The patch titled
Subject: LoongArch: implement ARCH_HAS_KERNEL_FPU_SUPPORT
has been added to the -mm mm-nonmm-unstable branch. Its filename is
loongarch-implement-arch_has_kernel_fpu_support.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/loongarch-implement-arch_has_kernel_fpu_support.patch
This patch will later appear in the mm-nonmm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Samuel Holland <samuel.holland@xxxxxxxxxx>
Subject: LoongArch: implement ARCH_HAS_KERNEL_FPU_SUPPORT
Date: Wed, 27 Mar 2024 13:00:38 -0700
LoongArch already provides kernel_fpu_begin() and kernel_fpu_end() in
asm/fpu.h, so it only needs to add kernel_fpu_available() and export the
CFLAGS adjustments.
Link: https://lkml.kernel.org/r/20240327200157.1097089-8-samuel.holland@xxxxxxxxxx
Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
Acked-by: WANG Xuerui <git@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Cc: Borislav Petkov (AMD) <bp@xxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Huacai Chen <chenhuacai@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Cc: Nathan Chancellor <nathan@xxxxxxxxxx>
Cc: Nicolas Schier <nicolas@xxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/loongarch/Kconfig | 1 +
arch/loongarch/Makefile | 5 ++++-
arch/loongarch/include/asm/fpu.h | 1 +
3 files changed, 6 insertions(+), 1 deletion(-)
--- a/arch/loongarch/include/asm/fpu.h~loongarch-implement-arch_has_kernel_fpu_support
+++ a/arch/loongarch/include/asm/fpu.h
@@ -21,6 +21,7 @@
struct sigcontext;
+#define kernel_fpu_available() cpu_has_fpu
extern void kernel_fpu_begin(void);
extern void kernel_fpu_end(void);
--- a/arch/loongarch/Kconfig~loongarch-implement-arch_has_kernel_fpu_support
+++ a/arch/loongarch/Kconfig
@@ -18,6 +18,7 @@ config LOONGARCH
select ARCH_HAS_CURRENT_STACK_POINTER
select ARCH_HAS_FORTIFY_SOURCE
select ARCH_HAS_KCOV
+ select ARCH_HAS_KERNEL_FPU_SUPPORT if CPU_HAS_FPU
select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
select ARCH_HAS_PTE_SPECIAL
--- a/arch/loongarch/Makefile~loongarch-implement-arch_has_kernel_fpu_support
+++ a/arch/loongarch/Makefile
@@ -26,6 +26,9 @@ endif
32bit-emul = elf32loongarch
64bit-emul = elf64loongarch
+CC_FLAGS_FPU := -mfpu=64
+CC_FLAGS_NO_FPU := -msoft-float
+
ifdef CONFIG_UNWINDER_ORC
orc_hash_h := arch/$(SRCARCH)/include/generated/asm/orc_hash.h
orc_hash_sh := $(srctree)/scripts/orc_hash.sh
@@ -59,7 +62,7 @@ ld-emul = $(64bit-emul)
cflags-y += -mabi=lp64s
endif
-cflags-y += -pipe -msoft-float
+cflags-y += -pipe $(CC_FLAGS_NO_FPU)
LDFLAGS_vmlinux += -static -n -nostdlib
# When the assembler supports explicit relocation hint, we must use it.
_
Patches currently in -mm which might be from samuel.holland@xxxxxxxxxx are
arch-add-arch_has_kernel_fpu_support.patch
arm-implement-arch_has_kernel_fpu_support.patch
arm-crypto-use-cc_flags_fpu-for-neon-cflags.patch
arm64-implement-arch_has_kernel_fpu_support.patch
arm64-crypto-use-cc_flags_fpu-for-neon-cflags.patch
lib-raid6-use-cc_flags_fpu-for-neon-cflags.patch
loongarch-implement-arch_has_kernel_fpu_support.patch
powerpc-implement-arch_has_kernel_fpu_support.patch
x86-implement-arch_has_kernel_fpu_support.patch
riscv-add-support-for-kernel-mode-fpu.patch
drm-amd-display-use-arch_has_kernel_fpu_support.patch
selftests-fpu-move-fp-code-to-a-separate-translation-unit.patch
selftests-fpu-allow-building-on-other-architectures.patch
