Reducing the number of times balance_dirty_pages calls global_page_state
reduces the cache references and so improves write performance on a
variety of workloads.

'perf stats' of simple fio write tests shows the reduction in cache
access.  Where the test is fio 'write,mmap,600Mb,pre_read' on AMD AthlonX2
with 3Gb memory (dirty_threshold approx 600 Mb) running each test 10
times, dropping the fasted & slowest values then taking the average &
standard deviation

		average (s.d.) in millions (10^6)
2.6.31-rc8	648.6 (14.6)
+patch		620.1 (16.5)

Achieving this reduction is by dropping clip_bdi_dirty_limit as it rereads
the counters to apply the dirty_threshold and moving this check up into
balance_dirty_pages where it has already read the counters.

Also by rearrange the for loop to only contain one copy of the limit tests
allows the pdflush test after the loop to use the local copies of the
counters rather than rereading them.

In the common case with no throttling it now calls global_page_state 5
fewer times and bdi_stat 2 fewer.

Fengguang:

This patch slightly changes behavior by replacing clip_bdi_dirty_limit()
with the explicit check (nr_reclaimable + nr_writeback >= dirty_thresh) to
avoid exceeding the dirty limit.  Since the bdi dirty limit is mostly
accurate we don't need to do routinely clip.  A simple dirty limit check
would be enough.

The check is necessary because, in principle we should throttle everything
calling balance_dirty_pages() when we're over the total limit, as said by
Peter.

We now set and clear dirty_exceeded not only based on bdi dirty limits,
but also on the global dirty limit.  The global limit check is added in
place of clip_bdi_dirty_limit() for safety and not intended as a behavior
change.  The bdi limits should be tight enough to keep all dirty pages
under the global limit at most time; occasional small exceeding should be
OK though.  The change makes the logic more obvious: the global limit is
the ultimate goal and shall be always imposed.

We may now start background writeback work based on outdated conditions.
That's safe because the bdi flush thread will (and have to) double check
the states.  It reduces overall overheads because the test based on old
states still have good chance to be right.

[akpm@linux-foundation.org] fix uninitialized dirty_exceeded
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NWu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Acked-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

parisc __ioremap(): fix off-by-one error in page alignment of allocation
size for sizes where size%PAGE_SIZE==1.
Signed-off-by: NFlorian Zumbiehl <florz@florz.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: NHelge Deller <deller@gmx.de>
Tested-by: NHelge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't dereference vma if it's NULL.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Cc: Chen Liqin <liqin.chen@sunplusct.com>
Cc: Lennox Wu <lennox.wu@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix kconfig dependency warning for PC8736x_GPIO by restricting it to
X86_32.

  warning: (SCx200_GPIO && SCx200 || PC8736x_GPIO && X86) selects NSC_GPIO which has unmet direct dependencies (X86_32)

NSC_GPIO is X86_32 only.  The other driver (SCx200_GPIO) that selects
NSC_GPIO is X86_32 only (indirectly, since SCx200 depends on X86_32), so
limit this driver also.
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Cc: Jordan Crouse <jordan.crouse@amd.com>
Cc: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a fatal kernel-doc error due to a #define coming between a function's
kernel-doc notation and the function signature.  (kernel-doc cannot handle
this)
Signed-off-by: NRandy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ACPI_PREEMPTION_POINT() logic was introduced in commit 8bd108d1
(ACPICA: add preemption point after each opcode parse).  The follow up
commits abe1dfab, 138d1569, c084ca70 tried to fix the preemption logic
back and forth, but nobody noticed that the usage of
in_atomic_preempt_off() in that context is wrong.

The check which guards the call of cond_resched() is:

    if (!in_atomic_preempt_off() && !irqs_disabled())

in_atomic_preempt_off() is not intended for general use as the comment
above the macro definition clearly says:

 * Check whether we were atomic before we did preempt_disable():
 * (used by the scheduler, *after* releasing the kernel lock)

On a CONFIG_PREEMPT=n kernel the usage of in_atomic_preempt_off() works by
accident, but with CONFIG_PREEMPT=y it's just broken.

The whole purpose of the ACPI_PREEMPTION_POINT() is to reduce the latency
on a CONFIG_PREEMPT=n kernel, so make ACPI_PREEMPTION_POINT() depend on
CONFIG_PREEMPT=n and remove the in_atomic_preempt_off() check.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=16210

[akpm@linux-foundation.org: fix build]
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Len Brown <lenb@kernel.org>
Cc: Francois Valenduc <francois.valenduc@tvcablenet.be>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The current kfifo scatterlist implementation will not work with chained
scatterlists.  It assumes that struct scatterlist arrays are allocated
contiguously, which is not the case when chained scatterlists (struct
sg_table) are in use.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  isofs: Fix lseek() to position beyond 4 GB
  vfs: remove unused MNT_STRICTATIME
  vfs: show unreachable paths in getcwd and proc
  vfs: only add " (deleted)" where necessary
  vfs: add prepend_path() helper
  vfs: __d_path: dont prepend the name of the root dentry
  ia64: perfmon: add d_dname method
  vfs: add helpers to get root and pwd
  cachefiles: use path_get instead of lone dget
  fs/sysv/super.c: add support for non-PDP11 v7 filesystems
  V7: Adjust sanity checks for some volumes
  Add v7 alias
  v9fs: fixup for inode_setattr being removed

Manual merge to take Al's version of the fs/sysv/super.c file: it merged
cleanly, but Al had removed an unnecessary header include, so his side
was better.

* git://git.kernel.org/pub/scm/linux/kernel/git/pkl/squashfs-linus:
  Squashfs: fix checkpatch.pl warnings
  Squashfs: fix filename typo
  Squashfs: update Kconfig and documentation for LZO
  Squashfs: fix block size use in LZO decompressor
  Squashfs: Add LZO compression support
  squashfs: fix filename in header comment
  Squashfs: Make XATTR config name consistent with other file systems
  squashfs: fix compiler inline warning

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  exofs: Fix groups code when num_devices is not divisible by group_width
  exofs: Remove useless optimization
  exofs: exofs_file_fsync and exofs_file_flush correctness
  exofs: Remove superfluous dependency on buffer_head and writeback

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (39 commits)
  ceph: generalize mon requests, add pool op support
  ceph: only queue async writeback on cap revocation if there is dirty data
  ceph: do not ignore osd_idle_ttl mount option
  ceph: constify dentry_operations
  ceph: whitespace cleanup
  ceph: add flock/fcntl lock support
  ceph: define on-wire types, constants for file locking support
  ceph: add CEPH_FEATURE_FLOCK to the supported feature bits
  ceph: support v2 reconnect encoding
  ceph: support v2 client_caps encoding
  ceph: move AES iv definition to shared header
  ceph: fix decoding of pool snap info
  ceph: make ->sync_fs not wait if wait==0
  ceph: warn on missing snap realm
  ceph: print useful error message when crush rule not found
  ceph: use %pU to print uuid (fsid)
  ceph: sync header defs with server code
  ceph: clean up header guards
  ceph: strip misleading/obsolete version, feature info
  ceph: specify supported features in super.h
  ...

* 'msm-video' of git://codeaurora.org/quic/kernel/dwalker/linux-msm:
  video: msm: Fix section mismatch in mddi.c.
  drivers: video: msm: drop some unused variables

* 'ixp4xx' of git://git.kernel.org/pub/scm/linux/kernel/git/chris/linux-2.6:
  IXP4xx: Fix LL debugging on little-endian CPU.
  IXP4xx: Fix sparse warnings in I/O primitives.
  IXP4xx: Make mdio_bus struct static in the Ethernet driver.
  IXP4xx: Fix ixp4xx_crypto little-endian operation.
  IXP4xx: Prevent HSS transmitter lockup by disabling FRaMe signals.
  ixp4xx/vulcan: add PCI support
  ixp4xx: base support for Arcom Vulcan

* 'for-linus' of master.kernel.org:/home/rmk/linux-2.6-arm: (226 commits)
  ARM: 6323/1: cam60: don't use __init for cam60_spi_{flash_platform_data,partitions}
  ARM: 6324/1: cam60: move cam60_spi_devices to .init.data
  ARM: 6322/1: imx/pca100: Fix name of spi platform data
  ARM: 6321/1: fix syntax error in main Kconfig file
  ARM: 6297/1: move U300 timer to dynamic clock lookup
  ARM: 6296/1: clock U300 intcon and timer properly
  ARM: 6295/1: fix U300 apb_pclk split
  ARM: 6306/1: fix inverted MMC card detect in U300
  ARM: 6299/1: errata: TLBIASIDIS and TLBIMVAIS operations can broadcast a faulty ASID
  ARM: 6294/1: etm: do a dummy read from OSSRR during initialization
  ARM: 6292/1: coresight: add ETM management registers
  ARM: 6288/1: ftrace: document mcount formats
  ARM: 6287/1: ftrace: clean up mcount assembly indentation
  ARM: 6286/1: fix Thumb-2 decompressor broken by "Auto calculate ZRELADDR"
  ARM: 6281/1: video/imxfb.c: allow usage without BACKLIGHT_CLASS_DEVICE
  ARM: 6280/1: imx: Fix build failure when including <mach/gpio.h> without <linux/spinlock.h>
  ARM: S5PV210: Fix on missing s3c-sdhci card detection method for hsmmc3
  ARM: S5P: Fix on missing S5P_DEV_FIMC in plat-s5p/Kconfig
  ARM: S5PV210: Override FIMC driver name on Aquila board
  ARM: S5PC100: enable FIMC on SMDKC100
  ...

Fix up conflicts in arch/arm/mach-{s5pc100,s5pv210}/cpu.c due to
different subsystem 'setname' calls, and trivial port types in
include/linux/serial_core.h

Fix checkstack error:

lib/decompress_bunzip2.c: In function `get_next_block':
lib/decompress_bunzip2.c:511: warning: the frame size of 1932 bytes is larger than 1024 bytes

byteCount, symToByte, and mtfSymbol cannot be declared static or allocated
dynamically so place them in the bunzip_data struct.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Cc: Phillip Lougher <phillip@lougher.demon.co.uk>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add four examples to the kernel sample directory.

It shows how to handle:
- a byte stream fifo
- a integer type fifo
- a dynamic record sized fifo
- the fifo DMA functions

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simply replace the whole kfifo.c and kfifo.h files with the new generic
version and fix the kerneldoc API template file.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add the new version of the kfifo API files kfifo.c and kfifo.h.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are different types of a fifo which can not handled in C without a
lot of overhead.  So i decided to write the API as a set of macros, which
is the only way to do a kind of template meta programming without C++.
This macros handles the different types of fifos in a transparent way.

There are a lot of benefits:

- Compile time handling of the different fifo types
- Better performance (a save put or get of an integer does only generate
  9 assembly instructions on a x86)
- Type save
- Cleaner interface, the additional kfifo_..._rec() functions are gone
- Easier to use
- Less error prone
- Different types of fifos: it is now possible to define a int fifo or
  any other type. See below for an example.
- Smaller footprint for none byte type fifos
- No need of creating a second hidden variable, like in the old DEFINE_KFIFO

The API was not changed.

There are now real in place fifos where the data space is a part of the
structure.  The fifo needs now 20 byte plus the fifo space.  Dynamic
assigned or allocated create a little bit more code.

Most of the macros code will be optimized away and simple generate a
function call.  Only the really small one generates inline code.

Additionally you can now create fifos for any data type, not only the
"unsigned char" byte streamed fifos.

There is also a new kfifo_put and kfifo_get function, to handle a single
element in a fifo.  This macros generates inline code, which is lit bit
larger but faster.

I know that this kind of macros are very sophisticated and not easy to
maintain.  But i have all tested and it works as expected.  I analyzed the
output of the compiler and for the x86 the code is as good as hand written
assembler code.  For the byte stream fifo the generate code is exact the
same as with the current kfifo implementation.  For all other types of
fifos the code is smaller before, because the interface is easier to use.

The main goal was to provide an API which is very intuitive, save and easy
to use.  So linux will get now a powerful fifo API which provides all what
a developer needs.  This will save in the future a lot of kernel space,
since there is no need to write an own implementation.  Most of the device
driver developers need a fifo, and also deep kernel development will gain
benefit from this API.

Here are the results of the text section usage:

Example 1:
                        kfifo_put/_get  kfifo_in/out    current kfifo
dynamic allocated       0x000002a8      0x00000291      0x00000299
in place                0x00000291      0x0000026e      0x00000273

kfifo.c                 new             old
text section size       0x00000be5      0x000008b2

As you can see, kfifo_put/kfifo_get creates a little bit more code than
kfifo_in/kfifo_out, but it is much faster (the code is inline).

The code is complete hand crafted and optimized.  The text section size is
as small as possible.  You get all the fifo handling in only 3 kb.  This
includes type safe fix size records, dynamic records and DMA handling.

This should be the final version. All requested features are implemented.

Note: Most features of this API doesn't have any users.  All functions
which are not used in the next 9 months will be removed.  So, please adapt
your drivers and other sources as soon as possible to the new API and post
it.

This are the features which are currently not used in the kernel:

kfifo_to_user()
kfifo_from_user()
kfifo_dma_....() macros
kfifo_esize()
kfifo_recsize()
kfifo_put()
kfifo_get()

The fixed size record elements, exclude "unsigned char" fifo's and the
variable size records fifo's

This patch:

User of the kernel fifo should never bypass the API and directly access
the fifo structure.  Otherwise it will be very hard to maintain the API.
Signed-off-by: NStefani Seibold <stefani@seibold.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For consistency with other kfifo routines, return bool, not int.
Signed-off-by: NRobert P. J. Day <rpjday@crashcourse.ca>
Cc: Stefani Seibold <stefani@seibold.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This adds byte order autodetection (of PDP-11 and LE filesystems).  No
attempt is made to detect big-endian filesystems -- were there any?
Tested with PDP-11 v7 filesystems and PC-IX maintenance floppy.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Newly mkfs-ed filesystems from Seventh Edition have last modification time
set to zero, but are otherwise perfectly valid.

Also, tighten up other sanity checks to filter out most filesystems with

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

So that the module gets autoloaded when a v7 filesystem is mounted.
Signed-off-by: NLubomir Rintel <lkundrak@v3.sk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

copy_to/from_user() returns the number of bytes remaining to be copied.
It never returns a negative value.  The correct return code is -EFAULT and
not -EIO.

All the callers check for non-zero returns so that's Ok, but the return
code is passed to the user so we should fix this.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Simon Kagstrom <simon.kagstrom@netinsight.net>
Acked-by: NWANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 51dcdfec ("parport: Use the PCI IRQ if offered") added IRQ support
for PCI parallel port devices handled by parport_pc, but turned it off for
parport_serial, despite a printk() message to the contrary.
Signed-off-by: NFr?d?ric Bri?re <fbriere@fbriere.net>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We are missing the oops end marker for the exception based WARN implementation
in lib/bug.c. This is useful for logfile analysis tools.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There are a few issues with the exception based WARN implementation in
lib/bug.c:

- Inconsistent printk flags. The "cut here" line is printed at KERN_EMERG, so
  the console and all logged in users see the single line:

------------[ cut here ]------------

  for each WARN. Fix this so we print everything at KERN_WARNING to match the
  kernel/panic.c version.

- The lib/bug.c WARN would print "Badness at". Change it to match the
  kernel/panic.c version which prints "WARNING: at".

- Print the list of modules, similar to kernel/panic.c of modules, similar to
  kernel/panic.c

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NAnton Blanchard <anton@samba.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To keep panic_timeout accuracy when running under a hypervisor, the
current implementation only spins on long time (1 second) calls to mdelay.
 That brings a good effect, but the problem is the keyboard LEDs don't
blink at all on that situation.

This patch changes to call to panic_blink_enter() between every mdelay and
keeps blinking in spite of long spin timer mode.

The time to call to mdelay is now 100ms.  Even this change will keep
panic_timeout accuracy enough when running under a hypervisor.
Signed-off-by: NTAMUKI Shoichi <tamuki@linet.gr.jp>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: NDmitry Torokhov <dtor@mail.ru>
Cc: Anton Blanchard <anton@samba.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

We can clean up the work queue on this error path.  This function is
called from afs_init().
Signed-off-by: NDan Carpenter <error27@gmail.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

DMA_xxBIT_MASK macros were marked as deprecated in June 2009.  One more
year is long enough, I think.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It was replaced with the DMA unamp state API (which can be used for
any bus).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Architectures implement dma_is_consistent() in different ways (some
misinterpret the definition of API in DMA-API.txt).  So it hasn't been so
useful for drivers.  We have only one user of the API in tree.  Unlikely
out-of-tree drivers use the API.

Even if we fix dma_is_consistent() in some architectures, it doesn't look
useful at all.  It was invented long ago for some old systems that can't
allocate coherent memory at all.  It's better to export only APIs that are
definitely necessary for drivers.

Let's remove this API.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This driver is the only user of dma_is_consistent().  We plan to remove this
API.

The driver uses the API in the following way:

BUG_ON(!dma_is_consistent(hostdata->dev, pScript) && L1_CACHE_BYTES < dma_get_cache_alignment());

The above code tries to see if L1_CACHE_BYTES is greater than
dma_get_cache_alignment() on sysmtes that can not allocate coherent memory
(some old systems can't).

James Bottomley exmplained that this is necesary because the driver packs the
set of mailboxes into a single coherent area and separates the different
usages by a L1 cache stride.  So it's fatal if the dma

He also pointed out that we can kill this checking because we don't hit this
BUG_ON on all architectures that actually use the driver.

(akpm: stolen from the scsi tree because
dma-mapping-remove-dma_is_consistent-api.patch needs it)
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NJames Bottomley <James.Bottomley@suse.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Architectures that handle DMA-non-coherent memory need to set
ARCH_DMA_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe: the
buffer doesn't share a cache with the others.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <jejb@parisc-linux.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

dma_get_cache_alignment returns the minimum DMA alignment.  Architectures
defines it as ARCH_DMA_MINALIGN (formally ARCH_KMALLOC_MINALIGN).  So we
can unify dma_get_cache_alignment implementations.

Note that some architectures implement dma_get_cache_alignment wrongly.
dma_get_cache_alignment() should return the minimum DMA alignment.  So
fully-coherent architectures should return 1.  This patch also fixes this
issue.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Now each architecture has the own dma_get_cache_alignment implementation.

dma_get_cache_alignment returns the minimum DMA alignment.  Architectures
define it as ARCH_KMALLOC_MINALIGN (it's used to make sure that malloc'ed
buffer is DMA-safe; the buffer doesn't share a cache with the others).  So
we can unify dma_get_cache_alignment implementations.

This patch:

dma_get_cache_alignment() needs to know if an architecture defines
ARCH_KMALLOC_MINALIGN or not (needs to know if architecture has DMA
alignment restriction).  However, slab.h define ARCH_KMALLOC_MINALIGN if
architectures doesn't define it.

Let's rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN.
ARCH_KMALLOC_MINALIGN is used only in the internals of slab/slob/slub
(except for crypto).
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simply add proper IDs into the device table.
Signed-off-by: NAnton Vorontsov <avorontsov@mvista.com>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Peter Tyser <ptyser@xes-inc.com>
Cc: Dave Jiang <djiang@mvista.com>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

-EIO is not the only error code that pci_enable_device() may return, also
the set of errors can be enhanced in future.  We should compare return
code with zero, not with concrete error value.
Signed-off-by: NKulikov Vasiliy <segooon@gmail.com>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Cc: Jeff Roberson <jroberson@jroberson.net>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

-EIO is not the only error code that pci_enable_device() may return, also
the set of errors can be enhanced in future.  We should compare return
code with zero, not with concrete error value.
Signed-off-by: NKulikov Vasiliy <segooon@gmail.com>
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Cc: Jeff Roberson <jroberson@jroberson.net>
Cc: Doug Thompson <dougthompson@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>