Currently, for ARM kernels with CONFIG_ARM_LPAE and
CONFIG_STRICT_KERNEL_RWX enabled, the 2MiB pages mapping the
kernel code and rodata are writable. They are marked read-only in
a software bit (L_PMD_SECT_RDONLY) but the hardware read-only bit
is not set (PMD_SECT_AP2).

For user mappings, the logic that propagates the software bit
to the hardware bit is in set_pmd_at(); but for the kernel,
section_update() writes the PMDs directly, skipping this logic.

The fix is to set PMD_SECT_AP2 for read-only sections in
section_update(), at the same time as L_PMD_SECT_RDONLY.

Fixes: 1e347922 ("ARM: 8275/1: mm: fix PMD_SECT_RDONLY undeclared compile error")
Signed-off-by: NPhilip Derrin <philip@cog.systems>
Reported-by: NNeil Dick <neil@cog.systems>
Tested-by: NNeil Dick <neil@cog.systems>
Tested-by: NLaura Abbott <labbott@redhat.com>
Reviewed-by: NKees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

The code in question checks memory constrains to set default policy for
overcommit; however we support page size of 4K only thus condition is
always evaluated to false. Remove that dead code.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

The below backtrace can be observed on -rt kernel with
CONFIG_DEBUG_MODULE_RONX (4.9 kernel CONFIG_DEBUG_RODATA) option enabled:

 BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:993
 in_atomic(): 1, irqs_disabled(): 128, pid: 14, name: migration/0
 1 lock held by migration/0/14:
  #0:  (tasklist_lock){+.+...}, at: [<c01183e8>] update_sections_early+0x24/0xdc
 irq event stamp: 38
 hardirqs last  enabled at (37): [<c08f6f7c>] _raw_spin_unlock_irq+0x24/0x68
 hardirqs last disabled at (38): [<c01fdfe8>] multi_cpu_stop+0xd8/0x138
 softirqs last  enabled at (0): [<c01303ec>] copy_process.part.5+0x238/0x1b64
 softirqs last disabled at (0): [<  (null)>]   (null)
 Preemption disabled at: [<c01fe244>] cpu_stopper_thread+0x80/0x10c
 CPU: 0 PID: 14 Comm: migration/0 Not tainted 4.9.21-rt16-02220-g49e319c #15
 Hardware name: Generic DRA74X (Flattened Device Tree)
 [<c0112014>] (unwind_backtrace) from [<c010d370>] (show_stack+0x10/0x14)
 [<c010d370>] (show_stack) from [<c049beb8>] (dump_stack+0xa8/0xd4)
 [<c049beb8>] (dump_stack) from [<c01631a0>] (___might_sleep+0x1bc/0x2ac)
 [<c01631a0>] (___might_sleep) from [<c08f7244>] (__rt_spin_lock+0x1c/0x30)
 [<c08f7244>] (__rt_spin_lock) from [<c08f77a4>] (rt_read_lock+0x54/0x68)
 [<c08f77a4>] (rt_read_lock) from [<c01183e8>] (update_sections_early+0x24/0xdc)
 [<c01183e8>] (update_sections_early) from [<c01184b0>] (__fix_kernmem_perms+0x10/0x1c)
 [<c01184b0>] (__fix_kernmem_perms) from [<c01fe010>] (multi_cpu_stop+0x100/0x138)
 [<c01fe010>] (multi_cpu_stop) from [<c01fe24c>] (cpu_stopper_thread+0x88/0x10c)
 [<c01fe24c>] (cpu_stopper_thread) from [<c015edc4>] (smpboot_thread_fn+0x174/0x31c)
 [<c015edc4>] (smpboot_thread_fn) from [<c015a988>] (kthread+0xf0/0x108)
 [<c015a988>] (kthread) from [<c0108818>] (ret_from_fork+0x14/0x3c)
 Freeing unused kernel memory: 1024K (c0d00000 - c0e00000)

The stop_machine() is called with cpus = NULL from fix_kernmem_perms() and
mark_rodata_ro() which means only one CPU will execute
update_sections_early() while all other CPUs will spin and wait. Hence,
it's safe to remove tasklist locking from update_sections_early(). As part
of this change also mark functions which are local to this module as
static.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NLaura Abbott <labbott@redhat.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

We are going to split <linux/sched/task.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/task.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.
Acked-by: NLinus 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: NIngo Molnar <mingo@kernel.org>

We are going to split <linux/sched/signal.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder <linux/sched/signal.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.
Acked-by: NLinus 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: NIngo Molnar <mingo@kernel.org>

Round the initrd memblock reservation to page boundaries to prevent
other data sharing the initrd pages.  This prevents an allocation
possibly overlapping with the initrd, which would later get trampled
on in free_initrd_mem().
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

Rather than repeatedly testing phys_initrd_size to see if the initrd
is still enabled, return from the new function to avoid executing the
remaining initialisation.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

Move the ARM initrd initialisation code out of arm_memblock_init() into
its own function, so it can be cleaned up.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>

For MMU configurations, VECTORS_BASE is always 0xffff0000, a macro
definition will suffice.

For no-MMU, exception base address is dynamically determined in
subsequent patches. To preserve bisectability, now make the
macro applicable for no-MMU scenario too.

Thanks to 0-DAY kernel test infrastructure that found the
bisectability issue. This macro will be restricted to MMU case upon
dynamically determining exception base address for no-MMU.

Once exception address is handled dynamically for no-MMU,
VECTORS_BASE can be removed from Kconfig.
Signed-off-by: Nafzal mohammed <afzal.mohd.ma@gmail.com>
Tested-by: NVladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

In preparation for adding CONFIG_DEBUG_VIRTUAL support, define a set of
common constants: KERNEL_START and KERNEL_END which abstract
CONFIG_XIP_KERNEL vs. !CONFIG_XIP_KERNEL. Update the code where
relevant.
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Both of these options are poorly named. The features they provide are
necessary for system security and should not be considered debug only.
Change the names to CONFIG_STRICT_KERNEL_RWX and
CONFIG_STRICT_MODULE_RWX to better describe what these options do.
Signed-off-by: NLaura Abbott <labbott@redhat.com>
Acked-by: NJessica Yu <jeyu@redhat.com>
Signed-off-by: NKees Cook <keescook@chromium.org>

When rodata is large enough that it crosses a section boundary after the
kernel text, mark the rest NX. This is as close to full NX of rodata as
we can get without splitting page tables or doing section alignment via
CONFIG_DEBUG_ALIGN_RODATA.

When the config is:

 CONFIG_DEBUG_RODATA=y
 # CONFIG_DEBUG_ALIGN_RODATA is not set

Before:

---[ Kernel Mapping ]---
0x80000000-0x80100000           1M     RW NX SHD
0x80100000-0x80a00000           9M     ro x  SHD
0x80a00000-0xa0000000         502M     RW NX SHD

After:

---[ Kernel Mapping ]---
0x80000000-0x80100000           1M     RW NX SHD
0x80100000-0x80700000           6M     ro x  SHD
0x80700000-0x80a00000           3M     ro NX SHD
0x80a00000-0xa0000000         502M     RW NX SHD
Signed-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The use of CONFIG_DEBUG_RODATA is generally seen as an essential part of
kernel self-protection:
http://www.openwall.com/lists/kernel-hardening/2015/11/30/13
Additionally, its name has grown to mean things beyond just rodata. To
get ARM closer to this, we ought to rearrange the names of the configs
that control how the kernel protects its memory. What was called
CONFIG_ARM_KERNMEM_PERMS is realy doing the work that other architectures
call CONFIG_DEBUG_RODATA.

This redefines CONFIG_DEBUG_RODATA to actually do the bulk of the
ROing (and NXing). In the place of the old CONFIG_DEBUG_RODATA, use
CONFIG_DEBUG_ALIGN_RODATA, since that's what the option does: adds
section alignment for making rodata explicitly NX, as arm does not split
the page tables like arm64 does without _ALIGN_RODATA.

Also adds human readable names to the sections so I could more easily
debug my typos, and makes CONFIG_DEBUG_RODATA default "y" for CPU_V7.

Results in /sys/kernel/debug/kernel_page_tables for each config state:

 # CONFIG_DEBUG_RODATA is not set
 # CONFIG_DEBUG_ALIGN_RODATA is not set

---[ Kernel Mapping ]---
0x80000000-0x80900000           9M     RW x  SHD
0x80900000-0xa0000000         503M     RW NX SHD

 CONFIG_DEBUG_RODATA=y
 CONFIG_DEBUG_ALIGN_RODATA=y

---[ Kernel Mapping ]---
0x80000000-0x80100000           1M     RW NX SHD
0x80100000-0x80700000           6M     ro x  SHD
0x80700000-0x80a00000           3M     ro NX SHD
0x80a00000-0xa0000000         502M     RW NX SHD

 CONFIG_DEBUG_RODATA=y
 # CONFIG_DEBUG_ALIGN_RODATA is not set

---[ Kernel Mapping ]---
0x80000000-0x80100000           1M     RW NX SHD
0x80100000-0x80a00000           9M     ro x  SHD
0x80a00000-0xa0000000         502M     RW NX SHD
Signed-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NLaura Abbott <labbott@fedoraproject.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Take the new memblock attribute MEMBLOCK_NOMAP into account when
deciding whether a certain region is or should be covered by the
kernel direct mapping.
Tested-by: NRyan Harkin <ryan.harkin@linaro.org>
Reviewed-by: NMatt Fleming <matt@codeblueprint.co.uk>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>

Currently, when updating section permissions to mark areas RO
or NX, the only mm updated is current->mm. This is working off
the assumption that there are no additional mm structures at
the time. This may not always hold true. (Example: calling
modprobe early will trigger a fork/exec). Ensure all mm structres
get updated with the new section information.
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NLaura Abbott <labbott@fedoraproject.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This splits off the reservation of the memory occupied by the FDT
binary itself from the processing of the memory reservations it
contains. This is necessary because the physical address of the FDT,
which is needed to perform the reservation, may not be known to the
FDT driver core, i.e., it may be mapped outside the linear direct
mapping, in which case __pa() returns a bogus value.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: NRob Herring <robh@kernel.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Add support for memtest command line option.
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Acked-by: NWill Deacon <will.deacon@arm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Switch ARM to use the generic show_mem() implementation, which displays
the statistics from the mm zone rather than walking the page arrays.
Acked-by: NMel Gorman &lt;mgorman <mgorman@suse.de>
Tested-by: NGregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

DMA contiguous allocations have been able to use highmem since commit
"95b0e655 ARM: mm: don't limit default CMA region only to low memory"
but a comment still notes the earlier "low memory" limitation.  Update
the comment to remove the low memory limitation and fix the
s/contigouos/contiguous/ typo while we're at it.
Signed-off-by: NGeorge G. Davis <george_davis@mentor.com>
Acked-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

In v3.19-rc3 tree when CONFIG_ARM_LPAE and CONFIG_DEBUG_RODATA are enabled
image failed to compile with the following error:

arch/arm/mm/init.c:661:14: error: ‘PMD_SECT_RDONLY’ undeclared here (not in a function)

It seems that '80d6b0c2 ARM: mm: allow text and rodata sections to be read-only'
and 'ded94779 ARM: 8109/1: mm: Modify pte_write and pmd_write logic for LPAE'
commits crossed. 80d6b0c2 uses PMD_SECT_RDONLY macro but ded94779 renames it
and uses software bits L_PMD_SECT_RDONLY instead.

Fix is to use L_PMD_SECT_RDONLY instead PMD_SECT_RDONLY as ded94779 does in
another places.
Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org>
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert many (but not all) printk(KERN_* to pr_* to simplify the code.
We take the opportunity to join some printk lines together so we don't
split the message across several lines, and we also add a few levels
to some messages which were previously missing them.
Tested-by: NAndrew Lunn <andrew@lunn.ch>
Tested-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

GCC 4.9 complains if we take the difference of two pointers, and it's
printed with "%d".  Fix this by using the proper flag - "t" for
ptrdiff_t.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This introduces CONFIG_DEBUG_RODATA, making kernel text and rodata
read-only. Additionally, this splits rodata from text so that rodata can
also be NX, which may lead to wasted memory when aligning to SECTION_SIZE.
The read-only areas are made writable during ftrace updates and kexec.
Signed-off-by: NKees Cook <keescook@chromium.org>
Tested-by: NLaura Abbott <lauraa@codeaurora.org>
Acked-by: NNicolas Pitre <nico@linaro.org>

Adds CONFIG_ARM_KERNMEM_PERMS to separate the kernel memory regions
into section-sized areas that can have different permisions. Performs
the NX permission changes during free_initmem, so that init memory can be
reclaimed.

This uses section size instead of PMD size to reduce memory lost to
padding on non-LPAE systems.

Based on work by Brad Spengler, Larry Bassel, and Laura Abbott.
Signed-off-by: NKees Cook <keescook@chromium.org>
Tested-by: NLaura Abbott <lauraa@codeaurora.org>
Acked-by: NNicolas Pitre <nico@linaro.org>

ARM is different from other architectures in that fixmap pages are indexed
with a positive offset from FIXADDR_START.  Other architectures index with
a negative offset from FIXADDR_TOP.  In order to use the generic fixmap.h
definitions, this patch redefines FIXADDR_TOP to be inclusive of the
useable range.  That is, FIXADDR_TOP is the virtual address of the topmost
fixed page.  The newly defined FIXADDR_END is the first virtual address
past the fixed mappings.
Signed-off-by: NMark Salter <msalter@redhat.com>
Reviewed-by: NDoug Anderson <dianders@chromium.org>
[kees: update for a05e54c1 ("ARM: 8031/2: change fixmap ...")]
Signed-off-by: NKees Cook <keescook@chromium.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Rob Herring <robh@kernel.org>
Acked-by: NNicolas Pitre <nico@linaro.org>

DMA-mapping supports CMA regions places either in low or high memory, so
there is no longer needed to limit default CMA regions only to low memory.
 The real limit is still defined by architecture specific DMA limit.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Reported-by: NRussell King - ARM Linux <linux@arm.linux.org.uk>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Cc: Daniel Drake <drake@endlessm.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch extends the start and end address of initrd to be page aligned,
so that we can free all memory including the un-page aligned head or tail
page of initrd, if the start or end address of initrd are not page
aligned, the page can't be freed by free_initrd_mem() function.
Signed-off-by: NYalin Wang <yalin.wang@sonymobile.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

cr_no_alignment is really only used by the alignment code.  Since we no
longer change the setting of cr_alignment after boot, we can localise
this to alignment.c
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Several places open-code this manipulation, let's consolidate this.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

memblock is now fully integrated into the kernel and is the prefered
method for tracking memory. Rather than reinvent the wheel with
meminfo, migrate to using memblock directly instead of meminfo as
an intermediate.
Acked-by: NJason Cooper <jason@lakedaemon.net>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Acked-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: NKukjin Kim <kgene.kim@samsung.com>
Tested-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: NLeif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: NLaura Abbott <lauraa@codeaurora.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Move the /memreserve/ processing and dtb memory reservations into
early_init_fdt_scan_reserved_mem. This converts arm, arm64, and powerpc
as they are the only users of early_init_fdt_scan_reserved_mem.

memblock_reserve is safe to call on the same region twice, so the
reservation check for the dtb in powerpc 32-bit reservations is safe to
remove.
Signed-off-by: NRob Herring <robh@kernel.org>
Tested-by: NMichal Simek <michal.simek@xilinx.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Tested-by: NGrant Likely <grant.likely@linaro.org>
Tested-by: NStephen Chivers <schivers@csc.com>

Enable reserved memory initialization from device tree.
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: NGrant Likely <grant.likely@linaro.org>

Commit 65939301 (arm: set initrd_start/initrd_end for fdt scan)
caused the FDT initrd_start and initrd_end to override the
phys_initrd_start and phys_initrd_size set by the initrd= kernel
parameter.  With this patch initrd_start and initrd_end will be
overridden if phys_initrd_start and phys_initrd_size are set by the
kernel initrd= parameter.

Fixes: 65939301 (arm: set initrd_start/initrd_end for fdt scan)
Signed-off-by: NBen Peddell <klightspeed@killerwolves.net>
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Switch to memblock interfaces for early memory allocator instead of
bootmem allocator.  No functional change in beahvior than what it is in
current code from bootmem users points of view.

Archs already converted to NO_BOOTMEM now directly use memblock
interfaces instead of bootmem wrappers build on top of memblock.  And
the archs which still uses bootmem, these new apis just fallback to
exiting bootmem APIs.
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Lameter <cl@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 4b59e6c4 ("mm, show_mem: suppress page counts in
non-blockable contexts") introduced SHOW_MEM_FILTER_PAGE_COUNT to
suppress PFN walks on large memory machines.  Commit c78e9363 ("mm:
do not walk all of system memory during show_mem") avoided a PFN walk in
the generic show_mem helper which removes the requirement for
SHOW_MEM_FILTER_PAGE_COUNT in that case.

This patch removes PFN walkers from the arch-specific implementations
that report on a per-node or per-zone granularity.  ARM and unicore32
still do a PFN walk as they report memory usage on each bank which is a
much finer granularity where the debugging information may still be of
use.  As the remaining arches doing PFN walks have relatively small
amounts of memory, this patch simply removes SHOW_MEM_FILTER_PAGE_COUNT.

[akpm@linux-foundation.org: fix parisc]
Signed-off-by: NMel Gorman <mgorman@suse.de>
Acked-by: NDavid Rientjes <rientjes@google.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: James Bottomley <jejb@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 787b0d5c since
it is no longer required after 7909/1 was applied, and it causes
build regressions when ARM_PATCH_PHYS_VIRT is disabled and DMA_ZONE
is enabled.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Current code is using PHYS_OFFSET to calculate the arm_dma_limit which
will lead to wrong calculations in cases where PHYS_OFFSET is updated
runtime.

So fix the code by using __pv_phys_offset instead of PHYS_OFFSET.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Now with dma_mask series merged and max*pfn has consistent meaning on ARM
as rest of the arch's thanks to RMK's mega series, lets switch ARM code
to NO_BOOTMEM. With NO_BOOTMEM change, now we use memblock allocator to
reserve space for crash kernel to have one less dependency with nobootmem
allocator wrapper.

Tested with both flat memory and sparse (faked) memory models with highmem
enabled.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

If allowed by call to memblock_allow_resize() - The Memblock core will
try to allocate additional memory and rearrange its internal data in
case, if there are more then INIT_MEMBLOCK_REGIONS(128) memory regions
of any type have been allocated. If this happens before Low memory is
mapped (which is done now by map_lowmem()) the system will hang, because
the Memblock core will try to operate with virtual addresses which
aren't mapped yet.

In ARM code, the memblock resizing is allowed (memblock_allow_resize())
from arm_memblock_init() which is called before map_lowmem(), so
this may lead to an error as described above.

Hence, allow Memblock resizing later during init, from bootmem_init()
when all appropriate mappings are ready.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>

With commit  26ba47b1 {ARM: 7805/1: mm: change max*pfn to include
the physical offset of memory}, the max_pfn already contain
PHYS_PFN_OFFSET, so it shouldn't be taken into account again.

While at it, use use set_max_mapnr() helper.

Cc: Russell King <linux@arm.linux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicolas Pitre <nicolas.pitre@linaro.org>
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>