diff mbox series

[v2,08/14] powerpc: Implement ARCH_HAS_KERNEL_FPU_SUPPORT

Message ID	20231228014220.3562640-9-samuel.holland@sifive.com
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel+bounces-12375-ouuuleilei=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1; From: Samuel Holland <samuel.holland@sifive.com> To: linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, x86@kernel.org, linux-riscv@lists.infradead.org, Christoph Hellwig <hch@lst.de> Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org, linux-arch@vger.kernel.org, Samuel Holland <samuel.holland@sifive.com> Subject: [PATCH v2 08/14] powerpc: Implement ARCH_HAS_KERNEL_FPU_SUPPORT Date: Wed, 27 Dec 2023 17:41:58 -0800 Message-ID: <20231228014220.3562640-9-samuel.holland@sifive.com> In-Reply-To: <20231228014220.3562640-1-samuel.holland@sifive.com> References: <20231228014220.3562640-1-samuel.holland@sifive.com> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-getmail-retrieved-from-mailbox: INBOX
Series	Unified cross-architecture kernel-mode FPU API \| [v2,00/14] Unified cross-architecture kernel-mode FPU API [v2,01/14] arch: Add ARCH_HAS_KERNEL_FPU_SUPPORT [v2,02/14] ARM: Implement ARCH_HAS_KERNEL_FPU_SUPPORT [v2,03/14] ARM: crypto: Use CC_FLAGS_FPU for NEON CFLAGS [v2,04/14] arm64: Implement ARCH_HAS_KERNEL_FPU_SUPPORT [v2,05/14] arm64: crypto: Use CC_FLAGS_FPU for NEON CFLAGS [v2,06/14] lib/raid6: Use CC_FLAGS_FPU for NEON CFLAGS [v2,07/14] LoongArch: Implement ARCH_HAS_KERNEL_FPU_SUPPORT [v2,08/14] powerpc: Implement ARCH_HAS_KERNEL_FPU_SUPPORT [v2,09/14] x86: Implement ARCH_HAS_KERNEL_FPU_SUPPORT [v2,10/14] riscv: Add support for kernel-mode FPU [v2,11/14] drm/amd/display: Only use hard-float, not altivec on powerpc [v2,12/14] drm/amd/display: Use ARCH_HAS_KERNEL_FPU_SUPPORT [v2,13/14] selftests/fpu: Move FP code to a separate translation unit [v2,14/14] selftests/fpu: Allow building on other architectures

Commit Message

Samuel Holland Dec. 28, 2023, 1:41 a.m. UTC

  PowerPC provides an equivalent to the common kernel-mode FPU API, but in
a different header and using different function names. The PowerPC API
also requires a non-preemptible context. Add a wrapper header, and
export the CFLAGS adjustments.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

(no changes since v1)

 arch/powerpc/Kconfig           |  1 +
 arch/powerpc/Makefile          |  5 ++++-
 arch/powerpc/include/asm/fpu.h | 28 ++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 1 deletion(-)
 create mode 100644 arch/powerpc/include/asm/fpu.h

Comments

Michael Ellerman Dec. 28, 2023, 3:19 a.m. UTC | #1

Samuel Holland <samuel.holland@sifive.com> writes:
> PowerPC provides an equivalent to the common kernel-mode FPU API, but in
> a different header and using different function names. The PowerPC API
> also requires a non-preemptible context. Add a wrapper header, and
> export the CFLAGS adjustments.
>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
> ---
>
> (no changes since v1)
>
>  arch/powerpc/Kconfig           |  1 +
>  arch/powerpc/Makefile          |  5 ++++-
>  arch/powerpc/include/asm/fpu.h | 28 ++++++++++++++++++++++++++++
>  3 files changed, 33 insertions(+), 1 deletion(-)
>  create mode 100644 arch/powerpc/include/asm/fpu.h

Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)

cheers

diff mbox series

Patch

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 6f105ee4f3cf..e96cb5b7c571 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -137,6 +137,7 @@  config PPC
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_HUGEPD			if HUGETLB_PAGE
 	select ARCH_HAS_KCOV
+	select ARCH_HAS_KERNEL_FPU_SUPPORT	if PPC_FPU
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_MEMREMAP_COMPAT_ALIGN	if PPC_64S_HASH_MMU
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index f19dbaa1d541..91106970a8c1 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -142,6 +142,9 @@  CFLAGS-$(CONFIG_PPC32)	+= $(call cc-option, $(MULTIPLEWORD))
 
 CFLAGS-$(CONFIG_PPC32)	+= $(call cc-option,-mno-readonly-in-sdata)
 
+CC_FLAGS_FPU		:= $(call cc-option,-mhard-float)
+CC_FLAGS_NO_FPU		:= $(call cc-option,-msoft-float)
+
 ifdef CONFIG_FUNCTION_TRACER
 ifdef CONFIG_ARCH_USING_PATCHABLE_FUNCTION_ENTRY
 KBUILD_CPPFLAGS	+= -DCC_USING_PATCHABLE_FUNCTION_ENTRY
@@ -163,7 +166,7 @@  asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1)
 
 KBUILD_CPPFLAGS	+= -I $(srctree)/arch/$(ARCH) $(asinstr)
 KBUILD_AFLAGS	+= $(AFLAGS-y)
-KBUILD_CFLAGS	+= $(call cc-option,-msoft-float)
+KBUILD_CFLAGS	+= $(CC_FLAGS_NO_FPU)
 KBUILD_CFLAGS	+= $(CFLAGS-y)
 CPP		= $(CC) -E $(KBUILD_CFLAGS)
 
diff --git a/arch/powerpc/include/asm/fpu.h b/arch/powerpc/include/asm/fpu.h
new file mode 100644
index 000000000000..ca584e4bc40f
--- /dev/null
+++ b/arch/powerpc/include/asm/fpu.h
@@ -0,0 +1,28 @@ 
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2023 SiFive
+ */
+
+#ifndef _ASM_POWERPC_FPU_H
+#define _ASM_POWERPC_FPU_H
+
+#include <linux/preempt.h>
+
+#include <asm/cpu_has_feature.h>
+#include <asm/switch_to.h>
+
+#define kernel_fpu_available()	(!cpu_has_feature(CPU_FTR_FPU_UNAVAILABLE))
+
+static inline void kernel_fpu_begin(void)
+{
+	preempt_disable();
+	enable_kernel_fp();
+}
+
+static inline void kernel_fpu_end(void)
+{
+	disable_kernel_fp();
+	preempt_enable();
+}
+
+#endif /* ! _ASM_POWERPC_FPU_H */