ARCv3: Support ftrace and function graph tracer

Signed-off-by: Bruno Mauricio <brunoasmauricio@gmail.com>

Author: BrunoASMauricio

arch/arc/Kconfig

@@ -32,8 +32,8 @@ config ARC
 	select HAVE_ARCH_TRANSPARENT_HUGEPAGE if ARC_MMU_V4
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_DEBUG_KMEMLEAK
-	select HAVE_FUNCTION_TRACER if ISA_ARCV2
-	select HAVE_FUNCTION_GRAPH_TRACER if (ISA_ARCV2 && GCC_VERSION >= 140000)
+	select HAVE_FUNCTION_TRACER if (ISA_ARCV2 || ISA_ARCV3)
+	select HAVE_FUNCTION_GRAPH_TRACER if ISA_ARCV3 || (ISA_ARCV2 && GCC_VERSION >= 140000)
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_IOREMAP_PROT if !(ISA_ARCV3 && !64BIT)
 	select HAVE_KERNEL_GZIP

arch/arc/Makefile

@@ -19,6 +19,12 @@ endif
 endif
 endif
 
+ifdef CONFIG_FTRACE
+ifdef CONFIG_ISA_ARCV3
+cflags-y	+= -fno-omit-frame-pointer
+endif
+endif
+
 ifdef CONFIG_ISA_ARCV3
 ifdef CONFIG_64BIT
 UTS_MACHINE	:= arc64

arch/arc/kernel/mcount.S

@@ -7,28 +7,31 @@
 
 #include <linux/linkage.h>
 #include <asm-generic/export.h>
+#include <asm/assembler.h>
 
 ; ftrace placeholder, just return to caller
 ENTRY(ftrace_stub)
 	j_s	[blink]
 ENDPROC(ftrace_stub)
 
 .macro SAVE_ABI
-	push	blink
+	PUSHR	blink
+	PUSHR	fp
 .endm
 
 .macro LOAD_ABI
-	pop	blink
+	POPR	fp
+	POPR	blink
 .endm
 
 .macro SAVE_ABI_RET
-	push	r0
-	push	r1
+	PUSHR	r0
+	PUSHR	r1
 .endm
 
 .macro LOAD_ABI_RET
-	pop	r1
-	pop	r0
+	POPR	r1
+	POPR	r0
 .endm
 
 ; r0 has the frompc (targets parent ip)
@@ -38,17 +41,23 @@ ENTRY(_mcount)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 
 	; *ftrace_graph_return != ftrace_stub
-	ld	r3, [ftrace_graph_return]
-	brne	r3, @ftrace_stub, @do_ftrace_graph_caller
+	MOVA	r3, ftrace_graph_return
+	LDR	r3, r3
+	MOVA	r4, @ftrace_stub
+	brne	r3, r4, @do_ftrace_graph_caller
 	; *ftrace_graph_entry != *ftrace_graph_entry_stub
-	ld	r3, [ftrace_graph_entry]
-	brne	r3, @ftrace_graph_entry_stub, @do_ftrace_graph_caller
+	MOVA	r3, @ftrace_graph_entry
+	LDR	r3, r3
+	MOVA	r4, @ftrace_graph_entry_stub
+	brne	r3, r4, @do_ftrace_graph_caller
 
 #endif
 
 	; *ftrace_trace_function != ftrace_stub
-	ld	r2, [ftrace_trace_function]
-	brne	r2, @ftrace_stub, @do_trace
+	MOVA	r2, ftrace_trace_function
+	LDR	r2, r2
+	MOVA	r3, @ftrace_stub
+	brne	r2, r3, @do_trace
 	; Return
 	j_s	[blink]
 
@@ -61,31 +70,40 @@ ENTRY(return_to_handler)
 	; Save return value (if any) from handled routine
 	SAVE_ABI_RET
 	; Will return true blink on r0
-	jl	ftrace_return_to_handler
-	mov	r2, r0
+	MOVA	r0, @ftrace_return_to_handler
+	jl	[r0]
+	MOVR	r2, r0
 	LOAD_ABI_RET
 	j	[r2]
 
 ENDPROC(return_to_handler)
 
 do_ftrace_graph_caller:
+
+#ifndef CONFIG_ISA_ARCV3
 	; ABI does not allow us to infer blink location
 	; ARC GCC port inserts into r1 the delta between the pushed blink and
 	; the sp at call time
 	; We perform calculation before any push (sp change) happens
-	add	r0, r1, sp
+	ADDR	r0, r1, sp
+	SAVE_ABI
+	SUBR	r0, r0, REGSZASM
+#else
 	SAVE_ABI
-	sub	r0, r0, 4
-	mov	r1, blink
-	jl	prepare_ftrace_return
+	ADDR	r0, fp, REGSZASM
+#endif
+
+	MOVR	r1, blink
+	MOVA	r2, @prepare_ftrace_return
+	jl	[r2]
 	LOAD_ABI
 	j_s	[blink]
 #endif
 
 do_trace:
 	SAVE_ABI
-	mov	r1, r0
-	mov	r0, blink
+	MOVR	r1, r0
+	MOVR	r0, blink
 	jl	[r2]
 	; load ABI state and jump to blink (in stack)
 	LOAD_ABI