of: overlay: enable of_overlay_fdt_apply() kerneldoc

of_overlay_fdt_apply() already has a kerneldoc-formatted documentation,
except it is nor marked as such. Adding the second asterisk is enough for
the documentation to take it into account correctly.

Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20231106-of_overlay_fdt_apply-kerneldoc-v1-1-9a2d132bc6c1@bootlin.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Reorder struct fragment fields kerneldoc

The fields of the fragment structure were reordered, but the kerneldoc
was not updated.

Fixes: 81225ea682f45629 ("of: overlay: reorder fields in struct fragment")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/cfa36d2bb95e3c399c415dbf58057302c70ef375.1695893695.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Call of_changeset_init() early

When of_overlay_fdt_apply() fails, the changeset may be partially
applied, and the caller is still expected to call of_overlay_remove() to
clean up this partial state.

However, of_overlay_apply() calls of_resolve_phandles() before
init_overlay_changeset(). Hence if the overlay fails to apply due to an
unresolved symbol, the overlay_changeset.cset.entries list is still
uninitialized, and cleanup will crash with a NULL-pointer dereference in
overlay_removal_is_ok().

Fix this by moving the call to of_changeset_init() from
init_overlay_changeset() to of_overlay_fdt_apply(), where all other
early initialization is done.

Fixes: f948d6d8b792bb90 ("of: overlay: avoid race condition between applying multiple overlays")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/4f1d6d74b61cba2599026adb6d1948ae559ce91f.1690533838.git.geert+renesas@glider.be
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Extend of_overlay_fdt_apply() to specify the target node

Currently, in an overlay fdt fragment, it needs to specify the exact
location in base DT. In another word, when the fdt fragment is generated,
the base DT location for the fragment is already known.

There is new use case that the base DT location is unknown when fdt
fragment is generated. For example, the add-on device provide a fdt
overlay with its firmware to describe its downstream devices. Because it
is add-on device which can be plugged to different systems, its firmware
will not be able to know the overlay location in base DT. Instead, the
device driver will load the overlay fdt and apply it to base DT at runtime.
In this case, of_overlay_fdt_apply() needs to be extended to specify
the target node for device driver to apply overlay fdt.
int overlay_fdt_apply(..., struct device_node *base);

Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://lore.kernel.org/r/1692120000-46900-5-git-send-email-lizhi.hou@amd.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix missing of_node_put() in error case of init_overlay_changeset()

In init_overlay_changeset(), the variable "node" is from
of_get_child_by_name(), and the "node" should be discarded in error case.

Fixes: d1651b03c2df ("of: overlay: add overlay symbols to live device tree")
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://lore.kernel.org/r/20230602020502.11693-1-hayashi.kunihiko@socionext.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix trivial typo

Permitted is spelled with two t.

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Link: https://lore.kernel.org/r/20221220-permited-v1-3-52ea9857fa61@chromium.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: fix null pointer dereferencing in find_dup_cset_node_entry() and find_dup_cset_prop()

When kmalloc() fail to allocate memory in kasprintf(), fn_1 or fn_2 will
be NULL, and strcmp() will cause null pointer dereference.

Fixes: 2fe0e8769df9 ("of: overlay: check prevents multiple fragments touching same property")
Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20221211023337.592266-1-ruanjinjie@huawei.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Simplify of_overlay_fdt_apply() tail

It does not hurt to fill in the changeset id while the mutex is still
held. After doing so, the function tails for the success and failure
cases become identical, so they can be unified.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Tested-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/6a3357a8f7f29704350e3ffae768ee8a462b54d3.1657893306.git.geert+renesas@glider.be

of: overlay: Move devicetree_corrupt() check up

There is no point in doing several preparatory steps in
of_overlay_fdt_apply(), only to see of_overlay_apply() return early
because of a corrupt device tree.

Move the check for a corrupt device tree from of_overlay_apply() to
of_overlay_fdt_apply(), to check for this as early as possible.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Tested-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/c91ce7112eb5167ea46a43d8a980e76b920010ba.1657893306.git.geert+renesas@glider.be

of: overlay: do not free changeset when of_overlay_apply returns error

New unittests for overlay notifiers reveal a memory leak in
of_overlay_apply() when a notifier returns an error for action
OF_OVERLAY_POST_APPLY. The pr_err() message is:

OF: ERROR: memory leak, expected refcount 1 instead of 3,
of_node_get()/of_node_put() unbalanced - destroy cset entry: attach
overlay node /testcase-data/overlay-node/test-bus/test-unittest17

Change the error path to no longer call free_overlay_changeset(),
and document that the caller of of_overlay_fdt_apply() may choose
to remove the overlay.

Update the unittest that triggered the error to expect the changed
return values and to call of_overlay_remove().

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220502181742.1402826-4-frowand.list@gmail.com

of: overlay: add entry to of_overlay_action_name[]

The values of enum of_overlay_notify_action are used to index into
array of_overlay_action_name. Add an entry to of_overlay_action_name
for the value recently added to of_overlay_notify_action.

Array of_overlay_action_name[] is moved into include/linux/of.h
adjacent to enum of_overlay_notify_action to make the connection
between the two more obvious if either is modified in the future.

The only use of of_overlay_action_name is for error reporting in
overlay_notify(). All callers of overlay_notify() report the same
error, but with fewer details. Remove the redundant error reports
in the callers.

Fixes: 067c098766c6 ("of: overlay: rework overlay apply and remove kfree()s")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220502181742.1402826-2-frowand.list@gmail.com

of: overlay: rework overlay apply and remove kfree()s

Fix various kfree() issues related to of_overlay_apply().
- Double kfree() of fdt and tree when init_overlay_changeset()
returns an error.
- free_overlay_changeset() free the root of the unflattened
overlay (variable tree) instead of the memory that contains
the unflattened overlay.
- For the case of a failure during applying an overlay, move kfree()
of new_fdt and overlay_mem into free_overlay_changeset(), which
is called by the function that allocated them.
- For the case of removing an overlay, the kfree() of new_fdt and
overlay_mem remains in free_overlay_changeset().
- Check return value of of_fdt_unflatten_tree() for error instead
of checking the returned value of overlay_root.
- When storing pointers to allocated objects in ovcs, do so as
near to the allocation as possible instead of in deeply layered
function.

More clearly document policy related to lifetime of pointers into
overlay memory.

Double kfree()
Reported-by: Slawomir Stepien <slawomir.stepien@nokia.com>

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220420222505.928492-3-frowand.list@gmail.com

of: overlay: rename variables to be consistent

Variables change name across function calls when there is not a good
reason to do so. Fix by changing "fdt" to "new_fdt" and "tree" to
"overlay_root".

The name disparity was confusing when creating the following commit.
The name changes are in this separate commit to make review of the
following commmit less complex.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220420222505.928492-2-frowand.list@gmail.com

of: overlay: do not break notify on NOTIFY_{OK|STOP}

We should not break overlay notifications on NOTIFY_{OK|STOP}
otherwise we might break on the first fragment. We should only stop
notifications if a *real* errno is returned by one of the listeners.

Fixes: a1d19bd4cf1fe ("of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove")
Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220420130205.89435-1-nuno.sa@analog.com

of: overlay: Remove redundant assignment to ret

Variable ret is set to zero but this value is never read as it is
overwritten with a new value later on, hence it is a redundant
assignment and can be removed.

Cleans up the following clang-analyzer warning:

drivers/of/overlay.c:1197:2: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

drivers/of/overlay.c:1026:2: warning: Value stored to 'ret' is never
read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Link: https://lore.kernel.org/r/1619347258-55002-1-git-send-email-jiapeng.chong@linux.alibaba.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix kerneldoc warning in of_overlay_remove()

'*ovcs_id' causes a warning because '*' is treated as bold markup:

Documentation/devicetree/kernel-api:56: ../drivers/of/overlay.c:1184: WARNING: Inline emphasis start-string without end-string.

Fix this by using the normal '@' markup for function parameters. That
appears to be enough to keep the '*' from being interpretted as markup.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20210421154548.1192903-1-robh@kernel.org/
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: overlay: fix for_each_child.cocci warnings

Function "for_each_child_of_node" should have of_node_put() before goto.

Generated by: scripts/coccinelle/iterators/for_each_child.cocci

Fixes: 82c2d81361ec ("coccinelle: iterators: Add for_each_child.cocci script")
CC: Sumera Priyadarsini <sylphrenadin@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Julia Lawall <julia.lawall@inria.fr>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Tested-by: Frank Rowand <frank.rowand@sony.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2103221918450.2918@hadrien
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix function name disparity

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

drivers/of/overlay.c:147: warning: expecting prototype for of_overlay_notifier_register(). Prototype was for of_overlay_notifier_unregister() instead

Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
Cc: Frank Rowand <frowand.list@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
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/20210318104036.3175910-10-lee.jones@linaro.org

of: unittest: overlay: ensure proper alignment of copied FDT

The Devicetree standard specifies an 8 byte alignment of the FDT.
Code in libfdt expects this alignment for an FDT image in memory.
kmemdup() returns 4 byte alignment on openrisc. Replace kmemdup()
with kmalloc(), align pointer, memcpy() to get proper alignment.

The 4 byte alignment exposed a related bug which triggered a crash
on openrisc with:
commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
as reported in:
https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/

Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Link: https://lore.kernel.org/r/20210408204508.2276230-1-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: properly check for error returned by fdt_get_name()

fdt_get_name() returns error values via a parameter pointer
instead of in function return. Fix check for this error value
in populate_node() and callers of populate_node().

Chasing up the caller tree showed callers of various functions
failing to initialize the value of pointer parameters that
can return error values. Initialize those values to NULL.

The bug was introduced by
commit e6a6928c3ea1 ("of/fdt: Convert FDT functions to use libfdt")
but this patch can not be backported directly to that commit
because the relevant code has further been restructured by
commit dfbd4c6eff35 ("drivers/of: Split unflatten_dt_node()")

The bug became visible by triggering a crash on openrisc with:
commit 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
as reported in:
https://lore.kernel.org/lkml/20210327224116.69309-1-linux@roeck-us.net/

Fixes: 79edff12060f ("scripts/dtc: Update to upstream version v1.6.0-51-g183df9e9c2b9")
Reported-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210405032845.1942533-1-frowand.list@gmail.com
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: kmemleak in dup_and_fixup_symbol_prop()

kmemleak reports several memory leaks from devicetree unittest.
This is the fix for problem 4 of 5.

target_path was not freed in the non-error path.

Fixes: e0a58f3e08d4 ("of: overlay: remove a dependency on device node full_name")
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Remove blank line between assignment and check

There used to be blank lines between assignment and check of the
__of_changeset_revert_entries() result, to make the phandle cache
management operations stand out. After the removal of those operations
in commit 90dc0d1ce890419f ("of: Rework and simplify phandle cache to
use a fixed size"), there is no longer a reason to have such a blank
line.

Remove the blank line, to rejoin visibly the status assignement and
check, and to match coding style.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
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: overlay: add_changeset_property() memory leak

No changeset entries are created for #address-cells and #size-cells
properties, but the duplicated properties are never freed. This
results in a memory leak which is detected by kmemleak:

unreferenced object 0x85887180 (size 64):
backtrace:
kmem_cache_alloc_trace+0x1fb/0x1fc
__of_prop_dup+0x25/0x7c
add_changeset_property+0x17f/0x370
build_changeset_next_level+0x29/0x20c
of_overlay_fdt_apply+0x32b/0x6b4
...

Fixes: 6f75118800ac ("of: overlay: validate overlay properties #address-cells and #size-cells")
Reported-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Tested-by: Vincent Whitchurch <vincent.whitchurch@axis.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: 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: check prevents multiple fragments touching same property

Add test case of two fragments updating the same property. After
adding the test case, the system hangs at end of boot, after
after slub stack dumps from kfree() in crypto modprobe code.

Multiple overlay fragments adding, modifying, or deleting the same
property is not supported. Add check to detect the attempt and fail
the overlay apply.

Before this patch, the first fragment error would terminate
processing. Allow fragment checking to proceed and report all
of the fragment errors before terminating the overlay apply. This
is not a hot path, thus not a performance issue (the error is not
transient and requires fixing the overlay before attempting to
apply it again).

After applying this patch, the devicetree unittest messages will
include:

OF: overlay: ERROR: multiple fragments add, update, and/or delete property /testcase-data-2/substation@100/motor-1/rpm_avail

...

### dt-test ### end of unittest - 212 passed, 0 failed

The check to detect two fragments updating the same property is
folded into the patch that created the test case to maintain
bisectability.

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

of: overlay: check prevents multiple fragments add or delete same node

Multiple overlay fragments adding or deleting the same node is not
supported. Replace code comment of such, with check to detect the
attempt and fail the overlay apply.

Devicetree unittest where multiple fragments added the same node was
added in the previous patch in the series. After applying this patch
the unittest messages will no longer include:

Duplicate name in motor-1, renamed to "controller#1"
OF: overlay: of_overlay_apply() err=0
### dt-test ### of_overlay_fdt_apply() expected -22, ret=0, overlay_bad_add_dup_node
### dt-test ### FAIL of_unittest_overlay_high_level():2419 Adding overlay 'overlay_bad_add_dup_node' failed

...

### dt-test ### end of unittest - 210 passed, 1 failed

but will instead include:

OF: overlay: ERROR: multiple overlay fragments add and/or delete node /testcase-data-2/substation@100/motor-1/controller

...

### dt-test ### end of unittest - 211 passed, 0 failed

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

of: overlay: make all pr_debug() and pr_err() messages unique

Make overlay.c debug and error messages unique so that they can be
unambiguously found by grep.

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

of: overlay: validate overlay properties #address-cells and #size-cells

If overlay properties #address-cells or #size-cells are already in
the live devicetree for any given node, then the values in the
overlay must match the values in the live tree.

If the properties are already in the live tree then there is no
need to create a changeset entry to add them since they must
have the same value. This reduces the memory used by the
changeset and eliminates a possible memory leak.

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

of: overlay: reorder fields in struct fragment

Order the fields of struct fragment in the same order as
struct of_overlay_notify_data. The order in struct fragment is
not significant. If both structs are ordered the same then when
examining the data in a debugger or dump the human involved does
not have to remember which context they are examining.

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

of: overlay: do not duplicate properties from overlay for new nodes

When allocating a new node, add_changeset_node() was duplicating the
properties from the respective node in the overlay instead of
allocating a node with no properties.

When this patch is applied the errors reported by the devictree
unittest from patch "of: overlay: add tests to validate kfrees from
overlay removal" will no longer occur. These error messages are of
the form:

"OF: ERROR: ..."

and the unittest results will change from:

### dt-test ### end of unittest - 203 passed, 7 failed

to

### dt-test ### end of unittest - 210 passed, 0 failed

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

of: overlay: use prop add changeset entry for property in new nodes

The changeset entry 'update property' was used for new properties in
an overlay instead of 'add property'.

The decision of whether to use 'update property' was based on whether
the property already exists in the subtree where the node is being
spliced into. At the top level of creating a changeset describing the
overlay, the target node is in the live devicetree, so checking whether
the property exists in the target node returns the correct result.
As soon as the changeset creation algorithm recurses into a new node,
the target is no longer in the live devicetree, but is instead in the
detached overlay tree, thus all properties are incorrectly found to
already exist in the target.

This fix will expose another devicetree bug that will be fixed
in the following patch in the series.

When this patch is applied the errors reported by the devictree
unittest will change, and the unittest results will change from:

### dt-test ### end of unittest - 210 passed, 0 failed

to

### dt-test ### end of unittest - 203 passed, 7 failed

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

of: overlay: add missing of_node_put() after add new node to changeset

The refcount of a newly added overlay node decrements to one
(instead of zero) when the overlay changeset is destroyed. This
change will cause the final decrement be to zero.

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

OF: ERROR: memory leak before free overlay changeset, /testcase-data/overlay-node/test-bus/test-unittest4

This pre-existing devicetree bug will also trigger a WARN_ONCE() from
refcount_sub_and_test_checked() when an overlay changeset is
destroyed without having first been applied. This scenario occurs
when an error in the overlay is detected during the overlay changeset
creation:

WARNING: CPU: 0 PID: 1 at lib/refcount.c:187 refcount_sub_and_test_checked+0xa8/0xbc
refcount_t: underflow; use-after-free.

(unwind_backtrace) from (show_stack+0x10/0x14)
(show_stack) from (dump_stack+0x6c/0x8c)
(dump_stack) from (__warn+0xdc/0x104)
(__warn) from (warn_slowpath_fmt+0x44/0x6c)
(warn_slowpath_fmt) from (refcount_sub_and_test_checked+0xa8/0xbc)
(refcount_sub_and_test_checked) from (kobject_put+0x24/0x208)
(kobject_put) from (of_changeset_destroy+0x2c/0xb4)
(of_changeset_destroy) from (free_overlay_changeset+0x1c/0x9c)
(free_overlay_changeset) from (of_overlay_remove+0x284/0x2cc)
(of_overlay_remove) from (of_unittest_apply_revert_overlay_check.constprop.4+0xf8/0x1e8)
(of_unittest_apply_revert_overlay_check.constprop.4) from (of_unittest_overlay+0x960/0xed8)
(of_unittest_overlay) from (of_unittest+0x1cc4/0x2138)
(of_unittest) from (do_one_initcall+0x4c/0x28c)
(do_one_initcall) from (kernel_init_freeable+0x29c/0x378)
(kernel_init_freeable) from (kernel_init+0x8/0x110)
(kernel_init) from (ret_from_fork+0x14/0x2c)

Tested-by: Alan Tull <atull@kernel.org>
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: Convert to using %pOFn instead of device_node.name

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Cc: Andrew Lunn <andrew@lunn.ch>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: update phandle cache on overlay apply and remove

A comment in the review of the patch adding the phandle cache said that
the cache would have to be updated when modules are applied and removed.
This patch implements the cache updates.

Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()")
Reported-by: Alan Tull <atull@kernel.org>
Suggested-by: Alan Tull <atull@kernel.org>
Signed-off-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Stop leaking resources on overlay removal

Only the overlay notifier callbacks have a chance to potentially get
hold of references to those two resources, but they are not supposed to
store them beyond OF_OVERLAY_POST_REMOVE.

Document the overlay notifier API, its constraint regarding pointer
lifetime, and then remove intentional leaks of ovcs->overlay_tree and
ovcs->fdt from free_overlay_changeset.

See also https://lkml.org/lkml/2018/4/23/1063 and following.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix forgotten reference to of_overlay_apply()

While technically the ovcs_id is still returned by of_overlay_apply(),
this is an internal function. All public callers of of_overlay_remove()
pass an ovcs_id returned by the public function of_overlay_fdt_apply().

Fixes: 39a751a4cb7e4798 ("of: change overlay apply input data from unflattened to FDT")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>

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: improve reporting invalid overlay target path

Errors while developing the patch to create of_overlay_fdt_apply()
exposed inadequate error messages to debug problems when overlay
devicetree fragment nodes contain an invalid target path. Improve
the messages in find_target_node() to remedy this.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>

of: change overlay apply input data from unflattened to FDT

Move duplicating and unflattening of an overlay flattened devicetree
(FDT) into the overlay application code. To accomplish this,
of_overlay_apply() is replaced by of_overlay_fdt_apply().

The copy of the FDT (aka "duplicate FDT") now belongs to devicetree
code, which is thus responsible for freeing the duplicate FDT. The
caller of of_overlay_fdt_apply() remains responsible for freeing the
original FDT.

The unflattened devicetree now belongs to devicetree code, which is
thus responsible for freeing the unflattened devicetree.

These ownership changes prevent early freeing of the duplicated FDT
or the unflattened devicetree, which could result in use after free
errors.

of_overlay_fdt_apply() is a private function for the anticipated
overlay loader.

Update unittest.c to use of_overlay_fdt_apply() instead of
of_overlay_apply().

Move overlay fragments from artificial locations in
drivers/of/unittest-data/tests-overlay.dtsi into one devicetree
source file per overlay. This led to changes in
drivers/of/unitest-data/Makefile and drivers/of/unitest.c.

- Add overlay directives to the overlay devicetree source files so
that dtc will compile them as true overlays into one FDT data
chunk per overlay.

- Set CFLAGS for drivers/of/unittest-data/testcases.dts so that
symbols will be generated for overlay resolution of overlays
that are no longer artificially contained in testcases.dts

- Unflatten and apply each unittest overlay FDT using
of_overlay_fdt_apply().

- Enable the of_resolve_phandles() check for whether the unflattened
overlay is detached. This check was previously disabled because the
overlays from tests-overlay.dtsi were not unflattened into detached
trees.

- Other changes to unittest.c infrastructure to manage multiple test
FDTs built into the kernel image (access by name instead of
arbitrary number).

- of_unittest_overlay_high_level(): previously unused code to add
properties from the overlay_base devicetree to the live tree
was triggered by the restructuring of tests-overlay.dtsi and thus
testcases.dts. This exposed two bugs: (1) the need to dup a
property before adding it, and (2) property 'name' is
auto-generated in the unflatten code and thus will be a duplicate
in the __symbols__ node - do not treat this duplicate as an error.

Signed-off-by: Frank Rowand <frank.rowand@sony.com>

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: overlay: Make node skipping in init_overlay_changeset() clearer

Make it more clear that nodes without "__overlay__" subnodes are
skipped, by reverting the logic and using continue.
This also reduces indentation level.

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

of: overlay: Fix out-of-bounds write in init_overlay_changeset()

If an overlay has no "__symbols__" node, but it has nodes without
"__overlay__" subnodes at the end (e.g. a "__fixups__" node), after
filling in all fragments for nodes with "__overlay__" subnodes,
"fragment = &fragments[cnt]" will point beyond the end of the allocated
array.

Hence writing to "fragment->overlay" will overwrite unallocated memory,
which may lead to a crash later.

Fix this by deferring both the assignment to "fragment" and the
offending write afterwards until we know for sure the node has an
"__overlay__" subnode, and thus a valid entry in "fragments[]".

Fixes: 61b4de4e0b384f4a ("of: overlay: minor restructuring")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix (un)locking in of_overlay_apply()

The special overlay mutex is taken first, hence it should be released
last in the error path.

of_resolve_phandles() must be called with of_mutex held. Without it, a
node and new phandle could be added via of_attach_node(), making the max
phandle wrong.

free_overlay_changeset() must be called with of_mutex held, if any
non-trivial cleanup is to be done.

Hence move "mutex_lock(&of_mutex)" up, as suggested by Frank, and merge
the two tail statements of the success and error paths, now they became
identical.

Note that while the two mutexes are adjacent, we still need both:
__of_changeset_apply_notify(), which is called by __of_changeset_apply()
unlocks of_mutex, then does notifications then locks of_mutex. So the
mutex get released in the middle of of_overlay_apply()

Fixes: f948d6d8b792bb90 ("of: overlay: avoid race condition between applying multiple overlays")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Fix memory leak in of_overlay_apply() error path

If of_resolve_phandles() fails, free_overlay_changeset() is called in
the error path. However, that function returns early if the list hasn't
been initialized yet, before freeing the object.

Explicitly calling kfree() instead would solve that issue. However, that
complicates matter, by having to consider which of two different methods
to use to dispose of the same object.

Hence make free_overlay_changeset() consider initialization state of the
different parts of the object, making it always safe to call (once!) to
dispose of a (partially) initialized overlay_changeset:
- Only destroy the changeset if the list was initialized,
- Make init_overlay_changeset() store the ID in ovcs->id on success,
to avoid calling idr_remove() with an error value or an already
released ID.

Reported-by: Colin King <colin.king@canonical.com>
Fixes: f948d6d8b792bb90 ("of: overlay: avoid race condition between applying multiple overlays")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Frank Rowand <frank.rowand@sony.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: Remove else after goto

If an "if" branch is terminated by a "goto", there's no need to have an
"else" statement and an indented block of code.

Remove the "else" statement to simplify the code flow for the casual
reviewer.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
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: overlay: make pr_err() string unique

The same error string occurs in drivers/of/resolver.c. Change
the error here to more precisely describe this case, and avoid
the possible confusion of looking in the wrong source location
to understand the cause of an error.

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

of: overlay: pr_err from return NOTIFY_OK to overlay apply/remove

A device tree overlay notifier can return NOTIFY_OK, NOTIFY_STOP,
or an embedded errno. overlay_notify() incorrectly reports an
error for NOTIFY_OK.

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

of: overlay: remove unneeded check for NULL kbasename()

kbasename() will not return NULL if passed a valid string. If
the parameter passed to kbasename() in this case is already NULL
then the devicetree has been corrupted.

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

of: overlay: remove a dependency on device node full_name

The "%pOF" printf format was recently added to print the
full name of a device tree node, with the intent of changing
the node full_name field to contain only the node name instead
of the full path of the node.

dup_and_fixup_symbol_prop() duplicates a property from the
"/__symbols__" node of an overlay device tree. The value
of each duplicated property must be fixed up to include
the full path of a node in the live device tree. The
current code uses the node's full_name for that purpose.
Update the code to use the "%pOF" printf format to
determine the node's full path.

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

of: overlay: simplify applying symbols from an overlay

The code to apply symbols from an overlay to the live device tree
was implemented with the intent to be minimally intrusive on the
existing code. After recent restructuring of the overlay apply
code, it is easier to disintangle the code that applies the
symbols, and to make the overlay changeset creation code more
straight forward and understandable.

Remove the extra complexity, and make the code more obvious.

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

of: overlay: avoid race condition between applying multiple overlays

The process of applying an overlay consists of:
- unflatten an overlay FDT (flattened device tree) into an
EDT (expanded device tree)
- fixup the phandle values in the overlay EDT to fit in a
range above the phandle values in the live device tree
- create the overlay changeset to reflect the contents of
the overlay EDT
- apply the overlay changeset, to modify the live device tree,
potentially changing the maximum phandle value in the live
device tree

There is currently no protection against two overlay applies
concurrently determining what range of phandle values are in use
in the live device tree, and subsequently changing that range.
Add a mutex to prevent multiple overlay applies from occurring
simultaneously.

Move of_resolve_phandles() into of_overlay_apply() so that it does not
have to be duplicated by each caller of of_overlay_apply().

The test in of_resolve_phandles() that the overlay tree is detached is
temporarily disabled so that old style overlay unittests do not fail.

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

of: overlay: loosen overly strict phandle clash check

When an overlay contains a node that already exists in
the live device tree, the overlay node is not allowed
to change the phandle of the existing node.

The existing check refused to allow an overlay node to
set the node phandle even when the existing node did
not have a phandle. Relax the check to allow an
overlay node to set the phandle value if the existing
node does not have a phandle.

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

of: overlay: expand check of whether overlay changeset can be removed

The test of whether it is safe to remove an overlay changeset
looked at whether any node in the overlay changeset was in a
subtree rooted at any more recently applied overlay changeset
node.

The test failed to determine whether any node in the overlay
changeset was the root of a subtree that contained a more
recently applied overlay changeset node. Add this additional
check to the test.

The test is still lacking any check for any phandle dependencies.

Signed-off-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: minor restructuring

Continue improving the readability of overlay.c. The previous patches
renamed identifiers. This patch is split out from the previous patches
to make the previous patches easier to review.

Changes are:
- minor code restructuring
- some initialization of an overlay changeset occurred outside of
init_overlay_changeset(), move that into init_overlay_changeset()
- consolidate freeing an overlay changeset into free_overlay_changeset()

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: overlay: rename identifiers in dup_and_fixup_symbol_prop()

More renaming of identifiers to better reflect what they do.

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: overlay.c: Convert comparisons to zero or NULL to logical expressions

Use normal shorthand for comparing a variable to zero.
For variable "XXX":
convert (XXX == 0) to (!XXX)
convert (XXX != 0) to (XXX)

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

of: overlay.c: Remove comments that state the obvious, to reduce clutter

Follows recommendations in Documentation/process/coding-style.rst,
section 8, Commenting.

Some in function comments are promoted to function header comments.

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

of: overlay: fix memory leak related to duplicated property

Function of_changeset_add_property or of_changeset_update_property may
fails. In this case the property just allocated is never deallocated.

Signed-off-by: Lixin Wang <alan.1.wang@nokia-sbell.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: overlay: add overlay symbols to live device tree

Add overlay __symbols__ properties to live tree when an overlay
is added to the live tree so that the symbols are available to
subsequent overlays.

Expected test result is new __symbols__ entries for labels from
the overlay after this commit.

Before this commit:

Console error message near end of unittest:
### dt-test ### FAIL of_unittest_overlay_high_level():2296 Adding overlay 'overlay_bad_symbol' failed
### dt-test ### end of unittest - 190 passed, 1 failed

The new unittest "fails" because the expected result of loading the
new overlay is an error instead of success.

$ # node hvac-medium-2 exists because the overlay loaded
$ # since the duplicate symbol was not detected
$ cd /proc/device-tree/testcase-data-2/substation@100/
$ ls
compatible hvac-medium-2 motor-8 reg
hvac-large-1 linux,phandle name status
hvac-medium-1 motor-1 phandle

$ cd /proc/device-tree/__symbols__/
$ ls
electric_1 lights_1 name rides_1 spin_ctrl_2
hvac_1 lights_2 retail_1 spin_ctrl_1

After this commit:

Previous console error message no longer occurs, but expected error
occurs:
OF: overlay: Failed to apply prop @/__symbols__/hvac_1
OF: overlay: apply failed '/__symbols__'
### dt-test ### end of unittest - 191 passed, 0 failed

$ # node hvac-medium-2 does not exist because the overlay
$ # properly failed to load due to the duplicate symbol
$ cd /proc/device-tree/testcase-data-2/substation@100/
$ ls
compatible hvac-medium-1 motor-1 name reg
hvac-large-1 linux,phandle motor-8 phandle status

$ cd /proc/device-tree/__symbols__/
$ ls
electric_1 lights_1 retail_1 ride_200_right spin_ctrl_2
hvac_1 lights_2 ride_200 rides_1
hvac_2 name ride_200_left spin_ctrl_1
$ cat ride_200; echo
/testcase-data-2/fairway-1/ride@200
$ cat ride_200_left ; echo
/testcase-data-2/fairway-1/ride@200/track@10
$ cat ride_200_right ; echo
/testcase-data-2/fairway-1/ride@200/track@20

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

of: overlay: correctly apply overlay node with unit-address

Correct existing node name detection when overlay node name has
a unit-address.

Expected test result is overlay will update the nodes and properties
for /testcase-data-2/fairway-1/ride@100/ after this commit.

Before this commit:

Console error message near end of unittest:
OF: Duplicate name in fairway-1, renamed to "ride@100#1"

$ cd /proc/device-tree/testcase-data-2/fairway-1/
$ # extra node: ride@100#1
$ ls
#address-cells linux,phandle phandle ride@200
#size-cells name ride@100 status
compatible orientation ride@100#1
$ cd /proc/device-tree/testcase-data-2/fairway-1/ride@100/
$ ls track@30/incline-up
ls: track@30/incline-up: No such file or directory
$ ls track@40/incline-up
ls: track@40/incline-up: No such file or directory

After this commit:

Console error message no longer occurs

$ cd /proc/device-tree/testcase-data-2/fairway-1/
$ # no extra node: ride@100#1
$ ls
#address-cells compatible name phandle ride@200
#size-cells linux,phandle orientation ride@100 status
$ cd /proc/device-tree/testcase-data-2/fairway-1/ride@100/
$ ls track@30/incline-up
track@30/incline-up
$ ls track@40/incline-up
track@40/incline-up

Signed-off-by: Frank Rowand <frank.rowand@sony.com>
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: detect invalid phandle in overlay

Overlays are not allowed to modify phandle values of previously existing
nodes because there is no information available to allow fixup up
properties that use the previously existing phandle.

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

of: remove redundant memset in overlay

memset in of_build_overlay_info is redundant, the ovinfo has been
zeroed in of_fill_overlay_info when error.

Signed-off-by: YiPing Xu <xuyiping@hisilicon.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of: drop duplicate headers

Drop duplicate headers string.h and of_platform.h.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of/overlay: add of overlay notifications

This patch add of overlay notifications.

When DT overlays are being added, some drivers/subsystems
need to see device tree overlays before the changes go into
the live tree.

This is distinct from reconfig notifiers that are
post-apply or post-remove and which issue very granular
notifications without providing access to the context
of a whole overlay.

The following 4 notificatons are issued:
OF_OVERLAY_PRE_APPLY
OF_OVERLAY_POST_APPLY
OF_OVERLAY_PRE_REMOVE
OF_OVERLAY_POST_REMOVE

In the case of pre-apply notification, if the notifier
returns error, the overlay will be rejected.

This patch exports two functions for registering/unregistering
notifications:
of_overlay_notifier_register(struct notifier_block *nb)
of_overlay_notifier_unregister(struct notifier_block *nb)

The of_mutex is held during these notifications. The
notification data includes pointers to the overlay target
and the overlay:

struct of_overlay_notify_data {
struct device_node *overlay;
struct device_node *target;
};

Signed-off-by: Alan Tull <atull@opensource.altera.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Moritz Fischer <moritz.fischer@ettus.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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>

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/overlay: add missing of_node_put

for_each_child_of_node performs an of_node_get on each iteration, so
a break out of the loop requires an of_node_put.

A simplified version of the semantic patch that fixes this problem is as
follows (http://coccinelle.lip6.fr):

// <smpl>
@@
expression root,e;
local idexpression child;
@@

for_each_child_of_node(root, child) {
... when != of_node_put(child)
when != e = child
(
return child;
|
+ of_node_put(child);
? return ...;
)
...
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Rob Herring <robh@kernel.org>

of/overlay: Grammar s/an negative/a negative/

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

of/overlay: Remove unused variable

Commit 3e7f7626fd49a ("of/overlay: Do not generate duplicate nodes") removed
the only use of the 'grandchild' variable, which leads to the following build
warning:

drivers/of/overlay.c: In function 'of_overlay_apply_single_device_node':
drivers/of/overlay.c:89:31: warning: unused variable 'grandchild' [-Wunused-variable]
struct device_node *tchild, *grandchild;
^

Remove this unused variable.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Rob Herring <robh@kernel.org>

of/overlay: Directly include idr.h

The overlay code uses IDRs but does not explicitly include the header
providing the interface, instead relying on an implicit inclusion. Make
the dependency explicit to avoid potential future build issues if the
implicit inclusion goes away.

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

of/overlay: Do not generate duplicate nodes

During the course of the rewrites a bug sneaked in when dealing
with children nodes of overlays, which ends up duplicating
sub nodes.

Simply remove the duplicate traversal of child nodes to fix.

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

of/overlay: Introduce DT overlay support

Overlays are a method to dynamically modify part of the kernel's
device tree with dynamically loaded data. Add the core functionality to
parse, apply and remove an overlay changeset. The core functionality
takes care of managing the overlay data format and performing the add
and remove. Drivers are expected to use the overlay functionality to
support custom expansion busses commonly found on consumer development
boards like the BeagleBone or Raspberry Pi.

The overlay code uses CONFIG_OF_DYNAMIC changesets to perform the low
level work of modifying the devicetree.

Documentation about internal and APIs is provided in
Documentation/devicetree/overlay-notes.txt

v2:
- Switch from __of_node_alloc() to __of_node_dup()
- Documentation fixups
- Remove 2-pass processing of properties
- Remove separate ov_lock; just use the DT mutex.
v1:
- Drop delete capability using '-' prefix. The '-' prefixed names
are valid properties and nodes and there is no need for it just yet.
- Do not update special properties - name & phandle ones.
- Change order of node attachment, so that the special property update
works.

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