powerpc/ftrace: Remove ftrace_32.S

Functions in ftrace_32.S are common with PPC64.

Reuse the ones defined for PPC64 with slight modification
when required.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Squash in fixup diff from Christophe]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/5e837fc190504c4ef834272e70d60ae33f175d49.1640017960.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/trace/Makefile

@@ -8,13 +8,13 @@ ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
 endif
 
-obj32-$(CONFIG_FUNCTION_TRACER)		+= ftrace_32.o
-obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64.o
+obj32-$(CONFIG_FUNCTION_TRACER)		+= ftrace_mprofile.o
 ifdef CONFIG_MPROFILE_KERNEL
-obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_mprofile.o
+obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_mprofile.o
 else
 obj64-$(CONFIG_FUNCTION_TRACER)		+= ftrace_64_pg.o
 endif
+obj-$(CONFIG_FUNCTION_TRACER)		+= ftrace_low.o
 obj-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)		+= ftrace.o

arch/powerpc/kernel/trace/ftrace_32.S

-/* SPDX-License-Identifier: GPL-2.0-or-later */
-/*
- * Split from entry_32.S
- */
-
-#include <linux/magic.h>
-#include <asm/reg.h>
-#include <asm/ppc_asm.h>
-#include <asm/asm-offsets.h>
-#include <asm/ftrace.h>
-#include <asm/export.h>
-#include <asm/ptrace.h>
-
-_GLOBAL(mcount)
-_GLOBAL(_mcount)
-	/*
-	 * It is required that _mcount on PPC32 must preserve the
-	 * link register. But we have r12 to play with. We use r12
-	 * to push the return address back to the caller of mcount
-	 * into the ctr register, restore the link register and
-	 * then jump back using the ctr register.
-	 */
-	mflr	r12
-	mtctr	r12
-	mtlr	r0
-	bctr
-EXPORT_SYMBOL(_mcount)
-
-_GLOBAL(ftrace_caller)
-	stwu	r1, -INT_FRAME_SIZE(r1)
-
-	SAVE_GPRS(3, 10, r1)
-
-	addi	r8, r1, INT_FRAME_SIZE
-	stw	r8, GPR1(r1)
-
-	mflr	r3
-	stw	r3, _NIP(r1)
-	subi	r3, r3, MCOUNT_INSN_SIZE
-
-	stw	r0, _LINK(r1)
-	mr	r4, r0
-
-	lis	r5,function_trace_op@ha
-	lwz	r5,function_trace_op@l(r5)
-
-	addi	r6, r1, STACK_FRAME_OVERHEAD
-.globl ftrace_call
-ftrace_call:
-	bl	ftrace_stub
-	nop
-
-	lwz	r3, _NIP(r1)
-	mtctr	r3
-
-	REST_GPRS(3, 10, r1)
-
-	lwz	r0, _LINK(r1)
-	mtlr	r0
-
-	addi	r1, r1, INT_FRAME_SIZE
-	/* old link register ends up in ctr reg */
-	bctr
-
-
-_GLOBAL(ftrace_stub)
-	blr
-
-_GLOBAL(ftrace_regs_caller)
-	/* Create our stack frame + pt_regs */
-	stwu	r1,-INT_FRAME_SIZE(r1)
-
-	/* Save all gprs to pt_regs */
-	stw	r0, GPR0(r1)
-	stmw	r2, GPR2(r1)
-
-	/* Save previous stack pointer (r1) */
-	addi	r8, r1, INT_FRAME_SIZE
-	stw	r8, GPR1(r1)
-
-	/* Load special regs for save below */
-	mfmsr   r8
-	mfctr   r9
-	mfxer   r10
-	mfcr	r11
-
-	/* Get the _mcount() call site out of LR */
-	mflr	r7
-	/* Save it as pt_regs->nip */
-	stw     r7, _NIP(r1)
-	/* Save the read LR in pt_regs->link */
-	stw     r0, _LINK(r1)
-
-	lis	r3,function_trace_op@ha
-	lwz	r5,function_trace_op@l(r3)
-
-	/* Calculate ip from nip-4 into r3 for call below */
-	subi    r3, r7, MCOUNT_INSN_SIZE
-
-	/* Put the original return address in r4 as parent_ip */
-	mr	r4, r0
-
-	/* Save special regs */
-	stw     r8, _MSR(r1)
-	stw     r9, _CTR(r1)
-	stw     r10, _XER(r1)
-	stw     r11, _CCR(r1)
-
-	/* Load &pt_regs in r6 for call below */
-	addi    r6, r1, STACK_FRAME_OVERHEAD
-
-	/* ftrace_call(r3, r4, r5, r6) */
-.globl ftrace_regs_call
-ftrace_regs_call:
-	bl	ftrace_stub
-	nop
-
-	/* Load ctr with the possibly modified NIP */
-	lwz	r3, _NIP(r1)
-	mtctr	r3
-
-	/* Restore gprs */
-	lmw	r2, GPR2(r1)
-
-	/* Restore possibly modified LR */
-	lwz	r0, _LINK(r1)
-	mtlr	r0
-
-	/* Pop our stack frame */
-	addi r1, r1, INT_FRAME_SIZE
-	/* old link register ends up in ctr reg */
-	bctr
-
-#ifdef CONFIG_FUNCTION_GRAPH_TRACER
-_GLOBAL(return_to_handler)
-	/* need to save return values */
-	stwu	r1, -16(r1)
-	stw	r3, 8(r1)
-	stw	r4, 12(r1)
-
-	bl	ftrace_return_to_handler
-
-	/* return value has real return address */
-	mtlr	r3
-
-	lwz	r3, 8(r1)
-	lwz	r4, 12(r1)
-	addi	r1, r1, 16
-
-	/* Jump back to real return address */
-	blr
-#endif /* CONFIG_FUNCTION_GRAPH_TRACER */

arch/powerpc/kernel/trace/ftrace_64.S → arch/powerpc/kernel/trace/ftrace_low.S

@@ -10,6 +10,7 @@
 #include <asm/ppc-opcode.h>
 #include <asm/export.h>
 
+#ifdef CONFIG_PPC64
 .pushsection ".tramp.ftrace.text","aw",@progbits;
 .globl ftrace_tramp_text
 ftrace_tramp_text:
@@ -21,6 +22,7 @@ ftrace_tramp_text:
 ftrace_tramp_init:
 	.space 64
 .popsection
+#endif
 
 _GLOBAL(mcount)
 _GLOBAL(_mcount)
@@ -33,6 +35,7 @@ EXPORT_SYMBOL(_mcount)
 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 _GLOBAL(return_to_handler)
 	/* need to save return values */
+#ifdef CONFIG_PPC64
 	std	r4,  -32(r1)
 	std	r3,  -24(r1)
 	/* save TOC */
@@ -46,6 +49,11 @@ _GLOBAL(return_to_handler)
 	 * Switch to our TOC to run inside the core kernel.
 	 */
 	ld	r2, PACATOC(r13)
+#else
+	stwu	r1, -16(r1)
+	stw	r3, 8(r1)
+	stw	r4, 12(r1)
+#endif
 
 	bl	ftrace_return_to_handler
 	nop
@@ -53,11 +61,17 @@ _GLOBAL(return_to_handler)
 	/* return value has real return address */
 	mtlr	r3
 
+#ifdef CONFIG_PPC64
 	ld	r1, 0(r1)
 	ld	r4,  -32(r1)
 	ld	r3,  -24(r1)
 	ld	r2,  -16(r1)
 	ld	r31, -8(r1)
+#else
+	lwz	r3, 8(r1)
+	lwz	r4, 12(r1)
+	addi	r1, r1, 16
+#endif
 
 	/* Jump back to real return address */
 	blr