diff options
| author | Huacai Chen <chenhuacai@loongson.cn> | 2023-05-01 17:19:27 +0800 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2023-05-01 17:19:27 +0800 |
| commit | 2b3bd32ea3a22ea2d5e591da4ac2c2b1fb17c0e0 (patch) | |
| tree | 471e30e5fb3a312649f60e7ff597039a6e8d99d8 /arch/loongarch | |
| parent | c23e7f01cf621290770069d968ca4c8356a50d00 (diff) | |
LoongArch: Provide kernel fpu functions
Provide kernel_fpu_begin()/kernel_fpu_end() to allow the kernel itself
to use fpu. They can be used by some other kernel components, e.g., the
AMDGPU graphic driver for DCN.
Reported-by: WANG Xuerui <kernel@xen0n.name>
Tested-by: WANG Xuerui <kernel@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Diffstat (limited to 'arch/loongarch')
| -rw-r--r-- | arch/loongarch/include/asm/fpu.h | 3 | ||||
| -rw-r--r-- | arch/loongarch/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/loongarch/kernel/kfpu.c | 43 |
3 files changed, 47 insertions, 1 deletions
diff --git a/arch/loongarch/include/asm/fpu.h b/arch/loongarch/include/asm/fpu.h index 358b254d9c1d..192f8e35d912 100644 --- a/arch/loongarch/include/asm/fpu.h +++ b/arch/loongarch/include/asm/fpu.h @@ -21,6 +21,9 @@ struct sigcontext; +extern void kernel_fpu_begin(void); +extern void kernel_fpu_end(void); + extern void _init_fpu(unsigned int); extern void _save_fp(struct loongarch_fpu *); extern void _restore_fp(struct loongarch_fpu *); diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile index 78d4e3384305..9a72d91cd104 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -13,7 +13,7 @@ obj-y += head.o cpu-probe.o cacheinfo.o env.o setup.o entry.o genex.o \ obj-$(CONFIG_ACPI) += acpi.o obj-$(CONFIG_EFI) += efi.o -obj-$(CONFIG_CPU_HAS_FPU) += fpu.o +obj-$(CONFIG_CPU_HAS_FPU) += fpu.o kfpu.o obj-$(CONFIG_ARCH_STRICT_ALIGN) += unaligned.o diff --git a/arch/loongarch/kernel/kfpu.c b/arch/loongarch/kernel/kfpu.c new file mode 100644 index 000000000000..5c46ae8c6cac --- /dev/null +++ b/arch/loongarch/kernel/kfpu.c @@ -0,0 +1,43 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2023 Loongson Technology Corporation Limited + */ + +#include <linux/cpu.h> +#include <linux/init.h> +#include <asm/fpu.h> +#include <asm/smp.h> + +static DEFINE_PER_CPU(bool, in_kernel_fpu); + +void kernel_fpu_begin(void) +{ + preempt_disable(); + + WARN_ON(this_cpu_read(in_kernel_fpu)); + + this_cpu_write(in_kernel_fpu, true); + + if (!is_fpu_owner()) + enable_fpu(); + else + _save_fp(¤t->thread.fpu); + + write_fcsr(LOONGARCH_FCSR0, 0); +} +EXPORT_SYMBOL_GPL(kernel_fpu_begin); + +void kernel_fpu_end(void) +{ + WARN_ON(!this_cpu_read(in_kernel_fpu)); + + if (!is_fpu_owner()) + disable_fpu(); + else + _restore_fp(¤t->thread.fpu); + + this_cpu_write(in_kernel_fpu, false); + + preempt_enable(); +} +EXPORT_SYMBOL_GPL(kernel_fpu_end); |