The previous implementation of clear_user_highpage and copy_user_highpage
checked to see if there was a D-cache aliasing issue between the user
and kernel mappings of a page, but if there was they always did a
flush with writeback on the dirtied kernel alias.
However as we now have the ability to map a page into kernel space
with the same cache colour as the user mapping, there is no need to
write back this data.
Currently we also invalidate the kernel alias as a precaution, however
I'm not sure if this is actually required.
Also correct the definition of FIX_CMAP_END so that the mappings created
by kmap_coherent() are actually at the correct colour.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
In the SMP VIPT case the page copy/clear ops still perform colouring,
care needs to be taken that CPUs don't end up stepping on each other,
so we give them a bit of room to work with.
At the same time, we reduce the worst-case colouring given that these
pages are always consumed.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This follows the sparc changes a439fe51a1.
Most of the moving about was done with Sam's directions at:
http://marc.info/?l=linux-sh&m=121724823706062&w=2
with subsequent hacking and fixups entirely my fault.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Stuart Menefy