Commit 01db473e authored by Samuel Holland's avatar Samuel Holland Committed by Andrew Morton
Browse files

powerpc: implement ARCH_HAS_KERNEL_FPU_SUPPORT 

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.

Link: https://lkml.kernel.org/r/20240329072441.591471-9-samuel.holland@sifive.com


Signed-off-by: default avatarSamuel Holland <samuel.holland@sifive.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarChristian König <christian.koenig@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nicolas Schier <nicolas@fjasle.eu>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: WANG Xuerui <git@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 372f6623

arch/powerpc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -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

arch/powerpc/Makefile

+4 −1
Original line number Diff line number Diff line
@@ -149,6 +149,9 @@ 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
@@ -170,7 +173,7 @@ asinstr := $(call as-instr,lis 9$(comma)foo@high,-DHAVE_AS_ATHIGH=1) 


KBUILD_CPPFLAGS	+= -I $(srctree)/arch/powerpc $(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)

arch/powerpc/include/asm/fpu.h

0 → 100644
+28 −0
Original line number Diff line number Diff line 
/* 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 */