linuxppc_2_4_devel patch for 745x cache invalidate (in bootwrapper)

Mark A. Greer mgreer at
Thu Feb 20 04:23:34 EST 2003

Well, its Wednesday and no responses so...Tom, would you push this please.


Mark A. Greer wrote:

> There are some differences in the L2CR register between the 75x/74x0 and
> the 745x processors that weren't accounted for in the arch/ppc/boot/...
> bootwrapper code.  Also, there was no bootwrapper code to turn off L3
> cache on 745x processors.
> The attached patch does the following:
> a) Modify arch/ppc/boot/common/util.S:_setup_L2CR to poll on the proper
> bit when doing an L2 global invalidate.  On 75x & 74x0 processors, that
> means polling the L2IP bit; on 745x processors, that means polling on
> the L2I bit.  BTW, the code is already correct in arch/ppc/kernel/l2cr.S.
> b) Add arch/ppc/boot/common/util.S:_setup_l3CR routine which turns off
> L3 cache and does a global invalidate on it.
> c) Modify arch/ppc/boot/simple/head.S:start_ to call _setup_L3CR if
> running on a 745x processor.  This is #ifdef'd out for all platforms
> except CONFIG_FORCE, CONFIG_K2, CONFIG_EV64260, and CONFIG_PAL4--the
> #ifdef was already there.
> This patch has been successfully tested on a few platforms inside
> MontaVista.  However, those of you that use the bootwrapper on 745x
> platforms may want to test it as well.  If you do test it, please
> respond to this email with your results.  If there are no responses by
> mid-week next week, say, I will assume the patch is fine and ask that it
> get applied to the public linuxppc_2_4_devel source.
> Thanks,
> Mark

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