[PATCH] powerpc: fpr save/restore function cleanups (was Re: [powerpc:test 24/28] powerpc64-linux-gnu-ld: warning: orphan section `.text.save.restore' from `arch/powerpc/lib/built-in.o' being placed in section `.text.save.restore'.)
Nicholas Piggin
npiggin at gmail.com
Mon Oct 24 13:37:28 AEDT 2016
On Mon, 24 Oct 2016 12:57:34 +1100
Nicholas Piggin <npiggin at gmail.com> wrote:
> On Sat, 22 Oct 2016 15:53:03 +0800
> kbuild test robot <fengguang.wu at intel.com> wrote:
>
> > tree: https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git test
> > head: 8a4fd950c8ac67ad98135db4107ed6cae412606c
> > commit: b09fa228be430ba2745102ac8e668ad869320bd9 [24/28] powerpc: link warning for orphan sections
> > config: powerpc-ps3_defconfig (attached as .config)
> > compiler: powerpc64-linux-gnu-gcc (Debian 6.1.1-9) 6.1.1 20160705
> > reproduce:
> > wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
> > chmod +x ~/bin/make.cross
> > git checkout b09fa228be430ba2745102ac8e668ad869320bd9
> > # save the attached .config to linux build tree
> > make.cross ARCH=powerpc
> >
> > All warnings (new ones prefixed by >>):
> >
> > >> powerpc64-linux-gnu-ld: warning: orphan section `.text.save.restore' from `arch/powerpc/lib/built-in.o' being placed in section `.text.save.restore'.
> > >> powerpc64-linux-gnu-ld: warning: orphan section `.text.save.restore' from `arch/powerpc/lib/built-in.o' being placed in section `.text.save.restore'.
> > >> powerpc64-linux-gnu-ld: warning: orphan section `.text.save.restore' from `arch/powerpc/lib/built-in.o' being placed in section `.text.save.restore'.
>
> On powerpc64, ld creates these for us when required, and puts them into
> section ".sfpr". So we can avoid compiling in lib/crtsavres.S entirely
> there, I think.
>
> When I do that, I see the save/restore functions getting located at
> 0x8000. That actually works with my .linker_stub_catch patch, but there
> is probably no good reason to put those sections there, so I'll change
> .sfpr in the linker script to be near the end of the main text output
> section.
Something like this (appropriately split up and tested) might be the go
for 4.10. I just have to work out why these were added for 64-bit in
7fca5dc8aa7 ("powerpc: Fix module building for gcc 4.5 and 64 bit"). Must
have been some issues with early toolchains.
The powerpc64 linker generates fpr save/restore functions on-demand,
placing them in the .sfpr section. so 64 does not require these functions,
so remove them from the 64 build.
However the linker places .sfpr at the beginning of a group of input
sections, so the current linker script ends up locating them at the
start of main .text (right after head text), which is not necessary.
Move those to the end of the .text output section.
Have 32-bit put save/restore functions into .sfpr section, to match
64-bit.
---
arch/powerpc/Makefile | 2 +
arch/powerpc/boot/Makefile | 3 +-
arch/powerpc/boot/crtsavres.S | 3 +-
arch/powerpc/kernel/vmlinux.lds.S | 3 +-
arch/powerpc/lib/Makefile | 5 +-
arch/powerpc/lib/crtsavres.S | 238 +-------------------------------------
6 files changed, 12 insertions(+), 242 deletions(-)
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 093094c..113e057 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -180,7 +180,9 @@ else
CHECKFLAGS += -D__LITTLE_ENDIAN__
endif
+ifeq ($(CONFIG_PPC32),y)
KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
+endif
ifeq ($(CONFIG_476FPE_ERR46),y)
KBUILD_LDFLAGS_MODULE += --ppc476-workaround \
diff --git a/arch/powerpc/boot/Makefile b/arch/powerpc/boot/Makefile
index eae2dc8..6abee93 100644
--- a/arch/powerpc/boot/Makefile
+++ b/arch/powerpc/boot/Makefile
@@ -95,12 +95,13 @@ libfdtheader := fdt.h libfdt.h libfdt_internal.h
$(addprefix $(obj)/,$(libfdt) libfdt-wrapper.o simpleboot.o epapr.o opal.o): \
$(addprefix $(obj)/,$(libfdtheader))
-src-wlib-y := string.S crt0.S crtsavres.S stdio.c decompress.c main.c \
+src-wlib-y := string.S crt0.S stdio.c decompress.c main.c \
$(libfdt) libfdt-wrapper.c \
ns16550.c serial.c simple_alloc.c div64.S util.S \
elf_util.c $(zlib-y) devtree.c stdlib.c \
oflib.c ofconsole.c cuboot.c mpsc.c cpm-serial.c \
uartlite.c mpc52xx-psc.c opal.c opal-calls.S
+src-wlib-$(CONFIG_PPC32) += crtsavres.S
src-wlib-$(CONFIG_40x) += 4xx.c planetcore.c
src-wlib-$(CONFIG_44x) += 4xx.c ebony.c bamboo.c
src-wlib-$(CONFIG_8xx) += mpc8xx.c planetcore.c fsl-soc.c
diff --git a/arch/powerpc/boot/crtsavres.S b/arch/powerpc/boot/crtsavres.S
index f3d9b35..8c77437 100644
--- a/arch/powerpc/boot/crtsavres.S
+++ b/arch/powerpc/boot/crtsavres.S
@@ -38,10 +38,9 @@
*/
.file "crtsavres.S"
- .section ".text"
+ .section ".sfpr","ax", at progbits
/* On PowerPC64 Linux, these functions are provided by the linker. */
-#ifndef __powerpc64__
#define _GLOBAL(name) \
.type name, at function; \
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 534c8df..01d09e9 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -76,13 +76,14 @@ SECTIONS
*(.linker_stub_catch);
. = . ;
/* careful! __ftr_alt_* sections need to be close to .text */
- *(.text.hot .text .text.fixup .text.unlikely .fixup __ftr_alt_* .ref.text .sfpr);
+ *(.text.hot .text .text.fixup .text.unlikely .fixup __ftr_alt_* .ref.text);
SCHED_TEXT
CPUIDLE_TEXT
LOCK_TEXT
KPROBES_TEXT
IRQENTRY_TEXT
SOFTIRQENTRY_TEXT
+ *(.sfpr);
MEM_KEEP(init.text)
MEM_KEEP(exit.text)
diff --git a/arch/powerpc/lib/Makefile b/arch/powerpc/lib/Makefile
index 309361e8..b1304113 100644
--- a/arch/powerpc/lib/Makefile
+++ b/arch/powerpc/lib/Makefile
@@ -9,10 +9,9 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
CFLAGS_REMOVE_code-patching.o = $(CC_FLAGS_FTRACE)
CFLAGS_REMOVE_feature-fixups.o = $(CC_FLAGS_FTRACE)
-obj-y += string.o alloc.o crtsavres.o code-patching.o \
- feature-fixups.o
+obj-y += string.o alloc.o code-patching.o feature-fixups.o
-obj-$(CONFIG_PPC32) += div64.o copy_32.o
+obj-$(CONFIG_PPC32) += div64.o copy_32.o crtsavres.o
obj64-y += copypage_64.o copyuser_64.o usercopy_64.o mem_64.o hweight_64.o \
copyuser_power7.o string_64.o copypage_power7.o memcpy_power7.o \
diff --git a/arch/powerpc/lib/crtsavres.S b/arch/powerpc/lib/crtsavres.S
index 18af0b3..0c6ea3b 100644
--- a/arch/powerpc/lib/crtsavres.S
+++ b/arch/powerpc/lib/crtsavres.S
@@ -42,11 +42,11 @@
.file "crtsavres.S"
-#ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
+/* On PowerPC64 Linux, these functions are provided by the linker. */
-#ifndef CONFIG_PPC64
+#ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
- .section ".text"
+ .section ".sfpr","ax", at progbits
/* Routines for saving integer registers, called by the compiler. */
/* Called with r11 pointing to the stack header word of the caller of the */
@@ -312,236 +312,4 @@ _GLOBAL(_restvr_31)
#endif /* CONFIG_ALTIVEC */
-#else /* CONFIG_PPC64 */
-
- .section ".text.save.restore","ax", at progbits
-
-.globl _savegpr0_14
-_savegpr0_14:
- std r14,-144(r1)
-.globl _savegpr0_15
-_savegpr0_15:
- std r15,-136(r1)
-.globl _savegpr0_16
-_savegpr0_16:
- std r16,-128(r1)
-.globl _savegpr0_17
-_savegpr0_17:
- std r17,-120(r1)
-.globl _savegpr0_18
-_savegpr0_18:
- std r18,-112(r1)
-.globl _savegpr0_19
-_savegpr0_19:
- std r19,-104(r1)
-.globl _savegpr0_20
-_savegpr0_20:
- std r20,-96(r1)
-.globl _savegpr0_21
-_savegpr0_21:
- std r21,-88(r1)
-.globl _savegpr0_22
-_savegpr0_22:
- std r22,-80(r1)
-.globl _savegpr0_23
-_savegpr0_23:
- std r23,-72(r1)
-.globl _savegpr0_24
-_savegpr0_24:
- std r24,-64(r1)
-.globl _savegpr0_25
-_savegpr0_25:
- std r25,-56(r1)
-.globl _savegpr0_26
-_savegpr0_26:
- std r26,-48(r1)
-.globl _savegpr0_27
-_savegpr0_27:
- std r27,-40(r1)
-.globl _savegpr0_28
-_savegpr0_28:
- std r28,-32(r1)
-.globl _savegpr0_29
-_savegpr0_29:
- std r29,-24(r1)
-.globl _savegpr0_30
-_savegpr0_30:
- std r30,-16(r1)
-.globl _savegpr0_31
-_savegpr0_31:
- std r31,-8(r1)
- std r0,16(r1)
- blr
-
-.globl _restgpr0_14
-_restgpr0_14:
- ld r14,-144(r1)
-.globl _restgpr0_15
-_restgpr0_15:
- ld r15,-136(r1)
-.globl _restgpr0_16
-_restgpr0_16:
- ld r16,-128(r1)
-.globl _restgpr0_17
-_restgpr0_17:
- ld r17,-120(r1)
-.globl _restgpr0_18
-_restgpr0_18:
- ld r18,-112(r1)
-.globl _restgpr0_19
-_restgpr0_19:
- ld r19,-104(r1)
-.globl _restgpr0_20
-_restgpr0_20:
- ld r20,-96(r1)
-.globl _restgpr0_21
-_restgpr0_21:
- ld r21,-88(r1)
-.globl _restgpr0_22
-_restgpr0_22:
- ld r22,-80(r1)
-.globl _restgpr0_23
-_restgpr0_23:
- ld r23,-72(r1)
-.globl _restgpr0_24
-_restgpr0_24:
- ld r24,-64(r1)
-.globl _restgpr0_25
-_restgpr0_25:
- ld r25,-56(r1)
-.globl _restgpr0_26
-_restgpr0_26:
- ld r26,-48(r1)
-.globl _restgpr0_27
-_restgpr0_27:
- ld r27,-40(r1)
-.globl _restgpr0_28
-_restgpr0_28:
- ld r28,-32(r1)
-.globl _restgpr0_29
-_restgpr0_29:
- ld r0,16(r1)
- ld r29,-24(r1)
- mtlr r0
- ld r30,-16(r1)
- ld r31,-8(r1)
- blr
-
-.globl _restgpr0_30
-_restgpr0_30:
- ld r30,-16(r1)
-.globl _restgpr0_31
-_restgpr0_31:
- ld r0,16(r1)
- ld r31,-8(r1)
- mtlr r0
- blr
-
-#ifdef CONFIG_ALTIVEC
-/* Called with r0 pointing just beyond the end of the vector save area. */
-
-.globl _savevr_20
-_savevr_20:
- li r12,-192
- stvx v20,r12,r0
-.globl _savevr_21
-_savevr_21:
- li r12,-176
- stvx v21,r12,r0
-.globl _savevr_22
-_savevr_22:
- li r12,-160
- stvx v22,r12,r0
-.globl _savevr_23
-_savevr_23:
- li r12,-144
- stvx v23,r12,r0
-.globl _savevr_24
-_savevr_24:
- li r12,-128
- stvx v24,r12,r0
-.globl _savevr_25
-_savevr_25:
- li r12,-112
- stvx v25,r12,r0
-.globl _savevr_26
-_savevr_26:
- li r12,-96
- stvx v26,r12,r0
-.globl _savevr_27
-_savevr_27:
- li r12,-80
- stvx v27,r12,r0
-.globl _savevr_28
-_savevr_28:
- li r12,-64
- stvx v28,r12,r0
-.globl _savevr_29
-_savevr_29:
- li r12,-48
- stvx v29,r12,r0
-.globl _savevr_30
-_savevr_30:
- li r12,-32
- stvx v30,r12,r0
-.globl _savevr_31
-_savevr_31:
- li r12,-16
- stvx v31,r12,r0
- blr
-
-.globl _restvr_20
-_restvr_20:
- li r12,-192
- lvx v20,r12,r0
-.globl _restvr_21
-_restvr_21:
- li r12,-176
- lvx v21,r12,r0
-.globl _restvr_22
-_restvr_22:
- li r12,-160
- lvx v22,r12,r0
-.globl _restvr_23
-_restvr_23:
- li r12,-144
- lvx v23,r12,r0
-.globl _restvr_24
-_restvr_24:
- li r12,-128
- lvx v24,r12,r0
-.globl _restvr_25
-_restvr_25:
- li r12,-112
- lvx v25,r12,r0
-.globl _restvr_26
-_restvr_26:
- li r12,-96
- lvx v26,r12,r0
-.globl _restvr_27
-_restvr_27:
- li r12,-80
- lvx v27,r12,r0
-.globl _restvr_28
-_restvr_28:
- li r12,-64
- lvx v28,r12,r0
-.globl _restvr_29
-_restvr_29:
- li r12,-48
- lvx v29,r12,r0
-.globl _restvr_30
-_restvr_30:
- li r12,-32
- lvx v30,r12,r0
-.globl _restvr_31
-_restvr_31:
- li r12,-16
- lvx v31,r12,r0
- blr
-
-#endif /* CONFIG_ALTIVEC */
-
-#endif /* CONFIG_PPC64 */
-
#endif
--
2.9.3
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