On Mon, 2014-04-28 at 19:50 +0100, Marc Zyngier wrote: > Commit d57c33c5daa4 (add generic fixmap.h) added (among other > similar things) set_fixmap_io to deal with early ioremap of devices. > > More recently, commit bf4b558eba92 (arm64: add early_ioremap support) > converted the arm64 earlyprintk to use set_fixmap_io. A side effect of > this conversion is that my virtual machines have stopped booting when > I pass "earlyprintk=uart8250-8bit,0x3f8" to the guest kernel. > > Turns out that the new earlyprintk code doesn't care at all about > sub-page offsets, and just assumes that the earlyprintk device will > be page-aligned. Obviously, that doesn't play well with the above example. > > Further investigation shows that set_fixmap_io uses __set_fixmap instead > of __set_fixmap_offset. A fix is to introduce a set_fixmap_offset_io that > uses the latter, and to remove the superflous call to fix_to_virt > (which only returns the value that set_fixmap_io has already given us). > > With this applied, my VMs are back in business. Tested on a Cortex-A57 > platform with kvmtool as platform emulation. > > Cc: Mark Salter <msal...@redhat.com> > Cc: Catalin Marinas <catalin.mari...@arm.com> > Cc: Will Deacon <will.dea...@arm.com> > Signed-off-by: Marc Zyngier <marc.zyng...@arm.com> > ---
Acked-by: Mark Salter <msal...@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
