From 3a2df6323defbb42234aaae804a8ad6af397016a Mon Sep 17 00:00:00 2001 From: Greentime Hu Date: Mon, 5 Jun 2023 11:07:07 +0000 Subject: [PATCH] riscv: Add task switch support for vector MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman Co-developed-by: Nick Knight Signed-off-by: Nick Knight Co-developed-by: Guo Ren Signed-off-by: Guo Ren Co-developed-by: Vincent Chen Signed-off-by: Vincent Chen Co-developed-by: Ruinland Tsai Signed-off-by: Ruinland Tsai Signed-off-by: Greentime Hu Signed-off-by: Vineet Gupta Signed-off-by: Andy Chiu Reviewed-by: Conor Dooley Reviewed-by: Björn Töpel Reviewed-by: Heiko Stuebner Tested-by: Heiko Stuebner Link: https://lore.kernel.org/r/20230605110724.21391-11-andy.chiu@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/processor.h | 1 + arch/riscv/include/asm/switch_to.h | 3 +++ arch/riscv/include/asm/thread_info.h | 3 +++ arch/riscv/include/asm/vector.h | 38 ++++++++++++++++++++++++++++++++++++ arch/riscv/kernel/process.c | 19 ++++++++++++++++++ 5 files changed, 64 insertions(+) diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 94a0590..f0ddf69 100644 --- a/arch/riscv/include/asm/processor.h +++ b/arch/riscv/include/asm/processor.h @@ -39,6 +39,7 @@ struct thread_struct { unsigned long s[12]; /* s[0]: frame pointer */ struct __riscv_d_ext_state fstate; unsigned long bad_cause; + struct __riscv_v_ext_state vstate; }; /* Whitelist the fstate from the task_struct for hardened usercopy */ diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h index 4b96b13..a727be7 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -8,6 +8,7 @@ #include #include +#include #include #include #include @@ -78,6 +79,8 @@ do { \ struct task_struct *__next = (next); \ if (has_fpu()) \ __switch_to_fpu(__prev, __next); \ + if (has_vector()) \ + __switch_to_vector(__prev, __next); \ ((last) = __switch_to(__prev, __next)); \ } while (0) diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index e0d2021..97e6f65 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -81,6 +81,9 @@ struct thread_info { .preempt_count = INIT_PREEMPT_COUNT, \ } +void arch_release_task_struct(struct task_struct *tsk); +int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); + #endif /* !__ASSEMBLY__ */ /* diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index 3c29f4e..ce6a75e 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -12,6 +12,9 @@ #ifdef CONFIG_RISCV_ISA_V #include +#include +#include +#include #include #include #include @@ -124,6 +127,38 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_ riscv_v_disable(); } +static inline void riscv_v_vstate_save(struct task_struct *task, + struct pt_regs *regs) +{ + if ((regs->status & SR_VS) == SR_VS_DIRTY) { + struct __riscv_v_ext_state *vstate = &task->thread.vstate; + + __riscv_v_vstate_save(vstate, vstate->datap); + __riscv_v_vstate_clean(regs); + } +} + +static inline void riscv_v_vstate_restore(struct task_struct *task, + struct pt_regs *regs) +{ + if ((regs->status & SR_VS) != SR_VS_OFF) { + struct __riscv_v_ext_state *vstate = &task->thread.vstate; + + __riscv_v_vstate_restore(vstate, vstate->datap); + __riscv_v_vstate_clean(regs); + } +} + +static inline void __switch_to_vector(struct task_struct *prev, + struct task_struct *next) +{ + struct pt_regs *regs; + + regs = task_pt_regs(prev); + riscv_v_vstate_save(prev, regs); + riscv_v_vstate_restore(next, task_pt_regs(next)); +} + #else /* ! CONFIG_RISCV_ISA_V */ struct pt_regs; @@ -132,6 +167,9 @@ static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } #define riscv_v_vsize (0) +#define riscv_v_vstate_save(task, regs) do {} while (0) +#define riscv_v_vstate_restore(task, regs) do {} while (0) +#define __switch_to_vector(__prev, __next) do {} while (0) #define riscv_v_vstate_off(regs) do {} while (0) #define riscv_v_vstate_on(regs) do {} while (0) diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c index e2a0600..78eb5ac 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -24,6 +24,7 @@ #include #include #include +#include register unsigned long gp_in_global __asm__("gp"); @@ -146,12 +147,28 @@ void flush_thread(void) fstate_off(current, task_pt_regs(current)); memset(¤t->thread.fstate, 0, sizeof(current->thread.fstate)); #endif +#ifdef CONFIG_RISCV_ISA_V + /* Reset vector state */ + riscv_v_vstate_off(task_pt_regs(current)); + kfree(current->thread.vstate.datap); + memset(¤t->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); +#endif +} + +void arch_release_task_struct(struct task_struct *tsk) +{ + /* Free the vector context of datap. */ + if (has_vector()) + kfree(tsk->thread.vstate.datap); } int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { fstate_save(src, task_pt_regs(src)); *dst = *src; + /* clear entire V context, including datap for a new task */ + memset(&dst->thread.vstate, 0, sizeof(struct __riscv_v_ext_state)); + return 0; } @@ -176,6 +193,8 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) p->thread.s[1] = (unsigned long)args->fn_arg; } else { *childregs = *(current_pt_regs()); + /* Turn off status.VS */ + riscv_v_vstate_off(childregs); if (usp) /* User fork */ childregs->sp = usp; if (clone_flags & CLONE_SETTLS) -- 2.7.4