[PATCH v4 02/15] ARM: Implement ARCH_HAS_KERNEL_FPU_SUPPORT
From: Samuel Holland <samuel.holland@sifive.com>
Date: 2024-03-29 07:24:46
Also in:
amd-gfx, linux-arch, linux-arm-kernel, linux-riscv, lkml, loongarch
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
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. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Samuel Holland <samuel.holland@sifive.com> --- (no changes since v2) Changes in v2: - Remove file name from header comment arch/arm/Kconfig | 1 + arch/arm/Makefile | 7 +++++++ arch/arm/include/asm/fpu.h | 15 +++++++++++++++ 3 files changed, 23 insertions(+) create mode 100644 arch/arm/include/asm/fpu.h
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index b14aed3a17ab..b1751c2cab87 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig@@ -15,6 +15,7 @@ config ARM select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_KEEPINITRD select ARCH_HAS_KCOV + select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON select ARCH_HAS_MEMBARRIER_SYNC_CORE select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
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 */
--
2.44.0