1. 22 3月, 2014 3 次提交
    • D
      drm/helper: lock all around force mode restore · 3ea87855
      Dave Airlie 提交于
      Since Daniel documented things with a sledge hammer, we got lots of
      nice backtraces in suspend/resume operations, I've check the callers
      of this and they all seems safe to me,
      
      This fixes one set of warns I reported.
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      3ea87855
    • D
      drm/fb-helper: improve drm_fb_helper_initial_config locking · 53f1904b
      Daniel Vetter 提交于
      The locking in drm_fb_helper_initial_config is a bit troublesome for a
      few reasons:
      
      - We can't just wrap the entire function up into modeset locks since
        the fbdev registration might call down into fbcon code, which then
        through our ->set_par implementation needs to be able to grab all
        modeset locks. So we'd have a neat deadlock.
      
      - This implies though that all current callers don't hold any modeset
        locks by necessity, so we have free reign to grab any modeset locks
        we need to grab.
      
      - The private state of the fbdev helper doesn't need any protection
        through locks, since once we have the fbdev registered it is mostly
        invariant or protected through the modeset locking in ->set_par and
        other callbacks. We can fully rely on driver having non-racy setup
        sequences here. For the initial config computation we actually may
        not grab locks since drivers which provide their own magic sauce
        (like i915) might need to grab locks themselves.
      
      - We should grab locks though when we probe outputs. Currently there's
        not much risk, but already now userspace could start poking at sysfs
        files and so probe concurrently. I expect that in the future driver
        init will be much more async, and since probing is really
        time-consuming this is a prime candidate.
      
      - We must not hold any crtc->mutex locks while calling probe functions
        since those might need to lock a crtc for e.g. load detection. i915
        is such a driver.
      
      Also it's the probing calls which hit upon piles of new locking
      asserts I've recently added in
      
      commit 62ff94a5
      Author: Daniel Vetter <daniel.vetter@ffwll.ch>
      Date:   Thu Jan 23 22:18:47 2014 +0100
      
          drm/crtc-helper: remove LOCKING from kerneldoc
      
      and
      
      commit 63951385
      Author: Daniel Vetter <daniel.vetter@ffwll.ch>
      Date:   Thu Jan 23 15:14:15 2014 +0100
      
          drm/doc: Repleace LOCKING kerneldoc sections in drm_modes.c
      
      Hence the right fix is to grab the mode_config mutex, but only that
      and only right around the probe calls.
      
      It seems to be sufficient to shut up all the locking WARNINGs I see on
      i915 and nouveau in drm_fb_helper_initial_config.
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      Tested-by: NThierry Reding <treding@nvidia.com>
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      53f1904b
    • D
      drm/crtc-helper: fix locking for drm_helper_disable_unused_functions · b182cc59
      Daniel Vetter 提交于
      We have two calling contexts for thise function:
      
      - In the crtc helper code itself as part of the ->set_config
        implementation. In this calling context all modeset locks are
        already held, as they should.
      
      - In drivers not implementing fastboot before the fbdev/fbcon setup
        and initialization. This has been added for all drivers in
      
        commit 76a39dbf
        Author: Daniel Vetter <daniel.vetter@ffwll.ch>
        Date:   Sun Jan 20 23:12:54 2013 +0100
      
            drm/fb-helper: don't disable everything in initial_config
      
        In this calling context we do not hold any modeset locks since the
        immediately following call to initialize the fbev emulation grabs
        all these locks themselves.
      
      - There are two exceptions to the above rule: shmob doesn't have fbdev
        emulation support. I've manually checked the callchain up to the
        driver load function and no kms locks are held.
      
      The right fix therefore is to split this helper into an internal and
      external version and add the required locking to the function exported
      to drivers.
      
      This remedies locking inconsistencies exposed by me adding locking
      WARNs as part of the recent kerneldoc abi polishing done in
      
      commit 62ff94a5
      Author: Daniel Vetter <daniel.vetter@ffwll.ch>
      Date:   Thu Jan 23 22:18:47 2014 +0100
      
          drm/crtc-helper: remove LOCKING from kerneldoc
      
      and
      
      commit 63951385
      Author: Daniel Vetter <daniel.vetter@ffwll.ch>
      Date:   Thu Jan 23 15:14:15 2014 +0100
      
          drm/doc: Repleace LOCKING kerneldoc sections in drm_modes.c
      
      v2: It helps when I actually git add the entire thing.
      
      Cc: Chris Wilson <chris@chris-wilson.co.uk>
      Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      Reviewed-by: NChris Wilson <chris@chris-wilson.co.uk>
      Tested-by: NThierry Reding <treding@nvidia.com>
      Signed-off-by: NDave Airlie <airlied@redhat.com>
      b182cc59
  2. 20 3月, 2014 1 次提交
  3. 18 3月, 2014 18 次提交
  4. 17 3月, 2014 4 次提交
  5. 16 3月, 2014 14 次提交
    • D
      drm: make minors independent of global lock · 0d639883
      David Herrmann 提交于
      We used to protect minor-lookup and setup by the global drm lock. To
      continue our attempts of dropping drm_global_mutex, this patch makes the
      minor management independent of it. Furthermore, we make it all atomic and
      switch to spin-locks instead of a mutex.
      
      Now that minor-lookup is independent, we also move the
      "drm_is_unplugged()" test into the minor-lookup path. There is no reason
      to ever return a minor for unplugged objects, so keep that logic internal.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      0d639883
    • D
      drm: inline drm_minor_get_id() · 7d86cf1a
      David Herrmann 提交于
      We can significantly simplify this helper by using plain multiplication.
      Note that we converted the minor-type to an enum earlier so this didn't
      work before.
      
      We also fix a minor range-bug here: the limit argument of idr_alloc() is
      *exclusive*, not inclusive, so we should use 64 instead of 63 as offset.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      7d86cf1a
    • D
      drm: coding-style fixes in minor handling · 1abbc437
      David Herrmann 提交于
      Properly name goto-labels, remove empty lines and use DRM_ERROR if
      possible.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      1abbc437
    • D
      drm: remove redundant minor->device field · 5817878c
      David Herrmann 提交于
      Whenever we access minor->device, we are in a minor->kdev->...->fops
      callback so the minor->kdev pointer *must* be valid. Thus, simply use
      minor->kdev->devt instead of minor->device and remove the redundant field.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      5817878c
    • D
      drm: remove unneeded #ifdef CONFIG_DEBUGFS · cb0f9323
      David Herrmann 提交于
      No need to check for DEBUGFS, we already have dummy-fallbacks in our
      headers.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      cb0f9323
    • D
      drm: rename drm_unplug/get_minor() to drm_minor_register/unregister() · afcdbc86
      David Herrmann 提交于
      drm_get_minor() no longer allocates objects, and drm_unplug_minor() is now
      the exact reverse of it. Rename it to _register/unregister() so their
      name actually says what they do.
      
      Furthermore, remove the direct minor-ptr and instead pass the minor-type.
      This way we know the actual slot of the minor and can reset it if
      required.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      afcdbc86
    • D
      drm: move drm_put_minor() to drm_minor_free() · bd9dfa98
      David Herrmann 提交于
      _put/get() are used for ref-counting, which we clearly don't do here.
      Rename it to _free() and also use the common drm_minor_* prefix.
      Furthermore, avoid passing the minor directly but instead use the type
      like the other functions do, this allows us to reset the slot.
      
      We also drop the redundant call to drm_unplug_minor() as drm_minor_free()
      is only used from paths were that has already be called.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      bd9dfa98
    • D
      drm: allocate minors early · 05b701f6
      David Herrmann 提交于
      Instead of waiting for device-registration, we now allocate minor-objects
      during device allocation. The minors are not registered or assigned an ID.
      This is still postponed to device-registration.
      
      While at it, remove the superfluous output-parameter in drm_get_minor().
      
      The reason for this early allocation is to make
      dev->primary/control/render available atomically. So once the device is
      alive, all of them are already set and we never have the situation where
      one of them is set after another (they're either NULL or set, but never
      changed). This will eventually allow us to reduce minor-ID allocation to
      one base-ID instead of a single ID for each.
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      05b701f6
    • D
      drm: add minor-lookup/release helpers · 1616c525
      David Herrmann 提交于
      Instead of accessing drm_minors_idr directly, this adds a small helper to
      hide the internals. This will help us later to remove the drm_global_mutex
      requirement for minor-lookup.
      
      Furthermore, this also makes sure that minor->dev is always valid and
      takes a reference-count to the device as long as the minor is used in an
      open-file. This way, "struct file*"->private_data->dev is guaranteed to be
      valid (which it has to, as we cannot reset it).
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      1616c525
    • D
      drm: provide device-refcount · 099d1c29
      David Herrmann 提交于
      Lets not trick ourselves into thinking "drm_device" objects are not
      ref-counted. That's just utterly stupid. We manage "drm_minor" objects on
      each drm-device and each minor can have an unlimited number of open
      handles. Each of these handles has the drm_minor (and thus the drm_device)
      as private-data in the file-handle. Therefore, we may not destroy
      "drm_device" until all these handles are closed.
      
      It is *not* possible to reset all these pointers atomically and restrict
      access to them, and this is *not* how this is done! Instead, we use
      ref-counts to make sure the object is valid and not freed.
      
      Note that we currently use "dev->open_count" for that, which is *exactly*
      the same as a reference-count, just open coded. So this patch doesn't
      change any semantics on DRM devices (well, this patch just introduces the
      ref-count, anyway. Follow-up patches will replace open_count by it).
      
      Also note that generic VFS revoke support could allow us to drop this
      ref-count again. We could then just synchronously disable any fops->xy()
      calls. However, this is not the case, yet, and no such patches are
      in sight (and I seriously question the idea of dropping the ref-cnt
      again).
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      099d1c29
    • D
      drm: skip redundant minor-lookup in open path · f4aede2e
      David Herrmann 提交于
      The drm_open_helper() function is only used internally for drm_open() so
      we can safely pass in the minor-object directly instead of the minor-id.
      This way, we avoid the additional minor IDR lookup, which we already do
      twice in drm_stub_open() and drm_open().
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      Reviewed-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
      f4aede2e
    • D
      drm: init TTM dev_mapping in ttm_bo_device_init() · 44d847b7
      David Herrmann 提交于
      With dev->anon_inode we have a global address_space ready for operation
      right from the beginning. Therefore, there is no need to do a delayed
      setup with TTM. Instead, set dev_mapping during initialization in
      ttm_bo_device_init() and remove any "if (dev_mapping)" conditions.
      
      Cc: Dave Airlie <airlied@redhat.com>
      Cc: Ben Skeggs <bskeggs@redhat.com>
      Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
      Cc: Alex Deucher <alexdeucher@gmail.com>
      Cc: Thomas Hellstrom <thellstrom@vmware.com>
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      44d847b7
    • D
      drm: use anon-inode instead of relying on cdevs · 6796cb16
      David Herrmann 提交于
      DRM drivers share a common address_space across all character-devices of a
      single DRM device. This allows simple buffer eviction and mapping-control.
      However, DRM core currently waits for the first ->open() on any char-dev
      to mark the underlying inode as backing inode of the device. This delayed
      initialization causes ugly conditions all over the place:
        if (dev->dev_mapping)
          do_sth();
      
      To avoid delayed initialization and to stop reusing the inode of the
      char-dev, we allocate an anonymous inode for each DRM device and reset
      filp->f_mapping to it on ->open().
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      6796cb16
    • D
      drm: add pseudo filesystem for shared inodes · 31bbe16f
      David Herrmann 提交于
      Our current DRM design uses a single address_space for all users of the
      same DRM device. However, there is no way to create an anonymous
      address_space without an underlying inode. Therefore, we wait for the
      first ->open() callback on a registered char-dev and take-over the inode
      of the char-dev. This worked well so far, but has several drawbacks:
       - We screw with FS internals and rely on some non-obvious invariants like
         inode->i_mapping being the same as inode->i_data for char-devs.
       - We don't have any address_space prior to the first ->open() from
         user-space. This leads to ugly fallback code and we cannot allocate
         global objects early.
      
      As pointed out by Al-Viro, fs/anon_inode.c is *not* supposed to be used by
      drivers for anonymous inode-allocation. Therefore, this patch follows the
      proposed alternative solution and adds a pseudo filesystem mount-point to
      DRM. We can then allocate private inodes including a private address_space
      for each DRM device at initialization time.
      
      Note that we could use:
        sysfs_get_inode(sysfs_mnt->mnt_sb, drm_device->dev->kobj.sd);
      to get access to the underlying sysfs-inode of a "struct device" object.
      However, most of this information is currently hidden and it's not clear
      whether this address_space is suitable for driver access. Thus, unless
      linux allows anonymous address_space objects or driver-core provides a
      public inode per device, we're left with our own private internal mount
      point.
      
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
      31bbe16f