From: Benjamin Herrenschmidt Date: Thu, 16 Jul 2009 19:36:57 +0000 (+0000) Subject: powerpc: Remove use of a second scratch SPRG in STAB code X-Git-Tag: v2.6.32-rc1~675^2~114 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c5a8c0c99f67ae8a784faafbaaea1529825796e2;p=pandora-kernel.git powerpc: Remove use of a second scratch SPRG in STAB code The STAB code used on Power3 and RS/64 uses a second scratch SPRG to save a GPR in order to decide whether to go to do_stab_bolted_* or to handle a normal data access exception. This prevents our scheme of freeing SPRG3 which is user visible for user uses since we cannot use SPRG0 which, on RS/64, seems to be read-only for supervisor mode (like POWER4). This reworks the STAB exception entry to use the PACA as temporary storage instead. Signed-off-by: Benjamin Herrenschmidt --- Reading git-diff-tree failed