Page table entries are made invalid by writing a zero into the the PTE
slot in a page table.  This creates a race condition with the TLB
modify handlers when they are updating the PTE.

CPU0                              CPU1

Test for _PAGE_PRESENT
.                                 set to not _PAGE_PRESENT (zero)
Set to _PAGE_VALID

So now the page not present value (zero) is suddenly valid and user
space programs have access to physical page zero.

We close the race by putting the test for _PAGE_PRESENT and setting of
_PAGE_VALID into an atomic LL/SC section.  This requires more registers
than just K0 and K1 in the handlers, so we need to save some registers
to a save area and then restore them when we are done.

The save area is an array of cacheline aligned structures that should
not suffer cache line bouncing as they are CPU private.

[ralf@linux-mips.org: Fix !defined(CONFIG_MIPS_PGD_C0_CONTEXT) build error.]
Signed-off-by: NDavid Daney <david.daney@cavium.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2577/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This can be used from either 32-bit or 64-bit code to generate logical
right shifts of any constant amount.
Signed-off-by: NDavid Daney <david.daney@cavium.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2576/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Remove custom implementation of hex_to_bin().
Signed-off-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1580/Acked-by: NFlorian Fainelli <florian@openwrt.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Enable cpu_has_clo_clz only when CONFIG_CPU_MIPS32 or CONFIG_CPU_MIPS64
is selected.  This will optimize fls() and __fls() to use CLZ insn, and
eventually ffs() and __ffs() as well.

Malta and MIPSSim are development platforms, and need to take care of
various processor configurations, release rivisions and so on, even
across different MIPS ISAs.  For such platforms we have to be careful,
for instance, with turning on cpu_has_mips{32,64}r[12] features.

As for CLZ, all MIPS32/64 processors support it, regardless of release
revisions.
Signed-off-by: NShinya Kuribayashi <skuribay@pobox.com>
To: David VomLehn <dvomlehn@cisco.com>
To: macro@linux-mips.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1453/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This will optimize fls() and __fls() to use CLZ throughout the kernel,
and any other optimizations that depend on constant cpu_has_* values
will also be used.
Signed-off-by: NDavid VomLehn <dvomlehn@cisco.com>
Signed-off-by: NShinya Kuribayashi <skuribay@pobox.com>
To: David VomLehn <dvomlehn@cisco.com>
To: macro@linux-mips.org
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1452/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
To: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2391/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

fixrange_init() allocates page tables for all addresses higher than
FIXADDR_TOP.  On processors that override the default FIXADDR_TOP
address of 0xfffe_0000, this can consume up to 4 pages (1 page per 4MB)
for pgd's that are never used.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1980/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

BMIPS4350/4380/5000 CMT/SMT all use SW INT0/INT1 for inter-thread
signaling.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1709/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Memory maps and addressing quirks are normally defined in <spaces.h>.
There are already three targets that need to override FIXADDR_TOP, and
others exist.  This will be a cleaner approach than adding lots of
ifdefs in fixmap.h .
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Cc: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1573/Acked-by: NAtsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

On processors with deep write buffers, it is likely that many cycles
will pass between a CACHE instruction and the time the data actually
gets written out to DRAM.  Add a SYNC instruction to ensure that the
buffers get emptied before the flush functions return.

Actual problem seen in the wild:

1) dma_alloc_coherent() allocates cached memory

2) memset() is called to clear the new pages

3) dma_cache_wback_inv() is called to flush the zero data out to memory

4) dma_alloc_coherent() returns an uncached (kseg1) pointer to the
freshly allocated pages

5) Caller writes data through the kseg1 pointer

6) Buffered writeback data finally gets flushed out to DRAM

7) Part of caller's data is inexplicably zeroed out

This patch adds SYNC between steps 3 and 4, which fixed the problem.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: 
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

pfn_valid() compares the PFN to max_mapnr:

        __pfn >= min_low_pfn && __pfn < max_mapnr;

On HIGHMEM kernels, highend_pfn is used to set the value of max_mapnr.
Unfortunately, highend_pfn is left at zero if the system does not
actually have enough RAM to reach into the HIGHMEM range.  This causes
pfn_valid() to always return false, and when debug checks are enabled
the kernel will fail catastrophically:

Memory: 22432k/32768k available (2249k kernel code, 10336k reserved, 653k data, 1352k init, 0k highmem)
NR_IRQS:128
kfree_debugcheck: out of range ptr 81c02900h.
Kernel bug detected[#1]:
Cpu 0
$ 0   : 00000000 10008400 00000034 00000000
$ 4   : 8003e160 802a0000 8003e160 00000000
$ 8   : 00000000 0000003e 00000747 00000747
...

On such a configuration, max_low_pfn should be used to set max_mapnr.

This was seen on 2.6.34.
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1992/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

[v4: Patch applies to linux-queue.git with kmap_atomic patches:
 https://patchwork.kernel.org/patch/189932/
 https://patchwork.kernel.org/patch/194552/
 https://patchwork.kernel.org/patch/189912/ ]

The MIPS DMA coherency functions do not work properly (i.e. kernel oops)
when HIGHMEM pages are passed in as arguments.  Use kmap_atomic() to
temporarily map high pages for cache maintenance operations.

Tested on a 2.6.36-rc7 1GB HIGHMEM SMP no-alias system.
Signed-off-by: NDezhong Diao <dediao@cisco.com>
Signed-off-by: NKevin Cernekee <cernekee@gmail.com>
Cc: Dezhong Diao <dediao@cisco.com>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: David VomLehn <dvomlehn@cisco.com>
Cc: Sergei Shtylyov <sshtylyov@mvista.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1695/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch introduced topdown mmap support in user process address
space allocation policy.

Recently, we ran some large applications that use mmap heavily and
lead to OOM due to inflexible mmap allocation policy on MIPS32.

Since most other major archs supported it for years, it is reasonable
to follow the trend and reduce the pain of porting applications.

Due to cache aliasing concern, arch_get_unmapped_area_topdown() and
other helper functions are implemented in arch/mips/kernel/syscall.c.
Signed-off-by: NJian Peng <jipeng2005@gmail.com>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2389/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

The address limit is already set in flush_old_exec() via set_fs(USER_DS)
so this assignment is redundant.

[ralf@linux-mips.org: also see dac853ae for
further explanation.]
Signed-off-by: NMathias Krause <minipli@googlemail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/2466/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2491/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org

Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2490/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

This patch removes all the module loader hook implementations in the
architecture specific code where the functionality is the same as that
now provided by the recently added default hooks.
Signed-off-by: NJonas Bonn <jonas@southpole.se>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Tested-by: NMichal Simek <monstr@monstr.eu>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

virtio has been so far used only in the context of virtualization,
and the virtio Kconfig was sourced directly by the relevant arch
Kconfigs when VIRTUALIZATION was selected.

Now that we start using virtio for inter-processor communications,
we need to source the virtio Kconfig outside of the virtualization
scope too.

Moreover, some architectures might use virtio for both virtualization
and inter-processor communications, so directly sourcing virtio
might yield unexpected results due to conflicting selections.

The simple solution offered by this patch is to always source virtio's
Kconfig in drivers/Kconfig, and remove it from the appropriate arch
Kconfigs. Additionally, a virtio menu entry has been added so virtio
drivers don't show up in the general drivers menu.

This way anyone can use virtio, though it's arguably less accessible
(and neat!) for virtualization users now.

Note: some architectures (mips and sh) seem to have a VIRTUALIZATION
menu merely for sourcing virtio's Kconfig, so that menu is removed too.
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

pit_clockevent wants to replaced in the argument of the callback
function as well.

Reported-by; Ingo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

All these are instances of
  #define NAME value;
or
  #define NAME(params_opt) value;

These of course fail to build when used in contexts like
  if(foo $OP NAME)
  while(bar $OP NAME)
and may silently generate the wrong code in contexts such as
  foo = NAME + 1;    /* foo = value; + 1; */
  bar = NAME - 1;    /* bar = value; - 1; */
  baz = NAME & quux; /* baz = value; & quux; */

Reported on comp.lang.c,
Message-ID: <ab0d55fe-25e5-482b-811e-c475aa6065c3@c29g2000yqd.googlegroups.com>
Initial analysis of the dangers provided by Keith Thompson in that thread.

There are many more instances of more complicated macros having unnecessary
trailing semicolons, but this pile seems to be all of the cases of simple
values suffering from the problem. (Thus things that are likely to be found
in one of the contexts above, more complicated ones aren't.)
Signed-off-by: NPhil Carmody <ext-phil.2.carmody@nokia.com>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-of-by: NJohn Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2465/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NFlorian Fainelli <florian@openwrt.org>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2489/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Signed-off-by: NJonas Gorski <jonas.gorski@gmail.com>
Cc: linux-mips@linux-mips.org
Acked-by: NFlorian Fainelli <florian@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/2461/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Fix few issues in the Netlogic code:
- Use handle_percpu_irq to handle per-cpu interrupts
- Remove unused function nlm_common_ipi_handler()
- Call scheduler_ipi() on SMP_RESCHEDULE_YOURSELF
- Enable interrupts in nlm_smp_finish()
Signed-off-by: NJayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2460/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit d6d5d5c4 (MIPS: Sibyte: Convert to new irq_chip functions)
removed the mask function which breaks irq_shutdown(). Restore it.
Reported-by: NMatt Turner <mattst88@gmail.com>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2460/Tested-by: NMatt Turner <mattst88@gmail.com>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

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

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

This patch combines linux-mips.org patches
637d69600fb1773da56487271ec2a79c33d237ed [MIPS: Netlogic: Yank out crap.]
and 5e3c263b9658a4b1c6c5577793e9347efb44854e [MIPS: XLR, XLS: Add Kbuild
files for platform.]
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NJayachandran C <jayachandranc@netlogicmicro.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2415/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Since 6be63bbb (lmo) rsp.
af3a1f6f (kernel.org) the Malta code does
no longer probe for presence of GCMP if CMP is not configured.  This means
that the variable gcmp_present well be left at its default value of -1
which normally is meant to indicate that GCMP has not yet been mmapped.
This non-zero value is now interpreted as GCMP being present resulting
in a write attempt to a GCMP register resulting in a crash.

Reported and a build fix on top of my fix by Rob Landley <rob@landley.net>.
Reported-by: NRob Landley <rob@landley.net>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2413/

Renumbering was necessary because I had already wired up setns(2) in the
linux-mips.org tree in commit c3fce54644cabbb90700cc3acc040718a377f609
[MIPS: Wire up new sendmmsg syscall.] but the same syscall numbers were
used by 7b21fddd [ns: Wire up the setns
system call] resulting in a conflict.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit ee6114202e48dc282c6d04741e9c5d7171eb8bb8 (lmo) rsp.
1685f3b1 (kernel.org) ["MIPS: SMTC: Move
declaration of smtc_init_secondary to <asm/smtc.h>."] didn't quite do
that - it rather lost the declaration of smtc_init_secondary resulting in
a build error.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Commit a561b02a2577aec51277ba39c82bd192a79c0267 (lmo) rsp.
7c8d948f (kernel.org) ["MIPS: i8259: Convert
to new irq_chip functions"] missed one location to modify resulting in
build breakage.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

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

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

The code in arch/mips/kernel/i8259.c still hasn't been converted to
using struct syscore_ops instead of a sysdev for resume and shutdown.
As a result, this code doesn't build any more after suspend, resume
and shutdown callbacks have been removed from struct sysdev_class.
Fix this problem by converting i8259.c to using syscore_ops.
Reported-and-tested-by: NRoland Vossen <rvossen@broadcom.com>
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Acked-by: NRalf Baechle <ralf@linux-mips.org>

Make sure that the 'static' keywork is at the beginning of declaration
for arch/mips/include/asm/mach-jz4740/gpio.h

This gets rid of warnings like
  warning: ‘static’ is not at beginning of declaration
when building with -Wold-style-declaration (and/or -Wextra which also
enables it).
Also a few tiny whitespace changes.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Signed-off-by: NMichael Buesch <m@bues.ch>
Signed-off-by: NJiri Kosina <jkosina@suse.cz>

Add a NODE level to the generic cache events which is used to measure
local vs remote memory accesses. Like all other cache events, an
ACCESS is HIT+MISS, if there is no way to distinguish between reads
and writes do reads only etc..

The below needs filling out for !x86 (which I filled out with
unsupported events).

I'm fairly sure ARM can leave it like that since it doesn't strike me as
an architecture that even has NUMA support. SH might have something since
it does appear to have some NUMA bits.

Sparc64, PowerPC and MIPS certainly want a good look there since they
clearly are NUMA capable.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: David Miller <davem@davemloft.net>
Cc: Anton Blanchard <anton@samba.org>
Cc: David Daney <ddaney@caviumnetworks.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1303508226.4865.8.camel@laptopSigned-off-by: NIngo Molnar <mingo@elte.hu>

The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.

For the various event classes:

  - hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
    the PMI-tail (ARM etc.)
  - tracepoint: nmi=0; since tracepoint could be from NMI context.
  - software: nmi=[0,1]; some, like the schedule thing cannot
    perform wakeups, and hence need 0.

As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).

The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.orgSigned-off-by: NIngo Molnar <mingo@elte.hu>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20110609130622.133068765@linutronix.de