/[pkg-src]/trunk/kernel26-xen/patches-2.6.25-r1/1001-2.6.25-xen-linux-2.6.19-rc1-kexec-move_segment_code-i386.patch |
Annotation of /trunk/kernel26-xen/patches-2.6.25-r1/1001-2.6.25-xen-linux-2.6.19-rc1-kexec-move_segment_code-i386.patch
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Revision 609 -
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Fri May 23 17:35:37 2008 UTC (16 years, 4 months ago) by niro
File size: 5122 byte(s)
Fri May 23 17:35:37 2008 UTC (16 years, 4 months ago) by niro
File size: 5122 byte(s)
-using opensuse xen patchset, updated kernel configs
1 | niro | 609 | Subject: kexec: Move asm segment handling code to the assembly file (i386) |
2 | From: http://xenbits.xensource.com/xen-unstable.hg (tip 13816) | ||
3 | Patch-mainline: obsolete | ||
4 | |||
5 | This patch moves the idt, gdt, and segment handling code from machine_kexec.c | ||
6 | to relocate_kernel.S. The main reason behind this move is to avoid code | ||
7 | duplication in the Xen hypervisor. With this patch all code required to kexec | ||
8 | is put on the control page. | ||
9 | |||
10 | On top of that this patch also counts as a cleanup - I think it is much | ||
11 | nicer to write assembly directly in assembly files than wrap inline assembly | ||
12 | in C functions for no apparent reason. | ||
13 | |||
14 | Signed-off-by: Magnus Damm <magnus@valinux.co.jp> | ||
15 | Acked-by: jbeulich@novell.com | ||
16 | --- | ||
17 | |||
18 | Applies to 2.6.19-rc1. | ||
19 | |||
20 | machine_kexec.c | 59 ----------------------------------------------------- | ||
21 | relocate_kernel.S | 58 +++++++++++++++++++++++++++++++++++++++++++++++----- | ||
22 | 2 files changed, 53 insertions(+), 64 deletions(-) | ||
23 | |||
24 | Index: head-2008-02-26/arch/x86/kernel/machine_kexec_32.c | ||
25 | =================================================================== | ||
26 | --- head-2008-02-26.orig/arch/x86/kernel/machine_kexec_32.c 2008-02-26 11:43:15.000000000 +0100 | ||
27 | +++ head-2008-02-26/arch/x86/kernel/machine_kexec_32.c 2008-02-26 11:45:10.000000000 +0100 | ||
28 | @@ -30,48 +30,6 @@ static u32 kexec_pmd1[1024] PAGE_ALIGNED | ||
29 | static u32 kexec_pte0[1024] PAGE_ALIGNED; | ||
30 | static u32 kexec_pte1[1024] PAGE_ALIGNED; | ||
31 | |||
32 | -static void set_idt(void *newidt, __u16 limit) | ||
33 | -{ | ||
34 | - struct desc_ptr curidt; | ||
35 | - | ||
36 | - /* ia32 supports unaliged loads & stores */ | ||
37 | - curidt.size = limit; | ||
38 | - curidt.address = (unsigned long)newidt; | ||
39 | - | ||
40 | - load_idt(&curidt); | ||
41 | -}; | ||
42 | - | ||
43 | - | ||
44 | -static void set_gdt(void *newgdt, __u16 limit) | ||
45 | -{ | ||
46 | - struct desc_ptr curgdt; | ||
47 | - | ||
48 | - /* ia32 supports unaligned loads & stores */ | ||
49 | - curgdt.size = limit; | ||
50 | - curgdt.address = (unsigned long)newgdt; | ||
51 | - | ||
52 | - load_gdt(&curgdt); | ||
53 | -}; | ||
54 | - | ||
55 | -static void load_segments(void) | ||
56 | -{ | ||
57 | -#define __STR(X) #X | ||
58 | -#define STR(X) __STR(X) | ||
59 | - | ||
60 | - __asm__ __volatile__ ( | ||
61 | - "\tljmp $"STR(__KERNEL_CS)",$1f\n" | ||
62 | - "\t1:\n" | ||
63 | - "\tmovl $"STR(__KERNEL_DS)",%%eax\n" | ||
64 | - "\tmovl %%eax,%%ds\n" | ||
65 | - "\tmovl %%eax,%%es\n" | ||
66 | - "\tmovl %%eax,%%fs\n" | ||
67 | - "\tmovl %%eax,%%gs\n" | ||
68 | - "\tmovl %%eax,%%ss\n" | ||
69 | - ::: "eax", "memory"); | ||
70 | -#undef STR | ||
71 | -#undef __STR | ||
72 | -} | ||
73 | - | ||
74 | /* | ||
75 | * A architecture hook called to validate the | ||
76 | * proposed image and prepare the control pages | ||
77 | @@ -128,23 +86,6 @@ NORET_TYPE void machine_kexec(struct kim | ||
78 | page_list[PA_PTE_1] = __pa(kexec_pte1); | ||
79 | page_list[VA_PTE_1] = (unsigned long)kexec_pte1; | ||
80 | |||
81 | - /* The segment registers are funny things, they have both a | ||
82 | - * visible and an invisible part. Whenever the visible part is | ||
83 | - * set to a specific selector, the invisible part is loaded | ||
84 | - * with from a table in memory. At no other time is the | ||
85 | - * descriptor table in memory accessed. | ||
86 | - * | ||
87 | - * I take advantage of this here by force loading the | ||
88 | - * segments, before I zap the gdt with an invalid value. | ||
89 | - */ | ||
90 | - load_segments(); | ||
91 | - /* The gdt & idt are now invalid. | ||
92 | - * If you want to load them you must set up your own idt & gdt. | ||
93 | - */ | ||
94 | - set_gdt(phys_to_virt(0),0); | ||
95 | - set_idt(phys_to_virt(0),0); | ||
96 | - | ||
97 | - /* now call it */ | ||
98 | relocate_kernel((unsigned long)image->head, (unsigned long)page_list, | ||
99 | image->start, cpu_has_pae); | ||
100 | } | ||
101 | Index: head-2008-02-26/arch/x86/kernel/relocate_kernel_32.S | ||
102 | =================================================================== | ||
103 | --- head-2008-02-26.orig/arch/x86/kernel/relocate_kernel_32.S 2008-01-24 23:58:37.000000000 +0100 | ||
104 | +++ head-2008-02-26/arch/x86/kernel/relocate_kernel_32.S 2008-02-26 11:45:10.000000000 +0100 | ||
105 | @@ -154,14 +154,45 @@ relocate_new_kernel: | ||
106 | movl PTR(PA_PGD)(%ebp), %eax | ||
107 | movl %eax, %cr3 | ||
108 | |||
109 | + /* setup idt */ | ||
110 | + movl %edi, %eax | ||
111 | + addl $(idt_48 - relocate_kernel), %eax | ||
112 | + lidtl (%eax) | ||
113 | + | ||
114 | + /* setup gdt */ | ||
115 | + movl %edi, %eax | ||
116 | + addl $(gdt - relocate_kernel), %eax | ||
117 | + movl %edi, %esi | ||
118 | + addl $((gdt_48 - relocate_kernel) + 2), %esi | ||
119 | + movl %eax, (%esi) | ||
120 | + | ||
121 | + movl %edi, %eax | ||
122 | + addl $(gdt_48 - relocate_kernel), %eax | ||
123 | + lgdtl (%eax) | ||
124 | + | ||
125 | + /* setup data segment registers */ | ||
126 | + mov $(gdt_ds - gdt), %eax | ||
127 | + mov %eax, %ds | ||
128 | + mov %eax, %es | ||
129 | + mov %eax, %fs | ||
130 | + mov %eax, %gs | ||
131 | + mov %eax, %ss | ||
132 | + | ||
133 | /* setup a new stack at the end of the physical control page */ | ||
134 | lea 4096(%edi), %esp | ||
135 | |||
136 | - /* jump to identity mapped page */ | ||
137 | - movl %edi, %eax | ||
138 | - addl $(identity_mapped - relocate_kernel), %eax | ||
139 | - pushl %eax | ||
140 | - ret | ||
141 | + /* load new code segment and jump to identity mapped page */ | ||
142 | + movl %edi, %esi | ||
143 | + xorl %eax, %eax | ||
144 | + pushl %eax | ||
145 | + pushl %esi | ||
146 | + pushl %eax | ||
147 | + movl $(gdt_cs - gdt), %eax | ||
148 | + pushl %eax | ||
149 | + movl %edi, %eax | ||
150 | + addl $(identity_mapped - relocate_kernel),%eax | ||
151 | + pushl %eax | ||
152 | + iretl | ||
153 | |||
154 | identity_mapped: | ||
155 | /* store the start address on the stack */ | ||
156 | @@ -250,3 +281,20 @@ identity_mapped: | ||
157 | xorl %edi, %edi | ||
158 | xorl %ebp, %ebp | ||
159 | ret | ||
160 | + | ||
161 | + .align 16 | ||
162 | +gdt: | ||
163 | + .quad 0x0000000000000000 /* NULL descriptor */ | ||
164 | +gdt_cs: | ||
165 | + .quad 0x00cf9a000000ffff /* kernel 4GB code at 0x00000000 */ | ||
166 | +gdt_ds: | ||
167 | + .quad 0x00cf92000000ffff /* kernel 4GB data at 0x00000000 */ | ||
168 | +gdt_end: | ||
169 | + | ||
170 | +gdt_48: | ||
171 | + .word gdt_end - gdt - 1 /* limit */ | ||
172 | + .long 0 /* base - filled in by code above */ | ||
173 | + | ||
174 | +idt_48: | ||
175 | + .word 0 /* limit */ | ||
176 | + .long 0 /* base */ |