include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit...
[linux-3.10.git] / arch / x86 / kernel / machine_kexec_64.c
1 /*
2  * handle transition of Linux booting another kernel
3  * Copyright (C) 2002-2005 Eric Biederman  <ebiederm@xmission.com>
4  *
5  * This source code is licensed under the GNU General Public License,
6  * Version 2.  See the file COPYING for more details.
7  */
8
9 #include <linux/mm.h>
10 #include <linux/kexec.h>
11 #include <linux/string.h>
12 #include <linux/gfp.h>
13 #include <linux/reboot.h>
14 #include <linux/numa.h>
15 #include <linux/ftrace.h>
16 #include <linux/io.h>
17 #include <linux/suspend.h>
18
19 #include <asm/pgtable.h>
20 #include <asm/tlbflush.h>
21 #include <asm/mmu_context.h>
22 #include <asm/debugreg.h>
23
24 static int init_one_level2_page(struct kimage *image, pgd_t *pgd,
25                                 unsigned long addr)
26 {
27         pud_t *pud;
28         pmd_t *pmd;
29         struct page *page;
30         int result = -ENOMEM;
31
32         addr &= PMD_MASK;
33         pgd += pgd_index(addr);
34         if (!pgd_present(*pgd)) {
35                 page = kimage_alloc_control_pages(image, 0);
36                 if (!page)
37                         goto out;
38                 pud = (pud_t *)page_address(page);
39                 memset(pud, 0, PAGE_SIZE);
40                 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
41         }
42         pud = pud_offset(pgd, addr);
43         if (!pud_present(*pud)) {
44                 page = kimage_alloc_control_pages(image, 0);
45                 if (!page)
46                         goto out;
47                 pmd = (pmd_t *)page_address(page);
48                 memset(pmd, 0, PAGE_SIZE);
49                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
50         }
51         pmd = pmd_offset(pud, addr);
52         if (!pmd_present(*pmd))
53                 set_pmd(pmd, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
54         result = 0;
55 out:
56         return result;
57 }
58
59 static void init_level2_page(pmd_t *level2p, unsigned long addr)
60 {
61         unsigned long end_addr;
62
63         addr &= PAGE_MASK;
64         end_addr = addr + PUD_SIZE;
65         while (addr < end_addr) {
66                 set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
67                 addr += PMD_SIZE;
68         }
69 }
70
71 static int init_level3_page(struct kimage *image, pud_t *level3p,
72                                 unsigned long addr, unsigned long last_addr)
73 {
74         unsigned long end_addr;
75         int result;
76
77         result = 0;
78         addr &= PAGE_MASK;
79         end_addr = addr + PGDIR_SIZE;
80         while ((addr < last_addr) && (addr < end_addr)) {
81                 struct page *page;
82                 pmd_t *level2p;
83
84                 page = kimage_alloc_control_pages(image, 0);
85                 if (!page) {
86                         result = -ENOMEM;
87                         goto out;
88                 }
89                 level2p = (pmd_t *)page_address(page);
90                 init_level2_page(level2p, addr);
91                 set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE));
92                 addr += PUD_SIZE;
93         }
94         /* clear the unused entries */
95         while (addr < end_addr) {
96                 pud_clear(level3p++);
97                 addr += PUD_SIZE;
98         }
99 out:
100         return result;
101 }
102
103
104 static int init_level4_page(struct kimage *image, pgd_t *level4p,
105                                 unsigned long addr, unsigned long last_addr)
106 {
107         unsigned long end_addr;
108         int result;
109
110         result = 0;
111         addr &= PAGE_MASK;
112         end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE);
113         while ((addr < last_addr) && (addr < end_addr)) {
114                 struct page *page;
115                 pud_t *level3p;
116
117                 page = kimage_alloc_control_pages(image, 0);
118                 if (!page) {
119                         result = -ENOMEM;
120                         goto out;
121                 }
122                 level3p = (pud_t *)page_address(page);
123                 result = init_level3_page(image, level3p, addr, last_addr);
124                 if (result)
125                         goto out;
126                 set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE));
127                 addr += PGDIR_SIZE;
128         }
129         /* clear the unused entries */
130         while (addr < end_addr) {
131                 pgd_clear(level4p++);
132                 addr += PGDIR_SIZE;
133         }
134 out:
135         return result;
136 }
137
138 static void free_transition_pgtable(struct kimage *image)
139 {
140         free_page((unsigned long)image->arch.pud);
141         free_page((unsigned long)image->arch.pmd);
142         free_page((unsigned long)image->arch.pte);
143 }
144
145 static int init_transition_pgtable(struct kimage *image, pgd_t *pgd)
146 {
147         pud_t *pud;
148         pmd_t *pmd;
149         pte_t *pte;
150         unsigned long vaddr, paddr;
151         int result = -ENOMEM;
152
153         vaddr = (unsigned long)relocate_kernel;
154         paddr = __pa(page_address(image->control_code_page)+PAGE_SIZE);
155         pgd += pgd_index(vaddr);
156         if (!pgd_present(*pgd)) {
157                 pud = (pud_t *)get_zeroed_page(GFP_KERNEL);
158                 if (!pud)
159                         goto err;
160                 image->arch.pud = pud;
161                 set_pgd(pgd, __pgd(__pa(pud) | _KERNPG_TABLE));
162         }
163         pud = pud_offset(pgd, vaddr);
164         if (!pud_present(*pud)) {
165                 pmd = (pmd_t *)get_zeroed_page(GFP_KERNEL);
166                 if (!pmd)
167                         goto err;
168                 image->arch.pmd = pmd;
169                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
170         }
171         pmd = pmd_offset(pud, vaddr);
172         if (!pmd_present(*pmd)) {
173                 pte = (pte_t *)get_zeroed_page(GFP_KERNEL);
174                 if (!pte)
175                         goto err;
176                 image->arch.pte = pte;
177                 set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
178         }
179         pte = pte_offset_kernel(pmd, vaddr);
180         set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
181         return 0;
182 err:
183         free_transition_pgtable(image);
184         return result;
185 }
186
187
188 static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
189 {
190         pgd_t *level4p;
191         int result;
192         level4p = (pgd_t *)__va(start_pgtable);
193         result = init_level4_page(image, level4p, 0, max_pfn << PAGE_SHIFT);
194         if (result)
195                 return result;
196         /*
197          * image->start may be outside 0 ~ max_pfn, for example when
198          * jump back to original kernel from kexeced kernel
199          */
200         result = init_one_level2_page(image, level4p, image->start);
201         if (result)
202                 return result;
203         return init_transition_pgtable(image, level4p);
204 }
205
206 static void set_idt(void *newidt, u16 limit)
207 {
208         struct desc_ptr curidt;
209
210         /* x86-64 supports unaliged loads & stores */
211         curidt.size    = limit;
212         curidt.address = (unsigned long)newidt;
213
214         __asm__ __volatile__ (
215                 "lidtq %0\n"
216                 : : "m" (curidt)
217                 );
218 };
219
220
221 static void set_gdt(void *newgdt, u16 limit)
222 {
223         struct desc_ptr curgdt;
224
225         /* x86-64 supports unaligned loads & stores */
226         curgdt.size    = limit;
227         curgdt.address = (unsigned long)newgdt;
228
229         __asm__ __volatile__ (
230                 "lgdtq %0\n"
231                 : : "m" (curgdt)
232                 );
233 };
234
235 static void load_segments(void)
236 {
237         __asm__ __volatile__ (
238                 "\tmovl %0,%%ds\n"
239                 "\tmovl %0,%%es\n"
240                 "\tmovl %0,%%ss\n"
241                 "\tmovl %0,%%fs\n"
242                 "\tmovl %0,%%gs\n"
243                 : : "a" (__KERNEL_DS) : "memory"
244                 );
245 }
246
247 int machine_kexec_prepare(struct kimage *image)
248 {
249         unsigned long start_pgtable;
250         int result;
251
252         /* Calculate the offsets */
253         start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
254
255         /* Setup the identity mapped 64bit page table */
256         result = init_pgtable(image, start_pgtable);
257         if (result)
258                 return result;
259
260         return 0;
261 }
262
263 void machine_kexec_cleanup(struct kimage *image)
264 {
265         free_transition_pgtable(image);
266 }
267
268 /*
269  * Do not allocate memory (or fail in any way) in machine_kexec().
270  * We are past the point of no return, committed to rebooting now.
271  */
272 void machine_kexec(struct kimage *image)
273 {
274         unsigned long page_list[PAGES_NR];
275         void *control_page;
276         int save_ftrace_enabled;
277
278 #ifdef CONFIG_KEXEC_JUMP
279         if (image->preserve_context)
280                 save_processor_state();
281 #endif
282
283         save_ftrace_enabled = __ftrace_enabled_save();
284
285         /* Interrupts aren't acceptable while we reboot */
286         local_irq_disable();
287         hw_breakpoint_disable();
288
289         if (image->preserve_context) {
290 #ifdef CONFIG_X86_IO_APIC
291                 /*
292                  * We need to put APICs in legacy mode so that we can
293                  * get timer interrupts in second kernel. kexec/kdump
294                  * paths already have calls to disable_IO_APIC() in
295                  * one form or other. kexec jump path also need
296                  * one.
297                  */
298                 disable_IO_APIC();
299 #endif
300         }
301
302         control_page = page_address(image->control_code_page) + PAGE_SIZE;
303         memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
304
305         page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page);
306         page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
307         page_list[PA_TABLE_PAGE] =
308           (unsigned long)__pa(page_address(image->control_code_page));
309
310         if (image->type == KEXEC_TYPE_DEFAULT)
311                 page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
312                                                 << PAGE_SHIFT);
313
314         /*
315          * The segment registers are funny things, they have both a
316          * visible and an invisible part.  Whenever the visible part is
317          * set to a specific selector, the invisible part is loaded
318          * with from a table in memory.  At no other time is the
319          * descriptor table in memory accessed.
320          *
321          * I take advantage of this here by force loading the
322          * segments, before I zap the gdt with an invalid value.
323          */
324         load_segments();
325         /*
326          * The gdt & idt are now invalid.
327          * If you want to load them you must set up your own idt & gdt.
328          */
329         set_gdt(phys_to_virt(0), 0);
330         set_idt(phys_to_virt(0), 0);
331
332         /* now call it */
333         image->start = relocate_kernel((unsigned long)image->head,
334                                        (unsigned long)page_list,
335                                        image->start,
336                                        image->preserve_context);
337
338 #ifdef CONFIG_KEXEC_JUMP
339         if (image->preserve_context)
340                 restore_processor_state();
341 #endif
342
343         __ftrace_enabled_restore(save_ftrace_enabled);
344 }
345
346 void arch_crash_save_vmcoreinfo(void)
347 {
348         VMCOREINFO_SYMBOL(phys_base);
349         VMCOREINFO_SYMBOL(init_level4_pgt);
350
351 #ifdef CONFIG_NUMA
352         VMCOREINFO_SYMBOL(node_data);
353         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
354 #endif
355 }
356