mips: mm: add slab availability checking in ioremap_prot

Recent commit a5f616483110 ("mm/ioremap: add slab availability checking in
ioremap_prot") added the slab availability check to the generic
ioremap_prot() implementation. It is reasonable to be done for the
MIPS32-specific method too since it also relies on the
get_vm_area_caller() function (by means of get_vm_area()) which requires
the slab allocator being up and running before being called.

Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: use ioremap_page_range

Use the generic ioremap_page_range helper instead of reimplementing it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

MIPS: move ioremap_prot und iounmap out of line

Neither of these interfaces is anywhere near the fast path. Move them
out of line and avoid exposing implementation details to the drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

mips: add support for folded p4d page tables

Implement primitives necessary for the 4th level folding, add walks of p4d
level where appropriate, replace 5leve-fixup.h with pgtable-nop4d.h and
drop usage of __ARCH_USE_5LEVEL_HACK.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <jhogan@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: Mike Rapoport <rppt@kernel.org>

MIPS: Fix ioremap() RAM check

We currently attempt to check whether a physical address range provided
to __ioremap() may be in use by the page allocator by examining the
value of PageReserved for each page in the region - lowmem pages not
marked reserved are presumed to be in use by the page allocator, and
requests to ioremap them fail.

The way we check this has been broken since commit 92923ca3aace ("mm:
meminit: only set page reserved in the memblock region"), because
memblock will typically not have any knowledge of non-RAM pages and
therefore those pages will not have the PageReserved flag set. Thus when
we attempt to ioremap a region outside of RAM we incorrectly fail
believing that the region is RAM that may be in use.

In most cases ioremap() on MIPS will take a fast-path to use the
unmapped kseg1 or xkphys virtual address spaces and never hit this path,
so the only way to hit it is for a MIPS32 system to attempt to ioremap()
an address range in lowmem with flags other than _CACHE_UNCACHED.
Perhaps the most straightforward way to do this is using
ioremap_uncached_accelerated(), which is how the problem was discovered.

Fix this by making use of walk_system_ram_range() to test the address
range provided to __ioremap() against only RAM pages, rather than all
lowmem pages. This means that if we have a lowmem I/O region, which is
very common for MIPS systems, we're free to ioremap() address ranges
within it. A nice bonus is that the test is no longer limited to lowmem.

The approach here matches the way x86 performed the same test after
commit c81c8a1eeede ("x86, ioremap: Speed up check for RAM pages") until
x86 moved towards a slightly more complicated check using walk_mem_res()
for unrelated reasons with commit 0e4c12b45aa8 ("x86/mm, resource: Use
PAGE_KERNEL protection for ioremap of memory pages").

Signed-off-by: Paul Burton <paul.burton@mips.com>
Reported-by: Serge Semin <fancer.lancer@gmail.com>
Tested-by: Serge Semin <fancer.lancer@gmail.com>
Fixes: 92923ca3aace ("mm: meminit: only set page reserved in the memblock region")
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.2+
Patchwork: https://patchwork.linux-mips.org/patch/19786/

sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>

Update code that relied on sched.h including various MM types for them.

This will allow us to remove the <linux/mm_types.h> include from <linux/sched.h>.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

MIPS: mm: Audit and remove any unnecessary uses of module.h

Historically a lot of these existed because we did not have
a distinction between what was modular code and what was providing
support to modules via EXPORT_SYMBOL and friends. That changed
when we forked out support for the latter into the export.h file.

This means we should be able to reduce the usage of module.h
in code that is obj-y Makefile or bool Kconfig. The advantage
in doing so is that module.h itself sources about 15 other headers;
adding significantly to what we feed cpp, and it can obscure what
headers we are effectively using.

Since module.h was the source for init.h (for __init) and for
export.h (for EXPORT_SYMBOL) we consider each obj-y/bool instance
for the presence of either and replace as needed.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14033/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Replace use of phys_t with phys_addr_t.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Whitespace cleanup.

Having received another series of whitespace patches I decided to do this
once and for all rather than dealing with this kind of patches trickling
in forever.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

mips: Move __virt_addr_valid() to a place for MIPS 64

Commit d3ce88431892 "MIPS: Fix modpost error in modules attepting to use
virt_addr_valid()" moved __virt_addr_valid() from a macro in a header
file to a function in ioremap.c. But ioremap.c is only compiled for MIPS
32, and not for MIPS 64.

When compiling for my yeeloong2, which supposedly supports hibernation,
which compiles kernel/power/snapshot.c which calls virt_addr_valid(), I
got this error:

LD init/built-in.o
kernel/built-in.o: In function `memory_bm_free':
snapshot.c:(.text+0x4c9c4): undefined reference to `__virt_addr_valid'
snapshot.c:(.text+0x4ca58): undefined reference to `__virt_addr_valid'
kernel/built-in.o: In function `snapshot_write_next':
(.text+0x4e44c): undefined reference to `__virt_addr_valid'
kernel/built-in.o: In function `snapshot_write_next':
(.text+0x4e890): undefined reference to `__virt_addr_valid'
make[1]: *** [vmlinux] Error 1
make: *** [sub-make] Error 2

I suspect that __virt_addr_valid() is fine for mips 64. I moved it to
mmap.c such that it gets compiled for mips 64 and 32.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/4842/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

MIPS: Fix modpost error in modules attepting to use virt_addr_valid().

ERROR: "min_low_pfn" [drivers/block/aoe/aoe.ko] undefined!

Fixed by moving the implementation of virt_addr_valid() into the kernel
proper and exporting it which removes the pains of an inline or macro
implementation.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h

percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.

2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).

* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>

MIPS: Use BUG_ON() where possible.

Based on original patch by Stoyan Gaydarov <stoyboyker@gmail.com> which
missed a few places.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Detach sched.h from mm.h

First thing mm.h does is including sched.h solely for can_do_mlock() inline
function which has "current" dereference inside. By dealing with can_do_mlock()
mm.h can be detached from sched.h which is good. See below, why.

This patch
a) removes unconditional inclusion of sched.h from mm.h
b) makes can_do_mlock() normal function in mm/mlock.c
c) exports can_do_mlock() to not break compilation
d) adds sched.h inclusions back to files that were getting it indirectly.
e) adds less bloated headers to some files (asm/signal.h, jiffies.h) that were
getting them indirectly

Net result is:
a) mm.h users would get less code to open, read, preprocess, parse, ... if
they don't need sched.h
b) sched.h stops being dependency for significant number of files:
on x86_64 allmodconfig touching sched.h results in recompile of 4083 files,
after patch it's only 3744 (-8.3%).

Cross-compile tested on

all arm defconfigs, all mips defconfigs, all powerpc defconfigs,
alpha alpha-up
arm
i386 i386-up i386-defconfig i386-allnoconfig
ia64 ia64-up
m68k
mips
parisc parisc-up
powerpc powerpc-up
s390 s390-up
sparc sparc-up
sparc64 sparc64-up
um-x86_64
x86_64 x86_64-up x86_64-defconfig x86_64-allnoconfig

as well as my two usual configs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Revert "[PATCH] Generic ioremap_page_range: mips conversion"

The generic version truncates addresses.

This reverts commit 8e087929df884dbb13e383d49d192bdd6928ecbf.

[PATCH] Generic ioremap_page_range: mips conversion

Convert MIPS to use generic ioremap_page_range()

[yoichi_yuasa@tripeaks.co.jp: build fix]
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[MIPS] Fix iounmap argument to const volatile.

With the existing prototype the following code:

const void __iomem *io = ioremap();
x = readb(io);
iounmap(io);

did result in a warning.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

[PATCH] mm: init_mm without ptlock

First step in pushing down the page_table_lock. init_mm.page_table_lock has
been used throughout the architectures (usually for ioremap): not to serialize
kernel address space allocation (that's usually vmlist_lock), but because
pud_alloc,pmd_alloc,pte_alloc_kernel expect caller holds it.

Reverse that: don't lock or unlock init_mm.page_table_lock in any of the
architectures; instead rely on pud_alloc,pmd_alloc,pte_alloc_kernel to take
and drop it when allocating a new one, to check lest a racing task already
did. Similarly no page_table_lock in vmalloc's map_vm_area.

Some temporary ugliness in __pud_alloc and __pmd_alloc: since they also handle
user mms, which are converted only by a later patch, for now they have to lock
differently according to whether or not it's init_mm.

If sources get muddled, there's a danger that an arch source taking
init_mm.page_table_lock will be mixed with common source also taking it (or
neither take it). So break the rules and make another change, which should
break the build for such a mismatch: remove the redundant mm arg from
pte_alloc_kernel (ppc64 scrapped its distinct ioremap_mm in 2.6.13).

Exceptions: arm26 used pte_alloc_kernel on user mm, now pte_alloc_map; ia64
used pte_alloc_map on init_mm, now pte_alloc_kernel; parisc had bad args to
pmd_alloc and pte_alloc_kernel in unused USE_HPPA_IOREMAP code; ppc64
map_io_page forgot to unlock on failure; ppc mmu_mapin_ram and ppc64 im_free
took page_table_lock for no good reason.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Inline ioremap() calls for constant addresses that map to KSEG1.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Update MIPS to use the 4-level pagetable code thereby getting rid of
the compacrapability headers.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!