3 files changed, 34 insertions, 41 deletions
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h
index 345cbe982a8b..e8b460f39c58 100644
--- a/arch/s390/include/asm/ftrace.h
+++ b/arch/s390/include/asm/ftrace.h
@@ -18,7 +18,6 @@
 void ftrace_caller(void);
 
 extern char ftrace_graph_caller_end;
-extern unsigned long ftrace_plt;
 extern void *ftrace_func;
 
 struct dyn_arch_ftrace { };
@@ -31,10 +30,11 @@ struct dyn_arch_ftrace { };
 
 struct module;
 struct dyn_ftrace;
-/*
- * Either -mhotpatch or -mnop-mcount is used - no explicit init is required
- */
-static inline int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) { return 0; }
+
+bool ftrace_need_init_nop(void);
+#define ftrace_need_init_nop ftrace_need_init_nop
+
+int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec);
 #define ftrace_init_nop ftrace_init_nop
 
 static inline unsigned long ftrace_call_adjust(unsigned long addr)
@@ -42,42 +42,6 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
 	return addr;
 }
 
-struct ftrace_insn {
-	u16 opc;
-	s32 disp;
-} __packed;
-
-static inline void ftrace_generate_nop_insn(struct ftrace_insn *insn)
-{
-#ifdef CONFIG_FUNCTION_TRACER
-	/* brcl 0,0 */
-	insn->opc = 0xc004;
-	insn->disp = 0;
-#endif
-}
-
-static inline int is_ftrace_nop(struct ftrace_insn *insn)
-{
-#ifdef CONFIG_FUNCTION_TRACER
-	if (insn->disp == 0)
-		return 1;
-#endif
-	return 0;
-}
-
-static inline void ftrace_generate_call_insn(struct ftrace_insn *insn,
-					     unsigned long ip)
-{
-#ifdef CONFIG_FUNCTION_TRACER
-	unsigned long target;
-
-	/* brasl r0,ftrace_caller */
-	target = is_module_addr((void *) ip) ? ftrace_plt : FTRACE_ADDR;
-	insn->opc = 0xc005;
-	insn->disp = (target - ip) / 2;
-#endif
-}
-
 /*
  * Even though the system call numbers are identical for s390/s390x a
  * different system call table is used for compat tasks. This may lead
diff --git a/arch/s390/include/asm/ftrace.lds.h b/arch/s390/include/asm/ftrace.lds.h
new file mode 100644
index 000000000000..968adfd41240
--- /dev/null
+++ b/arch/s390/include/asm/ftrace.lds.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef DIV_ROUND_UP
+#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+#endif
+
+#define SIZEOF_MCOUNT_LOC_ENTRY 8
+#define SIZEOF_FTRACE_HOTPATCH_TRAMPOLINE 24
+#define FTRACE_HOTPATCH_TRAMPOLINES_SIZE(n)				       \
+	DIV_ROUND_UP(SIZEOF_FTRACE_HOTPATCH_TRAMPOLINE * (n),		       \
+		     SIZEOF_MCOUNT_LOC_ENTRY)
+
+#ifdef CONFIG_FUNCTION_TRACER
+#define FTRACE_HOTPATCH_TRAMPOLINES_TEXT				       \
+	. = ALIGN(8);							       \
+	__ftrace_hotpatch_trampolines_start = .;			       \
+	. = . + FTRACE_HOTPATCH_TRAMPOLINES_SIZE(__stop_mcount_loc -	       \
+						 __start_mcount_loc);	       \
+	__ftrace_hotpatch_trampolines_end = .;
+#else
+#define FTRACE_HOTPATCH_TRAMPOLINES_TEXT
+#endif
diff --git a/arch/s390/include/asm/module.h b/arch/s390/include/asm/module.h
index 71e57b8af757..9f1eea15872c 100644
--- a/arch/s390/include/asm/module.h
+++ b/arch/s390/include/asm/module.h
@@ -28,6 +28,14 @@ struct mod_arch_specific {
 	int nsyms;
 	/* Additional symbol information (got and plt offsets). */
 	struct mod_arch_syminfo *syminfo;
+#ifdef CONFIG_FUNCTION_TRACER
+	/* Start of memory reserved for ftrace hotpatch trampolines. */
+	struct ftrace_hotpatch_trampoline *trampolines_start;
+	/* End of memory reserved for ftrace hotpatch trampolines. */
+	struct ftrace_hotpatch_trampoline *trampolines_end;
+	/* Next unused ftrace hotpatch trampoline slot. */
+	struct ftrace_hotpatch_trampoline *next_trampoline;
+#endif /* CONFIG_FUNCTION_TRACER */
 };
 
 #endif /* _ASM_S390_MODULE_H */