of: dynamic: Synchronize of_changeset_destroy() with the devlink removals

In the following sequence:
1) of_platform_depopulate()
2) of_overlay_remove()

During the step 1, devices are destroyed and devlinks are removed.
During the step 2, OF nodes are destroyed but
__of_changeset_entry_destroy() can raise warnings related to missing
of_node_put():
ERROR: memory leak, expected refcount 1 instead of 2 ...

Indeed, during the devlink removals performed at step 1, the removal
itself releasing the device (and the attached of_node) is done by a job
queued in a workqueue and so, it is done asynchronously with respect to
function calls.
When the warning is present, of_node_put() will be called but wrongly
too late from the workqueue job.

In order to be sure that any ongoing devlink removals are done before
the of_node destruction, synchronize the of_changeset_destroy() with the
devlink removals.

Fixes: 80dd33cf72d1 ("drivers: base: Fix device link removal")
Cc: stable@vger.kernel.org
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Saravana Kannan <saravanak@google.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240325152140.198219-3-herve.codina@bootlin.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Fix of_reconfig_get_state_change() return value documentation

The documented numeric return values do not match the actual returned
values. Fix them by using the enum names instead of raw numbers.

Fixes: b53a2340d0d3 ("of/reconfig: Add of_reconfig_get_state_change() of notifier helper.")
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Link: https://lore.kernel.org/r/20231123-fix-of_reconfig_get_state_change-docs-v1-1-f51892050ff9@bootlin.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Fix potential memory leak in of_changeset_action()

Smatch complains that the error path where "action" is invalid leaks
the "ce" allocation:
drivers/of/dynamic.c:935 of_changeset_action()
warn: possible memory leak of 'ce'

Fix this by doing the validation before the allocation.

Note that there is not any actual problem with upstream kernels. All
callers of of_changeset_action() are static inlines with fixed action
values.

Fixes: 914d9d831e61 ("of: dynamic: Refactor action prints to not use "%pOF" inside devtree_lock")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/r/202309011059.EOdr4im9-lkp@intel.com/
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/7dfaf999-30ad-491c-9615-fb1138db121c@moroto.mountain
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Add interfaces for creating device node dynamically

of_changeset_create_node() creates device node dynamically and attaches
the newly created node to a changeset.

Expand of_changeset APIs to handle specific types of properties.
of_changeset_add_prop_string()
of_changeset_add_prop_string_array()
of_changeset_add_prop_u32_array()

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://lore.kernel.org/r/1692120000-46900-2-git-send-email-lizhi.hou@amd.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: Refactor node and property manipulation function locking

All callers of __of_{add,remove,update}_property() and
__of_{attach,detach}_node() wrap the call with the devtree_lock
spinlock. Let's move the spinlock into the functions. This allows moving
the sysfs update functions into those functions as well.

Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-6-5f0410e007dd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Move dead property list check into property add/update functions

The changeset code checks for a property in the deadprops list when
adding/updating a property, but of_add_property() and
of_update_property() do not. As the users of these functions are pretty
simple, they have not hit this scenario or else the property lists
would get corrupted.

With this there are 3 cases of removing a property from either deadprops
or properties lists, so add a helper to find and remove a matching
property.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-5-5f0410e007dd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Fix race in getting old property when updating property

__of_update_property() returns the existing property if there is one, but
that value is never added to the changeset. Updates work because the
existing property was also retrieved before in of_changeset_action(),
but that is racy as of_changeset_action() doesn't hold any locks. The
property could be changed before the changeset is applied.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-4-5f0410e007dd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Refactor changeset action printing to common helpers

Several places print the changeset action with node and property
details. Refactor these into a common printing helper. The complicating
factor is some prints are debug and some are errors. Solve this with a
bit of preprocessor magic.

Some cases printed the 'cset' which was the changeset entry pointer
rather than the whole changeset itself. The changeset entry is not all that
interesting and gets obfuscated by default anyways. So just drop it.

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-3-5f0410e007dd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Refactor action prints to not use "%pOF" inside devtree_lock

While originally it was fine to format strings using "%pOF" while
holding devtree_lock, this now causes a deadlock. Lockdep reports:

of_get_parent from of_fwnode_get_parent+0x18/0x24
^^^^^^^^^^^^^
of_fwnode_get_parent from fwnode_count_parents+0xc/0x28
fwnode_count_parents from fwnode_full_name_string+0x18/0xac
fwnode_full_name_string from device_node_string+0x1a0/0x404
device_node_string from pointer+0x3c0/0x534
pointer from vsnprintf+0x248/0x36c
vsnprintf from vprintk_store+0x130/0x3b4

Fix this by moving the printing in __of_changeset_entry_apply() outside
the lock. As the only difference in the multiple prints is the action
name, use the existing "action_names" to refactor the prints into a
single print.

Fixes: a92eb7621b9fb2c2 ("lib/vsprintf: Make use of fwnode API to obtain node names and separators")
Cc: stable@vger.kernel.org
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-2-5f0410e007dd@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

treewide: Fix probing of devices in DT overlays

When loading a DT overlay that creates a device, the device is not
probed, unless the DT overlay is unloaded and reloaded again.

After the recent refactoring to improve fw_devlink, it no longer depends
on the "compatible" property to identify which device tree nodes will
become struct devices. fw_devlink now picks up dangling consumers
(consumers pointing to descendent device tree nodes of a device that
aren't converted to child devices) when a device is successfully bound
to a driver. See __fw_devlink_pickup_dangling_consumers().

However, during DT overlay, a device's device tree node can have
sub-nodes added/removed without unbinding/rebinding the driver. This
difference in behavior between the normal device instantiation and
probing flow vs. the DT overlay flow has a bunch of implications that
are pointed out elsewhere[1]. One of them is that the fw_devlink logic
to pick up dangling consumers is never exercised.

This patch solves the fw_devlink issue by marking all DT nodes added by
DT overlays with FWNODE_FLAG_NOT_DEVICE (fwnode that won't become
device), and by clearing the flag when a struct device is actually
created for the DT node. This way, fw_devlink knows not to have
consumers waiting on these newly added DT nodes, and to propagate the
dependency to an ancestor DT node that has the corresponding struct
device.

Based on a patch by Saravana Kannan, which covered only platform and spi
devices.

[1] https://lore.kernel.org/r/CAGETcx_bkuFaLCiPrAWCPQz+w79ccDp6=9e881qmK=vx3hBMyg@mail.gmail.com

Fixes: 4a032827daa89350 ("of: property: Simplify of_link_to_phandle()")
Link: https://lore.kernel.org/r/CAGETcx_+rhHvaC_HJXGrr5_WAd2+k5f=rWYnkCZ6z5bGX-wj4w@mail.gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Shawn Guo <shawnguo@kernel.org>
Acked-by: Saravana Kannan <saravanak@google.com>
Tested-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
Link: https://lore.kernel.org/r/e1fa546682ea4c8474ff997ab6244c5e11b6f8bc.1680182615.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: Fix spelling mistake "kojbect" -> "kobject"

There is a spelling mistake in a pr_err message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20230220144422.873356-1-colin.i.king@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: add lifecycle docbook info to node creation functions

The existing docbook comments for the functions related to creating
a devicetree node do not explain the reference count of a newly
created node, how decrementing the reference count to zero will
free the associated memory, and the caller's responsibility to
call of_node_put() on the node. Explain what happens when the
reference count is decremented to zero.

Signed-off-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20230213185702.395776-8-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: add consistency check to of_node_release()

Add an additional consistency check to of_node_release(), which is
called when the reference count of a devicetree node is decremented
to zero. The node's children should have been deleted before the
node is deleted so check that no children exist.

Signed-off-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20230213185702.395776-7-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: do not use "%pOF" printk format on node with refcount of zero

of_node_release() can not use the "%pOF" printk format to report
the node name of a node when the node reference count is zero.
This is because the formatter device_node_string() calls
fwnode_full_name_string() which indirectly calls of_node_get().
Calling of_node_get() on the node with a zero reference count
results in a WARNING and stack trace.

When the reference count has been decremented to zero, this function
is in the subsequent call path which frees memory related to the node.

This commit resolves the unittest EXPECT errors that were created in
the previous commmit.

Signed-off-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20230213185702.395776-6-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: unittest: add node lifecycle tests

Add tests to exercise the actions that occur when the reference count
of devicetree nodes decrement to zero and beyond. Decrementing to
zero triggers freeing memory allocated for the node.

This commit will expose a pr_err() issue in of_node_release(), resulting
in some kernal warnings and stack traces.

When scripts/dtc/of_unittest_expect processes the console messages,
it will also report related problems for EXPECT messages due to the
pr_err() issue:
** missing EXPECT begin : 5

Signed-off-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20230213185702.395776-5-frowand.list@gmail.com
[robh: Fix !CONFIG_OF_DYNAMIC build]
Signed-off-by: Rob Herring <robh@kernel.org>

of: Add missing 'Return' section in kerneldoc comments

Many of the DT kerneldoc comments are lacking a 'Return' section. Let's
add the section in cases we have a description of return values. There's
still some cases where the return values are not documented.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/20210325164713.1296407-8-robh@kernel.org

of: dynamic: Fix incorrect parameter name and provide missing descriptions

Fixes the following W=1 kernel build warning(s):

drivers/of/dynamic.c:234: warning: Function parameter or member 'np' not described in 'of_attach_node'
drivers/of/dynamic.c:286: warning: Function parameter or member 'np' not described in 'of_detach_node'
drivers/of/dynamic.c:326: warning: Function parameter or member 'kobj' not described in 'of_node_release'
drivers/of/dynamic.c:326: warning: Excess function parameter 'kref' description in 'of_node_release'

Cc: Rob Herring <robh+dt@kernel.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210318104036.3175910-3-lee.jones@linaro.org

driver core: Add fwnode link support

Add support for creating supplier-consumer links between fwnodes. It is
intended for internal use the driver core and generic firmware support
code (eg. Device Tree, ACPI), so it is simple by design and the API
provided is limited.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20201121020232.908850-9-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

of: of_detach_node() remove unneeded local return variable

rc is unneeded, just return 0.

Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: Rework and simplify phandle cache to use a fixed size

The phandle cache was added to speed up of_find_node_by_phandle() by
avoiding walking the whole DT to find a matching phandle. The
implementation has several shortcomings:

- The cache is designed to work on a linear set of phandle values.
This is true for dtc generated DTs, but not for other cases such as
Power.
- The cache isn't enabled until of_core_init() and a typical system
may see hundreds of calls to of_find_node_by_phandle() before that
point.
- The cache is freed and re-allocated when the number of phandles
changes.
- It takes a raw spinlock around a memory allocation which breaks on
RT.

Change the implementation to a fixed size and use hash_32() as the
cache index. This greatly simplifies the implementation. It avoids
the need for any re-alloc of the cache and taking a reference on nodes
in the cache. We only have a single source of removing cache entries
which is of_detach_node().

Using hash_32() removes any assumption on phandle values improving
the hit rate for non-linear phandle values. The effect on linear values
using hash_32() is about a 10% collision. The chances of thrashing on
colliding values seems to be low.

To compare performance, I used a RK3399 board which is a pretty typical
system. I found that just measuring boot time as done previously is
noisy and may be impacted by other things. Also bringing up secondary
cores causes some issues with measuring, so I booted with 'nr_cpus=1'.
With no caching, calls to of_find_node_by_phandle() take about 20124 us
for 1248 calls. There's an additional 288 calls before time keeping is
up. Using the average time per hit/miss with the cache, we can calculate
these calls to take 690 us (277 hit / 11 miss) with a 128 entry cache
and 13319 us with no cache or an uninitialized cache.

Comparing the 3 implementations the time spent in
of_find_node_by_phandle() is:

no cache: 20124 us (+ 13319 us)
128 entry cache: 5134 us (+ 690 us)
current cache: 819 us (+ 13319 us)

We could move the allocation of the cache earlier to improve the
current cache, but that just further complicates the situation as it
needs to be after slab is up, so we can't do it when unflattening (which
uses memblock).

Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Frank Rowand <frowand.list@gmail.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Tested-by: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: Remove struct device_node.type pointer

Now that all users of device_node.type pointer have been removed in
favor of accessor functions, we can remove it.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: __of_detach_node() - remove node from phandle cache

Non-overlay dynamic devicetree node removal may leave the node in
the phandle cache. Subsequent calls to of_find_node_by_phandle()
will incorrectly find the stale entry. Remove the node from the
cache.

Add paranoia checks in of_find_node_by_phandle() as a second level
of defense (do not return cached node if detached, do not add node
to cache if detached).

Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Reported-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: set node fields from properties when add new overlay node

Overlay nodes added by add_changeset_node() do not have the node
fields name, phandle, and type set.

The node passed to __of_attach_node() when the add node changeset
entry is processed does not contain any properties. The node's
properties are located in add property changeset entries that will
be processed after the add node changeset is applied.

Set the node's fields in the node contained in the add node
changeset entry and do not set them to incorrect values in
add_changeset_node().

A visible symptom that is fixed by this patch is the names of nodes
added by overlays that have an entry in /sys/bus/platform/drivers/*/
will contain the unit-address but the node-name will be <NULL>, for
example, "fc4ab000.<NULL>". After applying the patch the name, in
this example, for node restart@fc4ab000 is "fc4ab000.restart".

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>

of: overlay: add missing of_node_get() in __of_attach_node_sysfs

There is a matching of_node_put() in __of_detach_node_sysfs()

Remove misleading comment from function header comment for
of_detach_node().

This patch may result in memory leaks from code that directly calls
the dynamic node add and delete functions directly instead of
using changesets.

This commit should result in powerpc systems that dynamically
allocate a node, then later deallocate the node to have a
memory leak when the node is deallocated.

The next commit will fix the leak.

Tested-by: Alan Tull <atull@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Frank Rowand <frank.rowand@sony.com>

of: overlay: add tests to validate kfrees from overlay removal

Add checks:
- attempted kfree due to refcount reaching zero before overlay
is removed
- properties linked to an overlay node when the node is removed
- node refcount > one during node removal in a changeset destroy,
if the node was created by the changeset

After applying this patch, several validation warnings will be
reported from the devicetree unittest during boot due to
pre-existing devicetree bugs. The warnings will be similar to:

OF: ERROR: of_node_release(), unexpected properties in /testcase-data/overlay-node/test-bus/test-unittest11
OF: ERROR: memory leak, expected refcount 1 instead of 2, of_node_get()/of_node_put() unbalanced - destroy cset entry: attach overlay node /testcase-data-2/substation@100/
hvac-medium-2

Tested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>

of: overlay: do not include path in full_name of added nodes

Struct device_node full_name no longer includes the full path name
when the devicetree is created from a flattened device tree (FDT).
The overlay node creation code was not modified to reflect this
change. Fix the node full_name generated by overlay code to contain
only the basename.

Unittests call an overlay internal function to create new nodes.
Fix up these calls to provide basename only instead of the full
path.

Fixes: a7e4cfb0a7ca ("of/fdt: only store the device node basename
in full_name")

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: Use SPDX license tag for DT files

Convert remaining DT files to use SPDX-License-Identifier tags.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: Spelling s/changset/changeset/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: fix memory leak related to properties of __of_node_dup

If a node with no properties is dynamically added, then a property is
dynamically added to the node, then the property is dynamically removed,
the result will be node->properties == NULL and node->deadprops != NULL.

Add a separate function to release the properties in both lists.

Signed-off-by: Lixin Wang <alan.1.wang@nokia-sbell.com>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: detect cases where device tree may become corrupt

When an attempt to apply an overlay changeset fails, an effort
is made to revert any partial application of the changeset.
When an attempt to remove an overlay changeset fails, an effort
is made to re-apply any partial reversion of the changeset.

The existing code does not check for failure to recover a failed
overlay changeset application or overlay changeset revert.

Add the missing checks and flag the devicetree as corrupt if the
state of the devicetree can not be determined.

Improve and expand the returned errors to more fully reflect the
result of the effort to undo the partial effects of a failed attempt
to apply or remove an overlay changeset.

If the device tree might be corrupt, do not allow further attempts
to apply or remove an overlay changeset.

When creating an overlay changeset from an overlay device tree,
add some additional warnings if the state of the overlay device
tree is not as expected.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: rename identifiers to more reflect what they do

This patch is aimed primarily at drivers/of/overlay.c, but those
changes also have a small impact in a few other files.

overlay.c is difficult to read and maintain. Improve readability:
- Rename functions, types and variables to better reflect what
they do and to be consistent with names in other places,
such as the device tree overlay FDT (flattened device tree),
and make the algorithms more clear
- Use the same names consistently throughout the file
- Update comments for name changes
- Fix incorrect comments

This patch is intended to not introduce any functional change.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: make kobject and bin_attribute support configurable

Having device_nodes be kobjects is only needed if sysfs or OF_DYNAMIC is
enabled. Otherwise, having a kobject in struct device_node is
unnecessary bloat in minimal kernel configurations.

Likewise, bin_attribute is only needed in struct property when sysfs is
enabled, so we can make it configurable too.

Tested-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <robh@kernel.org>

of: move kobj_to_device_node() into dynamic.c

The only user of kobj_to_device_node() is in dynamic.c, so move it
there. This avoids having to make it conditional once kobject is
configurable.

Tested-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <robh@kernel.org>

of: Convert to using %pOF instead of full_name

Now that we have a custom printf format specifier, convert users of
full_name to use %pOF instead. This is preparation to remove storing
of the full path string for each node.

Signed-off-by: Rob Herring <robh@kernel.org>

of: make __of_attach_node() static

__of_attach_node() is not used outside of drivers/of/dynamic.c. Make
it static and remove it from drivers/of/of_private.h.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: use pr_fmt prefix for all console printing

Clean-up all the DT printk functions to use common pr_fmt prefix.

Some print statements such as kmalloc errors were redundant, so just
drop those.

Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Reviewed-by: Frank Rowand <frank.rowand@am.sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: fix memory leak related to safe_name()

Fix a memory leak resulting from memory allocation in safe_name().
This patch fixes all call sites of safe_name().

Mathieu Malaterre reported the memory leak on boot:

On my PowerMac device-tree would generate a duplicate name:

[ 0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"

in this case a newly allocated name is generated by `safe_name`. However
in this case it is never deallocated.

The bug was found using kmemleak reported as:

unreferenced object 0xdf532e60 (size 32):
comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
hex dump (first 32 bytes):
6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2 l2-cache#1......
ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e ................
backtrace:
[<c02d3350>] kvasprintf+0x64/0xc8
[<c02d3400>] kasprintf+0x4c/0x5c
[<c0453814>] safe_name.isra.1+0x80/0xc4
[<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
[<c075f21c>] of_core_init+0x8c/0xf8
[<c0729594>] kernel_init_freeable+0xd4/0x208
[<c00047e8>] kernel_init+0x24/0x11c
[<c00158ec>] ret_from_kernel_thread+0x5c/0x64

Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331

Signed-off-by: Frank Rowand <frank.rowand@am.sony.com>
Reported-by: mathieu.malaterre@gmail.com
Tested-by: Mathieu Malaterre <mathieu.malaterre@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: dynamic: changeset prop-update revert fix

When reverting an update property changeset entry that created a
property the reverse operation is a remove property and not an update.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of: Export of_detach_node()

This exports of_detach_node() for PowerPC PowerNV PCI hotplug
driver. No functional changes introduced.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>

drivers/of: Export OF changeset functions

The PowerNV PCI hotplug driver is going to use the OF changeset
to manage the changed device sub-tree. This exports those OF
changeset functions for that.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of/dynamic: Fix test for PPC_PSERIES

"IS_ENABLED(PPC_PSERIES)" always evaluates to false, as IS_ENABLED() is
supposed to be used with the full Kconfig symbol name, including the
"CONFIG_" prefix.

Add the missing "CONFIG_" prefix to fix this.

Fixes: a25095d451ece23b ("of: Move dynamic node fixups out of powerpc and into common code")

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: stable@vger.kernel.org #+3.17
Signed-off-by: Grant Likely <grant.likely@linaro.org>

of/reconfig: Always use the same structure for notifiers

The OF_RECONFIG notifier callback uses a different structure depending
on whether it is a node change or a property change. This is silly, and
not very safe. Rework the code to use the same data structure regardless
of the type of notifier.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: <linuxppc-dev@lists.ozlabs.org>

of/reconfig: Add debug output for OF_RECONFIG notifiers

Add some additional debug output to cover OF_RECONFIG notifier activity.
At the same time, refactor the changeset debug output to use the same
strings as the notifier debug output.

Signed-off-by: Grant Likely <grant.likely@linaro.org>

of/reconfig: Add of_reconfig_get_state_change() of notifier helper.

Introduce of_reconfig_get_state_change() which allows an of notifier
to query about device state changes.

Signed-off-by: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

of: Refactor __of_node_alloc() into __of_node_dup()

Add a node argument to __of_node_alloc() and rename it to
__of_node_dup() so that it can also be used to duplicate a node with
its properties. This is important for the overlay code so that it can
create new nodes without using separate changeset items for every single
property.

At the same time rework the overlay code to use the new function and
drop the extra changeset items.

Signed-off-by: Grant Likely <grant.likely@linaro.org>

of: Use vargs in __of_node_alloc

The overlay code needs to construct a new full_name from the parent name
and the node name, but the current method has to allocate and then free
an temporary string which is wasteful. Fix this problem by using vargs
to pass in a format and arguments into __of_node_alloc().

At the same time remove the allocflags argument to __of_node_alloc().
The only users all use GFP_KERNEL, so there is no need to provide it as
an option. If there is ever a need later it can be added back.

Signed-off-by: Grant Likely <grant.likely@linaro.org>

of: Spelling s/stucture/structure/

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh+dt@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

of: Eliminate of_allnodes list

The device tree structure is composed of two lists; the 'allnodes' list
which is a singly linked list containing every node in the tree, and the
child->parent structure where each parent node has a singly linked list
of children. All of the data in the allnodes list can be easily
reproduced with the parent-child lists, so of_allnodes is actually
unnecessary. Remove it entirely which saves a bit of memory and
simplifies the data structure quite a lot.

Signed-off-by: Grant Likely <grant.likely@linaro.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Gaurav Minocha <gaurav.minocha.os@gmail.com>
Cc: Pantelis Antoniou <pantelis@pantelis.antoniou@konsulko.com>

of: Disabling OF functions that use sysfs if CONFIG_SYSFS disabled

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()

Fix a trivial typo in a comment block.

Signed-off-by: Grant Likely <grant.likely@linaro.org>

of: Transactional DT support.

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 notifiers

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 code

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 children

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.

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 functions

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 nodes

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 file

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>