Merge branch 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied...
[linux-2.6] / arch / x86 / kernel / machine_kexec_32.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/delay.h>
12 #include <linux/init.h>
13 #include <linux/numa.h>
14 #include <linux/ftrace.h>
15 #include <linux/suspend.h>
16
17 #include <asm/pgtable.h>
18 #include <asm/pgalloc.h>
19 #include <asm/tlbflush.h>
20 #include <asm/mmu_context.h>
21 #include <asm/io.h>
22 #include <asm/apic.h>
23 #include <asm/cpufeature.h>
24 #include <asm/desc.h>
25 #include <asm/system.h>
26 #include <asm/cacheflush.h>
27
28 #define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
29 static u32 kexec_pgd[1024] PAGE_ALIGNED;
30 #ifdef CONFIG_X86_PAE
31 static u32 kexec_pmd0[1024] PAGE_ALIGNED;
32 static u32 kexec_pmd1[1024] PAGE_ALIGNED;
33 #endif
34 static u32 kexec_pte0[1024] PAGE_ALIGNED;
35 static u32 kexec_pte1[1024] PAGE_ALIGNED;
36
37 static void set_idt(void *newidt, __u16 limit)
38 {
39         struct desc_ptr curidt;
40
41         /* ia32 supports unaliged loads & stores */
42         curidt.size    = limit;
43         curidt.address = (unsigned long)newidt;
44
45         load_idt(&curidt);
46 }
47
48
49 static void set_gdt(void *newgdt, __u16 limit)
50 {
51         struct desc_ptr curgdt;
52
53         /* ia32 supports unaligned loads & stores */
54         curgdt.size    = limit;
55         curgdt.address = (unsigned long)newgdt;
56
57         load_gdt(&curgdt);
58 }
59
60 static void load_segments(void)
61 {
62 #define __STR(X) #X
63 #define STR(X) __STR(X)
64
65         __asm__ __volatile__ (
66                 "\tljmp $"STR(__KERNEL_CS)",$1f\n"
67                 "\t1:\n"
68                 "\tmovl $"STR(__KERNEL_DS)",%%eax\n"
69                 "\tmovl %%eax,%%ds\n"
70                 "\tmovl %%eax,%%es\n"
71                 "\tmovl %%eax,%%fs\n"
72                 "\tmovl %%eax,%%gs\n"
73                 "\tmovl %%eax,%%ss\n"
74                 ::: "eax", "memory");
75 #undef STR
76 #undef __STR
77 }
78
79 /*
80  * A architecture hook called to validate the
81  * proposed image and prepare the control pages
82  * as needed.  The pages for KEXEC_CONTROL_PAGE_SIZE
83  * have been allocated, but the segments have yet
84  * been copied into the kernel.
85  *
86  * Do what every setup is needed on image and the
87  * reboot code buffer to allow us to avoid allocations
88  * later.
89  *
90  * Make control page executable.
91  */
92 int machine_kexec_prepare(struct kimage *image)
93 {
94         if (nx_enabled)
95                 set_pages_x(image->control_code_page, 1);
96         return 0;
97 }
98
99 /*
100  * Undo anything leftover by machine_kexec_prepare
101  * when an image is freed.
102  */
103 void machine_kexec_cleanup(struct kimage *image)
104 {
105         if (nx_enabled)
106                 set_pages_nx(image->control_code_page, 1);
107 }
108
109 /*
110  * Do not allocate memory (or fail in any way) in machine_kexec().
111  * We are past the point of no return, committed to rebooting now.
112  */
113 void machine_kexec(struct kimage *image)
114 {
115         unsigned long page_list[PAGES_NR];
116         void *control_page;
117         int save_ftrace_enabled;
118         asmlinkage unsigned long
119                 (*relocate_kernel_ptr)(unsigned long indirection_page,
120                                        unsigned long control_page,
121                                        unsigned long start_address,
122                                        unsigned int has_pae,
123                                        unsigned int preserve_context);
124
125 #ifdef CONFIG_KEXEC_JUMP
126         if (kexec_image->preserve_context)
127                 save_processor_state();
128 #endif
129
130         save_ftrace_enabled = __ftrace_enabled_save();
131
132         /* Interrupts aren't acceptable while we reboot */
133         local_irq_disable();
134
135         if (image->preserve_context) {
136 #ifdef CONFIG_X86_IO_APIC
137                 /* We need to put APICs in legacy mode so that we can
138                  * get timer interrupts in second kernel. kexec/kdump
139                  * paths already have calls to disable_IO_APIC() in
140                  * one form or other. kexec jump path also need
141                  * one.
142                  */
143                 disable_IO_APIC();
144 #endif
145         }
146
147         control_page = page_address(image->control_code_page);
148         memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
149
150         relocate_kernel_ptr = control_page;
151         page_list[PA_CONTROL_PAGE] = __pa(control_page);
152         page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
153         page_list[PA_PGD] = __pa(kexec_pgd);
154         page_list[VA_PGD] = (unsigned long)kexec_pgd;
155 #ifdef CONFIG_X86_PAE
156         page_list[PA_PMD_0] = __pa(kexec_pmd0);
157         page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
158         page_list[PA_PMD_1] = __pa(kexec_pmd1);
159         page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
160 #endif
161         page_list[PA_PTE_0] = __pa(kexec_pte0);
162         page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
163         page_list[PA_PTE_1] = __pa(kexec_pte1);
164         page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
165         page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page) << PAGE_SHIFT);
166
167         /* The segment registers are funny things, they have both a
168          * visible and an invisible part.  Whenever the visible part is
169          * set to a specific selector, the invisible part is loaded
170          * with from a table in memory.  At no other time is the
171          * descriptor table in memory accessed.
172          *
173          * I take advantage of this here by force loading the
174          * segments, before I zap the gdt with an invalid value.
175          */
176         load_segments();
177         /* The gdt & idt are now invalid.
178          * If you want to load them you must set up your own idt & gdt.
179          */
180         set_gdt(phys_to_virt(0),0);
181         set_idt(phys_to_virt(0),0);
182
183         /* now call it */
184         image->start = relocate_kernel_ptr((unsigned long)image->head,
185                                            (unsigned long)page_list,
186                                            image->start, cpu_has_pae,
187                                            image->preserve_context);
188
189 #ifdef CONFIG_KEXEC_JUMP
190         if (kexec_image->preserve_context)
191                 restore_processor_state();
192 #endif
193
194         __ftrace_enabled_restore(save_ftrace_enabled);
195 }
196
197 void arch_crash_save_vmcoreinfo(void)
198 {
199 #ifdef CONFIG_NUMA
200         VMCOREINFO_SYMBOL(node_data);
201         VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
202 #endif
203 #ifdef CONFIG_X86_PAE
204         VMCOREINFO_CONFIG(X86_PAE);
205 #endif
206 }
207