[PATCH v2 04/14] arm64: Implement ARCH_HAS_KERNEL_FPU_SUPPORT
From: Samuel Holland <samuel.holland@sifive.com>
Date: 2023-12-28 01:42:28
Also in:
amd-gfx, linux-arch, linux-arm-kernel, linux-riscv, lkml, loongarch
Subsystem:
arm64 port (aarch64 architecture), the rest · Maintainers:
Catalin Marinas, Will Deacon, Linus Torvalds
arm64 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> --- Changes in v2: - Remove file name from header comment arch/arm64/Kconfig | 1 + arch/arm64/Makefile | 9 ++++++++- arch/arm64/include/asm/fpu.h | 15 +++++++++++++++ 3 files changed, 24 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/include/asm/fpu.h
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7b071a00425d..485ac389ac11 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -30,6 +30,7 @@ config ARM64 select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_GIGANTIC_PAGE select ARCH_HAS_KCOV + select ARCH_HAS_KERNEL_FPU_SUPPORT if KERNEL_MODE_NEON select ARCH_HAS_KEEPINITRD select ARCH_HAS_MEMBARRIER_SYNC_CORE select ARCH_HAS_NMI_SAFE_THIS_CPU_OPS
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 9a2d3723cd0f..4a65f24c7998 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile@@ -36,7 +36,14 @@ ifeq ($(CONFIG_BROKEN_GAS_INST),y) $(warning Detected assembler with broken .inst; disassembly will be unreliable) endif -KBUILD_CFLAGS += -mgeneral-regs-only \ +# 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_NO_FPU := -mgeneral-regs-only + +KBUILD_CFLAGS += $(CC_FLAGS_NO_FPU) \ $(compat_vdso) $(cc_has_k_constraint) KBUILD_CFLAGS += $(call cc-disable-warning, psabi) KBUILD_AFLAGS += $(compat_vdso)
diff --git a/arch/arm64/include/asm/fpu.h b/arch/arm64/include/asm/fpu.h
new file mode 100644
index 000000000000..2ae50bdce59b
--- /dev/null
+++ b/arch/arm64/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 */
--
2.42.0