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authorSamuel Holland <samuel.holland@sifive.com>2024-03-29 00:18:23 -0700
committerAndrew Morton <akpm@linux-foundation.org>2024-05-19 14:36:18 -0700
commit01db473e1aa32d651477be80f79b309313636203 (patch)
tree2132f4691cadc3166b860fd4dee65ec955bf7374
parent372f662345d603c6e4e26864a8908826bf7a3e45 (diff)
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: Samuel Holland <samuel.holland@sifive.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Christoph Hellwig <hch@lst.de> Acked-by: Christian 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: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/Makefile5
-rw-r--r--arch/powerpc/include/asm/fpu.h28
3 files changed, 33 insertions, 1 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 56dcafbb83b3..3c968f2f4ac4 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 0a0c57aee1ae..a8479c881cac 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -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)
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 */