On Tue, Nov 10, 2020 at 07:33:53AM +0100, Rouven Czerwinski wrote: > On Mon, 2020-11-09 at 14:52 +0100, Lucas Stach wrote: > > Am Montag, den 09.11.2020, 14:44 +0100 schrieb Rouven Czerwinski: > > > Annotate the different read and write functions with > > > zero_page_{access/faulting}. This allows the cfi_flash driver to be used > > > on the QEMU virt machine with an enabled MMU. > > > > I don't like this zero-page access allow in a driver at all. If you > > have some free address space somewhere, you could also solve this issue > > by remapping the IO resource to somewhere else in the address space, > > deviating from the 1:1 mapping. The Tegra PCIe host driver does this, > > if you need some inspiration. > > I totally agree, remapping the IO region sounds like a much better > choice. But where should it be mapped to? Just 4k upwards and hope that the area just above the cfi flash isn't occupied by something else? Sascha -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox