From: Greentime Hu <greentime.hu@xxxxxxxxxx> This patch adds task switch support for vector. It also supports all lengths of vlen. Suggested-by: Andrew Waterman <andrew@xxxxxxxxxx> Co-developed-by: Nick Knight <nick.knight@xxxxxxxxxx> Signed-off-by: Nick Knight <nick.knight@xxxxxxxxxx> Co-developed-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx> Co-developed-by: Vincent Chen <vincent.chen@xxxxxxxxxx> Signed-off-by: Vincent Chen <vincent.chen@xxxxxxxxxx> Co-developed-by: Ruinland Tsai <ruinland.tsai@xxxxxxxxxx> Signed-off-by: Ruinland Tsai <ruinland.tsai@xxxxxxxxxx> Signed-off-by: Greentime Hu <greentime.hu@xxxxxxxxxx> Signed-off-by: Vineet Gupta <vineetg@xxxxxxxxxxxx> Signed-off-by: Andy Chiu <andy.chiu@xxxxxxxxxx> Reviewed-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx> Reviewed-by: Björn Töpel <bjorn@xxxxxxxxxxxx> --- 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 | 18 +++++++++++++ 5 files changed, 63 insertions(+) diff --git a/arch/riscv/include/asm/processor.h b/arch/riscv/include/asm/processor.h index 94a0590c6971..f0ddf691ac5e 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 4b96b13dee27..a727be723c56 100644 --- a/arch/riscv/include/asm/switch_to.h +++ b/arch/riscv/include/asm/switch_to.h @@ -8,6 +8,7 @@ #include <linux/jump_label.h> #include <linux/sched/task_stack.h> +#include <asm/vector.h> #include <asm/hwcap.h> #include <asm/processor.h> #include <asm/ptrace.h> @@ -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 f704c8dd57e0..9e28c0199030 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -80,6 +80,9 @@ 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 cb60637443be..4161352d6ea8 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -11,6 +11,9 @@ #ifdef CONFIG_RISCV_ISA_V #include <linux/stringify.h> +#include <linux/sched.h> +#include <linux/sched/task_stack.h> +#include <asm/ptrace.h> #include <asm/hwcap.h> #include <asm/csr.h> #include <asm/asm.h> @@ -123,6 +126,38 @@ 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; @@ -131,6 +166,9 @@ 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_setup_vsize() do {} while (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 774ffde386ab..44ca0be58ce7 100644 --- a/arch/riscv/kernel/process.c +++ b/arch/riscv/kernel/process.c @@ -24,6 +24,7 @@ #include <asm/switch_to.h> #include <asm/thread_info.h> #include <asm/cpuidle.h> +#include <asm/vector.h> register unsigned long gp_in_global __asm__("gp"); @@ -147,12 +148,28 @@ 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; } @@ -185,6 +202,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args) childregs->a0 = 0; /* Return value of fork() */ p->thread.ra = (unsigned long)ret_from_fork; } + riscv_v_vstate_off(childregs); p->thread.sp = (unsigned long)childregs; /* kernel sp */ return 0; } -- 2.17.1