From: Samuel Holland <samuel.holland@sifive.com>
To: Andrew Morton <akpm@linux-foundation.org>,
linux-arm-kernel@lists.infradead.org, x86@kernel.org
Cc: linux-arch@vger.kernel.org, Will Deacon <will@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
Samuel Holland <samuel.holland@sifive.com>,
loongarch@lists.linux.dev, linux-riscv@lists.infradead.org,
linuxppc-dev@lists.ozlabs.org, Christoph Hellwig <hch@lst.de>
Subject: [PATCH v3 04/14] arm64: Implement ARCH_HAS_KERNEL_FPU_SUPPORT
Date: Wed, 27 Mar 2024 13:00:35 -0700 [thread overview]
Message-ID: <20240327200157.1097089-5-samuel.holland@sifive.com> (raw)
In-Reply-To: <20240327200157.1097089-1-samuel.holland@sifive.com>
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 --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 */
--
2.43.1
next prev parent reply other threads:[~2024-03-27 20:05 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-27 20:00 [PATCH v3 00/14] Unified cross-architecture kernel-mode FPU API Samuel Holland
2024-03-27 20:00 ` [PATCH v3 01/14] arch: Add ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-27 20:00 ` [PATCH v3 02/14] ARM: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-27 20:00 ` [PATCH v3 03/14] ARM: crypto: Use CC_FLAGS_FPU for NEON CFLAGS Samuel Holland
2024-03-27 20:00 ` Samuel Holland [this message]
2024-03-27 20:00 ` [PATCH v3 05/14] arm64: " Samuel Holland
2024-03-27 20:00 ` [PATCH v3 06/14] lib/raid6: " Samuel Holland
2024-03-27 20:00 ` [PATCH v3 07/14] LoongArch: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-27 20:00 ` [PATCH v3 08/14] powerpc: " Samuel Holland
2024-03-27 20:00 ` [PATCH v3 09/14] x86: " Samuel Holland
2024-03-27 20:00 ` [PATCH v3 10/14] riscv: Add support for kernel-mode FPU Samuel Holland
2024-03-27 20:00 ` [PATCH v3 11/14] drm/amd/display: Only use hard-float, not altivec on powerpc Samuel Holland
2024-03-27 20:00 ` [PATCH v3 12/14] drm/amd/display: Use ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-27 21:25 ` Andrew Morton
2024-03-27 22:08 ` Samuel Holland
2024-03-27 20:00 ` [PATCH v3 13/14] selftests/fpu: Move FP code to a separate translation unit Samuel Holland
2024-03-27 20:00 ` [PATCH v3 14/14] selftests/fpu: Allow building on other architectures Samuel Holland
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