[PATCH stable 5.4 01/11] ARM: 8989/1: use .fpu assembler directives instead of assembler arguments

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Florian Fainelli

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Jun 29, 2022, 2:02:41 PM6/29/22
to sta...@vger.kernel.org, Stefan Agner, Russell King, Florian Fainelli, Russell King, Herbert Xu, David S. Miller, Tony Lindgren, Hans Ulli Kroll, Ard Biesheuvel, Nick Desaulniers, Nicolas Pitre, Andre Przywara, Greg Kroah-Hartman, Catalin Marinas, Jian Cai, moderated list:ARM PORT, open list, open list:CRYPTO API, open list:OMAP2+ SUPPORT, open list:CLANG/LLVM BUILD SUPPORT, Sasha Levin
From: Stefan Agner <ste...@agner.ch>

commit a6c30873ee4a5cc0549c1973668156381ab2c1c4 upstream

Explicit FPU selection has been introduced in commit 1a6be26d5b1a
("[ARM] Enable VFP to be built when non-VFP capable CPUs are selected")
to make use of assembler mnemonics for VFP instructions.

However, clang currently does not support passing assembler flags
like this and errors out with:
clang-10: error: the clang compiler does not support '-Wa,-mfpu=softvfp+vfp'

Make use of the .fpu assembler directives to select the floating point
hardware selectively. Also use the new unified assembler language
mnemonics. This allows to build these procedures with Clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/762

Signed-off-by: Stefan Agner <ste...@agner.ch>
Signed-off-by: Russell King <rmk+k...@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fai...@gmail.com>
---
arch/arm/vfp/Makefile | 2 --
arch/arm/vfp/vfphw.S | 30 ++++++++++++++++++++----------
2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/arch/arm/vfp/Makefile b/arch/arm/vfp/Makefile
index 9975b63ac3b0..749901a72d6d 100644
--- a/arch/arm/vfp/Makefile
+++ b/arch/arm/vfp/Makefile
@@ -8,6 +8,4 @@
# ccflags-y := -DDEBUG
# asflags-y := -DDEBUG

-KBUILD_AFLAGS :=$(KBUILD_AFLAGS:-msoft-float=-Wa,-mfpu=softvfp+vfp -mfloat-abi=soft)
-
obj-y += vfpmodule.o entry.o vfphw.o vfpsingle.o vfpdouble.o
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index b530db8f2c6c..772c6a3b1f72 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -253,11 +253,14 @@ vfp_current_hw_state_address:

ENTRY(vfp_get_float)
tbl_branch r0, r3, #3
+ .fpu vfpv2
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-1: mrc p10, 0, r0, c\dr, c0, 0 @ fmrs r0, s0
+1: vmov r0, s\dr
ret lr
.org 1b + 8
-1: mrc p10, 0, r0, c\dr, c0, 4 @ fmrs r0, s1
+ .endr
+ .irp dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
+1: vmov r0, s\dr
ret lr
.org 1b + 8
.endr
@@ -265,11 +268,14 @@ ENDPROC(vfp_get_float)

ENTRY(vfp_put_float)
tbl_branch r1, r3, #3
+ .fpu vfpv2
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-1: mcr p10, 0, r0, c\dr, c0, 0 @ fmsr r0, s0
+1: vmov s\dr, r0
ret lr
.org 1b + 8
-1: mcr p10, 0, r0, c\dr, c0, 4 @ fmsr r0, s1
+ .endr
+ .irp dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
+1: vmov s\dr, r0
ret lr
.org 1b + 8
.endr
@@ -277,15 +283,17 @@ ENDPROC(vfp_put_float)

ENTRY(vfp_get_double)
tbl_branch r0, r3, #3
+ .fpu vfpv2
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-1: fmrrd r0, r1, d\dr
+1: vmov r0, r1, d\dr
ret lr
.org 1b + 8
.endr
#ifdef CONFIG_VFPv3
@ d16 - d31 registers
- .irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-1: mrrc p11, 3, r0, r1, c\dr @ fmrrd r0, r1, d\dr
+ .fpu vfpv3
+ .irp dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
+1: vmov r0, r1, d\dr
ret lr
.org 1b + 8
.endr
@@ -299,15 +307,17 @@ ENDPROC(vfp_get_double)

ENTRY(vfp_put_double)
tbl_branch r2, r3, #3
+ .fpu vfpv2
.irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-1: fmdrr d\dr, r0, r1
+1: vmov d\dr, r0, r1
ret lr
.org 1b + 8
.endr
#ifdef CONFIG_VFPv3
+ .fpu vfpv3
@ d16 - d31 registers
- .irp dr,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15
-1: mcrr p11, 3, r0, r1, c\dr @ fmdrr r0, r1, d\dr
+ .irp dr,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31
+1: vmov d\dr, r0, r1
ret lr
.org 1b + 8
.endr
--
2.25.1

gre...@linuxfoundation.org

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Jun 30, 2022, 9:29:59 AM6/30/22
to andre.p...@arm.com, ar...@kernel.org, caij...@gmail.com, catalin...@arm.com, clang-bu...@googlegroups.com, da...@davemloft.net, f.fai...@gmail.com, gre...@linuxfoundation.org, her...@gondor.apana.org.au, linux-ar...@lists.infradead.org, li...@armlinux.org.uk, ndesau...@google.com, ni...@fluxnic.net, rmk+k...@armlinux.org.uk, sas...@kernel.org, ste...@agner.ch, to...@atomide.com, ulli....@googlemail.com, stable-...@vger.kernel.org

This is a note to let you know that I've just added the patch titled

ARM: 8989/1: use .fpu assembler directives instead of assembler arguments

to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arm-8989-1-use-.fpu-assembler-directives-instead-of-assembler-arguments.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <sta...@vger.kernel.org> know about it.


From foo@baz Thu Jun 30 03:27:07 PM CEST 2022
From: Florian Fainelli <f.fai...@gmail.com>
Date: Wed, 29 Jun 2022 11:02:17 -0700
Subject: ARM: 8989/1: use .fpu assembler directives instead of assembler arguments
To: sta...@vger.kernel.org
Cc: Stefan Agner <ste...@agner.ch>, Russell King <rmk+k...@armlinux.org.uk>, Florian Fainelli <f.fai...@gmail.com>, Russell King <li...@armlinux.org.uk>, Herbert Xu <her...@gondor.apana.org.au>, "David S. Miller" <da...@davemloft.net>, Tony Lindgren <to...@atomide.com>, Hans Ulli Kroll <ulli....@googlemail.com>, Ard Biesheuvel <ar...@kernel.org>, Nick Desaulniers <ndesau...@google.com>, Nicolas Pitre <ni...@fluxnic.net>, Andre Przywara <andre.p...@arm.com>, Greg Kroah-Hartman <gre...@linuxfoundation.org>, Catalin Marinas <catalin...@arm.com>, Jian Cai <caij...@gmail.com>, linux-ar...@lists.infradead.org (moderated list:ARM PORT), linux-...@vger.kernel.org (open list), linux-...@vger.kernel.org (open list:CRYPTO API), linux...@vger.kernel.org (open list:OMAP2+ SUPPORT), clang-bu...@googlegroups.com (open list:CLANG/LLVM BUILD SUPPORT), Sasha Levin <sas...@kernel.org>
Message-ID: <20220629180227.34...@gmail.com>

From: Stefan Agner <ste...@agner.ch>

commit a6c30873ee4a5cc0549c1973668156381ab2c1c4 upstream

Explicit FPU selection has been introduced in commit 1a6be26d5b1a
("[ARM] Enable VFP to be built when non-VFP capable CPUs are selected")
to make use of assembler mnemonics for VFP instructions.

However, clang currently does not support passing assembler flags
like this and errors out with:
clang-10: error: the clang compiler does not support '-Wa,-mfpu=softvfp+vfp'

Make use of the .fpu assembler directives to select the floating point
hardware selectively. Also use the new unified assembler language
mnemonics. This allows to build these procedures with Clang.

Link: https://github.com/ClangBuiltLinux/linux/issues/762

Signed-off-by: Stefan Agner <ste...@agner.ch>
Signed-off-by: Russell King <rmk+k...@armlinux.org.uk>
Signed-off-by: Florian Fainelli <f.fai...@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
arch/arm/vfp/Makefile | 2 --
arch/arm/vfp/vfphw.S | 30 ++++++++++++++++++++----------
2 files changed, 20 insertions(+), 12 deletions(-)

--- a/arch/arm/vfp/Makefile
+++ b/arch/arm/vfp/Makefile
@@ -8,6 +8,4 @@
# ccflags-y := -DDEBUG
# asflags-y := -DDEBUG

-KBUILD_AFLAGS :=$(KBUILD_AFLAGS:-msoft-float=-Wa,-mfpu=softvfp+vfp -mfloat-abi=soft)
-
obj-y += vfpmodule.o entry.o vfphw.o vfpsingle.o vfpdouble.o
Patches currently in stable-queue which might be from f.fai...@gmail.com are

queue-5.4/arm-8971-1-replace-the-sole-use-of-a-symbol-with-its-definition.patch
queue-5.4/arm-omap2-drop-unnecessary-adrl.patch
queue-5.4/arm-8933-1-replace-sun-solaris-style-flag-on-section-directive.patch
queue-5.4/crypto-arm-sha256-neon-avoid-adrl-pseudo-instruction.patch
queue-5.4/arm-9029-1-make-iwmmxt.s-support-clang-s-integrated-assembler.patch
queue-5.4/net-mscc-ocelot-allow-unregistered-ip-multicast-flooding.patch
queue-5.4/crypto-arm-sha512-neon-avoid-adrl-pseudo-instruction.patch
queue-5.4/arm-8989-1-use-.fpu-assembler-directives-instead-of-assembler-arguments.patch
queue-5.4/crypto-arm-ghash-ce-define-fpu-before-fpu-registers-are-referenced.patch
queue-5.4/arm-8929-1-use-apsr_nzcv-instead-of-r15-as-mrc-operand.patch
queue-5.4/crypto-arm-use-kconfig-based-compiler-checks-for-crypto-opcodes.patch
queue-5.4/arm-8990-1-use-vfp-assembler-mnemonics-in-register-load-store-macros.patch
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