clk_find function looks for clock with matching dev_id and con_id.
We should return from clk_find as soon as we get a clock with matching
dev_id and con_id. This can be done by comparing variable "match" with 3.
Acked-by: NUwe Kleine-Konig <u.kleine-koenig@pengutronix.de>
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

If support for COMMON_CLKDEV is enabled, we have CLK support.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: (96 commits)
  Blackfin: stop cleaning include/asm/asm-offsets.h
  Blackfin: scale calibration when cpu freq changes
  Blackfin: eat spurious space in asm/dpmc.h
  Blackfin: fix anomaly 283 handling with exact hardware error
  Blackfin: bf537-stamp: add example ADXL346 orientation resources
  Blackfin: bf537-stamp: add example AD2S1210 IIO resources
  Blackfin: don't support keypad wakeup from hibernate
  Blackfin: bf537-stamp: add example AD7416 IIO resources
  Blackfin: bf537-stamp: add example ADP8860 backlight/led resources
  Blackfin: bf537-stamp: add example AD7414 temp sensor resources
  Blackfin: rename AD1836 to AD183X in board files
  Blackfin: bf537-stamp: add example AD2S120x resources
  Blackfin: add support for the on-chip MAC status interrupts
  Blackfin: asm/page.h: pull in asm-generic headers
  Blackfin: mark gpio lib functions static
  Blackfin: bf537-stamp: add example ADAU1361 resources
  Blackfin: GPIO: implement to_irq handler
  Blackfin: bf537-stamp: add example ADP122/ADP150 power regulator resources
  Blackfin: bf537-stamp: add example AD2S90 resources
  Blackfin: bf537-stamp: add example AD5398 power regulator resources
  ...

* 'merge' of git://git.secretlab.ca/git/linux-2.6:
  powerpc/5200: Build fix for mpc52xx watchdog timer code
  of: Fix comparison of "compatible" properties
  powerpc/52xx: update defconfigs
  spi/omap2_mcspi: Use transaction speed if provided
  spi/omap2_mcspi: fix NULL pointer dereference
  uartlite: Fix build on sparc.

Merge branch 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6

* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
  ARM/OMAP: Remove the +x bit from a couple of source files
  omap: McBSP: Drop unnecessary status/error bit clearing on reg_cacheretrieved register values
  OMAP4: fix temporary hacks that break multi-omap PM
  OMAP2: cpu_is_omap2*: fix compile-time removal of unused code
  omap3: pandora: add missing i2c3 board_info
  omap: mach-omap2/io.c: fix function declarations
  omap: Fix gpio_resume_after_retention
  omap3: Fix support for the LEDs connected to GPIO outputs on IGEP v2board
  omap: Checkpatch cleanup for blizzard.h
  omap: pass the reboot command to the boot loader
  omap2/3/4: mailbox: remove compiler warning
  OMAP2: serial.c: Fix number of uarts in early_init
  omap: Enable PM_RUNTIME in defconfigs to avoid USB compile errors
  omap2: Update n8x0 defconfig to test multi-omap and DMA api changes
  omap2: add USB initialization for tusb6010
  omap4: Fix build break by moving omap_smc1 into a separate .S
  omap2/3/4: ehci: avoid compiler error with touchbook
  omap3: Fix compile for Touch Book early_param

* master.kernel.org:/home/rmk/linux-2.6-arm: (23 commits)
  ARM: Fix RiscPC decompressor build errors
  ARM: Fix sorting of platform group config options and includes
  ARM: 5991/1: Fix regression in restore_user_regs macro
  ARM: 5989/1: ARM: KGDB: add support for SMP platforms
  ARM: 5990/1: ARM: use __armv5tej_mmu_cache_flush for V5TEJ instead of __armv4_mmu_cache_flush
  ARM: Add final piece to fix XIP decompressor in read-only memory
  video: enable sh_mobile_lcdc on SH-Mobile ARM
  ARM: mach-shmobile: ap4evb SDHI0 platform data V2
  ARM: mach-shmobile: sh7372 SDHI vector merge
  ARM: mach-shmobile: sh7377 SDHI vector merge
  ARM: mach-shmobile: sh7367 SDHI vector merge
  ARM: mach-shmobile: G4EVM KEYSC platform data
  mtd: enable sh_flctl on SH-Mobile ARM
  ARM: mach-shmobile: G3EVM FLCTL platform data
  ARM: mach-shmobile: G3EVM KEYSC platform data
  Video: ARM CLCD: Better fix for swapped IENB and CNTL registers
  ARM: Add L2 cache handling to smp boot support
  ARM: 5960/1: ARM: perf-events: fix v7 event selection mask
  ARM: 5959/1: ARM: perf-events: request PMU interrupts with IRQF_NOBALANCING
  ARM: 5988/1: pgprot_dmacoherent() for non-mmu builds
  ...

* 'for-linus/samsung-fixes' of git://git.fluff.org/bjdooks/linux:
  ARM: SAMSUNG: Fixup commit 4e6d488a
  ARM: SAMSUNG: Fix build error from stale define in <plat/uncompress.h>
  ARM: SAMSUNG: Add suspend/resume support for S3C PWM driver
  ARM: S3C2440: Fix s3c2440 cpufreq compilation post move.

* 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze: (27 commits)
  microblaze: entry.S use delay slot for return handlers
  microblaze: Save current task directly
  microblaze: Simplify entry.S - save/restore r3/r4 - ret_from_trap
  microblaze: PCI early support for noMMU system
  microblaze: Fix dma alloc and free coherent dma functions
  microblaze: Add consistent code
  microblaze: pgtable.h: move consistent functions
  microblaze: Remove ancient Kconfig option for consistent mapping
  microblaze: Remove VMALLOC_VMADDR
  microblaze: Add define for ASM_LOOP
  microblaze: Preliminary support for dma drivers
  microblaze: remove trailing space in messages
  microblaze: Use generic show_mem()
  microblaze: Change temp register for cmdline
  microblaze: Preliminary support for dma drivers
  microblaze: Move cache function to cache.c
  microblaze: Add support from PREEMPT
  microblaze: Add support for Xilinx PCI host bridge
  microblaze: Enable PCI, missing files
  microblaze: Add core PCI files
  ...

* 'for-linus' of git://neil.brown.name/md:
  md: deal with merge_bvec_fn in component devices better.

* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (69 commits)
  [SCSI] scsi_transport_fc: Fix synchronization issue while deleting vport
  [SCSI] bfa: Update the driver version to 2.1.2.1.
  [SCSI] bfa: Remove unused header files and did some cleanup.
  [SCSI] bfa: Handle SCSI IO underrun case.
  [SCSI] bfa: FCS and include file changes.
  [SCSI] bfa: Modified the portstats get/clear logic
  [SCSI] bfa: Replace bfa_get_attr() with specific APIs
  [SCSI] bfa: New portlog entries for events (FIP/FLOGI/FDISC/LOGO).
  [SCSI] bfa: Rename pport to fcport in BFA FCS.
  [SCSI] bfa: IOC fixes, check for IOC down condition.
  [SCSI] bfa: In MSIX mode, ignore spurious RME interrupts when FCoE ports are in FW mismatch state.
  [SCSI] bfa: Fix Command Queue (CPE) full condition check and ack CPE interrupt.
  [SCSI] bfa: IOC recovery fix in fcmode.
  [SCSI] bfa: AEN and byte alignment fixes.
  [SCSI] bfa: Introduce a link notification state machine.
  [SCSI] bfa: Added firmware save clear feature for BFA driver.
  [SCSI] bfa: FCS authentication related changes.
  [SCSI] bfa: PCI VPD, FIP and include file changes.
  [SCSI] bfa: Fix to copy fpma MAC when requested by user space application.
  [SCSI] bfa: RPORT state machine: direct attach mode fix.
  ...

Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (35 commits)
  perf: Fix unexported generic perf_arch_fetch_caller_regs
  perf record: Don't try to find buildids in a zero sized file
  perf: export perf_trace_regs and perf_arch_fetch_caller_regs
  perf, x86: Fix hw_perf_enable() event assignment
  perf, ppc: Fix compile error due to new cpu notifiers
  perf: Make the install relative to DESTDIR if specified
  kprobes: Calculate the index correctly when freeing the out-of-line execution slot
  perf tools: Fix sparse CPU numbering related bugs
  perf_event: Fix oops triggered by cpu offline/online
  perf: Drop the obsolete profile naming for trace events
  perf: Take a hot regs snapshot for trace events
  perf: Introduce new perf_fetch_caller_regs() for hot regs snapshot
  perf/x86-64: Use frame pointer to walk on irq and process stacks
  lockdep: Move lock events under lockdep recursion protection
  perf report: Print the map table just after samples for which no map was found
  perf report: Add multiple event support
  perf session: Change perf_session post processing functions to take histogram tree
  perf session: Add storage for seperating event types in report
  perf session: Change add_hist_entry to take the tree root instead of session
  perf record: Add ID and to recorded event data when recording multiple events
  ...

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: avoid '\0' in hid debugfs events file
  HID: Add RGT Clutch Wheel clutch device id
  HID: ntrig: fix touch events
  HID: add quirk for UC-Logik WP4030 tablet
  HID: magicmouse: fix oops after device removal

* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (30 commits)
  Btrfs: fix the inode ref searches done by btrfs_search_path_in_tree
  Btrfs: allow treeid==0 in the inode lookup ioctl
  Btrfs: return keys for large items to the search ioctl
  Btrfs: fix key checks and advance in the search ioctl
  Btrfs: buffer results in the space_info ioctl
  Btrfs: use __u64 types in ioctl.h
  Btrfs: fix search_ioctl key advance
  Btrfs: fix gfp flags masking in the compression code
  Btrfs: don't look at bio flags after submit_bio
  btrfs: using btrfs_stack_device_id() get devid
  btrfs: use memparse
  Btrfs: add a "df" ioctl for btrfs
  Btrfs: cache the extent state everywhere we possibly can V2
  Btrfs: cache ordered extent when completing io
  Btrfs: cache extent state in find_delalloc_range
  Btrfs: change the ordered tree to use a spinlock instead of a mutex
  Btrfs: finish read pages in the order they are submitted
  btrfs: fix btrfs_mkdir goto for no free objectids
  Btrfs: flush data on snapshot creation
  Btrfs: make df be a little bit more understandable
  ...

* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
  NFS: ensure bdi_unregister is called on mount failure.
  NFS: Avoid a deadlock in nfs_release_page
  NFSv4: Don't ignore the NFS_INO_REVAL_FORCED flag in nfs_revalidate_inode()
  nfs4: Make the v4 callback service hidden
  nfs: fix unlikely memory leak
  rpc client can not deal with ENOSOCK, so translate it into ENOCONN

* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  ahci: pp->active_link is not reliable when FBS is enabled
  ahci: use BIOS date in broken_suspend list
  ahci: add missing nv IDs

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
  sound: sequencer: clean up remove bogus check
  ALSA: hda: Use LPIB and 6stack-dig for eMachines T5212
  ALSA: hda - Disable MSI for Nvidia controller
  ALSA: hda - Add PCI quirks for MSI NetOn AP1900 and Wind Top AE2220
  ALSA: hda - Fix secondary ADC of ALC260 basic model
  ALSA: hda - Add an error message for invalid mapping NID
  ALSA: hda - New Intel HDA controller

* 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight:
  backlight: panasonic-laptop - Fix incomplete registration failure handling
  backlight: msi-laptop, msi-wmi: fix incomplete registration failure handling
  backlight: blackfin - Fix missing registration failure handling
  backlight: classmate-laptop - Fix missing registration failure handling
  backlight: mbp_nvidia_bl - add five more MacBook variants
  backlight: Allow properties to be passed at registration
  backlight: Add backlight_device parameter to check_fb
  video: backlight/progear, fix pci device refcounting
  backlight: l4f00242t03: Fix module licence absence.
  backlight: Revert some const qualifiers
  backlight: Add Epson L4F00242T03 LCD driver

* 'for-linus' of git://git.o-hand.com/linux-rpurdie-leds:
  leds: Fix race between LED device uevent and actual attributes creation
  leds-gpio: fix default state handling on OF platforms
  leds: Add Dell Business Class Netbook LED driver
  leds: Kconfig cleanup
  leds: led-class.c - Quiet boot messages
  leds: make PCI device id constant
  leds: ALIX2: Add dependency to !GPIO_CS5335

* 'for-linus' of git://oss.sgi.com/xfs/xfs:
  xfs: don't warn about page discards on shutdown
  xfs: use scalable vmap API
  xfs: remove old vmap cache

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (39 commits)
  gigaset: fix build failure
  bridge: Make first arg to deliver_clone const.
  bridge br_multicast: Don't refer to BR_INPUT_SKB_CB(skb)->mrouters_only without IGMP snooping.
  route: Fix caught BUG_ON during rt_secret_rebuild_oneshot()
  bridge br_multicast: Fix skb leakage in error path.
  bridge br_multicast: Fix handling of Max Response Code in IGMPv3 message.
  NET: netpoll, fix potential NULL ptr dereference
  tipc: fix lockdep warning on address assignment
  l2tp: Fix UDP socket reference count bugs in the pppol2tp driver
  smsc95xx: wait for PHY to complete reset during init
  l2tp: Fix oops in pppol2tp_xmit
  smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver
  ne: Do not use slashes in irq name string
  NET: ksz884x, fix lock imbalance
  gigaset: correct range checking off by one error
  bridge: Fix br_forward crash in promiscuous mode
  bridge: Move NULL mdb check into br_mdb_ip_get
  ISDN: Add PCI ID for HFC-2S/4S Beronet Card PCIe
  net-2.6 [Bug-Fix][dccp]: fix oops caused after failed initialisation
  myri: remove dead code
  ...

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6:
  sunxvr1000: Add missing FB=y depenency.
  MAINTAINERS: Add entry for sparc serial drivers.
  drivers/serial/sunsab.c: adjust the constant used to initialize the interrupt_mask0 fields

* 'urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia-2.6:
  PCMCIA: resource, fix lock imbalance
  pcmcia: add important if statement
  pcmcia: re-route Cardbus IRQ to ISA on ti1130 bridges if necessary
  pcmcia: allow for cb_irq to differ from pci_dev's irq in yenta_socket
  pcmcia: honor saved flags in yenta_socket's I365_CSCINT register
  pcmcia: revert "irq probe can be done without risking an IRQ storm"
  pcmcia: pd6729, i82092: use parent (PCI) resources
  pcmcia/vrc4171: use local spinlock for device local lock.

This is used by the inode lookup ioctl to follow all the backrefs up
to the subvol root.  But the search being done would sometimes land one
past the last item in the leaf instead of finding the backref.

This changes the search to look for the highest possible backref and hop
back one item.  It also fixes a leaked path on failure to find the root.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

When a root id of 0 is sent to the inode lookup ioctl, it will
use the root of the file we're ioctling and pass the root id
back to userland along with the results.

This allows userland to do searches based on that root later on.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The search ioctl was skipping large items entirely (ones that are too
big for the results buffer).  This changes things to at least copy
the item header so that we can send information about the item back to
userland.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

The search ioctl was working well for finding tree roots, but using it for
generic searches requires a few changes to how the keys are advanced.
This treats the search control min fields for objectid, type and offset
more like a key, where we drop the offset to zero once we bump the type,
etc.

The downside of this is that we are changing the min_type and min_offset
fields during the search, and so the ioctl caller needs extra checks to make sure
the keys in the result are the ones it wanted.

This also changes key_in_sk to use btrfs_comp_cpu_keys, just to make
things more readable.
Signed-off-by: NChris Mason <chris.mason@oracle.com>

mpc52xx_gpt_wdt_setup is defined as 0, which causes the following build
failure with gcc 4.5, since it's built with -Werror.

arch/powerpc/platforms/52xx/mpc52xx_gpt.c:761:3: error: statement with no effect

Changing it to a static inline fixes the problem.
Reported-by: NJeff Mahoney <jeffm@suse.com>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

Commit 7c7b60cb
"of: put default string compare and #a/s-cell values into common header"

Breaks various things on powerpc due to using strncasecmp instead of
strcasecmp for comparing against "compatible" strings.

This causes things like the 4xx PCI code to fail miserably due to the
partial matches in code like this:

       for_each_compatible_node(np, NULL, "ibm,plb-pcix")
               ppc4xx_probe_pcix_bridge(np);
       for_each_compatible_node(np, NULL, "ibm,plb-pci")
               ppc4xx_probe_pci_bridge(np);

It's not quite right to do partial name match. Entries in a compatible
list are meant to be matched whole. If a device is compatible with both
"foo" and "foo1", then the device should have both strings in its
"compatible" property.

This patch reverts powerpc and microblaze us to use strcasecmp.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      (for patch description)
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Acked-by: NMichal Simek <michal.simek@petalogix.com>

Implement arch specific arch_get_memory_phys_device function and
initialize phys_device for each memory section.  That way we finally can
tell which piece of memory belongs to which physical device.

This makes s390's /sys/devices/system/memory/memoryX/phys_device display
the correct thing?
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

/sys/devices/system/memory/memoryX/phys_device is supposed to contain the
number of the physical device that the corresponding piece of memory
belongs to.

In case a physical device should be replaced or taken offline for whatever
reason it is necessary to set all corresponding memory pieces offline.
The current implementation always sets phys_device to '0' and there is no
way or hook to change that.  Seems like there was a plan to implement that
but it wasn't finished for whatever reason.

So add a weak function which architectures can override to actually set
the phys_device from within add_memory_block().
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace open-coded loop with for_each_set_bit().
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Clemens Ladisch <clemens@ladisch.de>
Cc: Bob Picco <bob.picco@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use bitmap_weight() instead of doing hweight32() for each u32 element in
the page.
Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

jffs2 uses rb_node = NULL; to zero rb_root.

The problem with this is that 17d9ddc7 ("rbtree: Add
support for augmented rbtrees") in the linux-next tree adds a new field
to that struct which needs to be NULL as well.  This patch uses RB_ROOT
as the intializer so all of the relevant fields will be NULL'd.
Signed-off-by: NVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Eric Paris <eparis@redhat.com>
Acked-by: NDavid Woodhouse <dwmw2@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

swap_cgroup uses 2bytes data and uses cmpxchg in a new operation.  2byte
cmpxchg/xchg is not available on some archs.  This patch replaces
cmpxchg/xchg with operations under lock.
Signed-off-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reported-by: Sachin Sant <sachinp@in.ibm.com> wrote:
Acked-by: NBalbir Singh <balbir@in.ibm.com>
Acked-by: NDaisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Update the dummy LL interface to the LL interface change
introduced by commit daab433c03c15fd642c71c94eb51bdd3f32602c8.
This fixes the build failure occurring after that commit when
enabling ISDN_DRV_GIGASET but neither ISDN_I4L nor ISDN_CAPI.

Impact: bugfix
Signed-off-by: NTilman Schmidt <tilman@imap.cc>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

pp->active_link is not reliable when FBS is enabled.
Both PORT_SCR_ACT and PORT_CMD_ISSUE should be checked
because mixed NCQ and non-NCQ commands may be in flight.
Signed-off-by: NShane Huang <shane.huang@amd.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

HP is recycling both DMI_PRODUCT_NAME and DMI_BIOS_VERSION making
ahci_broken_suspend() trigger for later products which are not
affected by the original problems.  Match BIOS date instead of version
and add references to bko's so that full information can be found
easier later.

This fixes http://bugzilla.kernel.org/show_bug.cgi?id=15462Signed-off-by: NTejun Heo <tj@kernel.org>
Reported-by: tigerfishdaisy@gmail.com
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

bko#15481 shows that we're missing some NVIDIA ahci PCI IDs.  Peer
Chen confirms that IDs 0x580-0x58f are reserved for cases where Linux
ID option is selected in the BIOS and are only used for mcp65-73.  Add
0x0581-0x058f.

  http://bugzilla.kernel.org/show_bug.cgi?id=15481Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Peer Chen <pchen@nvidia.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

perf_arch_fetch_caller_regs() is exported for the overriden x86
version, but not for the generic weak version.

As a general rule, weak functions should not have their symbol
exported in the same file they are defined.

So let's export it on trace_event_perf.c as it is used by trace
events only.

This fixes:

	ERROR: ".perf_arch_fetch_caller_regs" [fs/xfs/xfs.ko] undefined!
	ERROR: ".perf_arch_fetch_caller_regs" [arch/powerpc/platforms/cell/spufs/spufs.ko] undefined!

-v2: And also only build it if trace events are enabled.
-v3: Fix changelog mistake
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <1268697902-9518-1-git-send-regression-fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>