Function fpu_kern_leave

freebsd/arm64/arm64/vfp.c:317–357

}

int
fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx)
{
	struct pcb *pcb;

	pcb = td->td_pcb;

	if ((pcb->pcb_fpflags & PCB_FP_NOSAVE) != 0) {
		KASSERT(ctx == NULL, ("non-null ctx after FPU_KERN_NOCTX"));
		KASSERT(PCPU_GET(fpcurthread) == NULL,
		    ("non-NULL fpcurthread for PCB_FP_NOSAVE"));
		CRITICAL_ASSERT(td);

		vfp_disable();
		pcb->pcb_fpflags &= ~(PCB_FP_NOSAVE | PCB_FP_STARTED);
		critical_exit();
	} else {
		KASSERT((ctx->flags & FPU_KERN_CTX_INUSE) != 0,
		    ("FPU context not inuse"));
		ctx->flags &= ~FPU_KERN_CTX_INUSE;

		if (is_fpu_kern_thread(0) &&
		    (ctx->flags & FPU_KERN_CTX_DUMMY) != 0)
			return (0);
		KASSERT((ctx->flags & FPU_KERN_CTX_DUMMY) == 0, ("dummy ctx"));
		critical_enter();
		vfp_discard(td);
		critical_exit();
		pcb->pcb_fpflags &= ~PCB_FP_STARTED;
		pcb->pcb_fpusaved = ctx->prev;
	}

	if (pcb->pcb_fpusaved == &pcb->pcb_fpustate) {
		pcb->pcb_fpflags &= ~PCB_FP_KERN;
	} else {
		KASSERT((pcb->pcb_fpflags & PCB_FP_KERN) != 0,
		    ("unpaired fpu_kern_leave"));
	}

	return (0);
}

int
fpu_kern_thread(u_int flags)