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-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org,
Christoph Hellwig <hch@lst.de>,
loongarch@lists.linux.dev, amd-gfx@lists.freedesktop.org,
Samuel Holland <samuel.holland@sifive.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Subject: [PATCH v4 04/15] arm64: Implement ARCH_HAS_KERNEL_FPU_SUPPORT
Date: Fri, 29 Mar 2024 00:18:19 -0700 [thread overview]
Message-ID: <20240329072441.591471-5-samuel.holland@sifive.com> (raw)
In-Reply-To: <20240329072441.591471-1-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 */
--
2.44.0
next prev parent reply other threads:[~2024-03-29 7:24 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-29 7:18 [PATCH v4 00/15] Unified cross-architecture kernel-mode FPU API Samuel Holland
2024-03-29 7:18 ` [PATCH v4 01/15] arch: Add ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-29 7:18 ` [PATCH v4 02/15] ARM: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-29 7:18 ` [PATCH v4 03/15] ARM: crypto: Use CC_FLAGS_FPU for NEON CFLAGS Samuel Holland
2024-03-29 7:18 ` Samuel Holland [this message]
2024-03-29 7:18 ` [PATCH v4 05/15] arm64: " Samuel Holland
2024-03-29 7:18 ` [PATCH v4 06/15] lib/raid6: " Samuel Holland
2024-03-29 7:18 ` [PATCH v4 07/15] LoongArch: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-29 7:18 ` [PATCH v4 08/15] powerpc: " Samuel Holland
2024-03-29 7:18 ` [PATCH v4 09/15] x86/fpu: Fix asm/fpu/types.h include guard Samuel Holland
2024-03-29 17:30 ` Dave Hansen
2024-03-29 7:18 ` [PATCH v4 10/15] x86: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-29 17:28 ` Dave Hansen
2024-03-29 18:02 ` Samuel Holland
2024-03-29 7:18 ` [PATCH v4 11/15] riscv: Add support for kernel-mode FPU Samuel Holland
2024-03-29 7:18 ` [PATCH v4 12/15] drm/amd/display: Only use hard-float, not altivec on powerpc Samuel Holland
2024-04-30 17:28 ` Harry Wentland
2024-03-29 7:18 ` [PATCH v4 13/15] drm/amd/display: Use ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-04-10 22:21 ` Thiago Jung Bauermann
2024-04-10 22:47 ` Samuel Holland
2024-04-11 1:02 ` Thiago Jung Bauermann
2024-04-11 1:11 ` Samuel Holland
2024-04-11 1:27 ` Thiago Jung Bauermann
2024-04-11 7:15 ` Ard Biesheuvel
2024-04-11 7:31 ` Arnd Bergmann
2024-04-12 1:54 ` Dave Airlie
2024-04-30 17:29 ` Harry Wentland
2024-05-24 4:50 ` Guenter Roeck
2024-05-24 13:17 ` Alex Deucher
2024-05-24 13:18 ` Alex Deucher
2024-05-24 13:43 ` Guenter Roeck
2024-05-24 13:53 ` Guenter Roeck
2024-05-24 18:23 ` Guenter Roeck
2024-03-29 7:18 ` [PATCH v4 14/15] selftests/fpu: Move FP code to a separate translation unit Samuel Holland
2024-03-29 7:18 ` [PATCH v4 15/15] selftests/fpu: Allow building on other architectures Samuel Holland
2024-04-03 12:51 ` [PATCH v4 00/15] Unified cross-architecture kernel-mode FPU API Christian König
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