On Tue, 18 Dec 2001, Jim Paris wrote: > The ports are dealt with by /proc/ioports. What about /proc/iomem? > The ISA ports and ISA memory are seperate, and the ports work fine and > just as I would expect them to. But for memory, where should the > PCMCIA driver be reserving space? Should I > 1) make /proc/iomem contain addresses relative to the start of I/O memory, > just as /proc/ioports contains addresses relative to the start of > I/O port space? This will only work if I stop letting the kernel > reserve the iomem resource for system memory. There should probably be an ISA memory space reserved somewhere in the CPU memory space (/proc/iomem reflects memory addresses as seen by the CPU). You should reserve resources within it. There should be an ISA I/O space reserved somewhere in /proc/iomem, too, as the I/O space is real only for CPUs defining special bus cycles for I/O accesses (MIPS is not one of them, hence it must be done by the chipset). The /proc/ioports reports addresses relative to that space. > 2) make the i82365 driver use absolute addresses in /proc/iomem, by > adding (isa_slot_offset - KSEG1) to all *_mem_resource calls? > (breaks i82365 for other arches) Mapping between physical addresses and MIPS virtual addresses (KSEG1 is a virtual address) should be done by bus access functions (or macros), such as inb/outb/readl/readw/isa_readb/isa_readw, etc. See the Alpha port for how it should be done. It appears to have done it particularly cleanly. > 3) Invent a new resource "isamem", reserve the correct absolute > addresses in "iomem", and the modify the i82365 driver to use > "isamem" instead? (again breaks i82365 for other arches) Don't do it. > Given the current way the I/O memory is handled on MIPS, the only way > I can get the i82365 driver working breaks it for every other arch. Then the MIPS I/O memory handling is broken. -- + Maciej W. Rozycki, Technical University of Gdansk, Poland + +--------------------------------------------------------------+ + e-mail: macro@ds2.pg.gda.pl, PGP key available +
