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-rw-r--r--arch/i386/kernel/machine_kexec.c117
-rw-r--r--arch/i386/kernel/relocate_kernel.S162
2 files changed, 174 insertions, 105 deletions
diff --git a/arch/i386/kernel/machine_kexec.c b/arch/i386/kernel/machine_kexec.c
index 66c3dc99a655..91966bafb3dc 100644
--- a/arch/i386/kernel/machine_kexec.c
+++ b/arch/i386/kernel/machine_kexec.c
@@ -21,70 +21,13 @@
21#include <asm/system.h> 21#include <asm/system.h>
22 22
23#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE))) 23#define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE)))
24 24static u32 kexec_pgd[1024] PAGE_ALIGNED;
25#define L0_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) 25#ifdef CONFIG_X86_PAE
26#define L1_ATTR (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY) 26static u32 kexec_pmd0[1024] PAGE_ALIGNED;
27#define L2_ATTR (_PAGE_PRESENT) 27static u32 kexec_pmd1[1024] PAGE_ALIGNED;
28
29#define LEVEL0_SIZE (1UL << 12UL)
30
31#ifndef CONFIG_X86_PAE
32#define LEVEL1_SIZE (1UL << 22UL)
33static u32 pgtable_level1[1024] PAGE_ALIGNED;
34
35static void identity_map_page(unsigned long address)
36{
37 unsigned long level1_index, level2_index;
38 u32 *pgtable_level2;
39
40 /* Find the current page table */
41 pgtable_level2 = __va(read_cr3());
42
43 /* Find the indexes of the physical address to identity map */
44 level1_index = (address % LEVEL1_SIZE)/LEVEL0_SIZE;
45 level2_index = address / LEVEL1_SIZE;
46
47 /* Identity map the page table entry */
48 pgtable_level1[level1_index] = address | L0_ATTR;
49 pgtable_level2[level2_index] = __pa(pgtable_level1) | L1_ATTR;
50
51 /* Flush the tlb so the new mapping takes effect.
52 * Global tlb entries are not flushed but that is not an issue.
53 */
54 load_cr3(pgtable_level2);
55}
56
57#else
58#define LEVEL1_SIZE (1UL << 21UL)
59#define LEVEL2_SIZE (1UL << 30UL)
60static u64 pgtable_level1[512] PAGE_ALIGNED;
61static u64 pgtable_level2[512] PAGE_ALIGNED;
62
63static void identity_map_page(unsigned long address)
64{
65 unsigned long level1_index, level2_index, level3_index;
66 u64 *pgtable_level3;
67
68 /* Find the current page table */
69 pgtable_level3 = __va(read_cr3());
70
71 /* Find the indexes of the physical address to identity map */
72 level1_index = (address % LEVEL1_SIZE)/LEVEL0_SIZE;
73 level2_index = (address % LEVEL2_SIZE)/LEVEL1_SIZE;
74 level3_index = address / LEVEL2_SIZE;
75
76 /* Identity map the page table entry */
77 pgtable_level1[level1_index] = address | L0_ATTR;
78 pgtable_level2[level2_index] = __pa(pgtable_level1) | L1_ATTR;
79 set_64bit(&pgtable_level3[level3_index],
80 __pa(pgtable_level2) | L2_ATTR);
81
82 /* Flush the tlb so the new mapping takes effect.
83 * Global tlb entries are not flushed but that is not an issue.
84 */
85 load_cr3(pgtable_level3);
86}
87#endif 28#endif
29static u32 kexec_pte0[1024] PAGE_ALIGNED;
30static u32 kexec_pte1[1024] PAGE_ALIGNED;
88 31
89static void set_idt(void *newidt, __u16 limit) 32static void set_idt(void *newidt, __u16 limit)
90{ 33{
@@ -128,16 +71,6 @@ static void load_segments(void)
128#undef __STR 71#undef __STR
129} 72}
130 73
131typedef asmlinkage NORET_TYPE void (*relocate_new_kernel_t)(
132 unsigned long indirection_page,
133 unsigned long reboot_code_buffer,
134 unsigned long start_address,
135 unsigned int has_pae) ATTRIB_NORET;
136
137extern const unsigned char relocate_new_kernel[];
138extern void relocate_new_kernel_end(void);
139extern const unsigned int relocate_new_kernel_size;
140
141/* 74/*
142 * A architecture hook called to validate the 75 * A architecture hook called to validate the
143 * proposed image and prepare the control pages 76 * proposed image and prepare the control pages
@@ -170,25 +103,29 @@ void machine_kexec_cleanup(struct kimage *image)
170 */ 103 */
171NORET_TYPE void machine_kexec(struct kimage *image) 104NORET_TYPE void machine_kexec(struct kimage *image)
172{ 105{
173 unsigned long page_list; 106 unsigned long page_list[PAGES_NR];
174 unsigned long reboot_code_buffer; 107 void *control_page;
175
176 relocate_new_kernel_t rnk;
177 108
178 /* Interrupts aren't acceptable while we reboot */ 109 /* Interrupts aren't acceptable while we reboot */
179 local_irq_disable(); 110 local_irq_disable();
180 111
181 /* Compute some offsets */ 112 control_page = page_address(image->control_code_page);
182 reboot_code_buffer = page_to_pfn(image->control_code_page) 113 memcpy(control_page, relocate_kernel, PAGE_SIZE);
183 << PAGE_SHIFT; 114
184 page_list = image->head; 115 page_list[PA_CONTROL_PAGE] = __pa(control_page);
185 116 page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel;
186 /* Set up an identity mapping for the reboot_code_buffer */ 117 page_list[PA_PGD] = __pa(kexec_pgd);
187 identity_map_page(reboot_code_buffer); 118 page_list[VA_PGD] = (unsigned long)kexec_pgd;
188 119#ifdef CONFIG_X86_PAE
189 /* copy it out */ 120 page_list[PA_PMD_0] = __pa(kexec_pmd0);
190 memcpy((void *)reboot_code_buffer, relocate_new_kernel, 121 page_list[VA_PMD_0] = (unsigned long)kexec_pmd0;
191 relocate_new_kernel_size); 122 page_list[PA_PMD_1] = __pa(kexec_pmd1);
123 page_list[VA_PMD_1] = (unsigned long)kexec_pmd1;
124#endif
125 page_list[PA_PTE_0] = __pa(kexec_pte0);
126 page_list[VA_PTE_0] = (unsigned long)kexec_pte0;
127 page_list[PA_PTE_1] = __pa(kexec_pte1);
128 page_list[VA_PTE_1] = (unsigned long)kexec_pte1;
192 129
193 /* The segment registers are funny things, they have both a 130 /* The segment registers are funny things, they have both a
194 * visible and an invisible part. Whenever the visible part is 131 * visible and an invisible part. Whenever the visible part is
@@ -207,8 +144,8 @@ NORET_TYPE void machine_kexec(struct kimage *image)
207 set_idt(phys_to_virt(0),0); 144 set_idt(phys_to_virt(0),0);
208 145
209 /* now call it */ 146 /* now call it */
210 rnk = (relocate_new_kernel_t) reboot_code_buffer; 147 relocate_kernel((unsigned long)image->head, (unsigned long)page_list,
211 (*rnk)(page_list, reboot_code_buffer, image->start, cpu_has_pae); 148 image->start, cpu_has_pae);
212} 149}
213 150
214/* crashkernel=size@addr specifies the location to reserve for 151/* crashkernel=size@addr specifies the location to reserve for
diff --git a/arch/i386/kernel/relocate_kernel.S b/arch/i386/kernel/relocate_kernel.S
index d312616effa1..f151d6fae462 100644
--- a/arch/i386/kernel/relocate_kernel.S
+++ b/arch/i386/kernel/relocate_kernel.S
@@ -7,16 +7,138 @@
7 */ 7 */
8 8
9#include <linux/linkage.h> 9#include <linux/linkage.h>
10#include <asm/page.h>
11#include <asm/kexec.h>
12
13/*
14 * Must be relocatable PIC code callable as a C function
15 */
16
17#define PTR(x) (x << 2)
18#define PAGE_ALIGNED (1 << PAGE_SHIFT)
19#define PAGE_ATTR 0x63 /* _PAGE_PRESENT|_PAGE_RW|_PAGE_ACCESSED|_PAGE_DIRTY */
20#define PAE_PGD_ATTR 0x01 /* _PAGE_PRESENT */
21
22 .text
23 .align PAGE_ALIGNED
24 .globl relocate_kernel
25relocate_kernel:
26 movl 8(%esp), %ebp /* list of pages */
27
28#ifdef CONFIG_X86_PAE
29 /* map the control page at its virtual address */
30
31 movl PTR(VA_PGD)(%ebp), %edi
32 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
33 andl $0xc0000000, %eax
34 shrl $27, %eax
35 addl %edi, %eax
36
37 movl PTR(PA_PMD_0)(%ebp), %edx
38 orl $PAE_PGD_ATTR, %edx
39 movl %edx, (%eax)
40
41 movl PTR(VA_PMD_0)(%ebp), %edi
42 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
43 andl $0x3fe00000, %eax
44 shrl $18, %eax
45 addl %edi, %eax
46
47 movl PTR(PA_PTE_0)(%ebp), %edx
48 orl $PAGE_ATTR, %edx
49 movl %edx, (%eax)
50
51 movl PTR(VA_PTE_0)(%ebp), %edi
52 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
53 andl $0x001ff000, %eax
54 shrl $9, %eax
55 addl %edi, %eax
56
57 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
58 orl $PAGE_ATTR, %edx
59 movl %edx, (%eax)
60
61 /* identity map the control page at its physical address */
62
63 movl PTR(VA_PGD)(%ebp), %edi
64 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
65 andl $0xc0000000, %eax
66 shrl $27, %eax
67 addl %edi, %eax
68
69 movl PTR(PA_PMD_1)(%ebp), %edx
70 orl $PAE_PGD_ATTR, %edx
71 movl %edx, (%eax)
72
73 movl PTR(VA_PMD_1)(%ebp), %edi
74 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
75 andl $0x3fe00000, %eax
76 shrl $18, %eax
77 addl %edi, %eax
78
79 movl PTR(PA_PTE_1)(%ebp), %edx
80 orl $PAGE_ATTR, %edx
81 movl %edx, (%eax)
82
83 movl PTR(VA_PTE_1)(%ebp), %edi
84 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
85 andl $0x001ff000, %eax
86 shrl $9, %eax
87 addl %edi, %eax
88
89 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
90 orl $PAGE_ATTR, %edx
91 movl %edx, (%eax)
92#else
93 /* map the control page at its virtual address */
94
95 movl PTR(VA_PGD)(%ebp), %edi
96 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
97 andl $0xffc00000, %eax
98 shrl $20, %eax
99 addl %edi, %eax
100
101 movl PTR(PA_PTE_0)(%ebp), %edx
102 orl $PAGE_ATTR, %edx
103 movl %edx, (%eax)
104
105 movl PTR(VA_PTE_0)(%ebp), %edi
106 movl PTR(VA_CONTROL_PAGE)(%ebp), %eax
107 andl $0x003ff000, %eax
108 shrl $10, %eax
109 addl %edi, %eax
110
111 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
112 orl $PAGE_ATTR, %edx
113 movl %edx, (%eax)
114
115 /* identity map the control page at its physical address */
116
117 movl PTR(VA_PGD)(%ebp), %edi
118 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
119 andl $0xffc00000, %eax
120 shrl $20, %eax
121 addl %edi, %eax
122
123 movl PTR(PA_PTE_1)(%ebp), %edx
124 orl $PAGE_ATTR, %edx
125 movl %edx, (%eax)
126
127 movl PTR(VA_PTE_1)(%ebp), %edi
128 movl PTR(PA_CONTROL_PAGE)(%ebp), %eax
129 andl $0x003ff000, %eax
130 shrl $10, %eax
131 addl %edi, %eax
132
133 movl PTR(PA_CONTROL_PAGE)(%ebp), %edx
134 orl $PAGE_ATTR, %edx
135 movl %edx, (%eax)
136#endif
10 137
11 /*
12 * Must be relocatable PIC code callable as a C function, that once
13 * it starts can not use the previous processes stack.
14 */
15 .globl relocate_new_kernel
16relocate_new_kernel: 138relocate_new_kernel:
17 /* read the arguments and say goodbye to the stack */ 139 /* read the arguments and say goodbye to the stack */
18 movl 4(%esp), %ebx /* page_list */ 140 movl 4(%esp), %ebx /* page_list */
19 movl 8(%esp), %ebp /* reboot_code_buffer */ 141 movl 8(%esp), %ebp /* list of pages */
20 movl 12(%esp), %edx /* start address */ 142 movl 12(%esp), %edx /* start address */
21 movl 16(%esp), %ecx /* cpu_has_pae */ 143 movl 16(%esp), %ecx /* cpu_has_pae */
22 144
@@ -24,11 +146,26 @@ relocate_new_kernel:
24 pushl $0 146 pushl $0
25 popfl 147 popfl
26 148
27 /* set a new stack at the bottom of our page... */ 149 /* get physical address of control page now */
28 lea 4096(%ebp), %esp 150 /* this is impossible after page table switch */
151 movl PTR(PA_CONTROL_PAGE)(%ebp), %edi
29 152
30 /* store the parameters back on the stack */ 153 /* switch to new set of page tables */
31 pushl %edx /* store the start address */ 154 movl PTR(PA_PGD)(%ebp), %eax
155 movl %eax, %cr3
156
157 /* setup a new stack at the end of the physical control page */
158 lea 4096(%edi), %esp
159
160 /* jump to identity mapped page */
161 movl %edi, %eax
162 addl $(identity_mapped - relocate_kernel), %eax
163 pushl %eax
164 ret
165
166identity_mapped:
167 /* store the start address on the stack */
168 pushl %edx
32 169
33 /* Set cr0 to a known state: 170 /* Set cr0 to a known state:
34 * 31 0 == Paging disabled 171 * 31 0 == Paging disabled
@@ -113,8 +250,3 @@ relocate_new_kernel:
113 xorl %edi, %edi 250 xorl %edi, %edi
114 xorl %ebp, %ebp 251 xorl %ebp, %ebp
115 ret 252 ret
116relocate_new_kernel_end:
117
118 .globl relocate_new_kernel_size
119relocate_new_kernel_size:
120 .long relocate_new_kernel_end - relocate_new_kernel
generated by cgit v1.2.2 (git 2.25.0) at 2024-12-27 12:53:24 -0500