1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology
4 *
5 * Derived from MIPS:
6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf
7 * Copyright (C) 1999, 2000 Silicon Graphics,
8 * Copyright (C) 2001 MIPS Technologies, Inc.
9 */
10
11 #include <asm/asm.h>
12 #include <asm/asmmacro.h>
13 #include <asm/loongarch.h>
14 #include <asm/regdef.h>
15 #include <asm/stackframe.h>
16 #include <asm/thread_info.h>
17 #include <asm/unwind_hints.h>
18
19 .text
20 .cfi_sections .debug_frame
21 .align 5
22 SYM_CODE_START(handle_syscall)
23 UNWIND_HINT_UNDEFINED
24 csrrd t0, PERCPU_BASE_KS
25 la.pcrel t1, kernelsp
26 add.d t1, t1, t0
27 move t2, sp
28 ld.d sp, t1, 0
29
30 addi.d sp, sp, -PT_SIZE
31 cfi_st t2, PT_R3
32 cfi_rel_offset sp, PT_R3
33 st.d zero, sp, PT_R0
34 csrrd t2, LOONGARCH_CSR_PRMD
35 st.d t2, sp, PT_PRMD
36 csrrd t2, LOONGARCH_CSR_CRMD
37 st.d t2, sp, PT_CRMD
38 csrrd t2, LOONGARCH_CSR_EUEN
39 st.d t2, sp, PT_EUEN
40 csrrd t2, LOONGARCH_CSR_ECFG
41 st.d t2, sp, PT_ECFG
42 csrrd t2, LOONGARCH_CSR_ESTA
43 st.d t2, sp, PT_ESTAT
44 cfi_st ra, PT_R1
45 cfi_st a0, PT_R4
46 cfi_st a1, PT_R5
47 cfi_st a2, PT_R6
48 cfi_st a3, PT_R7
49 cfi_st a4, PT_R8
50 cfi_st a5, PT_R9
51 cfi_st a6, PT_R10
52 cfi_st a7, PT_R11
53 csrrd ra, LOONGARCH_CSR_ERA
54 st.d ra, sp, PT_ERA
55 cfi_rel_offset ra, PT_ERA
56
57 cfi_st tp, PT_R2
58 cfi_st u0, PT_R21
59 cfi_st fp, PT_R22
60
61 SAVE_STATIC
62 UNWIND_HINT_REGS
63
64 #ifdef CONFIG_KGDB
65 li.w t1, CSR_CRMD_WE
66 csrxchg t1, t1, LOONGARCH_CSR_
67 #endif
68
69 move u0, t0
70 li.d tp, ~_THREAD_MASK
71 and tp, tp, sp
72
73 move a0, sp
74 bl do_syscall
75
76 RESTORE_ALL_AND_RET
77 SYM_CODE_END(handle_syscall)
78 _ASM_NOKPROBE(handle_syscall)
79
80 SYM_CODE_START(ret_from_fork)
81 UNWIND_HINT_REGS
82 bl schedule_tail
83 move a0, sp
84 bl syscall_exit_to_user_m
85 RESTORE_STATIC
86 RESTORE_SOME
87 RESTORE_SP_AND_RET
88 SYM_CODE_END(ret_from_fork)
89
90 SYM_CODE_START(ret_from_kernel_thread)
91 UNWIND_HINT_REGS
92 bl schedule_tail
93 move a0, s1
94 jirl ra, s0, 0
95 move a0, sp
96 bl syscall_exit_to_user_m
97 RESTORE_STATIC
98 RESTORE_SOME
99 RESTORE_SP_AND_RET
100 SYM_CODE_END(ret_from_kernel_thread)
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