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path: root/drivers/of/dynamic.c
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* of: Disabling OF functions that use sysfs if CONFIG_SYSFS disabledGaurav Minocha2014-09-08
| | | | | | | | | | | | | | | | This patch is to the fix the recent runtime bug in kernel reported by <fengguang.wu@intel.com>. The bug was exposed by commit b951f9dc, "Enabling OF selftest to run without machine's devicetree" and is exposed when CONFIG_OF_SELFTEST is enabled and CONFIG_SYSFS is disabled. Mail Subject: [OF test] BUG: unable to handle kernel NULL pointer dereference at 00000038 Tested on x86 and arm architecture Signed-off-by: Gaurav Minocha <gaurav.minocha.os@gmail.com> Signed-off-by: Grant Likely <grant.likely@linaro.org>
* of: typo fix in __of_prop_dup()Grant Likely2014-07-30
| | | | | | Fix a trivial typo in a comment block. Signed-off-by: Grant Likely <grant.likely@linaro.org>
* of: Transactional DT support.Pantelis Antoniou2014-07-23
| | | | | | | | | | | | | | | | | Introducing DT transactional support. A DT transaction is a method which allows one to apply changes in the live tree, in such a way that either the full set of changes take effect, or the state of the tree can be rolled-back to the state it was before it was attempted. An applied transaction can be rolled-back at any time. Documentation is in Documentation/devicetree/changesets.txt Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [glikely: Removed device notifiers and reworked to be more consistent] Signed-off-by: Grant Likely <grant.likely@linaro.org>
* of: Reorder device tree changes and notifiersGrant Likely2014-07-23
| | | | | | | | | | | | | | | | | | | | | | | Currently, devicetree reconfig notifiers get emitted before the change is applied to the tree, but that behaviour is problematic if the receiver wants the determine the new state of the tree. The current users don't care, but the changeset code to follow will be making multiple changes at once. Reorder notifiers to get emitted after the change has been applied to the tree so that callbacks see the new tree state. At the same time, fixup the existing callbacks to expect the new order. There are a few callbacks that compare the old and new values of a changed property. Put both property pointers into the of_prop_reconfig structure. The current notifiers also allow the notifier callback to fail and cancel the change to the tree, but that feature isn't actually used. It really isn't valid to ignore a tree modification provided by firmware anyway, so remove the ability to cancel a change to the tree. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Nathan Fontenot <nfont@austin.ibm.com>
* of: Move dynamic node fixups out of powerpc and into common codeGrant Likely2014-07-23
| | | | | | | | | | | | | | | | | | PowerPC does an odd thing with dynamic nodes. It uses a notifier to catch new node additions and set some of the values like name and type. This makes no sense since that same code can be put directly into of_attach_node(). Besides, all dynamic node users need this, not just powerpc. Fix this problem by moving the logic out of arch/powerpc and into drivers/of/dynamic.c. It is also important to remove this notifier because we want to move the firing of notifiers from before the tree is modified to after so that the receiver gets a consistent view of the tree, but that is incompatible with notifiers that modify the node. Signed-off-by: Grant Likely <grant.likely@linaro.org> Cc: Nathan Fontenot <nfont@austin.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* of: Make sure attached nodes don't carry along extra childrenGrant Likely2014-07-23
| | | | | | | | | The child pointer does not get cleared when attaching new nodes which could cause the tree to be inconsistent. Clear the child pointer in __of_attach_node() to be absolutely sure that the structure remains in a consistent layout. Signed-off-by: Grant Likely <grant.likely@linaro.org>
* of: Make devicetree sysfs update functions consistent.Grant Likely2014-07-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | All of the DT modification functions are split into two parts, the first part manipulates the DT data structure, and the second part updates sysfs, but the code isn't very consistent about how the second half is called. They don't all enforce the same rules about when it is valid to update sysfs, and there isn't any clarity on locking. The transactional DT modification feature that is coming also needs access to these functions so that it can perform all the structure changes together, and then all the sysfs updates as a second stage instead of doing each one at a time. Fix up the second have by creating a separate __of_*_sysfs() function for each of the helpers. The new functions have consistent naming (ie. of_node_add() becomes __of_attach_node_sysfs()) and all of them now defer if of_init hasn't been called yet. Callers of the new functions must hold the of_mutex to ensure there are no race conditions with of_init(). The mutex ensures that there will only ever be one writer to the tree at any given time. There can still be any number of readers and the raw_spin_lock is still used to make sure access to the data structure is still consistent. Finally, put the function prototypes into of_private.h so they are accessible to the transaction code. Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [grant.likely: Changed suffix from _post to _sysfs to match existing code] [grant.likely: Reorganized to eliminate trivial wrappers] Signed-off-by: Grant Likely <grant.likely@linaro.org>
* of: Create unlocked versions of node and property add/remove functionsPantelis Antoniou2014-07-16
| | | | | | | | | | | | | | | | | | | | The DT overlay code will need to manipulate nodes and properties while already holding the devicetree lock, or on nodes that are not yet attached to the tree, but the current helper functions don't allow that. Extract the core behaviour from the accessors and create the following unlocked variants. The unlocked variants require either the lock to already be held or for the nodes to be detached from the tree. Changes to live nodes will not get updated in sysfs, so the caller must arrange for housekeeping to take place after dropping the lock. The new functions are: __of_add_property(), __of_remove_property(), __of_update_property(), __of_attach_node() and __of_detach_node(). Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [Remove unnecessary diff hunks and rewrite commit text] Signed-off-by: Grant Likely <grant.likely@linaro.org>
* OF: Utility helper functions for dynamic nodesPantelis Antoniou2014-07-16
| | | | | | | | | | | | | | | | Introduce helper functions for working with the live DT tree, all of them related to dynamically adding/removing nodes and properties. __of_prop_dup() copies a property dynamically __of_node_alloc() creates an empty node Bug fix about prop->len == 0 by Ionut Nicu <ioan.nicu.ext@nsn.com> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> [glikely: Added unittest for of_copy_property and dropped fine-grained allocations] [glikely: removed name, type and phandle arguments from __of_node_alloc] Signed-off-by: Grant Likely <grant.likely@linaro.org>
* of: Move CONFIG_OF_DYNAMIC code into a separate fileGrant Likely2014-07-07
Split the dynamic device tree code into a separate file to make it really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not get sent. Enabling it turns on reference counting, notifiers and the ability to add and remove nodes. v2: Moved of_node_release() into dynamic.c Signed-off-by: Grant Likely <grant.likely@linaro.org> Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com> Cc: Rob Herring <robh+dt@kernel.org>