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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/loongarch/kernel/mcount_dyn.S
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/loongarch/kernel/mcount_dyn.S')
-rw-r--r--arch/loongarch/kernel/mcount_dyn.S160
1 files changed, 160 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/mcount_dyn.S b/arch/loongarch/kernel/mcount_dyn.S
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+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+
+#include <asm/ftrace.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+
+ .text
+/*
+ * Due to -fpatchable-function-entry=2: the compiler inserted 2 NOPs before the
+ * regular C function prologue. When PC arrived here, the last 2 instructions
+ * are as follows:
+ * move t0, ra
+ * bl callsite (for modules, callsite is a tramplione)
+ *
+ * modules trampoline is as follows:
+ * lu12i.w t1, callsite[31:12]
+ * lu32i.d t1, callsite[51:32]
+ * lu52i.d t1, t1, callsite[63:52]
+ * jirl zero, t1, callsite[11:0] >> 2
+ *
+ * See arch/loongarch/kernel/ftrace_dyn.c for details. Here, pay attention to
+ * that the T series regs are available and safe because each C functions
+ * follows the LoongArch's psABI as well.
+ */
+
+ .macro ftrace_regs_entry allregs=0
+ PTR_ADDI sp, sp, -PT_SIZE
+ PTR_S t0, sp, PT_R1 /* Save parent ra at PT_R1(RA) */
+ PTR_S a0, sp, PT_R4
+ PTR_S a1, sp, PT_R5
+ PTR_S a2, sp, PT_R6
+ PTR_S a3, sp, PT_R7
+ PTR_S a4, sp, PT_R8
+ PTR_S a5, sp, PT_R9
+ PTR_S a6, sp, PT_R10
+ PTR_S a7, sp, PT_R11
+ PTR_S fp, sp, PT_R22
+ .if \allregs
+ PTR_S tp, sp, PT_R2
+ PTR_S t0, sp, PT_R12
+ PTR_S t2, sp, PT_R14
+ PTR_S t3, sp, PT_R15
+ PTR_S t4, sp, PT_R16
+ PTR_S t5, sp, PT_R17
+ PTR_S t6, sp, PT_R18
+ PTR_S t7, sp, PT_R19
+ PTR_S t8, sp, PT_R20
+ PTR_S u0, sp, PT_R21
+ PTR_S s0, sp, PT_R23
+ PTR_S s1, sp, PT_R24
+ PTR_S s2, sp, PT_R25
+ PTR_S s3, sp, PT_R26
+ PTR_S s4, sp, PT_R27
+ PTR_S s5, sp, PT_R28
+ PTR_S s6, sp, PT_R29
+ PTR_S s7, sp, PT_R30
+ PTR_S s8, sp, PT_R31
+ /* Clear it for later use as a flag sometimes. */
+ PTR_S zero, sp, PT_R0
+ .endif
+ PTR_S ra, sp, PT_ERA /* Save trace function ra at PT_ERA */
+ move t1, zero
+ PTR_S t1, sp, PT_R13
+ PTR_ADDI t8, sp, PT_SIZE
+ PTR_S t8, sp, PT_R3
+ .endm
+
+SYM_FUNC_START(ftrace_stub)
+ jr ra
+SYM_FUNC_END(ftrace_stub)
+
+SYM_CODE_START(ftrace_common)
+ PTR_ADDI a0, ra, -8 /* arg0: ip */
+ move a1, t0 /* arg1: parent_ip */
+ la.pcrel t1, function_trace_op
+ PTR_L a2, t1, 0 /* arg2: op */
+ move a3, sp /* arg3: regs */
+
+SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
+ bl ftrace_stub
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
+ nop /* b ftrace_graph_caller */
+#endif
+
+/*
+ * As we didn't use S series regs in this assmembly code and all calls
+ * are C function which will save S series regs by themselves, there is
+ * no need to restore S series regs. The T series is available and safe
+ * at the callsite, so there is no need to restore the T series regs.
+ */
+ftrace_common_return:
+ PTR_L ra, sp, PT_R1
+ PTR_L a0, sp, PT_R4
+ PTR_L a1, sp, PT_R5
+ PTR_L a2, sp, PT_R6
+ PTR_L a3, sp, PT_R7
+ PTR_L a4, sp, PT_R8
+ PTR_L a5, sp, PT_R9
+ PTR_L a6, sp, PT_R10
+ PTR_L a7, sp, PT_R11
+ PTR_L fp, sp, PT_R22
+ PTR_L t0, sp, PT_ERA
+ PTR_L t1, sp, PT_R13
+ PTR_ADDI sp, sp, PT_SIZE
+ bnez t1, .Ldirect
+ jr t0
+.Ldirect:
+ jr t1
+SYM_CODE_END(ftrace_common)
+
+SYM_CODE_START(ftrace_caller)
+ ftrace_regs_entry allregs=0
+ b ftrace_common
+SYM_CODE_END(ftrace_caller)
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+SYM_CODE_START(ftrace_regs_caller)
+ ftrace_regs_entry allregs=1
+ b ftrace_common
+SYM_CODE_END(ftrace_regs_caller)
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+SYM_CODE_START(ftrace_graph_caller)
+ PTR_L a0, sp, PT_ERA
+ PTR_ADDI a0, a0, -8 /* arg0: self_addr */
+ PTR_ADDI a1, sp, PT_R1 /* arg1: parent */
+ bl prepare_ftrace_return
+ b ftrace_common_return
+SYM_CODE_END(ftrace_graph_caller)
+
+SYM_CODE_START(return_to_handler)
+ /* Save return value regs */
+ PTR_ADDI sp, sp, -FGRET_REGS_SIZE
+ PTR_S a0, sp, FGRET_REGS_A0
+ PTR_S a1, sp, FGRET_REGS_A1
+ PTR_S zero, sp, FGRET_REGS_FP
+
+ move a0, sp
+ bl ftrace_return_to_handler
+ move ra, a0
+
+ /* Restore return value regs */
+ PTR_L a0, sp, FGRET_REGS_A0
+ PTR_L a1, sp, FGRET_REGS_A1
+ PTR_ADDI sp, sp, FGRET_REGS_SIZE
+
+ jr ra
+SYM_CODE_END(return_to_handler)
+#endif
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+SYM_CODE_START(ftrace_stub_direct_tramp)
+ jr t0
+SYM_CODE_END(ftrace_stub_direct_tramp)
+#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */