From: Maciej W. Rozycki Date: Mon, 23 Sep 2013 13:01:53 +0000 (+0100) Subject: MIPS: Tell R4k SC and MC variations apart X-Git-Tag: omap-for-v3.13/fixes-for-merge-window-take2~57^2~27 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7f177a52a13e3d3751b599ae2b46d3d4658985cd;p=pandora-kernel.git MIPS: Tell R4k SC and MC variations apart There is no reliable way to tell R4000/R4400 SC and MC variations apart, however simple heuristic should give good results. Only the MC version supports coherent caching so we can rely on such a mode having been set for KSEG0 by the power-on firmware to reliably indicate an MC processor. SC processors reportedly hang on coherent cached memory accesses and Linux is linked to a cached load address so the firmware has to use the correct caching mode to download the kernel image in a cached mode successfully. OTOH if the firmware chooses to use either the non-coherent cached or the uncached mode for KSEG0 on an MC processor, then the SC variant will be reported, just as we currently do, so no regression here. Signed-off-by: Maciej W. Rozycki Cc: Jonas Gorski Cc: MIPS Mailing List Patchwork: https://patchwork.linux-mips.org/patch/5882/ Signed-off-by: Ralf Baechle --- Reading git-diff-tree failed