From Bspec, Vol 2a, Section 1.9.3.4 "PIPE_CONTROL", intro section
detailing the various workarounds:

"[DevIVB {W/A}, DevHSW {W/A}]: Pipe_control with CS-stall bit
set must be issued before a pipe-control command that has the State
Cache Invalidate bit set."

Note that public Bspec has different numbering, it's Vol2Part1,
Section 1.10.4.1 "PIPE_CONTROL" there.

There's also a second workaround for the PIPE_CONTROL command itself:

"[DevIVB, DevVLV, DevHSW] {WA}: Every 4th PIPE_CONTROL command, not
counting the PIPE_CONTROL with only read-cache-invalidate bit(s) set,
must have a CS_STALL bit set"

For simplicity we simply set the CS_STALL bit on every pipe_control on
gen7+

Note that this massively helps on some hsw machines, together with the
following patch to unconditionally set the CS_STALL bit on every
pipe_control it prevents a gpu hang every few seconds.

This is a regression that has been introduced in the pipe_control
cleanup:

commit 6c6cf5aa
Author: Chris Wilson <chris@chris-wilson.co.uk>
Date:   Fri Jul 20 18:02:28 2012 +0100

    drm/i915: Only apply the SNB pipe control w/a to gen6

It looks like the massive snb pipe_control workaround also papered
over any issues on ivb and hsw.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
[danvet: squashed both workarounds together, pimped commit message
with Bsepc citations, regression commit citation and changed the
comment in the code a bit to clarify that we unconditionally set
CS_STALL to avoid being hurt by trying to be clever.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Since gen 7+ now run the new gen7_render_ring_flush function.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

For now, just a copy of gen6_render_ring_flush. Different gens have
different workarounds, so we want different functions.
Signed-off-by: NPaulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Otherwise it just won't compile ...
Reported-by: NFengguang Wu <fengguang.wu@intel.com>
Reviewed-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: NDave Airlie <airlied@gmail.com>

Daniel writes:
"New stuff for -next. Highlights:
- prep patches for the modeset rework. Note that one of those patches
  touches the fb helper in the common drm code.
- hasw hdmi audio support (Wang Xingchao)
- improved instdone dumping for gen7 (Ben)
- unbound tracking and a few follow-up patches from Chris
- dma_buf->begin/end_cpu_access plus fix for drm/udl (Dave)
- improve mmio error reporting for hsw
- prep patch for WQ_NON_REENTRANT removal (Tejun Heo)
"

* 'for-airlied' of git://people.freedesktop.org/~danvet/drm-intel: (41 commits)
  drm/i915: Remove __GFP_NO_KSWAPD
  drm/i915: disable rc6 on ilk when vt-d is enabled
  drm/i915: Avoid unbinding due to an interrupted pin_and_fence during execbuffer
  drm/i915: Use new INSTDONE registers (Gen7+)
  drm/i915: Add new INSTDONE registers
  drm/i915: Extract reading INSTDONE
  drm/i915: Use a non-blocking wait for set-to-domain ioctl
  drm/i915: Juggle code order to ease flow of the next patch
  drm/i915: Use cpu relocations if the object is in the GTT but not mappable
  drm/i915: Extract general object init routine
  drm/i915: Protect private gem objects from truncate (such as imported dmabuf)
  drm/i915: Only pwrite through the GTT if there is space in the aperture
  i915: use alloc_ordered_workqueue() instead of explicit UNBOUND w/ max_active = 1
  drm/i915: Find unclaimed MMIO writes.
  drm/i915: Add ERR_INT to gen7 error state
  drm/i915: Cantiga+ cannot handle a hsync front porch of 0
  drm/i915: fix reassignment of variable "intel_dp->DP"
  drm/i915: Try harder to allocate an mmap_offset
  drm/i915: Show pin count in debugfs
  drm/i915: Show (count, size) of purgeable objects in i915_gem_objects
  ...

When I pulled-in today's drm-intel-next into linux-next (next-20120824)
I saw this build-breakage:

drivers/gpu/drm/i915/i915_gem.c: In function 'i915_gem_object_get_pages_gtt':
drivers/gpu/drm/i915/i915_gem.c:1778:40: error: '__GFP_NO_KSWAPD' undeclared (first use in this function)
drivers/gpu/drm/i915/i915_gem.c:1778:40: note: each undeclared identifier is reported only once for each function it appears in

This is caused by commit ba099ef165f8 ("mm: remove __GFP_NO_KSWAPD")
and commit b6beae2c2014 ("mm: remove __GFP_NO_KSWAPD fixes") in
linux-next (next-20120824).

Fix this by removing __GFP_NO_KSWAPD from drm/i915 driver.
Signed-off-by: NSedat Dilek <sedat.dilek@gmail.com>
Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

There was some merge conflicts in -next and they weren't so pretty, so
backmerge now to avoid them.

Conflicts:
	drivers/gpu/drm/i915/i915_gem.c
	drivers/gpu/drm/i915/intel_modes.c

Pull a hwmon fix from Guenter Roeck:
 "Fix sensor readings for Asus M5A78L in asus_atk0110 driver."

* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (asus_atk0110) Add quirk for Asus M5A78L

It blows up. And hopefully this is the root-cause of the mysterious
rc6 related hang on ilk. For reference, the commit that enabled rc6 on
ilk again is:

commit 456470eb
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Wed Aug 8 23:35:40 2012 +0200

    drm/i915: enable rc6 on ilk again
Reported-by: NDave Airlie <airlied@gmail.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Pull LogFS bugfixes from Prasad Joshi:

 - "logfs: query block device for number of pages to send with bio"

	This BUG was found when LogFS was used on KVM. The patch fixes
	the problem by asking for underlaying block device the number
	of pages to send with each BIO.

 - "logfs: maintain the ordering of meta-inode destruction"

	LogFS maintains file system meta-data in special inodes. These
	inodes are releated to each other, therefore they must be
	destroyed in a proper order.

 - "logfs: initialize the number of iovecs in bio"

	LogFS used to panic when it was created on an encrypted LVM
	volume. The patch fixes the problem by properly initializing
	the BIO.

Plus a couple more:
 - logfs: create a pagecache page if it is not present
 - logfs: destroy the reserved inodes while unmounting

* tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream:
  logfs: query block device for number of pages to send with bio
  logfs: maintain the ordering of meta-inode destruction
  logfs: create a pagecache page if it is not present
  logfs: initialize the number of iovecs in bio
  logfs: destroy the reserved inodes while unmounting

Pull arm-soc fixes from Arnd Bergmann:
 "Bug fixes for various ARM platforms.  About half of these are for OMAP
  and submitted before but did not make it into v3.6-rc2."

* tag 'fixes-3.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (39 commits)
  ARM: ux500: don't select LEDS_GPIO for snowball
  ARM: imx: build i.MX6 functions only when needed
  ARM: imx: select CPU_FREQ_TABLE when needed
  ARM: imx: fix ksz9021rn_phy_fixup
  ARM: imx: build pm-imx5 code only when PM is enabled
  ARM: omap: allow building omap44xx without SMP
  ARM: dts: imx51-babbage: fix esdhc cd/wp properties
  ARM: imx6: spin the cpu until hardware takes it down
  ARM: ux500: Ensure probing of Audio devices when Device Tree is enabled
  ARM: ux500: Fix merge error, no matching driver name for 'snd_soc_u8500'
  ARM i.MX6q: Add virtual 1/3.5 dividers in the LDB clock path
  ARM: Kirkwood: fix Makefile.boot
  ARM: Kirkwood: Fix iconnect leds
  ARM: Orion: Set eth packet size csum offload limit
  ARM: mv78xx0: fix win_cfg_base prototype
  ARM: OMAP: dmtimers: Fix locking issue in omap_dm_timer_request*()
  ARM: mmp: fix potential NULL dereference
  ARM: OMAP4: Register the OPP table only for 4430 device
  cpufreq: OMAP: Handle missing frequency table on SMP systems
  ARM: OMAP4: sleep: Save the complete used register stack frame
  ...

Merge tag 'stable/for-linus-3.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen

Pull three xen bug-fixes from Konrad Rzeszutek Wilk:
 - Revert the kexec fix which caused on non-kexec shutdowns a race.
 - Reuse existing P2M leafs - instead of requiring to allocate a large
   area of bootup virtual address estate.
 - Fix a one-off error when adding PFNs for balloon pages.

* tag 'stable/for-linus-3.6-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen/setup: Fix one-off error when adding for-balloon PFNs to the P2M.
  xen/p2m: Reuse existing P2M leafs if they are filled with 1:1 PFNs or INVALID.
  Revert "xen PVonHVM: move shared_info to MMIO before kexec"

Pull powerpc fixes from Benjamin Herrenschmidt:
 "I meant to sent that earlier but got swamped with other things, so
  here are some powerpc fixes for 3.6.  A few regression fixes and some
  bug fixes that I deemed should still make it.

  There's a FSL update from Kumar with a bunch of defconfig updates
  along with a few embedded fixes.

  I also reverted my g5_defconfig update that I merged earlier as it was
  completely busted, not too sure what happened there, I'll do a new one
  later."

* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
  Revert "powerpc: Update g5_defconfig"
  powerpc/perf: Use pmc_overflow() to detect rolled back events
  powerpc: Fix VMX in interrupt check in POWER7 copy loops
  powerpc: POWER7 copy_to_user/copy_from_user patch applied twice
  powerpc: Fix personality handling in ppc64_personality()
  powerpc/dma-iommu: Fix IOMMU window check
  powerpc: Remove unnecessary ifdefs
  powerpc/kgdb: Restore current_thread_info properly
  powerpc/kgdb: Bail out of KGDB when we've been triggered
  powerpc/kgdb: Do not set kgdb_single_step on ppc
  powerpc/mpic_msgr: Add missing includes
  powerpc: Fix null pointer deref in perf hardware breakpoints
  powerpc: Fixup whitespace in xmon
  powerpc: Fix xmon dl command for new printk implementation
  powerpc/fsl: fix "Failed to mount /dev: No such device" errors
  powerpc/fsl: update defconfigs
  booke/wdt: some ioctls do not return values properly
  powerpc/p4080ds: dts - add usb controller version info and port0
  powerpc/85xx: mpc85xx_defconfig - add VIA PATA support for MPC85xxCDS
  powerpc/fsl-pci: Only scan PCI bus if configured as a host

Pull kvm fixes from Marcelo Tosatti.

* git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86 emulator: use stack size attribute to mask rsp in stack ops
  KVM: MMU: Fix mmu_shrink() so that it can free mmu pages as intended
  ppc: e500_tlb memset clears nothing
  KVM: PPC: Add cache flush on page map
  KVM: PPC: Book3S HV: Fix incorrect branch in H_CEDE code
  KVM: x86: update KVM_SAVE_MSRS_BEGIN to correct value

Pull xfs bugfixes from Ben Myers:
 - fix uninitialised variable in xfs_rtbuf_get()
 - unlock the AGI buffer when looping in xfs_dialloc
 - check for possible overflow in xfs_ioc_trim

* tag 'for-linus-v3.6-rc4' of git://oss.sgi.com/xfs/xfs:
  xfs: check for possible overflow in xfs_ioc_trim
  xfs: unlock the AGI buffer when looping in xfs_dialloc
  xfs: fix uninitialised variable in xfs_rtbuf_get()

Pull MIPS fixes from Ralf Baechle:
 "Random fixes across the MIPS tree.  The two hotspots are several bugs
  in the module loader and the ath79 SOC support; also noteworthy is the
  restructuring of the code to synchronize CPU timers across CPUs on
  startup; the old code recently ceased to work due to unrelated
  changes.

  All except one of these patches have sat for a significant time in
  linux-next for testing."

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
  MIPS: pci-ar724x: avoid data bus error due to a missing PCIe module
  MIPS: Malta: Delete duplicate PCI fixup.
  MIPS: ath79: don't hardcode the unavailability of the DSP ASE
  MIPS: Synchronize MIPS count one CPU at a time
  MIPS: BCM63xx: Fix SPI message control register handling for BCM6338/6348.
  MIPS: Module: Deal with malformed HI16/LO16 relocation sequences.
  MIPS: Fix race condition in module relocation code.
  MIPS: Fix memory leak in error path of HI16/LO16 relocation handling.
  MIPS: MTX-1: Add udelay to mtx1_pci_idsel
  MIPS: ath79: select HAVE_CLK
  MIPS: ath79: Use correct IRQ number for the OHCI controller on AR7240
  MIPS: ath79: Fix number of GPIO lines for AR724[12]
  MIPS: Octeon: Fix broken interrupt controller code.

Pull nfsd bugfixes from J. Bruce Fields:
 "Particular thanks to Michael Tokarev, Malahal Naineni, and Jamie
  Heilman for their testing and debugging help."

* 'for-3.6' of git://linux-nfs.org/~bfields/linux:
  svcrpc: fix svc_xprt_enqueue/svc_recv busy-looping
  svcrpc: sends on closed socket should stop immediately
  svcrpc: fix BUG() in svc_tcp_clear_pages
  nfsd4: fix security flavor of NFSv4.0 callback

Pull block-related fixes from Jens Axboe:

 - Improvements to the buffered and direct write IO plugging from
   Fengguang.

 - Abstract out the mapping of a bio in a request, and use that to
   provide a blk_bio_map_sg() helper.  Useful for mapping just a bio
   instead of a full request.

 - Regression fix from Hugh, fixing up a patch that went into the
   previous release cycle (and marked stable, too) attempting to prevent
   a loop in __getblk_slow().

 - Updates to discard requests, fixing up the sizing and how we align
   them.  Also a change to disallow merging of discard requests, since
   that doesn't really work properly yet.

 - A few drbd fixes.

 - Documentation updates.

* 'for-linus' of git://git.kernel.dk/linux-block:
  block: replace __getblk_slow misfix by grow_dev_page fix
  drbd: Write all pages of the bitmap after an online resize
  drbd: Finish requests that completed while IO was frozen
  drbd: fix drbd wire compatibility for empty flushes
  Documentation: update tunable options in block/cfq-iosched.txt
  Documentation: update tunable options in block/cfq-iosched.txt
  Documentation: update missing index files in block/00-INDEX
  block: move down direct IO plugging
  block: remove plugging at buffered write time
  block: disable discard request merge temporarily
  bio: Fix potential memory leak in bio_find_or_create_slab()
  block: Don't use static to define "void *p" in show_partition_start()
  block: Add blk_bio_map_sg() helper
  block: Introduce __blk_segment_map_sg() helper
  fs/block-dev.c:fix performance regression in O_DIRECT writes to md block devices
  block: split discard into aligned requests
  block: reorganize rounding of max_discard_sectors

Pull libata fixes from Jeff Garzik:
 - libata-acpi regression fix
 - additional or corrected drive quirks for ata_blacklist
 - Kconfig text tweaking
 - new PCI IDs
 - pata_atiixp: quirk for MSI motherboard
 - export ahci_dev_classify for an ahci_platform driver

* tag 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
  libata: Add a space to " 2GB ATA Flash Disk" DMA blacklist entry
  [libata] new quirk, lift bridge limits for Buffalo DriveStation Quattro
  [libata] Kconfig: Elaborate that SFF is meant for legacy and PATA stuff
  [libata] acpi: call ata_acpi_gtm during ata port init time
  ata_piix: Add Device IDs for Intel Lynx Point-LP PCH
  ahci: Add Device IDs for Intel Lynx Point-LP PCH
  pata_atiixp: override cable detection on MSI E350DM-E33
  ahci: un-staticize ahci_dev_classify

commit d70e551c, Add " 2GB ATA Flash
Disk"/"ADMA428M" to DMA blacklist, should have added a space before 2GB.
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>

If we need to stall in order to complete the pin_and_fence operation
during execbuffer reservation, there is a high likelihood that the
operation will be interrupted by a signal (thanks X!). In order to
simplify the cleanup along that error path, the object was
unconditionally unbound and the error propagated. However, being
interrupted here is far more common than I would like and so we can
strive to avoid the extra work by eliminating the forced unbind.

v2: In discussion over the indecent colour of the new functions and
unwind path, we realised that we can use the new unreserve function to
clean up the code even further.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Using the extracted INSTDONE reading, and our new register definitions,
update our hangcheck detection and error collection to use it. This
primarily means changing == to memcmp, and changing = to memcpy.
Hopefully this will give more info on error dump, and provide more
accurate hangcheck detection (both are actually TBD).

Also, remove the reading of instdone1 from the ring error collection
function, and just crap everything in capture_error_state (that could be
split into a separate patch if it wasn't so trivial).

v2: Now assuming i915_get_extra_instdone does the memset we can clean up the
code a bit (Jani)

v3: use ARRAY_SIZE as requested earlier by Jani (didn't change sizeof)
Updated commit msg

Cc: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

INSTDONE is used in many places, and it varies from generation to
generation. This provides a good reason for us to extract the logic to
read the relevant information.

The patch has no functional change. It's prep for some new stuff.

v2: move the memset inside of i915_get_extra_instdone (Jani)
v3,4: bugs caught by (Jani)
Reviewed-by: NJani Nikula <jani.nikula@intel.com>
Signed-off-by: NBen Widawsky <ben@bwidawsk.net>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

This reverts commit b1acf1bb.

Something went horribly wrong when I did savedefconfig, not sure what,
but what's in there is busted so let's revert it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For certain speculative events on Power7, 'perf stat' reports far higher
event count than 'perf record' for the same event.

As described in following commit, a performance monitor exception is raised
even when the the performance events are rolled back.

        commit 0837e324
        Author: Anton Blanchard <anton@samba.org>
        Date:   Wed Mar 9 14:38:42 2011 +1100

perf_event_interrupt() records an event only when an overflow occurs. But
this check for overflow is a simple 'if (val < 0)'.

Because the events are rolled back, this check for overflow fails and the
event is not recorded. perf_event_interrupt() later uses pmc_overflow() to
detect the overflow and resets the counters and the events are lost completely.

To properly detect the overflow of rolled back events, use pmc_overflow()
even when recording events.

To reproduce:
        $ cat strcpy.c
        #include <stdio.h>
        #include <string.h>
        main()
        {
                char buf[256];

                alarm(5);
                while(1)
                        strcpy(buf, "string1");
        }

        $ perf record -e r20014 ./strcpy
        $ perf report -n > report.1
        $ perf stat -e r20014 > report.2
        # Compare report.1 and report.2
Reported-by: NMaynard Johnson <mpjohn@us.ibm.com>
Signed-off-by: NSukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The enhanced prefetch hint patches corrupt the condition register
that was used to check if we are in interrupt. Fix this by using cr1.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

"powerpc: Use enhanced touch instructions in POWER7
copy_to_user/copy_from_user" was applied twice. Remove one.
Signed-off-by: NAnton Blanchard <anton@samba.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Directly comparing current->personality against PER_LINUX32 doesn't work
in cases when any of the personality flags stored in the top three bytes
are used.

Directly forcefully setting personality to PER_LINUX32 or PER_LINUX
discards any flags stored in the top three bytes

Use personality() macro to compare only PER_MASK bytes and make sure that
we are setting only the bits that should be set, instead of overwriting
the whole value.
Signed-off-by: NJiri Kosina <jkosina@suse.cz>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Checking for device mask to cover the whole IOMMU table is too strict.
IOMMU allocators should handle mask constraint properly for each
allocation.

The patch enables to use old AirPort Extreme cards on PowerMacs with
more than 1GB of memory; without the patch the driver init fails with:

  b43-pci-bridge 0001:01:01.0: Warning: IOMMU window too big for device mask
  b43-pci-bridge 0001:01:01.0: mask: 0x3fffffff, table end: 0x80000000
  b43-phy0 ERROR: The machine/kernel does not support the required 30-bit DMA mask
Signed-off-by: NAaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

For powerpc BooKE and e200, singlestep is handled on the critical/dbg
exception stack. This causes current_thread_info() to fail for kgdb
internal, so previously We work around this issue by copying
the thread_info from the kernel stack before calling kgdb_handle_exception,
and copying it back afterwards.

But actually we don't do this properly. We should backup current_thread_info
then restore that when exit.
Signed-off-by: NTiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We need to skip a breakpoint exception when it occurs after
a breakpoint has already been removed.
Signed-off-by: NTiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The kgdb_single_step flag has the possibility to indefinitely
hang the system on an SMP system.

The x86 arch have the same problem, and that problem was fixed by
commit 8097551d(kgdb,x86: do not set kgdb_single_step
on x86). This patch does the same behaviors as x86's patch.
Signed-off-by: NDongdong Deng <dongdong.deng@windriver.com>
Signed-off-by: NJason Wessel <jason.wessel@windriver.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Add several #includes that mpic_msgr relies on being pulled implicitly,
which only happens on certain configs.
Signed-off-by: NScott Wood <scottwood@freescale.com>
Cc: Meador Inge <meador_inge@mentor.com>
Cc: Jia Hongtao <B38951@freescale.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Currently if you are doing a global perf recording with hardware
breakpoints (ie perf record -e mem:0xdeadbeef -a), you can oops with:

  Faulting instruction address: 0xc000000000738890
  cpu 0xc: Vector: 300 (Data Access) at [c0000003f76af8d0]
      pc: c000000000738890: .hw_breakpoint_handler+0xa0/0x1e0
      lr: c000000000738830: .hw_breakpoint_handler+0x40/0x1e0
      sp: c0000003f76afb50
     msr: 8000000000001032
     dar: 6f0
   dsisr: 42000000
    current = 0xc0000003f765ac00
    paca    = 0xc00000000f262a00   softe: 0        irq_happened: 0x01
    pid   = 6810, comm = loop-read
  enter ? for help
  [c0000003f76afbe0] c00000000073cd04 .notifier_call_chain.isra.0+0x84/0xe0
  [c0000003f76afc80] c00000000073cdbc .notify_die+0x3c/0x60
  [c0000003f76afd20] c0000000000139f0 .do_dabr+0x40/0xf0
  [c0000003f76afe30] c000000000005a9c handle_dabr_fault+0x14/0x48
  --- Exception: 300 (Data Access) at 0000000010000480
  SP (ff8679e0) is in userspace

This is because we don't check to see if the break point is associated
with task before we deference the task_struct pointer.

This changes the update to use current.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

There are a few whitespace goolies in xmon.c, some of them appear to
be my fault. Fix them all in one go.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Since the printk internals were reworked the xmon 'dl' command which
dumps the content of __log_buf has stopped working.

It is now a structured buffer, so just dumping it doesn't really work.

Use the helpers added for kgdb to print out the content.
Signed-off-by: NMichael Ellerman <michael@ellerman.id.au>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The principal use for set-to-domain is for userspace to serialise
operations with a particular buffer, for example to maintain coherency
with a CPU map or to ratelimit its rendering by waiting on all previous
operations before continuing. As such we tend to hold the struct_mutex
for long periods during the synchronisation and so cause contention
issues with other users of the graphics device, even for independent
operations as memory management. An example is the contention between
compiz and X which causes jitter in the display and a drop in peak
throughput.

The ultimate solution would be a set of fine grained locks and lockless
operations, but an intermediate step is to first attempt the
synchronisation for set-to-domain without holding the mutex. This
introduces a number of race conditions, so we limit it use to the ioctl
periphery where we have no dependent state and can safely complete with
a locked synchronisation afterwards.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

Move the wait-for-rendering logic around in the file so that we can
group it together with the subsequent variations. The general goal is to
have the lower level routines clustered together and then the higher
level logic building upon those low level routines that came before.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>