Pull cpuidle into release branch
[linux-2.6] / 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/reboot.h>
13 #include <linux/numa.h>
14 #include <asm/pgtable.h>
15 #include <asm/tlbflush.h>
16 #include <asm/mmu_context.h>
17 #include <asm/io.h>
18
19 #define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
20 static u64 kexec_pgd[512] PAGE_ALIGNED;
21 static u64 kexec_pud0[512] PAGE_ALIGNED;
22 static u64 kexec_pmd0[512] PAGE_ALIGNED;
23 static u64 kexec_pte0[512] PAGE_ALIGNED;
24 static u64 kexec_pud1[512] PAGE_ALIGNED;
25 static u64 kexec_pmd1[512] PAGE_ALIGNED;
26 static u64 kexec_pte1[512] PAGE_ALIGNED;
27
28 static void init_level2_page(pmd_t *level2p, unsigned long addr)
29 {
30         unsigned long end_addr;
31
32         addr &= PAGE_MASK;
33         end_addr = addr + PUD_SIZE;
34         while (addr < end_addr) {
35                 set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
36                 addr += PMD_SIZE;
37         }
38 }
39
40 static int init_level3_page(struct kimage *image, pud_t *level3p,
41                                 unsigned long addr, unsigned long last_addr)
42 {
43         unsigned long end_addr;
44         int result;
45
46         result = 0;
47         addr &= PAGE_MASK;
48         end_addr = addr + PGDIR_SIZE;
49         while ((addr < last_addr) && (addr < end_addr)) {
50                 struct page *page;
51                 pmd_t *level2p;
52
53                 page = kimage_alloc_control_pages(image, 0);
54                 if (!page) {
55                         result = -ENOMEM;
56                         goto out;
57                 }
58                 level2p = (pmd_t *)page_address(page);
59                 init_level2_page(level2p, addr);
60                 set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE));
61                 addr += PUD_SIZE;
62         }
63         /* clear the unused entries */
64         while (addr < end_addr) {
65                 pud_clear(level3p++);
66                 addr += PUD_SIZE;
67         }
68 out:
69         return result;
70 }
71
72
73 static int init_level4_page(struct kimage *image, pgd_t *level4p,
74                                 unsigned long addr, unsigned long last_addr)
75 {
76         unsigned long end_addr;
77         int result;
78
79         result = 0;
80         addr &= PAGE_MASK;
81         end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE);
82         while ((addr < last_addr) && (addr < end_addr)) {
83                 struct page *page;
84                 pud_t *level3p;
85
86                 page = kimage_alloc_control_pages(image, 0);
87                 if (!page) {
88                         result = -ENOMEM;
89                         goto out;
90                 }
91                 level3p = (pud_t *)page_address(page);
92                 result = init_level3_page(image, level3p, addr, last_addr);
93                 if (result) {
94                         goto out;
95                 }
96                 set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE));
97                 addr += PGDIR_SIZE;
98         }
99         /* clear the unused entries */
100         while (addr < end_addr) {
101                 pgd_clear(level4p++);
102                 addr += PGDIR_SIZE;
103         }
104 out:
105         return result;
106 }
107
108
109 static int init_pgtable(struct kimage *image, unsigned long start_pgtable)
110 {
111         pgd_t *level4p;
112         level4p = (pgd_t *)__va(start_pgtable);
113         return init_level4_page(image, level4p, 0, end_pfn << PAGE_SHIFT);
114 }
115
116 static void set_idt(void *newidt, u16 limit)
117 {
118         struct desc_ptr curidt;
119
120         /* x86-64 supports unaliged loads & stores */
121         curidt.size    = limit;
122         curidt.address = (unsigned long)newidt;
123
124         __asm__ __volatile__ (
125                 "lidtq %0\n"
126                 : : "m" (curidt)
127                 );
128 };
129
130
131 static void set_gdt(void *newgdt, u16 limit)
132 {
133         struct desc_ptr curgdt;
134
135         /* x86-64 supports unaligned loads & stores */
136         curgdt.size    = limit;
137         curgdt.address = (unsigned long)newgdt;
138
139         __asm__ __volatile__ (
140                 "lgdtq %0\n"
141                 : : "m" (curgdt)
142                 );
143 };
144
145 static void load_segments(void)
146 {
147         __asm__ __volatile__ (
148                 "\tmovl %0,%%ds\n"
149                 "\tmovl %0,%%es\n"
150                 "\tmovl %0,%%ss\n"
151                 "\tmovl %0,%%fs\n"
152                 "\tmovl %0,%%gs\n"
153                 : : "a" (__KERNEL_DS) : "memory"
154                 );
155 }
156
157 int machine_kexec_prepare(struct kimage *image)
158 {
159         unsigned long start_pgtable;
160         int result;
161
162         /* Calculate the offsets */
163         start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT;
164
165         /* Setup the identity mapped 64bit page table */
166         result = init_pgtable(image, start_pgtable);
167         if (result)
168                 return result;
169
170         return 0;
171 }
172
173 void machine_kexec_cleanup(struct kimage *image)
174 {
175         return;
176 }
177
178 /*
179  * Do not allocate memory (or fail in any way) in machine_kexec().
180  * We are past the point of no return, committed to rebooting now.
181  */
182 NORET_TYPE void machine_kexec(struct kimage *image)
183 {
184         unsigned long page_list[PAGES_NR];
185         void *control_page;
186
187         /* Interrupts aren't acceptable while we reboot */
188         local_irq_disable();
189
190         control_page = page_address(image->control_code_page) + PAGE_SIZE;
191         memcpy(control_page, relocate_kernel, PAGE_SIZE);
192
193         page_list[PA_CONTROL_PAGE] = virt_to_phys(control_page);
194         page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel;
195         page_list[PA_PGD] = virt_to_phys(&kexec_pgd);
196         page_list[VA_PGD] = (unsigned long)kexec_pgd;
197         page_list[PA_PUD_0] = virt_to_phys(&kexec_pud0);
198         page_list[VA_PUD_0] = (unsigned long)kexec_pud0;
199         page_list[PA_PMD_0] = virt_to_phys(&kexec_pmd0);
200         page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
201         page_list[PA_PTE_0] = virt_to_phys(&kexec_pte0);
202         page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
203         page_list[PA_PUD_1] = virt_to_phys(&kexec_pud1);
204         page_list[VA_PUD_1] = (unsigned long)kexec_pud1;
205         page_list[PA_PMD_1] = virt_to_phys(&kexec_pmd1);
206         page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
207         page_list[PA_PTE_1] = virt_to_phys(&kexec_pte1);
208         page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
209
210         page_list[PA_TABLE_PAGE] =
211           (unsigned long)__pa(page_address(image->control_code_page));
212
213         /* The segment registers are funny things, they have both a
214          * visible and an invisible part.  Whenever the visible part is
215          * set to a specific selector, the invisible part is loaded
216          * with from a table in memory.  At no other time is the
217          * descriptor table in memory accessed.
218          *
219          * I take advantage of this here by force loading the
220          * segments, before I zap the gdt with an invalid value.
221          */
222         load_segments();
223         /* The gdt & idt are now invalid.
224          * If you want to load them you must set up your own idt & gdt.
225          */
226         set_gdt(phys_to_virt(0),0);
227         set_idt(phys_to_virt(0),0);
228
229         /* now call it */
230         relocate_kernel((unsigned long)image->head, (unsigned long)page_list,
231                         image->start);
232 }
233
234 void arch_crash_save_vmcoreinfo(void)
235 {
236         VMCOREINFO_SYMBOL(init_level4_pgt);
237
238 #ifdef CONFIG_ARCH_DISCONTIGMEM_ENABLE
239         VMCOREINFO_SYMBOL(node_data);
240         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
241 #endif
242 }
243