Function vfp_save_state

freebsd/arm64/arm64/vfp.c:166–200

}

void
vfp_save_state(struct thread *td, struct pcb *pcb)
{
	uint32_t cpacr;

	KASSERT(pcb != NULL, ("NULL vfp pcb"));
	KASSERT(td == NULL || td->td_pcb == pcb, ("Invalid vfp pcb"));

	/* 
	 * savectx() will be called on panic with dumppcb as an argument,
	 * dumppcb doesn't have pcb_fpusaved set, so set it to save
	 * the VFP registers.
	 */
	if (pcb->pcb_fpusaved == NULL)
		pcb->pcb_fpusaved = &pcb->pcb_fpustate;

	if (td == NULL)
		td = curthread;

	critical_enter();
	/*
	 * Only store the registers if the VFP is enabled,
	 * i.e. return if we are trapping on FP access.
	 */
	cpacr = READ_SPECIALREG(cpacr_el1);
	if ((cpacr & CPACR_FPEN_MASK) == CPACR_FPEN_TRAP_NONE) {
		KASSERT(PCPU_GET(fpcurthread) == td,
		    ("Storing an invalid VFP state"));

		vfp_store(pcb->pcb_fpusaved);
		dsb(ish);
		vfp_disable();
	}
	critical_exit();
}

void
vfp_restore_state(void)