PCI_IO_SIZE        24 arch/arm64/include/asm/memory.h #define PCI_IO_SIZE		SZ_16M
PCI_IO_SIZE       123 arch/m68k/include/asm/io_no.h #define PCI_IO_SIZE	0x00010000		/* 64k */
PCI_IO_SIZE        90 arch/riscv/include/asm/pgtable.h #define PCI_IO_SIZE      SZ_16M