1. This is a mistake in LS1028ARM, there is no this section "The GPIO module as implemented on the chip".
2. The base addresses of these 3 sets are different.
GPIO1 base address: 230_0000h
GPIO2 base address: 231_0000h
GPIO3 base address: 232_0000h
You can use GPIO1_DAT0 and GPIO2_DAT0 simultaneously.