+ loongarch-implement-arch_has_kernel_fpu_support.patch added to mm-nonmm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

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@sifive.com>
Subject: LoongArch: implement ARCH_HAS_KERNEL_FPU_SUPPORT
Date: Fri, 29 Mar 2024 00:18:22 -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/20240329072441.591471-8-samuel.holland@sifive.com
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
Acked-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 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@sifive.com are

x86-fpu-fix-asm-fpu-typesh-include-guard.patch
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