Most fasync implementations do something like:

     return fasync_helper(...);

But fasync_helper() will return a positive value at times - a feature used
in at least one place.  Thus, a number of other drivers do:

     err = fasync_helper(...);
     if (err < 0)
             return err;
     return 0;

In the interests of consistency and more concise code, it makes sense to
map positive return values onto zero where ->fasync() is called.

Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: NJonathan Corbet <corbet@lwn.net>

This is done by
1) Wake up lock waiters when we close the master file descriptor.
   Not when the master structure is removed, since the latter
   requires the waiters themselves to release the refcount on the
   master structure -> Deadlock.
2) Send a SIGTERM to all clients waiting for the lock.
   Normally these clients will get a SIGPIPE when the X server dies,
   but clients may also spin trying to grab the DRM lock, without
   getting any sort of notification.
Signed-off-by: NThomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: NDave Airlie <airlied@linux.ie>

Avoids leaking fbs and associated buffers on release.
Signed-off-by: NKristian Høgsberg <krh@redhat.com>
Tested-by: NTested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@linux.ie>

Several subsystem open handlers dereference the fops_get() return value
without checking it for nullness.  This opens a race condition between the
open handler and module unloading.

A module can be marked as being unloaded (MODULE_STATE_GOING) before its
exit function is called and gets the chance to unregister the driver.
During that window open handlers can still be called, and fops_get() will
fail in try_module_get() and return a NULL pointer.

This change checks the fops_get() return value and returns -ENODEV if NULL.
Reported-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: NLaurent Pinchart <laurent.pinchart@skynet.be>
Acked-by: NTakashi Iwai <tiwai@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Airlie <airlied@linux.ie>
Acked-by: NMauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add mode setting support to the DRM layer.

This is a fairly big chunk of work that allows DRM drivers to provide
full output control and configuration capabilities to userspace.  It was
motivated by several factors:
  - the fb layer's APIs aren't suited for anything but simple
    configurations
  - coordination between the fb layer, DRM layer, and various userspace
    drivers is poor to non-existent (radeonfb excepted)
  - user level mode setting drivers makes displaying panic & oops
    messages more difficult
  - suspend/resume of graphics state is possible in many more
    configurations with kernel level support

This commit just adds the core DRM part of the mode setting APIs.
Driver specific commits using these new structure and APIs will follow.

Co-authors: Jesse Barnes <jbarnes@virtuousgeek.org>, Jakob Bornecrantz <jakob@tungstengraphics.com>
Contributors: Alan Hourihane <alanh@tungstengraphics.com>, Maarten Maathuis <madman2003@gmail.com>
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Add core support for mapping of GEM objects.  Drivers should provide a
vm_operations_struct if they want to support page faulting of objects.
The code for handling GEM object offsets was taken from TTM, which was
written by Thomas Hellström.
Signed-off-by: NJesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

This is step one towards having multiple masters sharing a drm
device in order to get fast-user-switching to work.

It splits out the information associated with the drm master
into a separate kref counted structure, and allocates this when
a master opens the device node. It also allows the current master
to abdicate (say while VT switched), and a new master to take over
the hardware.

It moves the Intel and radeon drivers to using the sarea from
within the new master structures.
Signed-off-by: NDave Airlie <airlied@redhat.com>

As it is, all instances of ->release() for files that have ->fasync()
need to remember to evict file from fasync lists; forgetting that
creates a hole and we actually have a bunch that *does* forget.

So let's keep our lives simple - let __fput() check FASYNC in
file->f_flags and call ->fasync() there if it's been set.  And lose that
crap in ->release() instances - leaving it there is still valid, but we
don't have to bother anymore.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

GEM allows the creation of persistent buffer objects accessible by the
graphics device through new ioctls for managing execution of commands on the
device.  The userland API is almost entirely driver-specific to ensure that
any driver building on this model can easily map the interface to individual
driver requirements.

GEM is used by the 2d driver for managing its internal state allocations and
will be used for pixmap storage to reduce memory consumption and enable
zero-copy GLX_EXT_texture_from_pixmap, and in the 3d driver is used to enable
GL_EXT_framebuffer_object and GL_ARB_pixel_buffer_object.
Signed-off-by: NEric Anholt <eric@anholt.net>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Wrap access to task credentials so that they can be separated more easily from
the task_struct during the introduction of COW creds.

Change most current->(|e|s|fs)[ug]id to current_(|e|s|fs)[ug]id().

Change some task->e?[ug]id to task_e?[ug]id().  In some places it makes more
sense to use RCU directly rather than a convenient wrapper; these will be
addressed by later patches.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Reviewed-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NDavid Airlie <airlied@redhat.com>

With the coming of kernel based modesetting and the memory manager stuff,
the everything in one directory approach was getting very ugly and
starting to be unmanageable.

This restructures the drm along the lines of other kernel components.

It creates a drivers/gpu/drm directory and moves the hw drivers into
subdirectores. It moves the includes into an include/drm, and
sets up the unifdef for the userspace headers we should be exporting.
Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NJonathan Corbet <corbet@lwn.net>

Signed-off-by: NDave Airlie <airlied@redhat.com>

Signed-off-by: NDave Airlie <airlied@linux.ie>

rips out the head crap and replaces it with an idr and drm_minor structure
Signed-off-by: NDave Airlie <airlied@redhat.com>

The i915_vblank_swap() function schedules an automatic buffer swap
upon receipt of the vertical sync interrupt.  Such an operation is
lengthy so it can't be allowed to happen in normal interrupt context,
thus the DRM implements this by scheduling the work in a kernel
softirq-scheduled tasklet.  In order for the buffer swap to work
safely, the DRM's central lock must be taken, via a call to
drm_lock_take() located in drivers/char/drm/drm_irq.c within the
function drm_locked_tasklet_func().  The lock-taking logic uses a
non-interrupt-blocking spinlock to implement the manipulations needed
to take the lock.  This semantic would be safe if all attempts to use
the spinlock only happen from process context.  However this buffer
swap happens from softirq context which is really a form of interrupt
context.  Thus we have an unsafe situation, in that
drm_locked_tasklet_func() can block on a spinlock already taken by a
thread in process context which will never get scheduled again because
of the blocked softirq tasklet.  This wedges the kernel hard.

To trigger this bug, run a dual-head cloned mode configuration which
uses the i915 drm, then execute an opengl application which
synchronizes buffer swaps against the vertical sync interrupt.  In my
testing, a lockup always results after running anywhere from 5 minutes
to an hour and a half.  I believe dual-head is needed to really
trigger the problem because then the vertical sync interrupt handling
is no longer predictable (due to being interrupt-sourced from two
different heads running at different speeds).  This raises the
probability of the tasklet trying to run while the userspace DRI is
doing things to the GPU (and manipulating the DRM lock).

The fix is to change the relevant spinlock semantics to be the
interrupt-blocking form.  After this change I am no longer able to
trigger the lockup; the longest test run so far was 20 hours (test
stopped after that point).

Note: I have examined the places where this spinlock is being
employed; all are reasonably short bounded sequences and should be
suitable for interrupts being blocked without impacting overall kernel
interrupt response latency.
Signed-off-by: NMike Isely <isely@pobox.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

The task_struct->pid member is going to be deprecated, so start
using the helpers (task_pid_nr/task_pid_vnr/task_pid_nr_ns) in
the kernel.

The first thing to start with is the pid, printed to dmesg - in
this case we may safely use task_pid_nr(). Besides, printks produce
more (much more) than a half of all the explicit pid usage.

[akpm@linux-foundation.org: git-drm went and changed lots of stuff]
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The data is now in kernel space, copied in/out as appropriate according to t
This results in DRM_COPY_{TO,FROM}_USER going away, and error paths to deal
with those failures.  This also means that XFree86 4.2.0 support for i810 DR
is lost.
Signed-off-by: NDave Airlie <airlied@linux.ie>

As a fallout, replace filp storage with file_priv storage for "unique
identifier of a client" all over the DRM.  There is a 1:1 mapping, so this
should be a noop.  This could be a minor performance improvement, as everyth
on Linux dereferenced filp to get file_priv anyway, while only the mmap ioct
went the other direction.
Signed-off-by: NDave Airlie <airlied@linux.ie>

Signed-off-by: NDave Airlie <airlied@linux.ie>

some drivers still todo.
Signed-off-by: NDave Airlie <airlied@linux.ie>

Signed-off-by: NDave Airlie <airlied@linux.ie>

This makes the drms use of the list handling macros a lot cleaner
and more along the lines of how they should be used and uses them
in some more places.
Signed-off-by: NDave Airlie <airlied@linux.ie>

Bugzilla Bug #9457

Add refcounting of user waiters to the DRM hardware lock, so that we can use
DRM_LOCK_CONT flag more conservatively.

Also add a kernel waiter refcount that if nonzero transfers the lock for the
kernel context when it is released. This is useful when waiting for idle and can be used for very simple fence object driver implementations for the new memory manager
Signed-off-by: NDave Airlie <airlied@linux.ie>

drivers/char/drm/drm_fops.c: In function 'drm_setup':
drivers/char/drm/drm_fops.c:60: warning: comparison of distinct pointer types lacks a cast

Unfortunately PAGE_SIZE has different types on different architectures.
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NDave Airlie <airlied@linux.ie>

Signed-off-by: NDave Airlie <airlied@linux.ie>

Signed-off-by: NDave Airlie <airlied@linux.ie>

Fix drm_remove_magic potential memory leak / corruption. Move drm
authentication token hashing to new generic hash table implementation.
Signed-off-by: NDave Airlie <airlied@linux.ie>

This patch removes some of the old compatibility macros from the DRM,
and removes use of DRM wrappers from Linux specific code.
Signed-off-by: NDave Airlie <airlied@linux.ie>

Mark the f_ops members of inodes as const, as well as fix the
ripple-through this causes by places that copy this f_ops and then "do
stuff" with it.
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

From: Arjan van de Ven <arjan@infradead.org>

Semaphore to mutex conversion.

The conversion was generated via scripts, and the result was validated
automatically via a script as well.
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NDave Airlie <airlied@linux.ie>

This patch pull in a lot of changes from CVS to the main core DRM,
and updates the radeon driver to 1.21.0 that supports r300 texrect
and radeon card type ioctl.
Signed-off-by: NDave Airlie <airlied@linux.ie>

drm_flush is no longer needed remove.
Signed-off-by: NDave Airlie <airlied@linux.ie>

Move drm_cpu_valid into drm_fops.c
Signed-off-by: NDave Airlie <airlied@linux.ie>

Rename the driver hooks in the DRM to something a little more understandable:
preinit         ->      load
postinit        ->      (removed)
presetup        ->      firstopen
postsetup       ->      (removed)
open_helper     ->      open
prerelease      ->      preclose
free_filp_priv  ->      postclose
pretakedown     ->      lastclose
postcleanup     ->      unload
release         ->      reclaim_buffers_locked
version         ->      (removed)

postinit and version were replaced with generic code in the Linux DRM (drivers
now set their version numbers and description in the driver structure, like on
BSD).  postsetup wasn't used at all.  Fixes the savage hooks for
initializing and tearing down mappings at the right times.  Testing involved at
least starting X, running glxgears, killing glxgears, exiting X, and repeating.

Tested on:      FreeBSD (g200, g400, r200, r128)
                Linux (r200, savage4)

From: Eric Anholt <anholt@freebsd.org>
Signed-off-by: NDave Airlie <airlied@linux.ie>

These haven't been used in quite a long time, takes 1K buffer out of structures.
Signed-off-by: NDave Airlie <airlied@linux.ie>

I've been threatening this for a while, so no point hanging around.
This lindents the DRM code which was always really bad in tabbing department.
I've also fixed some misnamed files in comments and removed some trailing
whitespace.
Signed-off-by: NDave Airlie <airlied@linux.ie>

This is a patch from DRM CVS that cleans up some code that was in CVS
that I never moved to the kernel, this patch produces the result of the
cleanups and puts it into the kernel drm.

From: Eric Anholt <anholt@freebsd.org>, Jon Smirl, Dave Airlie
Signed-off-by: NDave Airlie <airlied@linux.ie>

This patch contains the following cleanups:
- make needlessly global functions static
- remove the following unused global functions:
 - drm_fops.c: drm_read
 - i915_dma.c: i915_do_cleanup_pageflip
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NDave Airlie <airlied@linux.ie>

From: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: NDave Airlie <airlied@linux.ie>