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
41 static pgd_t *save_pgd __initdata;
42 static unsigned long efi_flags __initdata;
43
early_code_mapping_set_exec(int executable)44 static 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
efi_call_phys_prelog(void)61 void __init efi_call_phys_prelog(void)
62 {
63 unsigned long vaddress;
64 int pgd;
65 int n_pgds;
66
67 early_code_mapping_set_exec(1);
68 local_irq_save(efi_flags);
69
70 n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
71 save_pgd = kmalloc(n_pgds * sizeof(pgd_t), GFP_KERNEL);
72
73 for (pgd = 0; pgd < n_pgds; pgd++) {
74 save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
75 vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
76 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), *pgd_offset_k(vaddress));
77 }
78 __flush_tlb_all();
79 }
80
efi_call_phys_epilog(void)81 void __init efi_call_phys_epilog(void)
82 {
83 /*
84 * After the lock is released, the original page table is restored.
85 */
86 int pgd;
87 int n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
88 for (pgd = 0; pgd < n_pgds; pgd++)
89 set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), save_pgd[pgd]);
90 kfree(save_pgd);
91 __flush_tlb_all();
92 local_irq_restore(efi_flags);
93 early_code_mapping_set_exec(0);
94 }
95
efi_ioremap(unsigned long phys_addr,unsigned long size,u32 type)96 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size,
97 u32 type)
98 {
99 unsigned long last_map_pfn;
100
101 if (type == EFI_MEMORY_MAPPED_IO)
102 return ioremap(phys_addr, size);
103
104 last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
105 if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size) {
106 unsigned long top = last_map_pfn << PAGE_SHIFT;
107 efi_ioremap(top, size - (top - phys_addr), type);
108 }
109
110 return (void __iomem *)__va(phys_addr);
111 }
112