tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Extensible Firmware Interface
3 *
4 * Based on Extensible Firmware Interface Specification version 1.0
5 *
6 * Copyright (C) 1999 VA Linux Systems
7 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
8 * Copyright (C) 1999-2002 Hewlett-Packard Co.
9 * David Mosberger-Tang <davidm@hpl.hp.com>
10 * Stephane Eranian <eranian@hpl.hp.com>
11 *
12 * All EFI Runtime Services are not implemented yet as EFI only
13 * supports physical mode addressing on SoftSDV. This is to be fixed
14 * in a future version. --drummond 1999-07-20
15 *
16 * Implemented EFI runtime services and virtual mode calls. --davidm
17 *
18 * Goutham Rao: <goutham.rao@intel.com>
19 * Skip non-WB memory and ignore empty memory ranges.
20 */
21
22#include <linux/kernel.h>
23#include <linux/types.h>
24#include <linux/ioport.h>
25#include <linux/efi.h>
26
27#include <asm/io.h>
28#include <asm/desc.h>
29#include <asm/page.h>
30#include <asm/pgtable.h>
31#include <asm/tlbflush.h>
32#include <asm/efi.h>
33
34/*
35 * To make EFI call EFI runtime service in physical addressing mode we need
36 * prelog/epilog before/after the invocation to disable interrupt, to
37 * claim EFI runtime service handler exclusively and to duplicate a memory in
38 * low memory space say 0 - 3G.
39 */
40static unsigned long efi_rt_eflags;
41
42void efi_sync_low_kernel_mappings(void) {}
43void efi_setup_page_tables(void) {}
44
45void __init efi_map_region(efi_memory_desc_t *md)
46{
47 old_map_region(md);
48}
49
50void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
51void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
52
53void efi_call_phys_prelog(void)
54{
55 struct desc_ptr gdt_descr;
56
57 local_irq_save(efi_rt_eflags);
58
59 load_cr3(initial_page_table);
60 __flush_tlb_all();
61
62 gdt_descr.address = __pa(get_cpu_gdt_table(0));
63 gdt_descr.size = GDT_SIZE - 1;
64 load_gdt(&gdt_descr);
65}
66
67void efi_call_phys_epilog(void)
68{
69 struct desc_ptr gdt_descr;
70
71 gdt_descr.address = (unsigned long)get_cpu_gdt_table(0);
72 gdt_descr.size = GDT_SIZE - 1;
73 load_gdt(&gdt_descr);
74
75 load_cr3(swapper_pg_dir);
76 __flush_tlb_all();
77
78 local_irq_restore(efi_rt_eflags);
79}
80
81void __init efi_runtime_mkexec(void)
82{
83 if (__supported_pte_mask & _PAGE_NX)
84 runtime_code_page_mkexec();
85}