[PATCH v2 2/8] toolchain/musl: ppc64: check for AltiVec in setjmp/longjmp

[Stijn Tintel]

Please ignore this patch, it's not required for the M300 and upstream 
requested changes. I'll omit it when pushing this series and work on it 
before continuing on the M200 and BSAP-3040.

On 20/12/2021 21:00, Stijn Tintel wrote:
> Signed-off-by: Stijn Tintel <stijn at linux-ipv6.be>
> ---
>   ...-check-for-AltiVec-in-setjmp-longjmp.patch | 82 +++++++++++++++++++
>   1 file changed, 82 insertions(+)
>   create mode 100644 toolchain/musl/patches/100-ppc64-check-for-AltiVec-in-setjmp-longjmp.patch
>
> diff --git a/toolchain/musl/patches/100-ppc64-check-for-AltiVec-in-setjmp-longjmp.patch b/toolchain/musl/patches/100-ppc64-check-for-AltiVec-in-setjmp-longjmp.patch
> new file mode 100644
> index 0000000000..8b27819022
> --- /dev/null
> +++ b/toolchain/musl/patches/100-ppc64-check-for-AltiVec-in-setjmp-longjmp.patch
> @@ -0,0 +1,82 @@
> +From 0b6f90a930fcda6df287065d39e6b865428e3c69 Mon Sep 17 00:00:00 2001
> +From: Stijn Tintel <stijn at linux-ipv6.be>
> +Date: Sat, 27 Nov 2021 04:58:50 +0200
> +Subject: [PATCH] ppc64: check for AltiVec in setjmp/longjmp
> +
> +On machines without AltiVec, the lvx and stvx instructions are not
> +supported. Use __hwcap to test if AltiVec is supported.
> +
> +Fixes SIGILL on PowerPC 64 processors without AltiVec support.
> +Runtime-tested on e5500 and e6500.
> +
> +Signed-off-by: Stijn Tintel <stijn at linux-ipv6.be>
> +---
> + src/setjmp/powerpc64/longjmp.s | 13 ++++++++++++-
> + src/setjmp/powerpc64/setjmp.s  | 13 ++++++++++++-
> + 2 files changed, 24 insertions(+), 2 deletions(-)
> +
> +diff --git a/src/setjmp/powerpc64/longjmp.s b/src/setjmp/powerpc64/longjmp.s
> +index 81d45ff6..da7172af 100644
> +--- a/src/setjmp/powerpc64/longjmp.s
> ++++ b/src/setjmp/powerpc64/longjmp.s
> +@@ -56,7 +56,17 @@ longjmp:
> + 	lfd 30, 38*8(3)
> + 	lfd 31, 39*8(3)
> +
> +-	# 6) restore vector registers v20-v31
> ++	# 6) restore vector registers v20-v31 if hardware supports AltiVec
> ++	mflr 0
> ++	bl 1f
> ++	.hidden __hwcap
> ++	.long __hwcap-.
> ++1:      mflr 4
> ++	lwz 5, 0(4)
> ++	add 4, 4, 5
> ++	ld 4, 0(4)
> ++	andis. 4, 4, 0x1000
> ++	beq 1f
> + 	addi 3, 3, 40*8
> + 	lvx 20, 0, 3 ; addi 3, 3, 16
> + 	lvx 21, 0, 3 ; addi 3, 3, 16
> +@@ -70,6 +80,7 @@ longjmp:
> + 	lvx 29, 0, 3 ; addi 3, 3, 16
> + 	lvx 30, 0, 3 ; addi 3, 3, 16
> + 	lvx 31, 0, 3
> ++1:	mtlr 0
> +
> + 	# 7) return r4 ? r4 : 1
> + 	mr    3,   4
> +diff --git a/src/setjmp/powerpc64/setjmp.s b/src/setjmp/powerpc64/setjmp.s
> +index 37683fda..32853693 100644
> +--- a/src/setjmp/powerpc64/setjmp.s
> ++++ b/src/setjmp/powerpc64/setjmp.s
> +@@ -69,7 +69,17 @@ __setjmp_toc:
> + 	stfd 30, 38*8(3)
> + 	stfd 31, 39*8(3)
> +
> +-	# 5) store vector registers v20-v31
> ++	# 5) store vector registers v20-v31 if hardware supports AltiVec
> ++	mflr 0
> ++	bl 1f
> ++	.hidden __hwcap
> ++	.long __hwcap-.
> ++1:	mflr 4
> ++	lwz 5, 0(4)
> ++	add 4, 4, 5
> ++	ld 4, 0(4)
> ++	andis. 4, 4, 0x1000
> ++	beq 1f
> + 	addi  3, 3, 40*8
> + 	stvx 20, 0, 3 ; addi 3, 3, 16
> + 	stvx 21, 0, 3 ; addi 3, 3, 16
> +@@ -83,6 +93,7 @@ __setjmp_toc:
> + 	stvx 29, 0, 3 ; addi 3, 3, 16
> + 	stvx 30, 0, 3 ; addi 3, 3, 16
> + 	stvx 31, 0, 3
> ++1:	mtlr 0
> +
> + 	# 6) return 0
> + 	li 3, 0
> +--
> +2.32.0
> +