1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5#include <linux/init.h>
6#include <linux/threads.h>
7
8#include <asm/addrspace.h>
9#include <asm/asm.h>
10#include <asm/asmmacro.h>
11#include <asm/bug.h>
12#include <asm/regdef.h>
13#include <asm/loongarch.h>
14#include <asm/stackframe.h>
15
16#ifdef CONFIG_EFI_STUB
17
18#include "efi-header.S"
19
20 __HEAD
21
22_head:
23 .word MZ_MAGIC /* "MZ", MS-DOS header */
24 .org 0x8
25 .dword kernel_entry /* Kernel entry point */
26 .dword _kernel_asize /* Kernel image effective size */
27 .quad PHYS_LINK_KADDR /* Kernel image load offset from start of RAM */
28 .org 0x38 /* 0x20 ~ 0x37 reserved */
29 .long LINUX_PE_MAGIC
30 .long pe_header - _head /* Offset to the PE header */
31
32pe_header:
33 __EFI_PE_HEADER
34
35SYM_DATA(kernel_asize, .long _kernel_asize);
36SYM_DATA(kernel_fsize, .long _kernel_fsize);
37
38#endif
39
40 __REF
41
42 .align 12
43
44SYM_CODE_START(kernel_entry) # kernel entry point
45
46 /* Config direct window and set PG */
47 li.d t0, CSR_DMW0_INIT # UC, PLV0, 0x8000 xxxx xxxx xxxx
48 csrwr t0, LOONGARCH_CSR_DMWIN0
49 li.d t0, CSR_DMW1_INIT # CA, PLV0, 0x9000 xxxx xxxx xxxx
50 csrwr t0, LOONGARCH_CSR_DMWIN1
51
52 JUMP_VIRT_ADDR t0, t1
53
54 /* Enable PG */
55 li.w t0, 0xb0 # PLV=0, IE=0, PG=1
56 csrwr t0, LOONGARCH_CSR_CRMD
57 li.w t0, 0x04 # PLV=0, PIE=1, PWE=0
58 csrwr t0, LOONGARCH_CSR_PRMD
59 li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0
60 csrwr t0, LOONGARCH_CSR_EUEN
61
62 la.pcrel t0, __bss_start # clear .bss
63 st.d zero, t0, 0
64 la.pcrel t1, __bss_stop - LONGSIZE
651:
66 addi.d t0, t0, LONGSIZE
67 st.d zero, t0, 0
68 bne t0, t1, 1b
69
70 la.pcrel t0, fw_arg0
71 st.d a0, t0, 0 # firmware arguments
72 la.pcrel t0, fw_arg1
73 st.d a1, t0, 0
74 la.pcrel t0, fw_arg2
75 st.d a2, t0, 0
76
77#ifdef CONFIG_PAGE_SIZE_4KB
78 li.d t0, 0
79 li.d t1, CSR_STFILL
80 csrxchg t0, t1, LOONGARCH_CSR_IMPCTL1
81#endif
82 /* KSave3 used for percpu base, initialized as 0 */
83 csrwr zero, PERCPU_BASE_KS
84 /* GPR21 used for percpu base (runtime), initialized as 0 */
85 move u0, zero
86
87 la.pcrel tp, init_thread_union
88 /* Set the SP after an empty pt_regs. */
89 PTR_LI sp, (_THREAD_SIZE - PT_SIZE)
90 PTR_ADD sp, sp, tp
91 set_saved_sp sp, t0, t1
92
93#ifdef CONFIG_RELOCATABLE
94
95 bl relocate_kernel
96
97#ifdef CONFIG_RANDOMIZE_BASE
98 /* Repoint the sp into the new kernel */
99 PTR_LI sp, (_THREAD_SIZE - PT_SIZE)
100 PTR_ADD sp, sp, tp
101 set_saved_sp sp, t0, t1
102
103 /* Jump to the new kernel: new_pc = current_pc + random_offset */
104 pcaddi t0, 0
105 add.d t0, t0, a0
106 jirl zero, t0, 0xc
107#endif /* CONFIG_RANDOMIZE_BASE */
108
109#endif /* CONFIG_RELOCATABLE */
110
111#ifdef CONFIG_KASAN
112 bl kasan_early_init
113#endif
114
115 bl start_kernel
116 ASM_BUG()
117
118SYM_CODE_END(kernel_entry)
119
120#ifdef CONFIG_SMP
121
122/*
123 * SMP slave cpus entry point. Board specific code for bootstrap calls this
124 * function after setting up the stack and tp registers.
125 */
126SYM_CODE_START(smpboot_entry)
127 li.d t0, CSR_DMW0_INIT # UC, PLV0
128 csrwr t0, LOONGARCH_CSR_DMWIN0
129 li.d t0, CSR_DMW1_INIT # CA, PLV0
130 csrwr t0, LOONGARCH_CSR_DMWIN1
131
132 JUMP_VIRT_ADDR t0, t1
133
134#ifdef CONFIG_PAGE_SIZE_4KB
135 li.d t0, 0
136 li.d t1, CSR_STFILL
137 csrxchg t0, t1, LOONGARCH_CSR_IMPCTL1
138#endif
139 /* Enable PG */
140 li.w t0, 0xb0 # PLV=0, IE=0, PG=1
141 csrwr t0, LOONGARCH_CSR_CRMD
142 li.w t0, 0x04 # PLV=0, PIE=1, PWE=0
143 csrwr t0, LOONGARCH_CSR_PRMD
144 li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0
145 csrwr t0, LOONGARCH_CSR_EUEN
146
147 la.pcrel t0, cpuboot_data
148 ld.d sp, t0, CPU_BOOT_STACK
149 ld.d tp, t0, CPU_BOOT_TINFO
150
151 bl start_secondary
152 ASM_BUG()
153
154SYM_CODE_END(smpboot_entry)
155
156#endif /* CONFIG_SMP */
157
158SYM_ENTRY(kernel_entry_end, SYM_L_GLOBAL, SYM_A_NONE)
159

source code of linux/arch/loongarch/kernel/head.S