[parisc-linux] use of (*PAGE0->mem_pdc)()

[Frank Rowand <frank_rowand@hp.com>]

Ryan Bradetich wrote:

< stuff deleted >

> [Taken from arch/parisc/kernel/realmode_setup.c]
> 
>  /* This whole VM setup stuff may be removed ultimately.  It seems
>    * to me that once the TLB miss handlers are ready, we just switch
>    * to VM and let them handle TLB population -PB
>    */
> 
>   pret = (*PAGE0->mem_pdc)(
>   PDC_BLOCK_TLB,
>   PDC_BTLB_INSERT,


A comment that is totally unrelated to the question Ryan was asking...

I would recommend that we quit using the pointer to PDCE_PROC() that
is in page zero, because the newer machines have a PDC procedure,
PDC_RELOCATE(), that copies PDCE_PROC into real memory, where it
executes much faster.  The page zero pointer to PDCE_PROC() is not
updated by PDC_RELOCATE(), but instead a pointer to the in-memory
PDCE_PROC() is returned.

I recommend using a global variable to hold the pointer to PDCE_PROC(),
which would be the value from page zero initially, then updated to
the value returned by PDC_RELOCATE().

-Frank