2 * prepare to run common code
4 * Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
7 #define DISABLE_BRANCH_PROFILING
8 #include <linux/init.h>
9 #include <linux/linkage.h>
10 #include <linux/types.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/percpu.h>
14 #include <linux/start_kernel.h>
16 #include <linux/memblock.h>
18 #include <asm/processor.h>
19 #include <asm/proto.h>
21 #include <asm/setup.h>
23 #include <asm/pgtable.h>
24 #include <asm/tlbflush.h>
25 #include <asm/sections.h>
26 #include <asm/kdebug.h>
27 #include <asm/e820/api.h>
28 #include <asm/bios_ebda.h>
29 #include <asm/bootparam_utils.h>
30 #include <asm/microcode.h>
31 #include <asm/kasan.h>
34 * Manage page tables very early on.
36 extern pgd_t early_top_pgt
[PTRS_PER_PGD
];
37 extern pmd_t early_dynamic_pgts
[EARLY_DYNAMIC_PAGE_TABLES
][PTRS_PER_PMD
];
38 static unsigned int __initdata next_early_pgt
;
39 pmdval_t early_pmd_flags
= __PAGE_KERNEL_LARGE
& ~(_PAGE_GLOBAL
| _PAGE_NX
);
41 #define __head __section(.head.text)
43 static void __head
*fixup_pointer(void *ptr
, unsigned long physaddr
)
45 return ptr
- (void *)_text
+ (void *)physaddr
;
48 void __head
__startup_64(unsigned long physaddr
)
50 unsigned long load_delta
, *p
;
54 pmdval_t
*pmd
, pmd_entry
;
57 /* Is the address too large? */
58 if (physaddr
>> MAX_PHYSMEM_BITS
)
62 * Compute the delta between the address I am compiled to run at
63 * and the address I am actually running at.
65 load_delta
= physaddr
- (unsigned long)(_text
- __START_KERNEL_map
);
67 /* Is the address not 2M aligned? */
68 if (load_delta
& ~PMD_PAGE_MASK
)
71 /* Fixup the physical addresses in the page table */
73 pgd
= fixup_pointer(&early_top_pgt
, physaddr
);
74 pgd
[pgd_index(__START_KERNEL_map
)] += load_delta
;
76 if (IS_ENABLED(CONFIG_X86_5LEVEL
)) {
77 p4d
= fixup_pointer(&level4_kernel_pgt
, physaddr
);
78 p4d
[511] += load_delta
;
81 pud
= fixup_pointer(&level3_kernel_pgt
, physaddr
);
82 pud
[510] += load_delta
;
83 pud
[511] += load_delta
;
85 pmd
= fixup_pointer(level2_fixmap_pgt
, physaddr
);
86 pmd
[506] += load_delta
;
89 * Set up the identity mapping for the switchover. These
90 * entries should *NOT* have the global bit set! This also
91 * creates a bunch of nonsense entries but that is fine --
92 * it avoids problems around wraparound.
95 pud
= fixup_pointer(early_dynamic_pgts
[next_early_pgt
++], physaddr
);
96 pmd
= fixup_pointer(early_dynamic_pgts
[next_early_pgt
++], physaddr
);
98 if (IS_ENABLED(CONFIG_X86_5LEVEL
)) {
99 p4d
= fixup_pointer(early_dynamic_pgts
[next_early_pgt
++], physaddr
);
101 i
= (physaddr
>> PGDIR_SHIFT
) % PTRS_PER_PGD
;
102 pgd
[i
+ 0] = (pgdval_t
)p4d
+ _KERNPG_TABLE
;
103 pgd
[i
+ 1] = (pgdval_t
)p4d
+ _KERNPG_TABLE
;
105 i
= (physaddr
>> P4D_SHIFT
) % PTRS_PER_P4D
;
106 p4d
[i
+ 0] = (pgdval_t
)pud
+ _KERNPG_TABLE
;
107 p4d
[i
+ 1] = (pgdval_t
)pud
+ _KERNPG_TABLE
;
109 i
= (physaddr
>> PGDIR_SHIFT
) % PTRS_PER_PGD
;
110 pgd
[i
+ 0] = (pgdval_t
)pud
+ _KERNPG_TABLE
;
111 pgd
[i
+ 1] = (pgdval_t
)pud
+ _KERNPG_TABLE
;
114 i
= (physaddr
>> PUD_SHIFT
) % PTRS_PER_PUD
;
115 pud
[i
+ 0] = (pudval_t
)pmd
+ _KERNPG_TABLE
;
116 pud
[i
+ 1] = (pudval_t
)pmd
+ _KERNPG_TABLE
;
118 pmd_entry
= __PAGE_KERNEL_LARGE_EXEC
& ~_PAGE_GLOBAL
;
119 pmd_entry
+= physaddr
;
121 for (i
= 0; i
< DIV_ROUND_UP(_end
- _text
, PMD_SIZE
); i
++) {
122 int idx
= i
+ (physaddr
>> PMD_SHIFT
) % PTRS_PER_PMD
;
123 pmd
[idx
] = pmd_entry
+ i
* PMD_SIZE
;
127 * Fixup the kernel text+data virtual addresses. Note that
128 * we might write invalid pmds, when the kernel is relocated
129 * cleanup_highmap() fixes this up along with the mappings
133 pmd
= fixup_pointer(level2_kernel_pgt
, physaddr
);
134 for (i
= 0; i
< PTRS_PER_PMD
; i
++) {
135 if (pmd
[i
] & _PAGE_PRESENT
)
136 pmd
[i
] += load_delta
;
139 /* Fixup phys_base */
140 p
= fixup_pointer(&phys_base
, physaddr
);
144 /* Wipe all early page tables except for the kernel symbol map */
145 static void __init
reset_early_page_tables(void)
147 memset(early_top_pgt
, 0, sizeof(pgd_t
)*(PTRS_PER_PGD
-1));
149 write_cr3(__pa_nodebug(early_top_pgt
));
152 /* Create a new PMD entry */
153 int __init
early_make_pgtable(unsigned long address
)
155 unsigned long physaddr
= address
- __PAGE_OFFSET
;
156 pgdval_t pgd
, *pgd_p
;
157 p4dval_t p4d
, *p4d_p
;
158 pudval_t pud
, *pud_p
;
159 pmdval_t pmd
, *pmd_p
;
161 /* Invalid address or early pgt is done ? */
162 if (physaddr
>= MAXMEM
|| read_cr3_pa() != __pa_nodebug(early_top_pgt
))
166 pgd_p
= &early_top_pgt
[pgd_index(address
)].pgd
;
170 * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
171 * critical -- __PAGE_OFFSET would point us back into the dynamic
172 * range and we might end up looping forever...
174 if (!IS_ENABLED(CONFIG_X86_5LEVEL
))
177 p4d_p
= (p4dval_t
*)((pgd
& PTE_PFN_MASK
) + __START_KERNEL_map
- phys_base
);
179 if (next_early_pgt
>= EARLY_DYNAMIC_PAGE_TABLES
) {
180 reset_early_page_tables();
184 p4d_p
= (p4dval_t
*)early_dynamic_pgts
[next_early_pgt
++];
185 memset(p4d_p
, 0, sizeof(*p4d_p
) * PTRS_PER_P4D
);
186 *pgd_p
= (pgdval_t
)p4d_p
- __START_KERNEL_map
+ phys_base
+ _KERNPG_TABLE
;
188 p4d_p
+= p4d_index(address
);
192 pud_p
= (pudval_t
*)((p4d
& PTE_PFN_MASK
) + __START_KERNEL_map
- phys_base
);
194 if (next_early_pgt
>= EARLY_DYNAMIC_PAGE_TABLES
) {
195 reset_early_page_tables();
199 pud_p
= (pudval_t
*)early_dynamic_pgts
[next_early_pgt
++];
200 memset(pud_p
, 0, sizeof(*pud_p
) * PTRS_PER_PUD
);
201 *p4d_p
= (p4dval_t
)pud_p
- __START_KERNEL_map
+ phys_base
+ _KERNPG_TABLE
;
203 pud_p
+= pud_index(address
);
207 pmd_p
= (pmdval_t
*)((pud
& PTE_PFN_MASK
) + __START_KERNEL_map
- phys_base
);
209 if (next_early_pgt
>= EARLY_DYNAMIC_PAGE_TABLES
) {
210 reset_early_page_tables();
214 pmd_p
= (pmdval_t
*)early_dynamic_pgts
[next_early_pgt
++];
215 memset(pmd_p
, 0, sizeof(*pmd_p
) * PTRS_PER_PMD
);
216 *pud_p
= (pudval_t
)pmd_p
- __START_KERNEL_map
+ phys_base
+ _KERNPG_TABLE
;
218 pmd
= (physaddr
& PMD_MASK
) + early_pmd_flags
;
219 pmd_p
[pmd_index(address
)] = pmd
;
224 /* Don't add a printk in there. printk relies on the PDA which is not initialized
226 static void __init
clear_bss(void)
228 memset(__bss_start
, 0,
229 (unsigned long) __bss_stop
- (unsigned long) __bss_start
);
232 static unsigned long get_cmd_line_ptr(void)
234 unsigned long cmd_line_ptr
= boot_params
.hdr
.cmd_line_ptr
;
236 cmd_line_ptr
|= (u64
)boot_params
.ext_cmd_line_ptr
<< 32;
241 static void __init
copy_bootdata(char *real_mode_data
)
244 unsigned long cmd_line_ptr
;
246 memcpy(&boot_params
, real_mode_data
, sizeof boot_params
);
247 sanitize_boot_params(&boot_params
);
248 cmd_line_ptr
= get_cmd_line_ptr();
250 command_line
= __va(cmd_line_ptr
);
251 memcpy(boot_command_line
, command_line
, COMMAND_LINE_SIZE
);
255 asmlinkage __visible
void __init
x86_64_start_kernel(char * real_mode_data
)
260 * Build-time sanity checks on the kernel image and module
261 * area mappings. (these are purely build-time and produce no code)
263 BUILD_BUG_ON(MODULES_VADDR
< __START_KERNEL_map
);
264 BUILD_BUG_ON(MODULES_VADDR
- __START_KERNEL_map
< KERNEL_IMAGE_SIZE
);
265 BUILD_BUG_ON(MODULES_LEN
+ KERNEL_IMAGE_SIZE
> 2*PUD_SIZE
);
266 BUILD_BUG_ON((__START_KERNEL_map
& ~PMD_MASK
) != 0);
267 BUILD_BUG_ON((MODULES_VADDR
& ~PMD_MASK
) != 0);
268 BUILD_BUG_ON(!(MODULES_VADDR
> __START_KERNEL
));
269 BUILD_BUG_ON(!(((MODULES_END
- 1) & PGDIR_MASK
) ==
270 (__START_KERNEL
& PGDIR_MASK
)));
271 BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses
) <= MODULES_END
);
275 /* Kill off the identity-map trampoline */
276 reset_early_page_tables();
280 clear_page(init_top_pgt
);
284 for (i
= 0; i
< NUM_EXCEPTION_VECTORS
; i
++)
285 set_intr_gate(i
, early_idt_handler_array
[i
]);
286 load_idt((const struct desc_ptr
*)&idt_descr
);
288 copy_bootdata(__va(real_mode_data
));
291 * Load microcode early on BSP.
295 /* set init_top_pgt kernel high mapping*/
296 init_top_pgt
[511] = early_top_pgt
[511];
298 x86_64_start_reservations(real_mode_data
);
301 void __init
x86_64_start_reservations(char *real_mode_data
)
303 /* version is always not zero if it is copied */
304 if (!boot_params
.hdr
.version
)
305 copy_bootdata(__va(real_mode_data
));
307 x86_early_init_platform_quirks();
309 switch (boot_params
.hdr
.hardware_subarch
) {
310 case X86_SUBARCH_INTEL_MID
:
311 x86_intel_mid_early_setup();