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, linux-kernel@vger.kernel.org,
amd-gfx@lists.freedesktop.org,
Samuel Holland <samuel.holland@sifive.com>,
loongarch@lists.linux.dev, Russell King <linux@armlinux.org.uk>,
linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org,
Christoph Hellwig <hch@lst.de>
Subject: [PATCH v3 02/14] ARM: Implement ARCH_HAS_KERNEL_FPU_SUPPORT
Date: Wed, 27 Mar 2024 13:00:33 -0700 [thread overview]
Message-ID: <20240327200157.1097089-3-samuel.holland@sifive.com> (raw)
In-Reply-To: <20240327200157.1097089-1-samuel.holland@sifive.com>
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 */
--
2.43.1
next prev parent reply other threads:[~2024-03-27 20:02 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 ` Samuel Holland [this message]
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 ` [PATCH v3 04/14] arm64: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Samuel Holland
2024-03-27 20:00 ` [PATCH v3 05/14] arm64: crypto: Use CC_FLAGS_FPU for NEON CFLAGS 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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