1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * relocate_kernel.S for kexec
4 *
5 * Copyright (C) 2022 Loongson Technology Corp
6 */
7
8 #include <linux/kexec.h>
9
10 #include <asm/asm.h>
11 #include <asm/asmmacro.h>
12 #include <asm/regdef.h>
13 #include <asm/loongarch.h>
14 #include <asm/stackframe.h>
15 #include <asm/addrspace.h>
16
17 SYM_CODE_START(relocate_new_kernel)
18 UNWIND_HINT_UNDEFINED
19 /*
20 * a0: EFI boot flag for the new kerne
21 * a1: Command line pointer for the ne
22 * a2: System table pointer for the ne
23 * a3: Start address to jump to after
24 * a4: Pointer to the current indirect
25 */
26 move s0, a4
27
28 /*
29 * In case of a kdump/crash kernel, th
30 * populated as the kernel is directly
31 */
32 beqz s0, done
33
34 process_entry:
35 PTR_L s1, s0, 0
36 PTR_ADDI s0, s0, SZREG
37
38 /* destination page */
39 andi s2, s1, IND_DESTINATIO
40 beqz s2, 1f
41 li.w t0, ~0x1
42 and s3, s1, t0 /* sto
43 b process_entry
44
45 1:
46 /* indirection page, update s0 */
47 andi s2, s1, IND_INDIRECTIO
48 beqz s2, 1f
49 li.w t0, ~0x2
50 and s0, s1, t0
51 b process_entry
52
53 1:
54 /* done page */
55 andi s2, s1, IND_DONE
56 beqz s2, 1f
57 b done
58
59 1:
60 /* source page */
61 andi s2, s1, IND_SOURCE
62 beqz s2, process_entry
63 li.w t0, ~0x8
64 and s1, s1, t0
65 li.w s5, (1 << _PAGE_SHIFT)
66
67 copy_word:
68 /* copy page word by word */
69 REG_L s4, s1, 0
70 REG_S s4, s3, 0
71 PTR_ADDI s3, s3, SZREG
72 PTR_ADDI s1, s1, SZREG
73 LONG_ADDI s5, s5, -1
74 beqz s5, process_entry
75 b copy_word
76
77 done:
78 ibar 0
79 dbar 0
80
81 /*
82 * Jump to the new kernel,
83 * make sure the values of a0, a1, a2
84 */
85 jr a3
86 SYM_CODE_END(relocate_new_kernel)
87
88 #ifdef CONFIG_SMP
89 /*
90 * Other CPUs should wait until code is reloca
91 * then start at the entry point from LOONGARC
92 */
93 SYM_CODE_START(kexec_smp_wait)
94 UNWIND_HINT_UNDEFINED
95 1: li.w t0, 0x100
96 2: addi.w t0, t0, -1
97 bnez t0, 2b
98 li.w t1, LOONGARCH_IOCSR_MB
99 iocsrrd.w s0, t1
100 beqz s0, 1b
101 iocsrrd.d s0, t1
102
103 li.d t0, CACHE_BASE
104 or s0, s0, t0
105 jr s0
106 SYM_CODE_END(kexec_smp_wait)
107 #endif
108
109 relocate_new_kernel_end:
110
111 .section ".data"
112 SYM_DATA(relocate_new_kernel_size, .long reloc
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