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183 lines · 3.5 KiB

1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * relocate_kernel.S for kexec
4 * Created by <nschichan@corp.free.fr> on Thu Oct 12 17:49:57 2006
5 */
6
7#include <asm/asm.h>
8#include <asm/asmmacro.h>
9#include <asm/regdef.h>
10#include <asm/mipsregs.h>
11#include <asm/stackframe.h>
12#include <asm/addrspace.h>
13
14#include <kernel-entry-init.h>
15
16LEAF(relocate_new_kernel)
17 PTR_L a0, arg0
18 PTR_L a1, arg1
19 PTR_L a2, arg2
20 PTR_L a3, arg3
21
22 PTR_L s0, kexec_indirection_page
23 PTR_L s1, kexec_start_address
24
25process_entry:
26 PTR_L s2, (s0)
27 PTR_ADDIU s0, s0, SZREG
28
29 /*
30 * In case of a kdump/crash kernel, the indirection page is not
31 * populated as the kernel is directly copied to a reserved location
32 */
33 beqz s2, done
34
35 /* destination page */
36 and s3, s2, 0x1
37 beq s3, zero, 1f
38 and s4, s2, ~0x1 /* store destination addr in s4 */
39 b process_entry
40
411:
42 /* indirection page, update s0 */
43 and s3, s2, 0x2
44 beq s3, zero, 1f
45 and s0, s2, ~0x2
46 b process_entry
47
481:
49 /* done page */
50 and s3, s2, 0x4
51 beq s3, zero, 1f
52 b done
531:
54 /* source page */
55 and s3, s2, 0x8
56 beq s3, zero, process_entry
57 and s2, s2, ~0x8
58 li s6, (1 << _PAGE_SHIFT) / SZREG
59
60copy_word:
61 /* copy page word by word */
62 REG_L s5, (s2)
63 REG_S s5, (s4)
64 PTR_ADDIU s4, s4, SZREG
65 PTR_ADDIU s2, s2, SZREG
66 LONG_ADDIU s6, s6, -1
67 beq s6, zero, process_entry
68 b copy_word
69
70done:
71#ifdef CONFIG_SMP
72 /* kexec_flag reset is signal to other CPUs what kernel
73 was moved to its location. Note - we need relocated address
74 of kexec_flag. */
75
76 bal 1f
77 1: move t1,ra;
78 PTR_LA t2,1b
79 PTR_LA t0,kexec_flag
80 PTR_SUB t0,t0,t2;
81 PTR_ADD t0,t1,t0;
82 LONG_S zero,(t0)
83#endif
84
85#ifdef CONFIG_CPU_CAVIUM_OCTEON
86 /* We need to flush I-cache before jumping to new kernel.
87 * Unfortunately, this code is cpu-specific.
88 */
89 .set push
90 .set noreorder
91 syncw
92 syncw
93 synci 0($0)
94 .set pop
95#else
96 sync
97#endif
98 /* jump to kexec_start_address */
99 j s1
100 END(relocate_new_kernel)
101
102#ifdef CONFIG_SMP
103/*
104 * Other CPUs should wait until code is relocated and
105 * then start at entry (?) point.
106 */
107LEAF(kexec_smp_wait)
108 PTR_L a0, s_arg0
109 PTR_L a1, s_arg1
110 PTR_L a2, s_arg2
111 PTR_L a3, s_arg3
112 PTR_L s1, kexec_start_address
113
114 /* Non-relocated address works for args and kexec_start_address ( old
115 * kernel is not overwritten). But we need relocated address of
116 * kexec_flag.
117 */
118
119 bal 1f
1201: move t1,ra;
121 PTR_LA t2,1b
122 PTR_LA t0,kexec_flag
123 PTR_SUB t0,t0,t2;
124 PTR_ADD t0,t1,t0;
125
1261: LONG_L s0, (t0)
127 bne s0, zero,1b
128
129#ifdef USE_KEXEC_SMP_WAIT_FINAL
130 kexec_smp_wait_final
131#else
132 sync
133#endif
134 j s1
135 END(kexec_smp_wait)
136#endif
137
138#ifdef __mips64
139 /* all PTR's must be aligned to 8 byte in 64-bit mode */
140 .align 3
141#endif
142
143/* All parameters to new kernel are passed in registers a0-a3.
144 * kexec_args[0..3] are used to prepare register values.
145 */
146
147EXPORT(kexec_args)
148arg0: PTR_WD 0x0
149arg1: PTR_WD 0x0
150arg2: PTR_WD 0x0
151arg3: PTR_WD 0x0
152 .size kexec_args,PTRSIZE*4
153
154#ifdef CONFIG_SMP
155/*
156 * Secondary CPUs may have different kernel parameters in
157 * their registers a0-a3. secondary_kexec_args[0..3] are used
158 * to prepare register values.
159 */
160EXPORT(secondary_kexec_args)
161s_arg0: PTR_WD 0x0
162s_arg1: PTR_WD 0x0
163s_arg2: PTR_WD 0x0
164s_arg3: PTR_WD 0x0
165 .size secondary_kexec_args,PTRSIZE*4
166kexec_flag:
167 LONG 0x1
168
169#endif
170
171EXPORT(kexec_start_address)
172 PTR_WD 0x0
173 .size kexec_start_address, PTRSIZE
174
175EXPORT(kexec_indirection_page)
176 PTR_WD 0
177 .size kexec_indirection_page, PTRSIZE
178
179relocate_new_kernel_end:
180
181EXPORT(relocate_new_kernel_size)
182 PTR_WD relocate_new_kernel_end - relocate_new_kernel
183 .size relocate_new_kernel_size, PTRSIZE