The PMB initialization code walks the entries and synchronizes the
software PMB state with the hardware mappings, preserving the slot index.
Unfortunately pmb_alloc() only tested the bit position in the entry map
and failed to set it, resulting in subsequent remaps being able to be
dynamically assigned a slot that trampled an existing boot mapping with
general badness ensuing.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This splits out the uncached mapping support under its own config option,
presently only used by 29-bit mode and 32-bit + PMB. This will make it
possible to optionally add an uncached mapping on sh64 as well as booting
without an uncached mapping for 32-bit.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This kills off the deprected fixed memory range accessors for
the cases of non-translatable ioremapping.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The old ctrl in/out routines are non-portable and unsuitable for
cross-platform use. While drivers/sh has already been sanitized, there
is still quite a lot of code that is not. This converts the arch/sh/ bits
over, which permits us to flag the routines as deprecated whilst still
building with -Werror for the architecture code, and to ensure that
future users are not added.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Now that cached_to_uncached works as advertized in 32-bit mode and we're
never going to be able to map < 16MB anyways, there's no need for the
special uncached section. Kill it off.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This provides a variable for tracking the uncached mapping size, and uses
it for pretty printing the uncached lowmem range. Beyond this, we'll also
be building on top of this for figuring out from where the remainder of
P2 becomes usable when constructing unrelated mappings.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This cribs the pretty printing from arch/x86/mm/init_32.c to dump the
virtual memory layout on boot. This is primarily intended as a debugging
aid, given that the newer CPUs have full control over their address space
and as such have little to nothing in common with the legacy layout.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

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: NPaul Mundt <lethal@linux-sh.org>

Presently __in_29bit_mode() is only defined for the PMB case, but
it's also easily derived from the CONFIG_29BIT and CONFIG_32BIT &&
CONFIG_PMB=n cases.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the build bails with the following:

  CC      arch/sh/mm/alignment.o
cc1: warnings being treated as errors
arch/sh/mm/alignment.c: In function 'unaligned_fixups_notify':
arch/sh/mm/alignment.c:69: warning: cast to pointer from integer of different size
arch/sh/mm/alignment.c:74: warning: cast to pointer from integer of different size
make[2]: *** [arch/sh/mm/alignment.o] Error 1

This is due to the fact that regs->pc is always 64-bit, while the pointer size
depends on the ABI. Wrapping through instruction_pointer() takes care of the
appropriate casting for both configurations.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The plans for _PAGE_WIRED were detailed in a comment with the fixmap
code, but as it's now all taken care of, we no longer have any reason for
keeping it around, particularly since it's no longer accurate. Kill it
off.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently this is duplicated between tlb-sh4 and tlb-pteaex. Split the
helpers out in to a generic tlb-urb that can be used by any parts
equipped with MMUCR.URB.

At the same time, move the SH-5 code out-of-line, as we require single
global state for DTLB entry wiring.
Signed-off-by: NPaul 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: NPaul Mundt <lethal@linux-sh.org>

Presently 'flags' gets passed around a lot between the various ioremap
helpers and implementations, which is only 32-bits. In the X2TLB case
we use 64-bit pgprots which presently results in the upper 32bits being
chopped off (which handily include our read/write/exec permissions).

As such, we convert everything internally to using pgprot_t directly and
simply convert over with pgprot_val() where needed. With this in place,
transparent fixmap utilization for early ioremap works as expected.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The mem_init_done test makes sure that this path is only entered in
__init cases, so leaving ioremap_fixed() as __init and flagging the
caller __init_refok is sufficient.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

iounmap() should balance whatever is done by ioremap(). Presently
ioremap() can do any of fixed mappings, PMB mappings, or page table
mappings. Presently only the latter two are handled through the standard
unmap path, so tie in the fixed unmapping, too.
Signed-off-by: NPaul 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: NPaul Mundt <lethal@linux-sh.org>

There is nothing of interest in the _64 version anymore, so the _32 one
can be renamed and used unconditionally.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds in a mem_init_done to work out when a standard ioremap() is
possible, falling back to the fixmap based ioremap otherwise.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

More and more boards are going to start shipping that boot with the MMU
in 32BIT mode by default. Previously we relied on the bootloader to
setup PMB mappings for use by the kernel but we also need to cater for
boards whose bootloaders don't set them up.

If CONFIG_PMB_LEGACY is not enabled we have full control over our PMB
mappings and can compress our address space. Usually, the distance
between the the cached and uncached mappings of RAM is always 512MB,
however we can compress the distance to be the amount of RAM on the
board.

pmb_init() now becomes much simpler. It no longer has to calculate any
mappings, it just has to synchronise the software PMB table with the
hardware.

Tested on SDK7786 and SH7785LCR.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This tidies up the iounmap path with consolidated checks for
nontranslatable mappings. This is in preparation of unifying
the implementations.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Use the fixmap-based memory mapping implementation for SH-5's ioremap()
functions and delete the old static allocator that was borrowed from
sparc.
Signed-off-by: NMatt Fleming <matt@console-pimps.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: NMatt Fleming <matt@console-pimps.org>

Generalise the code for setting and clearing pte's and allow TLB entries
to be pinned and unpinned if the _PAGE_WIRED flag is present.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>

We need some more page flags to hook up _PAGE_WIRED (and eventually
other things). So use the unused PTE bits above the PPN field as no
implementations use these for anything currently.

Now that we have _PAGE_WIRED let's provide the SH-5 functions for wiring
up TLB entries.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>

Provide a new extended page flag, _PAGE_WIRED and an SH4 implementation
for wiring TLB entries and use it in the fixmap code path so that we can
wire the fixmap TLB entry.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>

flush_cache_all() gets called in to when we do some early ioremapping.
Unfortunately on SDK7786 the interrupt controller itself requires
ioremapping, leading to a bit of a chicken and egg scenario. For now,
don't bother with IPI crosscalls if there aren't any other CPUs online.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

All SH-X2 and SH-X3 parts support an extended TLB mode, which has been
left as experimental since support was originally merged. Now that it's
had some time to stabilize and get some exposure to various platforms,
we can drop it as an option and default enable it across the board.

This is also good future proofing for newer parts that will drop support
for the legacy TLB mode completely.

This will also force 3-level page tables for all newer parts, which is
necessary both for the varying page sizes and larger memories.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This introduces some much overdue chainsawing of the fixed PMB support.
fixed PMB was introduced initially to work around the fact that dynamic
PMB mode was relatively broken, though they were never intended to
converge. The main areas where there are differences are whether the
system is booted in 29-bit mode or 32-bit mode, and whether legacy
mappings are to be preserved. Any system booting in true 32-bit mode will
not care about legacy mappings, so these are roughly decoupled.

Regardless of the entry point, PMB and 32BIT are directly related as far
as the kernel is concerned, so we also switch back to having one select
the other.

With legacy mappings iterated through and applied in the initialization
path it's now possible to finally merge the two implementations and
permit dynamic remapping overtop of remaining entries regardless of
whether boot mappings are crafted by hand or inherited from the boot
loader.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the thread_info allocators are special cased, depending on
THREAD_SHIFT < PAGE_SHIFT. This provides a sensible definition for them
regardless of configuration, in preparation for extended CPU state.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This splits out the unaligned access counters and userspace bits in to
their own generic interface, which will allow them to be wired up on sh64
too.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

pgtable_cache_init() has been moved out-of-line, so we also need a dummy
definition for it on nommu to fix up the build.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This has the adverse effect of converting many 29bit configs to 32bit
mode, while this is a change that needs to be done manually for each
platform. Turn it off by default in order to cut down on spurious bug
reports.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

While the PMB is available on SH-4A parts, SH4AL-DSP parts exclude it
altogether. As such, explicitly disable PMB support for these parts. If
this changes in the future for newer subtypes, this will have to be made
more fine-grained.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

We also switched away from quicklists and instead moved to slab
caches. After benchmarking both implementations the difference is
negligible. The slab caches suit us better though because the size of a
pgd table is just 4 entries when we're using a 3-level page table layout
and quicklists always deal with pages.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>

If the page is not mapped into any process's address space then aliases
cannot exist in the cache. So reduce the amount of flushing we perform.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>

The previous expressions were wrong which made free_pmd_range() explode
when using anything other than 4KB pages (which is why 8KB and 64KB
pages were disabled with the 3-level page table layout).

The problem was that pmd_offset() was returning an index of non-zero
when it should have been returning 0. This non-zero offset was used to
calculate the address of the pmd table to free in free_pmd_range(),
which ended up trying to free an object that was not aligned on a page
boundary.

Now 3-level page tables should work with 4KB, 8KB and 64KB pages.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>

With some of the cache rework an address aliasing optimization was added,
but this managed to fail on certain mappings resulting in pages with
PG_dcache_dirty set never writing back their dcache lines. This patch
reverts to the earlier behaviour of simply always writing back when the
dirty bit is set.
Signed-off-by: NMarkus Pietrek <Markus.Pietrek@emtrion.de>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

If using 64-bit PTEs and 4K pages then each page table has 512 entries
(as opposed to 1024 entries with 32-bit PTEs). Unlike MIPS, SH follows
the convention that all structures in the page table (pgd_t, pmd_t,
pgprot_t, etc) must be the same size. Therefore, 64-bit PTEs require
64-bit PGD entries, etc. Using 2-levels of page tables and 64-bit PTEs
it is only possible to map 1GB of virtual address space.

In order to map all 4GB of virtual address space we need to adopt a
3-level page table layout. This actually works out better for
CONFIG_SUPERH32 because we only waste 2 PGD entries on the P1 and P2
areas (which are untranslated) instead of 256.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This wires up the caller information for the ioremap VMA, which allows
for more helpful caller tracking via /proc/vmallocinfo. Follows the x86
and powerpc changes of the same nature.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>