No users for the copy_from_user_page() routine exist outside of the
core kernel code. Therefore, EXPORT_SYMBOL(copy_from_user_page) is
useless, and this patch removes it.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The copy_to_user_page() function is called only in the core kernel
code. Therefore, there is no need to export it. This patch removes
EXPORT_SYMBOL(copy_to_user_page).
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The copy_user_highpage() routine has no users outside of the
core kernel code, so exporting this symbol is pointless.
This patch removes EXPORT_SYMBOL(copy_user_highpage).
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
kmap_coherent will only work correctly if the page it is called on is
not marked dirty. If it's dirty the kernel address of the page should
be used instead of a temporary mapping.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Sibyte SOCs only have 32-bit PCI. Due to the sparse use of the address
space only the first 1GB of memory is mapped at physical addresses
below 1GB. If a system has more than 1GB of memory 32-bit DMA will
not be able to reach all of it.
For now this patch is good enough to keep Sibyte users happy but it seems
eventually something like swiotlb will be needed for Sibyte.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Turns out b868868ae0 wasn't quite right.
When called for a page that isn't marked dirty it would artificially
create an alias instead of doing the obvious thing and access the page
via KSEG0.
The same issue also exists in copy_to_user_page and copy_from_user_page
which was causing the machine to die under rare circumstances for example
when running ps if the BUG_ON() assertion added by the earlier fix was
getting triggered.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Copy_user_highpage was written assuming it was only being called for
breaking COW pages in which case the source page isn't cached as in
marked cachable under it kernel virtual address. If it is called anyway
the aliasing avoidance strategy implemented by kmap_coherent will fail.
Avoid the use of kmap_coherent for pages marked dirty and to avoid
another instance of this sort of bug, place a BUG_ON in kmap_coherent.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
> WARNING: vmlinux.o(.text+0xbf20): Section mismatch: reference to
> .init.text:prom_free_prom_memory (between 'free_initmem' and 'copy_from_user_page')
prom_free_prom_memory() is called _before_ freeing init sections, so
it is false positive. __init_refok can be used for such cases.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This fixes some sparse warnings.
pgtable-32.c:15:6: warning: symbol 'pgd_init' was not declared. Should it be static?
pgtable-32.c:32:13: warning: symbol 'pagetable_init' was not declared. Should it be static?
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This get rid of some undesirable hole in BSS section due to random
order of placement.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch makes a better usage of these two globals.
'min_low_pfn' is now correctly setup for all configs, which
allow us to rely on it in boot memory code init.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Current prom_free_prom_memory() implementations are almost same as
free_init_pages(), or no-op. Make free_init_pages() extern (again)
and make prom_free_prom_memory() use it.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Provide a custom copy_user_highpage() to deal with aliasing issues on
MIPS. It uses kmap_coherent() to map an user page for kernel with same
color. Rewrite copy_to_user_page() and copy_from_user_page() with the
new interfaces to avoid extra cache flushing.
The main part of this patch was originally written by Ralf Baechle;
Atushi Nemoto did the the debugging.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch makes paging_init() use highend_pfn/highstart_pfn globals.
It removes the need of 'high' local which was needed only by HIGHMEM config.
More important perhaps, it fixes a bug when HIGHMEM is set but there's
actually no physical highmem (highend_pfn = 0)
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
