Commit Graph

28 Commits

Author SHA1 Message Date
Chris Wilson ce7ec768d6 drm/i915: dma_buf_vunmap is presumed not to fail, don't let it
Since dma_buf_vunmap() procedes blithely on ignorant of whether the
driver failed to actually unmap the backing storage for the dma-buf, we
need to make a best-effort to do so. This involves not allowing
ourselves to be susceptible to signals causing us to leak the storage.

This should have been detectable with the current i-g-t as a misplaced
signal should have left the pages pinned upon freeing the object where
we have a warning in place.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2014-04-09 15:03:05 +02:00
Chris Wilson 993fc6ebaf drm/i915: Pin pages whilst allocating for dma-buf vmap()
During the vmap() routine for the dma-buf, we first grab the pages and
then try to allocate a temporary array to pass to the vmap(). However,
the shrinker can and will reap any object that is unbound if the
allocation for the array first fails. This includes the object which we
are attempting to vmap(). The solution is to mark the object's pages as
pinned whilst we try the allocation to prevent the use-after-free
introduced by the potential shrinkage.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-11-29 15:51:20 +01:00
Chris Wilson 5cfacdedb1 drm/i915: Pin pages whilst mapping the dma-buf
As we attempt to kmalloc after calling get_pages, there is a possibility
that the shrinker may reap the pages we just acquired. To prevent this
we need to increment the pages_pin_count early, so rearrange the code
and error paths to make it so.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-09-03 19:17:58 +02:00
Dave Airlie efa27f9cec Merge tag 'drm-intel-next-2013-08-23' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
Need to get my stuff out the door ;-) Highlights:
- pc8+ support from Paulo
- more vma patches from Ben.
- Kconfig option to enable preliminary support by default (Josh
  Triplett)
- Optimized cpu cache flush handling and support for write-through caching
  of display planes on Iris (Chris)
- rc6 tuning from Stéphane Marchesin for more stability
- VECS seqno wrap/semaphores fix (Ben)
- a pile of smaller cleanups and improvements all over

Note that I've ditched Ben's execbuf vma conversion for 3.12 since not yet
ready. But there's still other vma conversion stuff in here.

* tag 'drm-intel-next-2013-08-23' of git://people.freedesktop.org/~danvet/drm-intel: (62 commits)
  drm/i915: Print seqnos as unsigned in debugfs
  drm/i915: Fix context size calculation on SNB/IVB/VLV
  drm/i915: Use POSTING_READ in lcpll code
  drm/i915: enable Package C8+ by default
  drm/i915: add i915.pc8_timeout function
  drm/i915: add i915_pc8_status debugfs file
  drm/i915: allow package C8+ states on Haswell (disabled)
  drm/i915: fix SDEIMR assertion when disabling LCPLL
  drm/i915: grab force_wake when restoring LCPLL
  drm/i915: drop WaMbcDriverBootEnable workaround
  drm/i915: Cleaning up the relocate entry function
  drm/i915: merge HSW and SNB PM irq handlers
  drm/i915: fix how we mask PMIMR when adding work to the queue
  drm/i915: don't queue PM events we won't process
  drm/i915: don't disable/reenable IVB error interrupts when not needed
  drm/i915: add dev_priv->pm_irq_mask
  drm/i915: don't update GEN6_PMIMR when it's not needed
  drm/i915: wrap GEN6_PMIMR changes
  drm/i915: wrap GTIMR changes
  drm/i915: add the FCLK case to intel_ddi_get_cdclk_freq
  ...
2013-08-30 09:47:41 +10:00
Daniel Vetter 608806a549 drm/i915: explicit store base gem object in dma_buf->priv
Makes it more obviously correct what tricks we play by reusing the drm
prime release helper.

Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-08-22 13:31:49 +02:00
Daniel Vetter f214266c0d drm/i915: unpin backing storage in dmabuf_unmap
This fixes a WARN in i915_gem_free_object when the
obj->pages_pin_count isn't 0.

v2: Add locking to unmap, noticed by Chris Wilson. Note that even
though we call unmap with our own dev->struct_mutex held that won't
result in an immediate deadlock since we never go through the dma_buf
interfaces for our own, reimported buffers. But it's still easy to
blow up and anger lockdep, but that's already the case with our ->map
implementation. Fixing this for real will involve per dma-buf ww mutex
locking by the callers. And lots of fun. So go with the duct-tape
approach for now.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Reported-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Tested-by: Armin K. <krejzi@email.com> (v1)
Acked-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-08-22 13:31:49 +02:00
Daniel Vetter c1d6798d20 drm: use common drm_gem_dmabuf_release in i915/exynos drivers
Note that this is slightly tricky since both drivers store their
native objects in dma_buf->priv. But both also embed the base
drm_gem_object at the first position, so the implicit cast is ok.

To use the release helper we need to export it, too.

Cc: Inki Dae <inki.dae@samsung.com>
Cc: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-08-19 10:44:58 +10:00
David Herrmann 89c8233f82 drm/gem: simplify object initialization
drm_gem_object_init() and drm_gem_private_object_init() do exactly the
same (except for shmem alloc) so make the first use the latter to reduce
code duplication.

Also drop the return code from drm_gem_private_object_init(). It seems
unlikely that we will extend it any time soon so no reason to keep it
around. This simplifies code paths in drivers, too.

Last but not least, fix gma500 to call drm_gem_object_release() before
freeing objects that were allocated via drm_gem_private_object_init().
That isn't actually necessary for now, but might be in the future.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Acked-by: Rob Clark <robdclark@gmail.com>
Signed-off-by: Dave Airlie <airlied@gmail.com>
2013-07-23 19:37:53 +10:00
Dave Airlie b11b88ef0e drm/i915: fix dmabuf vmap support
Sometimes that extra semicolon can really be hard to spot.

Acked-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-05-01 16:09:31 +10:00
Imre Deak 011c2282c7 drm: prime: fix refcounting on the dmabuf import error path
In commit be8a42ae60 we inroduced a refcount problem, where on the
drm_gem_prime_fd_to_handle() error path we'll call dma_buf_put() for
self imported dma buffers.

Fix this by taking a reference on the dma buffer in the .gem_import
hook instead of assuming the caller had taken one. Besides fixing the
bug this is also more logical.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: stable@vger.kernel.org
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-05-01 09:40:21 +10:00
Imre Deak 2db76d7c3c lib/scatterlist: sg_page_iter: support sg lists w/o backing pages
The i915 driver uses sg lists for memory without backing 'struct page'
pages, similarly to other IO memory regions, setting only the DMA
address for these. It does this, so that it can program the HW MMU
tables in a uniform way both for sg lists with and without backing pages.

Without a valid page pointer we can't call nth_page to get the current
page in __sg_page_iter_next, so add a helper that relevant users can
call separately. Also add a helper to get the DMA address of the current
page (idea from Daniel).

Convert all places in i915, to use the new API.

Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-03-27 17:13:44 +01:00
Imre Deak 67d5a50c04 drm/i915: handle walking compact dma scatter lists
So far the assumption was that each dma scatter list entry contains only
a single page. This might not hold in the future, when we'll introduce
compact scatter lists, so prepare for this everywhere in the i915 code
where we walk such a list.

We'll fix the place _creating_ these lists separately in the next patch
to help the reviewing/bisectability.

Reference: http://www.spinics.net/lists/dri-devel/msg33917.html
Signed-off-by: Imre Deak <imre.deak@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2013-03-23 12:16:36 +01:00
Dave Airlie b5cc6c0387 Merge tag 'drm-intel-next-2012-12-21' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
Daniel writes:
- seqno wrap fixes and debug infrastructure from Mika Kuoppala and Chris
  Wilson
- some leftover kill-agp on gen6+ patches from Ben
- hotplug improvements from Damien
- clear fb when allocated from stolen, avoids dirt on the fbcon (Chris)
- Stolen mem support from Chris Wilson, one of the many steps to get to
  real fastboot support.
- Some DDI code cleanups from Paulo.
- Some refactorings around lvds and dp code.
- some random little bits&pieces

* tag 'drm-intel-next-2012-12-21' of git://people.freedesktop.org/~danvet/drm-intel: (93 commits)
  drm/i915: Return the real error code from intel_set_mode()
  drm/i915: Make GSM void
  drm/i915: Move GSM mapping into dev_priv
  drm/i915: Move even more gtt code to i915_gem_gtt
  drm/i915: Make next_seqno debugs entry to use i915_gem_set_seqno
  drm/i915: Introduce i915_gem_set_seqno()
  drm/i915: Always clear semaphore mboxes on seqno wrap
  drm/i915: Initialize hardware semaphore state on ring init
  drm/i915: Introduce ring set_seqno
  drm/i915: Missed conversion to gtt_pte_t
  drm/i915: Bug on unsupported swizzled platforms
  drm/i915: BUG() if fences are used on unsupported platform
  drm/i915: fixup overlay stolen memory leak
  drm/i915: clean up PIPECONF bpc #defines
  drm/i915: add intel_dp_set_signal_levels
  drm/i915: remove leftover display.update_wm assignment
  drm/i915: check for the PCH when setting pch_transcoder
  drm/i915: Clear the stolen fb before enabling
  drm/i915: Access to snooped system memory through the GTT is incoherent
  drm/i915: Remove stale comment about intel_dp_detect()
  ...

Conflicts:
	drivers/gpu/drm/i915/intel_display.c
2013-01-17 20:34:08 +10:00
Seung-Woo Kim be8a42ae60 drm/prime: drop reference on imported dma-buf come from gem
Increasing ref counts of both dma-buf and gem for imported dma-buf come from gem
makes memory leak. release function of dma-buf cannot be called because f_count
of dma-buf increased by importing gem and gem ref count cannot be decrease
because of exported dma-buf.

So I add dma_buf_put() for imported gem come from its own gem into each drivers
having prime_import and prime_export capabilities. With this, only gem ref
count is increased if importing gem exported from gem of same driver.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Kyungmin.park <kyungmin.park@samsung.com>
Cc: Inki Dae <inki.dae@samsung.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Rob Clark <rob.clark@linaro.org>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-01-08 14:41:53 +10:00
Dave Airlie 5b42427fc3 drm/i915: fix flags in dma buf exporting
As pointed out by Seung-Woo Kim this should have been
passing flags like nouveau/radeon have.

Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-12-20 11:17:31 +01:00
Chris Wilson 42dcedd4f2 drm/i915: Use a slab for object allocation
The primary purpose of this was to debug some use-after-free memory
corruption that was causing an OOPS inside drm/i915. As it turned out
the corruption was being caused elsewhere and i915.ko as a major user of
many objects was being hit hardest.

Indeed as we do frequent the generic kmalloc caches, dedicating one to
ourselves (or at least naming one for us depending upon the core) aids
debugging our own slab usage.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-11-30 23:44:05 +01:00
Linus Torvalds 612a9aab56 Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
Pull drm merge (part 1) from Dave Airlie:
 "So first of all my tree and uapi stuff has a conflict mess, its my
  fault as the nouveau stuff didn't hit -next as were trying to rebase
  regressions out of it before we merged.

  Highlights:
   - SH mobile modesetting driver and associated helpers
   - some DRM core documentation
   - i915 modesetting rework, haswell hdmi, haswell and vlv fixes, write
     combined pte writing, ilk rc6 support,
   - nouveau: major driver rework into a hw core driver, makes features
     like SLI a lot saner to implement,
   - psb: add eDP/DP support for Cedarview
   - radeon: 2 layer page tables, async VM pte updates, better PLL
     selection for > 2 screens, better ACPI interactions

  The rest is general grab bag of fixes.

  So why part 1? well I have the exynos pull req which came in a bit
  late but was waiting for me to do something they shouldn't have and it
  looks fairly safe, and David Howells has some more header cleanups
  he'd like me to pull, that seem like a good idea, but I'd like to get
  this merge out of the way so -next dosen't get blocked."

Tons of conflicts mostly due to silly include line changes, but mostly
mindless.  A few other small semantic conflicts too, noted from Dave's
pre-merged branch.

* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (447 commits)
  drm/nv98/crypt: fix fuc build with latest envyas
  drm/nouveau/devinit: fixup various issues with subdev ctor/init ordering
  drm/nv41/vm: fix and enable use of "real" pciegart
  drm/nv44/vm: fix and enable use of "real" pciegart
  drm/nv04/dmaobj: fixup vm target handling in preparation for nv4x pcie
  drm/nouveau: store supported dma mask in vmmgr
  drm/nvc0/ibus: initial implementation of subdev
  drm/nouveau/therm: add support for fan-control modes
  drm/nouveau/hwmon: rename pwm0* to pmw1* to follow hwmon's rules
  drm/nouveau/therm: calculate the pwm divisor on nv50+
  drm/nouveau/fan: rewrite the fan tachometer driver to get more precision, faster
  drm/nouveau/therm: move thermal-related functions to the therm subdev
  drm/nouveau/bios: parse the pwm divisor from the perf table
  drm/nouveau/therm: use the EXTDEV table to detect i2c monitoring devices
  drm/nouveau/therm: rework thermal table parsing
  drm/nouveau/gpio: expose the PWM/TOGGLE parameter found in the gpio vbios table
  drm/nouveau: fix pm initialization order
  drm/nouveau/bios: check that fixed tvdac gpio data is valid before using it
  drm/nouveau: log channel debug/error messages from client object rather than drm client
  drm/nouveau: have drm debugging macros build on top of core macros
  ...
2012-10-03 23:29:23 -07:00
David Howells 760285e7e7 UAPI: (Scripted) Convert #include "..." to #include <path/...> in drivers/gpu/
Convert #include "..." to #include <path/...> in drivers/gpu/.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-02 18:01:07 +01:00
Chris Wilson 2f745ad3d3 drm/i915: Convert the dmabuf object to use the new i915_gem_object_ops
By providing a callback for when we need to bind the pages, and then
release them again later, we can shorten the amount of time we hold the
foreign pages mapped and pinned, and importantly the dmabuf objects then
behave as any other normal object with respect to the shrinker and
memory management.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-09-20 14:23:10 +02:00
Chris Wilson 9da3da660d drm/i915: Replace the array of pages with a scatterlist
Rather than have multiple data structures for describing our page layout
in conjunction with the array of pages, we can migrate all users over to
a scatterlist.

One major advantage, other than unifying the page tracking structures,
this offers is that we replace the vmalloc'ed array (which can be up to
a megabyte in size) with a chain of individual pages which helps reduce
memory pressure.

The disadvantage is that we then do not have a simple array to iterate,
or to access randomly. The common case for this is in the relocation
processing, which will typically fit within a single scatterlist page
and so be almost the same cost as the simple array. For iterating over
the array, the extra function call could be optimised away, but in
reality is an insignificant cost of either binding the pages, or
performing the pwrite/pread.

v2: Fix drm_clflush_sg() to not invoke wbinvd as well! And fix the
trivial compile error from rebasing.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-09-20 14:22:57 +02:00
Chris Wilson a5570178c0 drm/i915: Pin backing pages whilst exporting through a dmabuf vmap
We need to refcount our pages in order to prevent reaping them at
inopportune times, such as when they currently vmapped or exported to
another driver. However, we also wish to keep the lazy deallocation of
our pages so we need to take a pin/unpinned approach rather than a
simple refcount.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-09-20 14:22:56 +02:00
Chris Wilson 37e680a15f drm/i915: Introduce drm_i915_gem_object_ops
In order to specialise functions depending upon the type of object, we
can attach vfuncs to each object via a new ->ops pointer.

For instance, this will be used in future patches to only bind pages from
a dma-buf for the duration that the object is used by the GPU - and so
prevent them from pinning those pages for the entire of the object.

v2: Bonus comments.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-09-20 14:22:55 +02:00
Chris Wilson 6c085a728c drm/i915: Track unbound pages
When dealing with a working set larger than the GATT, or even the
mappable aperture when touching through the GTT, we end up with evicting
objects only to rebind them at a new offset again later. Moving an
object into and out of the GTT requires clflushing the pages, thus
causing a double-clflush penalty for rebinding.

To avoid having to clflush on rebinding, we can track the pages as they
are evicted from the GTT and only relinquish those pages on memory
pressure.

As usual, if it were not for the handling of out-of-memory condition and
having to manually shrink our own bo caches, it would be a net reduction
of code. Alas.

Note: The patch also contains a few changes to the last-hope
evict_everything logic in i916_gem_execbuffer.c - we no longer try to
only evict the purgeable stuff in a first try (since that's superflous
and only helps in OOM corner-cases, not fragmented-gtt trashing
situations).

Also, the extraction of the get_pages retry loop from bind_to_gtt (and
other callsites) to get_pages should imo have been a separate patch.

v2: Ditch the newly added put_pages (for unbound objects only) in
i915_gem_reset. A quick irc discussion hasn't revealed any important
reason for this, so if we need this, I'd like to have a git blame'able
explanation for it.

v3: Undo the s/drm_malloc_ab/kmalloc/ in get_pages that Chris noticed.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
[danvet: Split out code movements and rant a bit in the commit message
with a few Notes. Done v2]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-08-21 14:34:11 +02:00
Dave Airlie ec6f1bb90c drm/i915: implement dma buf begin_cpu_access (v2)
In order for udl vmap to work properly, we need to push the object
into the CPU domain before we start copying the data to the USB device.

This along with the udl change avoids userspace explicit mapping to
be used.

v2: add a flag for userspace to query to know if Intel kernel driver can
deal with the vmap flushing properly. In theory udl would need a flag also,
but I intend to push the patches very close to each other and other drivers
should do the right thing from the start.

I've added a test to my intel-gpu-tools prime branch, however testing
this is a bit messy since the only way to get udl to vmap is to rendering
something. I've tested this with real code as well to make sure it works.

Signed-off-by: Dave Airlie <airlied@redhat.com>
[danvet: resolved conflict, which required reallocating the PARAM
number to 21.]
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-08-17 10:10:06 +02:00
Dave Airlie 9a70cc2a78 i915: add dma-buf vmap support for exporting vmapped buffer
This is used to export a vmapping to the udl driver so that
i915 and udl can share the udl scanout.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-05-31 14:13:57 +01:00
Dave Airlie 2dad9d4d05 i915: add stub dma-buf mmap callback.
This just adds a stub for now, until we have some users in
place to test this functionality properly.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-05-31 13:13:31 +01:00
Dave Airlie 6a101cb209 drm/i915: make some dmabuf things static
these functions and the table can all be static/static const.

Reported-by: wfg@linux.intel.com
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-05-23 14:09:32 +01:00
Daniel Vetter 1286ff7397 i915: add dmabuf/prime buffer sharing support.
This adds handle->fd and fd->handle support to i915, this is to allow
for offloading of rendering in one direction and outputs in the other.

v2 from Daniel Vetter:
- fixup conflicts with the prepare/finish gtt prep work.
- implement ppgtt binding support.

Note that we have squat i-g-t testcoverage for any of the lifetime and
access rules dma_buf/prime support brings along. And there are quite a
few intricate situations here.

Also note that the integration with the existing code is a bit
hackish, especially around get_gtt_pages and put_gtt_pages. It imo
would be easier with the prep code from Chris Wilson's unbound series,
but that is for 3.6.

Also note that I didn't bother to put the new prepare/finish gtt hooks
to good use by moving the dma_buf_map/unmap_attachment calls in there
(like we've originally planned for).

Last but not least this patch is only compile-tested, but I've changed
very little compared to Dave Airlie's version. So there's a decent
chance v2 on drm-next works as well as v1 on 3.4-rc.

v3: Right when I've hit sent I've noticed that I've screwed up one
obj->sg_list (for dmar support) and obj->sg_table (for prime support)
disdinction. We should be able to merge these 2 paths, but that's
material for another patch.

v4: fix the error reporting bugs pointed out by ickle.

v5: fix another error, and stop non-gtt mmaps on shared objects
stop pread/pwrite on imported objects, add fake kmap

Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2012-05-23 10:47:10 +01:00