Re: [PATCH] m68k: mm: Remove check for VM_IO to fix deferred I/O

Finn Thain
2022-01-28T23:55:37Z

On Sat, 29 Jan 2022, Michael Schmitz wrote:

> Hi Geert,
>
> for hwregs_present(), the exception fixup will handle any access error
> (through send_fault_sig()), so this should continue to work.
>
> Why the special handling of VM_IO pages? Maybe hp300 had marked all IO
> register pages VM_IO to distinguish IO faults from VM faults...
>
> The only other area I can imagine this might have an impact is the Mac's
> pseudo-DMA - FInn might want to give this some testing.
>

mac_scsi.c and mac_esp.c don't use ioremap(). They rely on head.S:

mmu_map_eq #0x50000000,#0x03000000,%d3

Having said that, I will run some tests if you still think it necessary.