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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.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.S')
-rw-r--r--arch/loongarch/kernel/mcount.S98
1 files changed, 98 insertions, 0 deletions
diff --git a/arch/loongarch/kernel/mcount.S b/arch/loongarch/kernel/mcount.S
new file mode 100644
index 0000000000..3015896016
--- /dev/null
+++ b/arch/loongarch/kernel/mcount.S
@@ -0,0 +1,98 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * LoongArch specific _mcount support
+ *
+ * Copyright (C) 2022 Loongson Technology Corporation Limited
+ */
+
+#include <linux/export.h>
+#include <asm/ftrace.h>
+#include <asm/regdef.h>
+#include <asm/stackframe.h>
+
+ .text
+
+#define MCOUNT_S0_OFFSET (0)
+#define MCOUNT_RA_OFFSET (SZREG)
+#define MCOUNT_STACK_SIZE (2 * SZREG)
+
+ .macro MCOUNT_SAVE_REGS
+ PTR_ADDI sp, sp, -MCOUNT_STACK_SIZE
+ PTR_S s0, sp, MCOUNT_S0_OFFSET
+ PTR_S ra, sp, MCOUNT_RA_OFFSET
+ move s0, a0
+ .endm
+
+ .macro MCOUNT_RESTORE_REGS
+ move a0, s0
+ PTR_L ra, sp, MCOUNT_RA_OFFSET
+ PTR_L s0, sp, MCOUNT_S0_OFFSET
+ PTR_ADDI sp, sp, MCOUNT_STACK_SIZE
+ .endm
+
+SYM_FUNC_START(_mcount)
+ la.pcrel t1, ftrace_stub
+ la.pcrel t2, ftrace_trace_function /* Prepare t2 for (1) */
+ PTR_L t2, t2, 0
+ beq t1, t2, fgraph_trace
+
+ MCOUNT_SAVE_REGS
+
+ move a0, ra /* arg0: self return address */
+ move a1, s0 /* arg1: parent's return address */
+ jirl ra, t2, 0 /* (1) call *ftrace_trace_function */
+
+ MCOUNT_RESTORE_REGS
+
+fgraph_trace:
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ la.pcrel t1, ftrace_stub
+ la.pcrel t3, ftrace_graph_return
+ PTR_L t3, t3, 0
+ bne t1, t3, ftrace_graph_caller
+ la.pcrel t1, ftrace_graph_entry_stub
+ la.pcrel t3, ftrace_graph_entry
+ PTR_L t3, t3, 0
+ bne t1, t3, ftrace_graph_caller
+#endif
+
+SYM_INNER_LABEL(ftrace_stub, SYM_L_GLOBAL)
+ jr ra
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+SYM_INNER_LABEL(ftrace_graph_func, SYM_L_GLOBAL)
+ bl ftrace_stub
+#endif
+SYM_FUNC_END(_mcount)
+EXPORT_SYMBOL(_mcount)
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+SYM_FUNC_START(ftrace_graph_caller)
+ MCOUNT_SAVE_REGS
+
+ PTR_ADDI a0, ra, -4 /* arg0: Callsite self return addr */
+ PTR_ADDI a1, sp, MCOUNT_STACK_SIZE /* arg1: Callsite sp */
+ move a2, s0 /* arg2: Callsite parent ra */
+ bl prepare_ftrace_return
+
+ MCOUNT_RESTORE_REGS
+ jr ra
+SYM_FUNC_END(ftrace_graph_caller)
+
+SYM_FUNC_START(return_to_handler)
+ 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
+
+ /* Restore the real parent address: a0 -> ra */
+ move ra, a0
+
+ PTR_L a0, sp, FGRET_REGS_A0
+ PTR_L a1, sp, FGRET_REGS_A1
+ PTR_ADDI sp, sp, FGRET_REGS_SIZE
+ jr ra
+SYM_FUNC_END(return_to_handler)
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */