[PATCH v2 13/13] powerpc/ftrace: Remove ftrace_32.S

From: Christophe Leroy <christophe.leroy@csgroup.eu>
To: Josh Poimboeuf <jpoimboe@redhat.com>,
	Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
	Petr Mladek <pmladek@suse.com>,
	Joe Lawrence <joe.lawrence@redhat.com>,
	Steven Rostedt <rostedt@goodmis.org>,
	Ingo Molnar <mingo@redhat.com>,
	"Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
	"live-patching@vger.kernel.org" <live-patching@vger.kernel.org>
Subject: [PATCH v2 13/13] powerpc/ftrace: Remove ftrace_32.S
Date: Mon, 20 Dec 2021 16:38:44 +0000	[thread overview]
Message-ID: <5e837fc190504c4ef834272e70d60ae33f175d49.1640017960.git.christophe.leroy@csgroup.eu> (raw)
In-Reply-To: <cover.1640017960.git.christophe.leroy@csgroup.eu>

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>
---
 arch/powerpc/kernel/trace/Makefile            |   7 +-
 arch/powerpc/kernel/trace/ftrace_32.S         | 152 ------------------
 .../trace/{ftrace_64.S => ftrace_low.S}       |  14 ++
 ...ftrace_64_mprofile.S => ftrace_mprofile.S} |   0
 4 files changed, 17 insertions(+), 156 deletions(-)
 delete mode 100644 arch/powerpc/kernel/trace/ftrace_32.S
 rename arch/powerpc/kernel/trace/{ftrace_64.S => ftrace_low.S} (85%)
 rename arch/powerpc/kernel/trace/{ftrace_64_mprofile.S => ftrace_mprofile.S} (100%)

diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index 858503775c58..ac7d42a4e8d0 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -8,15 +8,14 @@ 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-$(CONFIG_DYNAMIC_FTRACE)		+= ftrace.o
-obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER)	+= ftrace.o ftrace_low.o
 obj-$(CONFIG_FTRACE_SYSCALLS)		+= ftrace.o
 obj-$(CONFIG_TRACING)			+= trace_clock.o
 
diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S
deleted file mode 100644
index 2b425da97a6b..000000000000
--- a/arch/powerpc/kernel/trace/ftrace_32.S
+++ /dev/null
@@ -1,152 +0,0 @@
-/* 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 */
diff --git a/arch/powerpc/kernel/trace/ftrace_64.S b/arch/powerpc/kernel/trace/ftrace_low.S
similarity index 85%
rename from arch/powerpc/kernel/trace/ftrace_64.S
rename to arch/powerpc/kernel/trace/ftrace_low.S
index 25e5b9e47c06..0bddf1fa6636 100644
--- a/arch/powerpc/kernel/trace/ftrace_64.S
+++ b/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
diff --git a/arch/powerpc/kernel/trace/ftrace_64_mprofile.S b/arch/powerpc/kernel/trace/ftrace_mprofile.S
similarity index 100%
rename from arch/powerpc/kernel/trace/ftrace_64_mprofile.S
rename to arch/powerpc/kernel/trace/ftrace_mprofile.S
-- 
2.33.1
