Both ARM946 and ARM940 setup functions were corrupting r1 and r2,
which is not permissible - these are used to carry the machine ID
and boot data into the kernel, and must be preserved.

The code responsible for this was the same in both files: they were
using the registers to generate a protection region register value.

Fix this by turning this process into a macro, and using that macro
in both these files with an alternative register allocation.  r0,
r3 and r7 can be used for temporary values here.
Reported-by: NAlex Dumitrache <broscutamaker@gmail.com>
Tested-by: NGeorg Hofstetter <g3gg0.de@gmail.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

We've replaced remap_file_pages(2) implementation with emulation.  Nobody
creates non-linear mapping anymore.

This patch also adjust __SWP_TYPE_SHIFT, effectively increase size of
possible swap file to 128G.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Ifdef around cpu_\name\()_do_suspend and cpu_\name\()_do_resume
ops in proc-macros.S should check for CONFIG_ARM_CPU_SUSPEND and
not CONFIG_PM_SLEEP.  Fix it.

[ Please note that cpu_v7_do_[suspend,resume] code in proc-v7.S
  already correctly checks for CONFIG_ARM_CPU_SUSPEND, same is
  true for functions for other architectures. ]

This fix is needed for decoupling suspend/resume and advanced
cpuidle support on Exynos platform (next patch fixes build for
config with CONFIG_PM_SLEEP=n and CONFIG_ARM_EXYNOS_CPUIDLE=y).

If this fix is not present then the following OOPS happens on
the first attempt to go into advanced cpuidle mode (AFTR):

[   22.244143] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[   22.250759] pgd = c0004000
[   22.253445] [00000000] *pgd=00000000
[   22.257012] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM
[   22.262906] Modules linked in:
[   22.265949] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 3.16.0-next-20140811-dirty #730
[   22.273757] task: c05dce68 ti: c05d2000 task.ti: c05d2000
[   22.279139] PC is at 0x0
[   22.281661] LR is at __cpu_suspend_save+0x4c/0xa8
[   22.286344] pc : [<00000000>]    lr : [<c00125e0>]    psr: a0000093
[   22.286344] sp : c05d3ef4  ip : c05da414  fp : 00000001
[   22.297799] r10: c05da414  r9 : c0609cb0  r8 : 0000000f
[   22.303008] r7 : c05da444  r6 : 00000038  r5 : ea802c00  r4 : c05d3f14
[   22.309517] r3 : 00000000  r2 : c05d3f4c  r1 : 00000038  r0 : c05d3f20
[   22.316029] Flags: NzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
[   22.323406] Control: 10c5387d  Table: 69d5404a  DAC: 00000015
[   22.329135] Process swapper/0 (pid: 0, stack limit = 0xc05d2240)
[   22.335124] Stack: (0xc05d3ef4 to 0xc05d4000)
[   22.339466] 3ee0:                                              ea802c00 00000038 c05d3f4c
[   22.347626] 3f00: 00000000 00000007 c00123bc 00000000 c001d468 6a888000 c05d3f4c 80000000
[   22.355785] 3f20: 00000007 c003d3a0 0000193d eaf9dde4 eaf9dde4 c02ef0c8 c000969c fffffffe
[   22.363944] 3f40: 00000000 c0037b54 eaf9dbb8 e9d1a380 00000000 c001d468 c0609cb0 00000000
[   22.372103] 3f60: c0609cb0 c061649e 00000001 c001250c eaf9dbb8 00000001 c0609cb0 c001d618
[   22.380262] 3f80: c001d5d0 c02ef56c 2d9d2e1e 00000005 eaf9dbb8 c02edcc4 2d9d2e1e 00000005
[   22.388421] 3fa0: c040446c c05da4ec c040446c eaf9dbb8 c05cfbb0 c004c580 c05dce68 c05b3ae8
[   22.396580] 3fc0: 00000000 c058bb24 ffffffff ffffffff c058b5e4 00000000 00000000 c05b3ae8
[   22.404740] 3fe0: c0616994 c05da47c c05b3ae4 c05ddeec 4000406a 40008074 00000000 00000000
[   22.412909] [<c00125e0>] (__cpu_suspend_save) from [<c00123bc>] (__cpu_suspend+0x5c/0x70)
[   22.421074] [<c00123bc>] (__cpu_suspend) from [<c05d3f4c>] (init_thread_union+0x1f4c/0x2000)
[   22.429479] Code: bad PC value
[   22.432518] ---[ end trace fb90ebf4217d0ad9 ]---
[   22.437116] Kernel panic - not syncing: Attempted to kill the idle task!
[   22.443800] Rebooting in 5 seconds..

This patch has been tested on Exynos4210 based Origen board.
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NKukjin Kim <kgene.kim@samsung.com>

CPU_32v6 currently selects CPU_USE_DOMAINS if CPU_V6 and MMU. This is
because ARM 1136 r0pX CPUs lack the v6k extensions, and therefore do
not have hardware thread registers. The lack of these registers requires
the kernel to update the vectors page at each context switch in order to
write a new TLS pointer. This write must be done via the userspace
mapping, since aliasing caches can lead to expensive flushing when using
kmap. Finally, this requires the vectors page to be mapped r/w for
kernel and r/o for user, which has implications for things like put_user
which must trigger CoW appropriately when targetting user pages.

The upshot of all this is that a v6/v7 kernel makes use of domains to
segregate kernel and user memory accesses. This has the nasty
side-effect of making device mappings executable, which has been
observed to cause subtle bugs on recent cores (e.g. Cortex-A15
performing a speculative instruction fetch from the GIC and acking an
interrupt in the process).

This patch solves this problem by removing the remaining domain support
from ARMv6. A new memory type is added specifically for the vectors page
which allows that page (and only that page) to be mapped as user r/o,
kernel r/w. All other user r/o pages are mapped also as kernel r/o.
Patch co-developed with Russell King.

Cc: <stable@vger.kernel.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This commit fixes the regression on Armada 370 (the kernal hang during
boot) introduced by the commit: "ARM: 7691/1: mm: kill unused
TLB_CAN_READ_FROM_L1_CACHE and use ALT_SMP instead".

When coming out of either a Wait for Interrupt (WFI) or a Wait for
Event (WFE) IDLE states, a specific timing sensitivity exists between
the retiring WFI/WFE instructions and the newly issued subsequent
instructions. This sensitivity can result in a CPU hang scenario.  The
workaround is to insert either a Data Synchronization Barrier (DSB) or
Data Memory Barrier (DMB) command immediately after the WFI/WFE
instruction.

This commit was based on the work of Lior Amsalem, but heavily
modified to apply the errata fix dynamically according to the
processor type thanks to the suggestions of Russell King and Nicolas
Pitre.
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Reviewed-by: NWill Deacon <will.deacon@arm.com>
Acked-by: NNicolas Pitre <nico@linaro.org>
Tested-by: NWilly Tarreau <w@1wt.eu>
Cc: <stable@vger.kernel.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Since the new ASID code in b5466f87
("ARM: mm: remove IPI broadcasting on ASID rollover") was changed to
use 64bit operations it has broken the BE operation due to an issue
with the MM code accessing sub-fields of mm->context.id.

When running in BE mode we see the values in mm->context.id are stored
with the highest value first, so the LDR in the arch/arm/mm/proc-macros.S
reads the wrong part of this field. To resolve this, change the LDR in
the mmid macro to load from +4.
Acked-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NBen Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

PROT_NONE mappings apply the page protection attributes defined by _P000
which translate to PAGE_NONE for ARM. These attributes specify an XN,
RDONLY pte that is inaccessible to userspace. However, on kernels
configured without support for domains, such a pte *is* accessible to
the kernel and can be read via get_user, allowing tasks to read
PROT_NONE pages via syscalls such as read/write over a pipe.

This patch introduces a new software pte flag, L_PTE_NONE, that is set
to identify faulting, present entries.
Signed-off-by: NWill Deacon <will.deacon@arm.com>

ARM v7 architecture introduced the concept of cache levels and related
control registers. New processors like A7 and A15 embed an L2 unified cache
controller that becomes part of the cache level hierarchy. Some operations in
the kernel like cpu_suspend and __cpu_disable do not require a flush of the
entire cache hierarchy to DRAM but just the cache levels belonging to the
Level of Unification Inner Shareable (LoUIS), which in most of ARM v7 systems
correspond to L1.

The current cache flushing API used in cpu_suspend and __cpu_disable,
flush_cache_all(), ends up flushing the whole cache hierarchy since for
v7 it cleans and invalidates all cache levels up to Level of Coherency
(LoC) which cripples system performance when used in hot paths like hotplug
and cpuidle.

Therefore a new kernel cache maintenance API must be added to cope with
latest ARM system requirements.

This patch adds flush_cache_louis() to the ARM kernel cache maintenance API.

This function cleans and invalidates all data cache levels up to the
Level of Unification Inner Shareable (LoUIS) and invalidates the instruction
cache for processors that support it (> v7).

This patch also creates an alias of the cache LoUIS function to flush_kern_all
for all processor versions prior to v7, so that the current cache flushing
behaviour is unchanged for those processors.

v7 cache maintenance code implements a cache LoUIS function that cleans and
invalidates the D-cache up to LoUIS and invalidates the I-cache, according
to the new API.
Reviewed-by: NSantosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: NNicolas Pitre <nico@linaro.org>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Tested-by: NShawn Guo <shawn.guo@linaro.org>

This patch adds the MMU initialisation for the LPAE page table format.
The swapper_pg_dir size with LPAE is 5 rather than 4 pages. A new
proc-v7-3level.S file contains the TTB initialisation, context switch
and PTE setting code with the LPAE. The TTBRx split is based on the
PAGE_OFFSET with TTBR1 used for the kernel mappings. The 36-bit mappings
(supersections) and a few other memory types in mmu.c are conditionally
compiled.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

Commit 66a625a8 (ARM: mm: proc-macros: Add generic proc/cache/tlb struct
definition macros) introduced build errors when PM_SLEEP is not enabled.
The per-CPU do_suspend/do_resume functions are defined via the
preprocessor to constant 0.  However, the macros which use these were
converted to assembly, resulting in undefined references to these
functions.  Fix that by moving the ! ifdef section into proc-macros.S
and deleting it from all effected proc-*.S files.
Acked-by: NDave Martin <dave.martin@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds some generic macros to reduce boilerplate when
declaring certain common structures in arch/arm/mm/*.S

Thanks to Russell King for outlining what the
define_processor_functions macro could look like.
Signed-off-by: NDave Martin <dave.martin@linaro.org>
Acked-by: NNicolas Pitre <nicolas.pitre@linaro.org>

Fixes generated by 'codespell' and manually reviewed.
Signed-off-by: NLucas De Marchi <lucas.demarchi@profusion.mobi>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The hardware page tables use an XN bit 'execute never'.  Historically,
we've had a Linux 'execute allow' bit, in the positive sense.  Get rid
of this artifact as future hardware will continue to have the XN sense.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This switches the ordering of the Linux vs hardware page tables in
each page, thereby eliminating some of the arithmetic in the page
table walks.  As we now place the Linux page table at the beginning
of the page, we can deal with the offset in the pgt by simply masking
it away, along with the other control bits.

This also makes the arithmetic all be positive, rather than a mixture.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The current implementation of the v7_coherent_*_range function assumes
that the D and I cache lines have the same size, which is incorrect
architecturally. This patch adds the icache_line_size macro which reads
the CTR register. The main loop in v7_coherent_*_range is split in two
independent loops or the D and I caches. This also has the performance
advantage that the DSB is moved outside the main loop.
Reported-by: NKevin Sapp <ksapp@quicinc.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The current implementation of the dcache_line_size macro reads the L1
cache size from the CCSIDR register. This, however, is not guaranteed to
be the smallest cache line in the cache hierarchy. The patch changes to
the macro to use the more architecturally correct CTR register.
Reported-by: NKevin Sapp <ksapp@quicinc.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch removes the domain switching functionality via the set_fs and
__switch_to functions on cores that have a TLS register.

Currently, the ioremap and vmalloc areas share the same level 1 page
tables and therefore have the same domain (DOMAIN_KERNEL). When the
kernel domain is modified from Client to Manager (via the __set_fs or in
the __switch_to function), the XN (eXecute Never) bit is overridden and
newer CPUs can speculatively prefetch the ioremap'ed memory.

Linux performs the kernel domain switching to allow user-specific
functions (copy_to/from_user, get/put_user etc.) to access kernel
memory. In order for these functions to work with the kernel domain set
to Client, the patch modifies the LDRT/STRT and related instructions to
the LDR/STR ones.

The user pages access rights are also modified for kernel read-only
access rather than read/write so that the copy-on-write mechanism still
works. CPU_USE_DOMAINS gets disabled only if the hardware has a TLS register
(CPU_32v6K is defined) since writing the TLS value to the high vectors page
isn't possible.

The user addresses passed to the kernel are checked by the access_ok()
function so that they do not point to the kernel space.
Tested-by: NAnton Vorontsov <cbouatmailru@gmail.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>

These old symbols are meaningless now that we have memory type
support implemented.  The entire memory type field needs to be
modified rather than just a few bits twiddled.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

As of the previous commit, MT_DEVICE_IXP2000 encodes to the same
PTE bit encoding as MT_DEVICE, so it's now redundant.  Convert
MT_DEVICE_IXP2000 to use MT_DEVICE instead, and remove its aliases.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

There are actually only four separate implementations of set_pte_ext.
Use assembler macros to insert code for these into the proc-*.S files.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

This patch adds support for the ARMv7 cores.
Signed-off-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Most MMU-based CPUs have a restriction on the setting of the data cache
enable and mmu enable bits in the control register, whereby if the data
cache is enabled, the MMU must also be enabled.  Enabling the data
cache without the MMU is an invalid combination.

However, there are CPUs where the data cache can be enabled without the
MMU.

In order to allow these CPUs to take advantage of that, provide a
method whereby each proc-*.S file defines the control regsiter value
for use with nommu (with the MMU disabled.)  Later on, when we add
support for enabling the MMU on these devices, we can adjust the
"crval" macro to also enable the data cache for nommu.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Delete obsoleted stuff from arch Makefile and rename
constants.h to asm-offsets.h
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

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!