static inline void write_desc(struct intel_engine_execlists *execlists, u64 desc, u32 port)
{
	if (execlists->ctrl_reg) {
		writel(lower_32_bits(desc), execlists->submit_reg + port * 2);
		writel(upper_32_bits(desc), execlists->submit_reg + port * 2 + 1);
	} else {
		writel(upper_32_bits(desc), execlists->submit_reg);
		writel(lower_32_bits(desc), execlists->submit_reg);
	}
}