tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * x86_64 specific EFI support functions
3 * Based on Extensible Firmware Interface Specification version 1.0
4 *
5 * Copyright (C) 2005-2008 Intel Co.
6 * Fenghua Yu <fenghua.yu@intel.com>
7 * Bibo Mao <bibo.mao@intel.com>
8 * Chandramouli Narayanan <mouli@linux.intel.com>
9 * Huang Ying <ying.huang@intel.com>
10 *
11 * Code to convert EFI to E820 map has been implemented in elilo bootloader
12 * based on a EFI patch by Edgar Hucek. Based on the E820 map, the page table
13 * is setup appropriately for EFI runtime code.
14 * - mouli 06/14/2007.
15 *
16 */
17
18#include <linux/kernel.h>
19#include <linux/init.h>
20#include <linux/mm.h>
21#include <linux/types.h>
22#include <linux/spinlock.h>
23#include <linux/bootmem.h>
24#include <linux/ioport.h>
25#include <linux/module.h>
26#include <linux/efi.h>
27#include <linux/uaccess.h>
28#include <linux/io.h>
29#include <linux/reboot.h>
30
31#include <asm/setup.h>
32#include <asm/page.h>
33#include <asm/e820.h>
34#include <asm/pgtable.h>
35#include <asm/tlbflush.h>
36#include <asm/proto.h>
37#include <asm/efi.h>
38#include <asm/cacheflush.h>
39#include <asm/fixmap.h>
40
41static pgd_t save_pgd __initdata;
42static unsigned long efi_flags __initdata;
43
44static void __init early_code_mapping_set_exec(int executable)
45{
46 efi_memory_desc_t *md;
47 void *p;
48
49 if (!(__supported_pte_mask & _PAGE_NX))
50 return;
51
52 /* Make EFI service code area executable */
53 for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
54 md = p;
55 if (md->type == EFI_RUNTIME_SERVICES_CODE ||
56 md->type == EFI_BOOT_SERVICES_CODE)
57 efi_set_executable(md, executable);
58 }
59}
60
61void __init efi_call_phys_prelog(void)
62{
63 unsigned long vaddress;
64
65 early_code_mapping_set_exec(1);
66 local_irq_save(efi_flags);
67 vaddress = (unsigned long)__va(0x0UL);
68 save_pgd = *pgd_offset_k(0x0UL);
69 set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
70 __flush_tlb_all();
71}
72
73void __init efi_call_phys_epilog(void)
74{
75 /*
76 * After the lock is released, the original page table is restored.
77 */
78 set_pgd(pgd_offset_k(0x0UL), save_pgd);
79 __flush_tlb_all();
80 local_irq_restore(efi_flags);
81 early_code_mapping_set_exec(0);
82}
83
84void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
85 u32 type)
86{
87 unsigned long last_map_pfn;
88
89 if (type == EFI_MEMORY_MAPPED_IO)
90 return ioremap(phys_addr, size);
91
92 last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
93 if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
94 unsigned long top = last_map_pfn << PAGE_SHIFT;
95 efi_ioremap(top, size - (top - phys_addr), type);
96 }
97
98 return (void __iomem *)__va(phys_addr);
99}