1 /* SPDX-License-Identifier: GPL-2.0 */
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
5 #include <linux/init.h>
6 #include <linux/threads.h>
8 #include <asm/addrspace.h>
10 #include <asm/asmmacro.h>
11 #include <asm/regdef.h>
12 #include <asm/loongarch.h>
13 #include <asm/stackframe.h>
19 SYM_CODE_START(kernel_entry) # kernel entry point
21 /* Config direct window and set PG */
22 li.d t0, CSR_DMW0_INIT # UC, PLV0, 0x8000 xxxx xxxx xxxx
23 csrwr t0, LOONGARCH_CSR_DMWIN0
24 li.d t0, CSR_DMW1_INIT # CA, PLV0, 0x9000 xxxx xxxx xxxx
25 csrwr t0, LOONGARCH_CSR_DMWIN1
27 /* We might not get launched at the address the kernel is linked to,
33 li.w t0, 0xb0 # PLV=0, IE=0, PG=1
34 csrwr t0, LOONGARCH_CSR_CRMD
35 li.w t0, 0x04 # PLV=0, PIE=1, PWE=0
36 csrwr t0, LOONGARCH_CSR_PRMD
37 li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0
38 csrwr t0, LOONGARCH_CSR_EUEN
40 la t0, __bss_start # clear .bss
42 la t1, __bss_stop - LONGSIZE
44 addi.d t0, t0, LONGSIZE
49 st.d a0, t0, 0 # firmware arguments
53 /* KSave3 used for percpu base, initialized as 0 */
54 csrwr zero, PERCPU_BASE_KS
55 /* GPR21 used for percpu base (runtime), initialized as 0 */
58 la tp, init_thread_union
59 /* Set the SP after an empty pt_regs. */
60 PTR_LI sp, (_THREAD_SIZE - 32 - PT_SIZE)
62 set_saved_sp sp, t0, t1
63 PTR_ADDI sp, sp, -4 * SZREG # init stack pointer
67 SYM_CODE_END(kernel_entry)
72 * SMP slave cpus entry point. Board specific code for bootstrap calls this
73 * function after setting up the stack and tp registers.
75 SYM_CODE_START(smpboot_entry)
76 li.d t0, CSR_DMW0_INIT # UC, PLV0
77 csrwr t0, LOONGARCH_CSR_DMWIN0
78 li.d t0, CSR_DMW1_INIT # CA, PLV0
79 csrwr t0, LOONGARCH_CSR_DMWIN1
85 li.w t0, 0xb0 # PLV=0, IE=0, PG=1
86 csrwr t0, LOONGARCH_CSR_CRMD
87 li.w t0, 0x04 # PLV=0, PIE=1, PWE=0
88 csrwr t0, LOONGARCH_CSR_PRMD
89 li.w t0, 0x00 # FPE=0, SXE=0, ASXE=0, BTE=0
90 csrwr t0, LOONGARCH_CSR_EUEN
92 la.abs t0, cpuboot_data
93 ld.d sp, t0, CPU_BOOT_STACK
94 ld.d tp, t0, CPU_BOOT_TINFO
97 SYM_CODE_END(smpboot_entry)
99 #endif /* CONFIG_SMP */
101 SYM_ENTRY(kernel_entry_end, SYM_L_GLOBAL, SYM_A_NONE)