Scott Wood <scottw...@freescale.com> wrote on 14/10/2009 19:20:03: > > On Sun, Oct 11, 2009 at 06:35:08PM +0200, Joakim Tjernlund wrote: > > This is an assembler version to fixup DAR not being set > > by dcbX, icbi instructions. There are two versions, one > > uses selfmodifing code, the other uses a > > jump table but is much bigger(default). > > --- > > arch/powerpc/kernel/head_8xx.S | 146 > > +++++++++++++++++++++++++++++++++++++++- > > 1 files changed, 145 insertions(+), 1 deletions(-) > > > > diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S > > index 093176c..9839e79 100644 > > --- a/arch/powerpc/kernel/head_8xx.S > > +++ b/arch/powerpc/kernel/head_8xx.S > > @@ -494,7 +494,8 @@ DataTLBError: > > > > mfspr r10, SPRN_DAR > > cmpwi cr0, r10, 0x00f0 > > - beq- 2f /* must be a buggy dcbX, icbi insn. */ > > + beq- FixDAR /* must be a buggy dcbX, icbi insn. */ > > +DARFix: /* Return from dcbx instruction bug workaround, r10 holds value > > of DAR */ > > Both FixDAR and DARFix? Could we make the labels a little clearer?
Yes, need to come up with better names :) > > > +/* This is the procedure to calculate the data EA for buggy dcbx,dcbi > > instructions > > + * by decoding the registers used by the dcbx instruction and adding them. > > + * DAR is set to the calculated address and r10 also holds the EA on exit. > > + */ > > How often does this happen? Could we just do it in C code after saving all > the registers, and avoid the self modifying stuff (or the big switch > statement equivalent)? I had some problems with the C-version. I got lots of extra TLB errors for the same address so I am not confident it will work in the long run. BTW, you could add a test and printk in do_page_fault on address 0x000000f0. if that ever hits there is a problem with dcbX fixup. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
