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-rw-r--r--arch/loongarch/kernel/entry.S89
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/entry.S b/arch/loongarch/kernel/entry.S
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+++ b/arch/loongarch/kernel/entry.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2001 MIPS Technologies, Inc.
+ */
+
+#include <asm/asm.h>
+#include <asm/asmmacro.h>
+#include <asm/loongarch.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+#include <asm/thread_info.h>
+
+ .text
+ .cfi_sections .debug_frame
+ .align 5
+SYM_FUNC_START(handle_syscall)
+ csrrd t0, PERCPU_BASE_KS
+ la.abs t1, kernelsp
+ add.d t1, t1, t0
+ move t2, sp
+ ld.d sp, t1, 0
+
+ addi.d sp, sp, -PT_SIZE
+ cfi_st t2, PT_R3
+ cfi_rel_offset sp, PT_R3
+ st.d zero, sp, PT_R0
+ csrrd t2, LOONGARCH_CSR_PRMD
+ st.d t2, sp, PT_PRMD
+ csrrd t2, LOONGARCH_CSR_CRMD
+ st.d t2, sp, PT_CRMD
+ csrrd t2, LOONGARCH_CSR_EUEN
+ st.d t2, sp, PT_EUEN
+ csrrd t2, LOONGARCH_CSR_ECFG
+ st.d t2, sp, PT_ECFG
+ csrrd t2, LOONGARCH_CSR_ESTAT
+ st.d t2, sp, PT_ESTAT
+ cfi_st ra, PT_R1
+ cfi_st a0, PT_R4
+ cfi_st a1, PT_R5
+ cfi_st a2, PT_R6
+ cfi_st a3, PT_R7
+ cfi_st a4, PT_R8
+ cfi_st a5, PT_R9
+ cfi_st a6, PT_R10
+ cfi_st a7, PT_R11
+ csrrd ra, LOONGARCH_CSR_ERA
+ st.d ra, sp, PT_ERA
+ cfi_rel_offset ra, PT_ERA
+
+ cfi_st tp, PT_R2
+ cfi_st u0, PT_R21
+ cfi_st fp, PT_R22
+
+ SAVE_STATIC
+
+ move u0, t0
+ li.d tp, ~_THREAD_MASK
+ and tp, tp, sp
+
+ move a0, sp
+ bl do_syscall
+
+ RESTORE_ALL_AND_RET
+SYM_FUNC_END(handle_syscall)
+
+SYM_CODE_START(ret_from_fork)
+ bl schedule_tail # a0 = struct task_struct *prev
+ move a0, sp
+ bl syscall_exit_to_user_mode
+ RESTORE_STATIC
+ RESTORE_SOME
+ RESTORE_SP_AND_RET
+SYM_CODE_END(ret_from_fork)
+
+SYM_CODE_START(ret_from_kernel_thread)
+ bl schedule_tail # a0 = struct task_struct *prev
+ move a0, s1
+ jirl ra, s0, 0
+ move a0, sp
+ bl syscall_exit_to_user_mode
+ RESTORE_STATIC
+ RESTORE_SOME
+ RESTORE_SP_AND_RET
+SYM_CODE_END(ret_from_kernel_thread)