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authorSamuel Holland <samuel.holland@sifive.com>2024-03-29 10:18:17 +0300
committerAndrew Morton <akpm@linux-foundation.org>2024-05-20 00:36:17 +0300
commitcb2b7b7de805cd649851fb8f2f36df3b8425682e (patch)
tree1f0913ff5dd69b9d7f4b033748f9bda8c9c239cf /arch/arm
parent6cbd1d6d36c5d8312de99d1dfa3bec40ac840ce0 (diff)
downloadlinux-cb2b7b7de805cd649851fb8f2f36df3b8425682e.tar.xz
ARM: implement ARCH_HAS_KERNEL_FPU_SUPPORT
ARM provides an equivalent to the common kernel-mode FPU API, but in a different header and using different function names. Add a wrapper header, and export CFLAGS adjustments as found in lib/raid6/Makefile. [samuel.holland@sifive.com: ARM: do not select ARCH_HAS_KERNEL_FPU_SUPPORT] Link: https://lkml.kernel.org/r/20240509013727.648600-1-samuel.holland@sifive.com Link: https://lkml.kernel.org/r/20240329072441.591471-3-samuel.holland@sifive.com Signed-off-by: Samuel Holland <samuel.holland@sifive.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian König <christian.koenig@amd.com> 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: WANG Xuerui <git@xen0n.name> Cc: Will Deacon <will@kernel.org> Cc: Thiago Jung Bauermann <thiago.bauermann@linaro.org> Cc: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/Makefile7
-rw-r--r--arch/arm/include/asm/fpu.h15
2 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index d82908b1b1bb..71afdd98ddf2 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -130,6 +130,13 @@ endif
# Accept old syntax despite ".syntax unified"
AFLAGS_NOWARN :=$(call as-option,-Wa$(comma)-mno-warn-deprecated,-Wa$(comma)-W)
+# The GCC option -ffreestanding is required in order to compile code containing
+# ARM/NEON intrinsics in a non C99-compliant environment (such as the kernel)
+CC_FLAGS_FPU := -ffreestanding
+# Enable <arm_neon.h>
+CC_FLAGS_FPU += -isystem $(shell $(CC) -print-file-name=include)
+CC_FLAGS_FPU += -march=armv7-a -mfloat-abi=softfp -mfpu=neon
+
ifeq ($(CONFIG_THUMB2_KERNEL),y)
CFLAGS_ISA :=-Wa,-mimplicit-it=always $(AFLAGS_NOWARN)
AFLAGS_ISA :=$(CFLAGS_ISA) -Wa$(comma)-mthumb
diff --git a/arch/arm/include/asm/fpu.h b/arch/arm/include/asm/fpu.h
new file mode 100644
index 000000000000..2ae50bdce59b
--- /dev/null
+++ b/arch/arm/include/asm/fpu.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023 SiFive
+ */
+
+#ifndef __ASM_FPU_H
+#define __ASM_FPU_H
+
+#include <asm/neon.h>
+
+#define kernel_fpu_available() cpu_has_neon()
+#define kernel_fpu_begin() kernel_neon_begin()
+#define kernel_fpu_end() kernel_neon_end()
+
+#endif /* ! __ASM_FPU_H */