diff mbox series

[v3,04/14] arm64: Implement ARCH_HAS_KERNEL_FPU_SUPPORT

Message ID 20240327200157.1097089-5-samuel.holland@sifive.com (mailing list archive)
State Superseded
Headers show
Series Unified cross-architecture kernel-mode FPU API | expand

Checks

Context Check Description
conchuod/vmtest-for-next-PR fail PR summary
conchuod/patch-4-test-1 success .github/scripts/patches/tests/build_rv32_defconfig.sh
conchuod/patch-4-test-2 success .github/scripts/patches/tests/build_rv64_clang_allmodconfig.sh
conchuod/patch-4-test-3 success .github/scripts/patches/tests/build_rv64_gcc_allmodconfig.sh
conchuod/patch-4-test-4 success .github/scripts/patches/tests/build_rv64_nommu_k210_defconfig.sh
conchuod/patch-4-test-5 success .github/scripts/patches/tests/build_rv64_nommu_virt_defconfig.sh
conchuod/patch-4-test-6 warning .github/scripts/patches/tests/checkpatch.sh
conchuod/patch-4-test-7 success .github/scripts/patches/tests/dtb_warn_rv64.sh
conchuod/patch-4-test-8 success .github/scripts/patches/tests/header_inline.sh
conchuod/patch-4-test-9 success .github/scripts/patches/tests/kdoc.sh
conchuod/patch-4-test-10 success .github/scripts/patches/tests/module_param.sh
conchuod/patch-4-test-11 success .github/scripts/patches/tests/verify_fixes.sh
conchuod/patch-4-test-12 success .github/scripts/patches/tests/verify_signedoff.sh

Commit Message

Samuel Holland March 27, 2024, 8 p.m. UTC 
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>
---

(no changes since v2)

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 mbox series

Patch

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7b11c98b3e84..67f0d3b5b7df 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 0e075d3c546b..3e863e5b0169 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 */