Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-3.10.git] / arch / x86 / kernel / head64.c
1 /*
2  *  prepare to run common code
3  *
4  *  Copyright (C) 2000 Andrea Arcangeli <andrea@suse.de> SuSE
5  */
6
7 #include <linux/init.h>
8 #include <linux/linkage.h>
9 #include <linux/types.h>
10 #include <linux/kernel.h>
11 #include <linux/string.h>
12 #include <linux/percpu.h>
13 #include <linux/start_kernel.h>
14 #include <linux/io.h>
15 #include <linux/memblock.h>
16
17 #include <asm/processor.h>
18 #include <asm/proto.h>
19 #include <asm/smp.h>
20 #include <asm/setup.h>
21 #include <asm/desc.h>
22 #include <asm/pgtable.h>
23 #include <asm/tlbflush.h>
24 #include <asm/sections.h>
25 #include <asm/kdebug.h>
26 #include <asm/e820.h>
27 #include <asm/bios_ebda.h>
28 #include <asm/bootparam_utils.h>
29 #include <asm/microcode.h>
30
31 /*
32  * Manage page tables very early on.
33  */
34 extern pgd_t early_level4_pgt[PTRS_PER_PGD];
35 extern pmd_t early_dynamic_pgts[EARLY_DYNAMIC_PAGE_TABLES][PTRS_PER_PMD];
36 static unsigned int __initdata next_early_pgt = 2;
37
38 /* Wipe all early page tables except for the kernel symbol map */
39 static void __init reset_early_page_tables(void)
40 {
41         unsigned long i;
42
43         for (i = 0; i < PTRS_PER_PGD-1; i++)
44                 early_level4_pgt[i].pgd = 0;
45
46         next_early_pgt = 0;
47
48         write_cr3(__pa(early_level4_pgt));
49 }
50
51 /* Create a new PMD entry */
52 int __init early_make_pgtable(unsigned long address)
53 {
54         unsigned long physaddr = address - __PAGE_OFFSET;
55         unsigned long i;
56         pgdval_t pgd, *pgd_p;
57         pudval_t pud, *pud_p;
58         pmdval_t pmd, *pmd_p;
59
60         /* Invalid address or early pgt is done ?  */
61         if (physaddr >= MAXMEM || read_cr3() != __pa(early_level4_pgt))
62                 return -1;
63
64 again:
65         pgd_p = &early_level4_pgt[pgd_index(address)].pgd;
66         pgd = *pgd_p;
67
68         /*
69          * The use of __START_KERNEL_map rather than __PAGE_OFFSET here is
70          * critical -- __PAGE_OFFSET would point us back into the dynamic
71          * range and we might end up looping forever...
72          */
73         if (pgd)
74                 pud_p = (pudval_t *)((pgd & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
75         else {
76                 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
77                         reset_early_page_tables();
78                         goto again;
79                 }
80
81                 pud_p = (pudval_t *)early_dynamic_pgts[next_early_pgt++];
82                 for (i = 0; i < PTRS_PER_PUD; i++)
83                         pud_p[i] = 0;
84                 *pgd_p = (pgdval_t)pud_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
85         }
86         pud_p += pud_index(address);
87         pud = *pud_p;
88
89         if (pud)
90                 pmd_p = (pmdval_t *)((pud & PTE_PFN_MASK) + __START_KERNEL_map - phys_base);
91         else {
92                 if (next_early_pgt >= EARLY_DYNAMIC_PAGE_TABLES) {
93                         reset_early_page_tables();
94                         goto again;
95                 }
96
97                 pmd_p = (pmdval_t *)early_dynamic_pgts[next_early_pgt++];
98                 for (i = 0; i < PTRS_PER_PMD; i++)
99                         pmd_p[i] = 0;
100                 *pud_p = (pudval_t)pmd_p - __START_KERNEL_map + phys_base + _KERNPG_TABLE;
101         }
102         pmd = (physaddr & PMD_MASK) + (__PAGE_KERNEL_LARGE & ~_PAGE_GLOBAL);
103         pmd_p[pmd_index(address)] = pmd;
104
105         return 0;
106 }
107
108 /* Don't add a printk in there. printk relies on the PDA which is not initialized 
109    yet. */
110 static void __init clear_bss(void)
111 {
112         memset(__bss_start, 0,
113                (unsigned long) __bss_stop - (unsigned long) __bss_start);
114 }
115
116 static unsigned long get_cmd_line_ptr(void)
117 {
118         unsigned long cmd_line_ptr = boot_params.hdr.cmd_line_ptr;
119
120         cmd_line_ptr |= (u64)boot_params.ext_cmd_line_ptr << 32;
121
122         return cmd_line_ptr;
123 }
124
125 static void __init copy_bootdata(char *real_mode_data)
126 {
127         char * command_line;
128         unsigned long cmd_line_ptr;
129
130         memcpy(&boot_params, real_mode_data, sizeof boot_params);
131         sanitize_boot_params(&boot_params);
132         cmd_line_ptr = get_cmd_line_ptr();
133         if (cmd_line_ptr) {
134                 command_line = __va(cmd_line_ptr);
135                 memcpy(boot_command_line, command_line, COMMAND_LINE_SIZE);
136         }
137 }
138
139 void __init x86_64_start_kernel(char * real_mode_data)
140 {
141         int i;
142
143         /*
144          * Build-time sanity checks on the kernel image and module
145          * area mappings. (these are purely build-time and produce no code)
146          */
147         BUILD_BUG_ON(MODULES_VADDR < KERNEL_IMAGE_START);
148         BUILD_BUG_ON(MODULES_VADDR-KERNEL_IMAGE_START < KERNEL_IMAGE_SIZE);
149         BUILD_BUG_ON(MODULES_LEN + KERNEL_IMAGE_SIZE > 2*PUD_SIZE);
150         BUILD_BUG_ON((KERNEL_IMAGE_START & ~PMD_MASK) != 0);
151         BUILD_BUG_ON((MODULES_VADDR & ~PMD_MASK) != 0);
152         BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
153         BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
154                                 (__START_KERNEL & PGDIR_MASK)));
155         BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
156
157         /* Kill off the identity-map trampoline */
158         reset_early_page_tables();
159
160         /* clear bss before set_intr_gate with early_idt_handler */
161         clear_bss();
162
163         for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)
164                 set_intr_gate(i, &early_idt_handlers[i]);
165         load_idt((const struct desc_ptr *)&idt_descr);
166
167         copy_bootdata(__va(real_mode_data));
168
169         /*
170          * Load microcode early on BSP.
171          */
172         load_ucode_bsp();
173
174         if (console_loglevel == 10)
175                 early_printk("Kernel alive\n");
176
177         clear_page(init_level4_pgt);
178         /* set init_level4_pgt kernel high mapping*/
179         init_level4_pgt[511] = early_level4_pgt[511];
180
181         x86_64_start_reservations(real_mode_data);
182 }
183
184 void __init x86_64_start_reservations(char *real_mode_data)
185 {
186         /* version is always not zero if it is copied */
187         if (!boot_params.hdr.version)
188                 copy_bootdata(__va(real_mode_data));
189
190         reserve_ebda_region();
191
192         start_kernel();
193 }