This patch supports the upcomming Intel IOMMU hardware a.k.a.  Intel(R)
Virtualization Technology for Directed I/O Architecture and the hardware spec
for the same can be found here
http://www.intel.com/technology/virtualization/index.htm

FAQ! (questions from akpm, answers from ak)

> So...  what's all this code for?
>
> I assume that the intent here is to speed things up under Xen, etc?

Yes in some cases, but not this code.  That would be the Xen version of this
code that could potentially assign whole devices to guests.  I expect this to
be only useful in some special cases though because most hardware is not
virtualizable and you typically want an own instance for each guest.

Ok at some point KVM might implement this too; i likely would use this code
for this.

> Do we
> have any benchmark results to help us to decide whether a merge would be
> justified?

The main advantage for doing it in the normal kernel is not performance, but
more safety.  Broken devices won't be able to corrupt memory by doing random
DMA.

Unfortunately that doesn't work for graphics yet, for that need user space
interfaces for the X server are needed.

There are some potential performance benefits too:

- When you have a device that cannot address the complete address range an
  IOMMU can remap its memory instead of bounce buffering.  Remapping is likely
  cheaper than copying.

- The IOMMU can merge sg lists into a single virtual block.  This could
  potentially speed up SG IO when the device is slow walking SG lists.  [I
  long ago benchmarked 5% on some block benchmark with an old MPT Fusion; but
  it probably depends a lot on the HBA]

And you get better driver debugging because unexpected memory accesses from
the devices will cause a trappable event.

>
> Does it slow anything down?

It adds more overhead to each IO so yes.

This patch:

Add support for early detection and parsing of DMAR's (DMA Remapping) reported
to OS via ACPI tables.

DMA remapping(DMAR) devices support enables independent address translations
for Direct Memory Access(DMA) from Devices.  These DMA remapping devices are
reported via ACPI tables and includes pci device scope covered by these DMA
remapping device.

For detailed info on the specification of "Intel(R) Virtualization Technology
for Directed I/O Architecture" please see
http://www.intel.com/technology/virtualization/index.htmSigned-off-by: NAnil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Muli Ben-Yehuda <muli@il.ibm.com>
Cc: "Siddha, Suresh B" <suresh.b.siddha@intel.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: Greg KH <greg@kroah.com>
Cc: Len Brown <lenb@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With 64KB blocksize, a directory entry can have size 64KB which does not
fit into 16 bits we have for entry length.  So we store 0xffff instead and
convert the value when read from / written to disk.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NJan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Well, it's not especially important that target->d_iname get the contents
of dentry->d_iname, but it's important that it get initialized with
*something*, otherwise we're just exposing some random piece of memory to
anyone who reads the link at /proc/<pid>/fd/<fd> for the deleted file, when
it's still held open by someone.

I've run a test program that copies a short (<36 character) name ontop of a
long (>=36 character) name and see that the first time I run it, without
this patch, I get unpredicatable results out of /proc/<pid>/fd/<fd>.
Signed-off-by: NJ. Bruce Fields <bfields@citi.umich.edu>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Simplify the vfs_cap_data structure.

Also fix get_file_caps which was declaring
__le32 v1caps[XATTR_CAPS_SZ] on the stack, but
XATTR_CAPS_SZ is already * sizeof(__le32).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NSerge E. Hallyn <serue@us.ibm.com>
Cc: Andrew Morgan <morgan@kernel.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a panic due to access NULL pointer of kmem_cache_node at discard_slab()
after memory online.

When memory online is called, kmem_cache_nodes are created for all SLUBs
for new node whose memory are available.

slab_mem_going_online_callback() is called to make kmem_cache_node() in
callback of memory online event.  If it (or other callbacks) fails, then
slab_mem_offline_callback() is called for rollback.

In memory offline, slab_mem_going_offline_callback() is called to shrink
all slub cache, then slab_mem_offline_callback() is called later.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: locking fix]
[akpm@linux-foundation.org: build fix]
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Current memory notifier has some defects yet.  (Fortunately, nothing uses
it.) This patch is to fix and rearrange for them.

  - Add information of start_pfn, nr_pages, and node id if node status is
    changes from/to memoryless node for callback functions.
    Callbacks can't do anything without those information.
  - Add notification going-online status.
    It is necessary for creating per node structure before the node's
    pages are available.
  - Move GOING_OFFLINE status notification after page isolation.
    It is good place for return memory like cache for callback,
    because returned page is not used again.
  - Make CANCEL events for rollingback when error occurs.
  - Delete MEM_MAPPING_INVALID notification. It will be not used.
  - Fix compile error of (un)register_memory_notifier().
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add description about event notification callback routine to the document
Signed-off-by: NYasunori Goto <y-goto@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This patch uses the updated boot protocol to do paravirtualized boot.
If the boot version is >= 2.07, then it will do two things:

 1. Check the bootparams loadflags to see if we should reload the
    segment registers and clear interrupts.  This is appropriate
    for normal native boot and some paravirtualized environments, but
    inapproprate for others.

 2. Check the hardware architecture, and dispatch to the appropriate
    kernel entrypoint.  If the bootloader doesn't set this, then we
    simply do the normal boot sequence.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Updates for version 2.07 of the boot protocol.  This includes:

load_flags.KEEP_SEGMENTS- flag to request/inhibit segment reloads
hardware_subarch	- what subarchitecture we're booting under
hardware_subarch_data	- per-architecture data

The intention of these changes is to make booting a paravirtualized
kernel work via the normal Linux boot protocol.
Signed-off-by: NJeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

* 'for-linus' of master.kernel.org:/pub/scm/linux/kernel/git/cooloney/blackfin-2.6:
  Blackfin arch: update boards files
  Blackfin arch: dma add some API and cleanup bf54x DMA definition
  Blackfin arch: cleanup and promote the general purpose timers api to a core blackfin component
  Blackfin arch: add a cheesy install target
  Blackfin arch: add functions for converting between sclks and usecs
  Blackfin arch: add assembly function for doing 64bit unsigned division
  Blackfin arch: -mno-fdpic works
  Blackfin arch: use "char bfin_board_name[]" rather than "char *bfin_board_name" per discussion on lkml as the former uses less storage
  Blackfin arch: Fixing Bug: balance calls to get_task_mm with corresponding mmput calls
  Blackfin serial driver Kconfig: depend on DMA not being enabled rather than a specific DMA size
  Blackfin arch: Fix bug: missing CHIPID register field definition of BF54x
  Blackfin arch: Fix up /proc/cpuinfo so it is like everyone else
  Blackfin arch: Optimization - no need to make additional math here
  Blackfin arch: force irq_flags into the .data section
  Blackfin arch BF548 defconfig: enable watchdog by default
  Blackfin arch: add new processor ADSP-BF52x arch/mach support

* 'audit.b43' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current:
  [PATCH] audit: watching subtrees
  [PATCH] new helper - inotify_evict_watch()
  [PATCH] new helper - inotify_clone_watch()
  [PATCH] new helpers - collect_mounts() and release_collected_mounts()
  [PATCH] pass dentry to audit_inode()/audit_inode_child()

This path mustn't have been tested :( I did attempt to exercise it
by injecting failures here, but I suspect PageMappedToDisk may have
been getting in the way. Will need more of a look, although I think
nobh mode is OK for an -rc1 (it shouldn't eat anyone's data).

Commit 03158cd7 ("fs: restore nobh")
introcduced a NULL deref.  Spotted by the Coverity checker.
Signed-off-by: NNick Piggin <npiggin@suse.de>
Cc: Badari Pulavarty <pbadari@us.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

now that -mno-fdpic works, force it on so that
we can use any blackfin toolchain to build up the
kernel and kernel modules

wrap -mno-fdpic in $(call cc-option,-mno-fdpic) so that older
toolchains will still work
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Blackfin arch: use "char bfin_board_name[]" rather than "char *bfin_board_name" per discussion on lkml as the former uses less storage
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

We must balance calls to get_task_mm with corresponding mmput calls, otherwise
refcounting is screwed up and mms don't get freed when their task exits.
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Fix up /proc/cpuinfo so it is like everyone else, and gets
parsed by various applications properly. Still needs some tweaking on
parts without full L1 sram, like 532, 531, so it doesn't print out L1
bank info that doesn't exist.
Signed-off-by: NRobin Getz <robin.getz@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

force irq_flags into the .data section by initializing it to
the hardware masks that cannot be disabled.  this way if we
use irq enable/disable functions before the .bss has been
zeroed out (as does our l1 relocate/dma functions), we dont
hit a problem where bss contains bogus crap.
Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMike Frysinger <michael.frysinger@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Signed-off-by: NBryan Wu <bryan.wu@analog.com>

New kind of audit rule predicates: "object is visible in given subtree".
The part that can be sanely implemented, that is.  Limitations:
	* if you have hardlink from outside of tree, you'd better watch
it too (or just watch the object itself, obviously)
	* if you mount something under a watched tree, tell audit
that new chunk should be added to watched subtrees
	* if you umount something in a watched tree and it's still mounted
elsewhere, you will get matches on events happening there.  New command
tells audit to recalculate the trees, trimming such sources of false
positives.

Note that it's _not_ about path - if something mounted in several places
(multiple mount, bindings, different namespaces, etc.), the match does
_not_ depend on which one we are using for access.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Kicks the watch out without dropping it.  Called under ->inotify_mutex
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Get a snapshot of a subtree, creating private clones of vfsmounts
for all its components and release such snapshot resp.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

makes caller simpler *and* allows to scan ancestors
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* 'master' of hera.kernel.org:/pub/scm/linux/kernel/git/kyle/parisc-2.6: (29 commits)
  [PARISC] fix uninitialized variable warning in asm/rtc.h
  [PARISC] Port checkstack.pl to parisc
  [PARISC] Make palo target work when $obj != $src
  [PARISC] Zap unused variable warnings in pci.c
  [PARISC] Fix tests in palo target
  [PARISC] Fix palo target
  [PARISC] Restore palo target
  [PARISC] Attempt to clean up parisc/Makefile
  [PARISC] Fix infinite loop in /proc/iomem
  [PARISC] Quiet sysfs_create_link __must_check warnings in pdc_stable
  [PARISC] Squelch pci_enable_device __must_check warning in superio
  [PARISC] Kill off broken irqstack code
  [PARISC] Remove hardcoded uses of PAGE_SIZE
  [PARISC] Clean up pointless ASM_PAGE_SIZE_DIV use
  [PARISC] Kill off the last vestiges of ASM_PAGE_SIZE
  [PARISC] Kill off ASM_PAGE_SIZE use
  [PARISC] Beautify parisc vmlinux.lds.S
  [PARISC] Clean up a resource_size_t warning in sba_iommu
  [PARISC] Kill incorrect cast warning in unwinder
  [PARISC] Kill zone_to_nid printk warning
  ...

Fixed trivial conflict in include/asm-parisc/tlbflush.h manually

* ssh://master.kernel.org/pub/scm/linux/kernel/git/sam/kbuild:
  kbuild: restore arch/{ppc/xtensa}/boot cflags
  kconfig: set title bar in xconfig
  kbuild: fix toplevel Makefile/depmod

Add new maintainers for the x86 (32-bit and 64-bit) architecture.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Acked-by: NThomas Gleixner <tglx@linutronix.de>
Acked-by: NH. Peter Anvin <hpa@zytor.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Commit 7b96dc02 ("[SPARC] Videopix Frame
Grabber: Convert device_lock_sem to mutex") missed one place.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>