On Mon, Mar 22, 2010 at 03:59:18PM +0100, Ralf Baechle wrote: > On Sun, Mar 21, 2010 at 12:02:41PM +0100, Sebastian Andrzej Siewior wrote: > > > Since commit 656be92f aka "Load modules to CKSEG0 if > > CONFIG_BUILD_ELF64=n" module support is broken on 64bit. Since then > > modules arr loaded into 32bit compat adresses which are sign extended > > 64bit addresses. The SiByte war handler was not updated and those > > addresses were not recognized by the TLB hadling. > > This patch fixes this by shifting away the upper bits including the R > > and Fill bits. Now we compare VPN2 of C0_ENTRYHI against the matching > > bits at C0_BADVADDR. > > Good detective work but I'll check against the errata documents (which > are non-public, sigh ...) before applying your patch. > > The M3 workaround in which you found this bug is currently applied to all > Sibyte SB1 cores while probably only a relativly small number of the cores > in circulation are affected so we should refine the workaround to be only > applied if the System Revision Register indicates a system older than > revision C0. This could get rid of 6 instructions which according to the > usual rule of thumb would result in a speedup of ~ 3%. I've just committed a patch on the master branch to handle this issue. On cores that are not affected by the M3 bug this also fixes the module issue. Ralf
