diff options
author | Greentime Hu <greentime.hu@sifive.com> | 2024-01-15 05:59:20 +0000 |
---|---|---|
committer | Palmer Dabbelt <palmer@rivosinc.com> | 2024-01-16 07:13:53 -0800 |
commit | ecd2ada8a5e0b464dab54f71d4ba7bbf5708711f (patch) | |
tree | 23dd7e28a56871c4286f8dd07bb1bf5dbda14e18 /arch/riscv/include/asm | |
parent | b85ea95d086471afb4ad062012a4d73cd328fa86 (diff) |
riscv: Add support for kernel mode vector
Add kernel_vector_begin() and kernel_vector_end() function declarations
and corresponding definitions in kernel_mode_vector.c
These are needed to wrap uses of vector in kernel mode.
Co-developed-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Signed-off-by: Greentime Hu <greentime.hu@sifive.com>
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Tested-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20240115055929.4736-2-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Diffstat (limited to 'arch/riscv/include/asm')
-rw-r--r-- | arch/riscv/include/asm/processor.h | 12 | ||||
-rw-r--r-- | arch/riscv/include/asm/simd.h | 44 | ||||
-rw-r--r-- | arch/riscv/include/asm/vector.h | 9 |
3 files changed, 64 insertions, 1 deletions
diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index f19f861cda54..4809f20a2053 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -73,6 +73,15 @@ struct task_struct; struct pt_regs; +/* + * We use a flag to track in-kernel Vector context. Currently the flag has the + * following meaning: + * + * - bit 0: indicates whether the in-kernel Vector context is active. The + * activation of this state disables the preemption. + */ +#define RISCV_KERNEL_MODE_V 0x1 + /* CPU-specific state of a task */ struct thread_struct { /* Callee-saved registers */ @@ -81,7 +90,8 @@ struct thread_struct { unsigned long s[12]; /* s[0]: frame pointer */ struct __riscv_d_ext_state fstate; unsigned long bad_cause; - unsigned long vstate_ctrl; + u32 riscv_v_flags; + u32 vstate_ctrl; struct __riscv_v_ext_state vstate; unsigned long align_ctl; }; diff --git a/arch/riscv/include/asm/simd.h b/arch/riscv/include/asm/simd.h new file mode 100644 index 000000000000..ef8af413a9fc --- /dev/null +++ b/arch/riscv/include/asm/simd.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2017 Linaro Ltd. <ard.biesheuvel@linaro.org> + * Copyright (C) 2023 SiFive + */ + +#ifndef __ASM_SIMD_H +#define __ASM_SIMD_H + +#include <linux/compiler.h> +#include <linux/irqflags.h> +#include <linux/percpu.h> +#include <linux/preempt.h> +#include <linux/types.h> + +#include <asm/vector.h> + +#ifdef CONFIG_RISCV_ISA_V +/* + * may_use_simd - whether it is allowable at this time to issue vector + * instructions or access the vector register file + * + * Callers must not assume that the result remains true beyond the next + * preempt_enable() or return from softirq context. + */ +static __must_check inline bool may_use_simd(void) +{ + /* + * RISCV_KERNEL_MODE_V is only set while preemption is disabled, + * and is clear whenever preemption is enabled. + */ + return !in_hardirq() && !in_nmi() && !(riscv_v_flags() & RISCV_KERNEL_MODE_V); +} + +#else /* ! CONFIG_RISCV_ISA_V */ + +static __must_check inline bool may_use_simd(void) +{ + return false; +} + +#endif /* ! CONFIG_RISCV_ISA_V */ + +#endif diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 87aaef656257..71af3404fda1 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -22,6 +22,15 @@ extern unsigned long riscv_v_vsize; int riscv_v_setup_vsize(void); bool riscv_v_first_use_handler(struct pt_regs *regs); +void kernel_vector_begin(void); +void kernel_vector_end(void); +void get_cpu_vector_context(void); +void put_cpu_vector_context(void); + +static inline u32 riscv_v_flags(void) +{ + return current->thread.riscv_v_flags; +} static __always_inline bool has_vector(void) { |