iounmap_fixed() had a couple of bugs in it that caused it to effectively
fail at life. The total number of pages to unmap factored in the mapping
offset and aligned up to the next page boundary, which doesn't match the
ioremap_fixed() behaviour.
When ioremap_fixed() pegs a slot, the address in the mapping data already
contains the offset displacement, and the size is recorded verbatim given
that we're only interested in total number of pages required. As such, we
need to calculate the total number from the original size in the unmap
path as well.
At the same time, there was also an off-by-1 problem in the fixmap index
calculation which has also been corrected.
Previously subsequent remaps of an identical fixmap index would trigger
the pte_ERROR() in set_pte_phys():
arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506).
arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506).
arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506).
arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506).
arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506).
arch/sh/mm/init.c:77: bad pte 8053ffb0(0000781003fff506).
With this patch in place, the iounmap-driven fixmap teardown actually
does what it's supposed to do.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This is already taken care of in the top-level ioremap, and now that
no one should be calling ioremap_fixed() directly we can simply throw the
mapping displacement in as an additional argument.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
This converts iounmap_fixed() to return success/error if it handled the
unmap request or not. At the same time, drop the __init label, as this
can be called in to later.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Some devices need to be ioremap'd and accessed very early in the boot
process. It is not possible to use the standard ioremap() function in
this case because that requires kmalloc()'ing some virtual address space
and kmalloc() may not be available so early in boot.
This patch provides fixmap mappings that allow physical address ranges
to be remapped into the kernel address space during the early boot
stages.
Signed-off-by: Matt Fleming <matt@console-pimps.org>
Paul Mundt