All EFI Runtime Services are not implemented yet as EFI only
* supports physical mode addressing on SoftSDV. This is to be fixed
* in a future version. --drummond 1999-07-20
*
* Implemented EFI runtime services and virtual mode calls. --davidm
*
* Goutham Rao: <goutham.rao@intel.com>
* Skip non-WB memory and ignore empty memory ranges.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/efi.h>
#include <asm/io.h>
#include <asm/desc.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/efi.h>
/*
* To make EFI call EFI runtime service in physical addressing mode we need
* prolog/epilog before/after the invocation to claim the EFI runtime service
* handler exclusively and to duplicate a memory mapping in low memory space,
* say 0 - 3G.
*/
int __init efi_alloc_page_tables(void)
{
return 0;
}
void efi_sync_low_kernel_mappings(void) {}
void __init efi_dump_pagetable(void)
{
#ifdef CONFIG_EFI_PGT_DUMP
ptdump_walk_pgd_level(NULL, swapper_pg_dir);
#endif
}
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
return 0;
}
void __init efi_map_region(efi_memory_desc_t *md)
{
old_map_region(md);
}
void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
pgd_t * __init efi_call_phys_prolog(void)
{
struct desc_ptr gdt_descr;
pgd_t *save_pgd;
/* Current pgd is swapper_pg_dir, we'll restore it later: */
save_pgd = swapper_pg_dir;
load_cr3(initial_page_table);
__flush_tlb_all();
gdt_descr.address = get_cpu_gdt_paddr(0);
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
return save_pgd;
}
void __init efi_call_phys_epilog(pgd_t *save_pgd)
{
struct desc_ptr gdt_descr;
gdt_descr.address = (unsigned long)get_cpu_gdt_rw(0);
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
load_cr3(save_pgd);
__flush_tlb_all();
}
void __init efi_runtime_update_mappings(void)
{
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
}