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1#include <linux/io.h>
2#include <linux/memblock.h>
3
4#include <asm/cacheflush.h>
5#include <asm/pgtable.h>
6#include <asm/realmode.h>
7
8struct real_mode_header *real_mode_header;
9u32 *trampoline_cr4_features;
10
11void __init setup_real_mode(void)
12{
13 phys_addr_t mem;
14 u16 real_mode_seg;
15 u32 *rel;
16 u32 count;
17 u32 *ptr;
18 u16 *seg;
19 int i;
20 unsigned char *base;
21 struct trampoline_header *trampoline_header;
22 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
23#ifdef CONFIG_X86_64
24 u64 *trampoline_pgd;
25 u64 efer;
26#endif
27
28 /* Has to be in very low memory so we can execute real-mode AP code. */
29 mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
30 if (!mem)
31 panic("Cannot allocate trampoline\n");
32
33 base = __va(mem);
34 memblock_reserve(mem, size);
35 real_mode_header = (struct real_mode_header *) base;
36 printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
37 base, (unsigned long long)mem, size);
38
39 memcpy(base, real_mode_blob, size);
40
41 real_mode_seg = __pa(base) >> 4;
42 rel = (u32 *) real_mode_relocs;
43
44 /* 16-bit segment relocations. */
45 count = rel[0];
46 rel = &rel[1];
47 for (i = 0; i < count; i++) {
48 seg = (u16 *) (base + rel[i]);
49 *seg = real_mode_seg;
50 }
51
52 /* 32-bit linear relocations. */
53 count = rel[i];
54 rel = &rel[i + 1];
55 for (i = 0; i < count; i++) {
56 ptr = (u32 *) (base + rel[i]);
57 *ptr += __pa(base);
58 }
59
60 /* Must be perfomed *after* relocation. */
61 trampoline_header = (struct trampoline_header *)
62 __va(real_mode_header->trampoline_header);
63
64#ifdef CONFIG_X86_32
65 trampoline_header->start = __pa(startup_32_smp);
66 trampoline_header->gdt_limit = __BOOT_DS + 7;
67 trampoline_header->gdt_base = __pa(boot_gdt);
68#else
69 /*
70 * Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR
71 * so we need to mask it out.
72 */
73 rdmsrl(MSR_EFER, efer);
74 trampoline_header->efer = efer & ~EFER_LMA;
75
76 trampoline_header->start = (u64) secondary_startup_64;
77 trampoline_cr4_features = &trampoline_header->cr4;
78 *trampoline_cr4_features = read_cr4();
79
80 trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
81 trampoline_pgd[0] = __pa(level3_ident_pgt) + _KERNPG_TABLE;
82 trampoline_pgd[511] = __pa(level3_kernel_pgt) + _KERNPG_TABLE;
83#endif
84}
85
86/*
87 * set_real_mode_permissions() gets called very early, to guarantee the
88 * availability of low memory. This is before the proper kernel page
89 * tables are set up, so we cannot set page permissions in that
90 * function. Thus, we use an arch_initcall instead.
91 */
92static int __init set_real_mode_permissions(void)
93{
94 unsigned char *base = (unsigned char *) real_mode_header;
95 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
96
97 size_t ro_size =
98 PAGE_ALIGN(real_mode_header->ro_end) -
99 __pa(base);
100
101 size_t text_size =
102 PAGE_ALIGN(real_mode_header->ro_end) -
103 real_mode_header->text_start;
104
105 unsigned long text_start =
106 (unsigned long) __va(real_mode_header->text_start);
107
108 set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
109 set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
110 set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
111
112 return 0;
113}
114
115arch_initcall(set_real_mode_permissions);
1#include <linux/io.h>
2#include <linux/memblock.h>
3
4#include <asm/cacheflush.h>
5#include <asm/pgtable.h>
6#include <asm/realmode.h>
7
8struct real_mode_header *real_mode_header;
9u32 *trampoline_cr4_features;
10
11void __init reserve_real_mode(void)
12{
13 phys_addr_t mem;
14 unsigned char *base;
15 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
16
17 /* Has to be under 1M so we can execute real-mode AP code. */
18 mem = memblock_find_in_range(0, 1<<20, size, PAGE_SIZE);
19 if (!mem)
20 panic("Cannot allocate trampoline\n");
21
22 base = __va(mem);
23 memblock_reserve(mem, size);
24 real_mode_header = (struct real_mode_header *) base;
25 printk(KERN_DEBUG "Base memory trampoline at [%p] %llx size %zu\n",
26 base, (unsigned long long)mem, size);
27}
28
29void __init setup_real_mode(void)
30{
31 u16 real_mode_seg;
32 const u32 *rel;
33 u32 count;
34 unsigned char *base;
35 unsigned long phys_base;
36 struct trampoline_header *trampoline_header;
37 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
38#ifdef CONFIG_X86_64
39 u64 *trampoline_pgd;
40 u64 efer;
41#endif
42
43 base = (unsigned char *)real_mode_header;
44
45 memcpy(base, real_mode_blob, size);
46
47 phys_base = __pa(base);
48 real_mode_seg = phys_base >> 4;
49
50 rel = (u32 *) real_mode_relocs;
51
52 /* 16-bit segment relocations. */
53 count = *rel++;
54 while (count--) {
55 u16 *seg = (u16 *) (base + *rel++);
56 *seg = real_mode_seg;
57 }
58
59 /* 32-bit linear relocations. */
60 count = *rel++;
61 while (count--) {
62 u32 *ptr = (u32 *) (base + *rel++);
63 *ptr += phys_base;
64 }
65
66 /* Must be perfomed *after* relocation. */
67 trampoline_header = (struct trampoline_header *)
68 __va(real_mode_header->trampoline_header);
69
70#ifdef CONFIG_X86_32
71 trampoline_header->start = __pa_symbol(startup_32_smp);
72 trampoline_header->gdt_limit = __BOOT_DS + 7;
73 trampoline_header->gdt_base = __pa_symbol(boot_gdt);
74#else
75 /*
76 * Some AMD processors will #GP(0) if EFER.LMA is set in WRMSR
77 * so we need to mask it out.
78 */
79 rdmsrl(MSR_EFER, efer);
80 trampoline_header->efer = efer & ~EFER_LMA;
81
82 trampoline_header->start = (u64) secondary_startup_64;
83 trampoline_cr4_features = &trampoline_header->cr4;
84 *trampoline_cr4_features = read_cr4();
85
86 trampoline_pgd = (u64 *) __va(real_mode_header->trampoline_pgd);
87 trampoline_pgd[0] = init_level4_pgt[pgd_index(__PAGE_OFFSET)].pgd;
88 trampoline_pgd[511] = init_level4_pgt[511].pgd;
89#endif
90}
91
92/*
93 * reserve_real_mode() gets called very early, to guarantee the
94 * availability of low memory. This is before the proper kernel page
95 * tables are set up, so we cannot set page permissions in that
96 * function. Also trampoline code will be executed by APs so we
97 * need to mark it executable at do_pre_smp_initcalls() at least,
98 * thus run it as a early_initcall().
99 */
100static int __init set_real_mode_permissions(void)
101{
102 unsigned char *base = (unsigned char *) real_mode_header;
103 size_t size = PAGE_ALIGN(real_mode_blob_end - real_mode_blob);
104
105 size_t ro_size =
106 PAGE_ALIGN(real_mode_header->ro_end) -
107 __pa(base);
108
109 size_t text_size =
110 PAGE_ALIGN(real_mode_header->ro_end) -
111 real_mode_header->text_start;
112
113 unsigned long text_start =
114 (unsigned long) __va(real_mode_header->text_start);
115
116 set_memory_nx((unsigned long) base, size >> PAGE_SHIFT);
117 set_memory_ro((unsigned long) base, ro_size >> PAGE_SHIFT);
118 set_memory_x((unsigned long) text_start, text_size >> PAGE_SHIFT);
119
120 return 0;
121}
122early_initcall(set_real_mode_permissions);