As explained in commit 1c0fe6e3, we want to call the architecture independent
oom killer when getting an unexplained OOM from handle_mm_fault, rather than
simply killing current.

Cc: linux-sh@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Signed-off-by: NNick Piggin <npiggin@suse.de>
Acked-by: NDavid Rientjes <rientjes@google.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This zeroes out the number of cache aliases in the cache info descriptors
when hardware alias avoidance is enabled. This cuts down on the amount of
flushing taken care of by common code, and also permits coherency control
to be disabled for the single CPU and 4k page size case.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This enables support for the hardware synonym avoidance handling on SH-X3
CPUs for the case where dcache aliases are possible. icache handling is
retained, but we flip on broadcasting of the block invalidations due to
the lack of coherency otherwise on SMP.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

While the MMUCR.URB and ITLB/UTLB differentiation works fine for all SH-4
and later TLBs, these features are absent on SH-3. This splits out
local_flush_tlb_all() in to SH-4 and PTEAEX copies while restoring the
old SH-3 one, subsequently fixing up the build.

This will probably want some further reordering and tidying in the
future, but that's out of scope at present.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Export the status of the utlb and itlb entries through debugfs.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently the TLB wiring code depends on MMUCR.URB for working out where
to place the wired entry, but fails to take the replacment counter in to
consideration. This fixes up the wiring logic and ensures that wired
entries remain so.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

set_pmb_entry() is now only used by a function that is wrapped in #ifdef
CONFIG_PM, so wrap set_pmb_entry() in CONFIG_PM too.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Setting the TI in MMUCR causes all the TLB bits in MMUCR to be
cleared. Unfortunately, the TLB wired bits are also cleared when setting
the TI bit, causing any wired TLB entries to become unwired.

Use local_flush_tlb_all() which implements TLB flushing in a safer
manner by using the memory-mapped TLB registers. As each CPU has its own
PMB the modifications in pmb_init() only affect the local CPU, so only
flush the local CPU's TLB.
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

flush_tlb_page() can be used to flush TLB entries that map executable
pages. Therefore, we need to ensure that the ITLB is also flushed in
local_flush_tlb_page().
Signed-off-by: NMatt Fleming <matt@console-pimps.org>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

oprofile and others need to get at these, so provide symbol exports.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The uncached_start was being set up properly for 32-bit but managed to
break 29-bit in the process, fix it up.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

... so the "sh_debugfs_root" is already available. Previously it
wasn't and in result its path was "/sys/kernel/debug/pmb" instead of
"/sys/kernel/debug/sh/pmb".
Signed-off-by: NPawel Moll <pawel.moll@st.com>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Presently we run in to issues with the MMU resetting the CPU when
variable sized mappings are employed. This takes a slightly more
aggressive approach to keeping the TLB and cache state sane before
establishing the mappings in order to cut down on races observed on
SMP configurations.

At the same time, we bump the VMA range up to the 0xb000...0xc000 range,
as there still seems to be some undocumented behaviour in setting up
variable mappings in the 0xa000...0xb000 range, resulting in reset by the
TLB.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

In the case of NUMA emulation when in range PPNs are being used for
secondary nodes, we need to make sure that the PMB has a mapping for it
before setting up the pgdat. This prevents the MMU from resetting.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

When entries are being bolted unconditionally it's possible that the boot
loader has established mappings that are within range that we don't want
to clobber. Perform some basic validation to ensure that the new mapping
is out of range before allowing the entry setup to take place.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This moves the pmb_remap_caller() mapping logic out in to
pmb_bolt_mapping(), which enables us to establish fixed mappings in
places such as the NUMA code.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This plugs in an early_param for permitting transparent PMB-backed
ioremapping to be enabled/disabled. For the time being, we use a
default-disabled policy.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This implements a fairly significant overhaul of the dynamic PMB mapping
code. The primary change here is that the PMB gets its own VMA that
follows the uncached mapping and we attempt to be a bit more intelligent
with dynamic sizing, multi-entry mapping, and so forth.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Since <linux/spinlock.h> already includes <linux/rwlock.h>, and the
latter file will warn about not having included the former file
anyway, there is no value in including rwlock.h explicitly.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This hooks up the SET/GET_UNALIGN_CTL knobs cribbing the bulk of it from
the PPC and ia64 implementations. The thread flags happen to be the
logical inverse of what the global fault mode is set to, so this works
out pretty cleanly. By default the global fault mode is used, with tasks
now being able to override their own settings via prctl().
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Follow the ARM change, which is what our alignment helpers are based on
in the first place.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

On VIVT ARM, when we have multiple shared mappings of the same file
in the same MM, we need to ensure that we have coherency across all
copies.  We do this via make_coherent() by making the pages
uncacheable.

This used to work fine, until we allowed highmem with highpte - we
now have a page table which is mapped as required, and is not available
for modification via update_mmu_cache().

Ralf Beache suggested getting rid of the PTE value passed to
update_mmu_cache():

  On MIPS update_mmu_cache() calls __update_tlb() which walks pagetables
  to construct a pointer to the pte again.  Passing a pte_t * is much
  more elegant.  Maybe we might even replace the pte argument with the
  pte_t?

Ben Herrenschmidt would also like the pte pointer for PowerPC:

  Passing the ptep in there is exactly what I want.  I want that
  -instead- of the PTE value, because I have issue on some ppc cases,
  for I$/D$ coherency, where set_pte_at() may decide to mask out the
  _PAGE_EXEC.

So, pass in the mapped page table pointer into update_mmu_cache(), and
remove the PTE value, updating all implementations and call sites to
suit.

Includes a fix from Stephen Rothwell:

  sparc: fix fallout from update_mmu_cache API change
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Acked-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This implements a bit of rework for the PMB code, which permits us to
kill off the legacy PMB mode completely. Rather than trusting the boot
loader to do the right thing, we do a quick verification of the PMB
contents to determine whether to have the kernel setup the initial
mappings or whether it needs to mangle them later on instead.

If we're booting from legacy mappings, the kernel will now take control
of them and make them match the kernel's initial mapping configuration.
This is accomplished by breaking the initialization phase out in to
multiple steps: synchronization, merging, and resizing. With the recent
rework, the synchronization code establishes page links for compound
mappings already, so we build on top of this for promoting mappings and
reclaiming unused slots.

At the same time, the changes introduced for the uncached helpers also
permit us to dynamically resize the uncached mapping without any
particular headaches. The smallest page size is more than sufficient for
mapping all of kernel text, and as we're careful not to jump to any far
off locations in the setup code the mapping can safely be resized
regardless of whether we are executing from it or not.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

The PMB code is an example of something that spends an absurd amount of
time running uncached when only a couple of operations really need to be.
This switches over to the shiny new uncached helpers, permitting us to
spend far more time running cached.

Additionally, MMUCR twiddling is perfectly safe from cached space given
that it's paired with a control register barrier, so fix that up, too.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This implements some locking for the PMB code. A high level rwlock is
added for dealing with rw accesses on the entry map while a per-entry
data structure spinlock is added to deal with the PMB entry changing out
from underneath us.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Write-through PMB mappings still require the cache bit to be set, even if
they're to be flagged with a different cache policy and bufferability
bit. To reduce some of the confusion surrounding the flag encoding we
centralize the cache mask based on the system cache policy while we're at
it.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This plugs in entry sizing support for existing mappings and then builds
on top of that for linking together entries that are mapping contiguous
areas. This will ultimately permit us to coalesce mappings and promote
head pages while reclaiming PMB slots for dynamic remapping.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This adds some helper routines for uncached mapping support. This
simplifies some of the cases where we need to check the uncached mapping
boundaries in addition to giving us a centralized location for building
more complex manipulation on top of.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Some overdue cleanup of the PMB code, killing off unused functionality
and duplication sprinkled about the tree.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Both the store queue API and the PMB remapping take unsigned long for
their pgprot flags, which cuts off the extended protection bits. In the
case of the PMB this isn't really a problem since the cache attribute
bits that we care about are all in the lower 32-bits, but we do it just
to be safe. The store queue remapping on the other hand depends on the
extended prot bits for enabling userspace access to the mappings.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

This merges the code for iterating over the legacy PMB mappings and the
code for synchronizing software state with the hardware mappings. There's
really no reason to do the same iteration twice, and this also buys us
the legacy entry logging facility for the dynamic PMB case.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

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>