[PATCH v4 08/15] powerpc: Implement ARCH_HAS_KERNEL_FPU_SUPPORT
From: Samuel Holland <samuel.holland@sifive.com>
Date: 2024-03-29 07:24:59
Also in:
amd-gfx, linux-arch, linux-arm-kernel, linux-riscv, lkml, loongarch
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
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. Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) 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
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 1c4be3373686..c42a57b6839d 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 65261cbe5bfd..93d89f055b70 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile@@ -153,6 +153,9 @@ 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
@@ -174,7 +177,7 @@ 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 */
--
2.44.0