Commit Graph

58 Commits

Author SHA1 Message Date
Geert Uytterhoeven 628d0e1cb7 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 90dc0d1ce8 ("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>
2020-01-08 10:49:23 -06:00
Rob Herring 90dc0d1ce8 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>
2019-12-24 14:17:52 -07:00
Frank Rowand 637392a850 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: 6f75118800 ("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>
2019-11-26 12:32:21 -07:00
Rob Herring 8ce5f84157 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>
2019-01-10 16:24:44 -06:00
Frank Rowand f962788101 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>
2018-11-08 22:12:17 -08:00
Frank Rowand 2fe0e8769d 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>
2018-11-08 22:12:03 -08:00
Frank Rowand c168263b5a 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>
2018-11-08 22:11:57 -08:00
Frank Rowand a15e824ff2 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>
2018-11-08 22:11:39 -08:00
Frank Rowand 6f75118800 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>
2018-11-08 22:11:32 -08:00
Frank Rowand 81225ea682 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>
2018-11-08 22:11:23 -08:00
Frank Rowand 8814dc46bd 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>
2018-11-08 22:11:15 -08:00
Frank Rowand 6b4955ba7b 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>
2018-11-08 22:11:08 -08:00
Frank Rowand 7c528e457d 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>
2018-11-08 22:10:44 -08:00
Frank Rowand 144552c786 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>
2018-11-08 22:10:35 -08:00
Rob Herring a613b26a50 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>
2018-09-07 11:04:41 -05:00
Frank Rowand b9952b5218 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: 0b3ce78e90 ("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>
2018-07-16 08:41:32 -06:00
Jan Kiszka 83ef4777f5 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>
2018-04-26 21:18:13 -05:00
Geert Uytterhoeven a514266ba6 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: 39a751a4cb ("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>
2018-03-17 18:18:38 -05:00
Frank Rowand b89dae1852 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: a7e4cfb0a7 ("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>
2018-03-05 15:38:34 -06:00
Frank Rowand e547c00316 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>
2018-03-04 00:29:40 -08:00
Frank Rowand 39a751a4cb 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>
2018-03-04 00:29:24 -08:00
Rob Herring af6074fc9a 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>
2018-01-08 08:22:45 -06:00
Geert Uytterhoeven 589b754df3 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>
2017-12-08 09:32:18 -06:00
Geert Uytterhoeven 35e691eddc 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: 61b4de4e0b ("of: overlay: minor restructuring")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-08 09:32:10 -06:00
Geert Uytterhoeven 5e4748175f 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: f948d6d8b7 ("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>
2017-12-06 16:08:30 -06:00
Geert Uytterhoeven 1352f09b4c 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: f948d6d8b7 ("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>
2017-12-06 16:04:36 -06:00
Geert Uytterhoeven 6de67de326 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>
2017-12-06 14:56:33 -06:00
Geert Uytterhoeven e9d92e40ac of: Spelling s/changset/changeset/
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rob Herring <robh@kernel.org>
2017-12-06 14:56:32 -06:00
Frank Rowand 4ee7c0d964 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>
2017-10-19 17:15:09 -05:00
Frank Rowand a1d19bd4cf 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>
2017-10-19 17:15:09 -05:00
Frank Rowand 34ca5d76f2 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>
2017-10-17 20:47:56 -05:00
Frank Rowand e0a58f3e08 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>
2017-10-17 20:47:37 -05:00
Frank Rowand 3912b7917a 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>
2017-10-17 20:47:34 -05:00
Frank Rowand f948d6d8b7 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>
2017-10-17 20:47:27 -05:00
Frank Rowand 6d0f5470db 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>
2017-10-17 20:47:22 -05:00
Frank Rowand 87f242c119 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>
2017-10-17 20:47:17 -05:00
Frank Rowand 24789c5ce5 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>
2017-10-17 20:47:14 -05:00
Frank Rowand 61b4de4e0b 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>
2017-10-17 20:46:59 -05:00
Frank Rowand 42b2e94fe8 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>
2017-10-17 20:46:55 -05:00
Frank Rowand 0290c4ca25 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>
2017-10-17 20:46:17 -05:00
Frank Rowand bbed8794d5 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>
2017-10-17 20:46:15 -05:00
Frank Rowand 646afc4ad7 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>
2017-10-17 20:46:13 -05:00
Lixin Wang ac0f3e30d8 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>
2017-10-17 08:55:54 -05:00
Frank Rowand d1651b03c2 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>
2017-07-20 09:40:05 -05:00
Frank Rowand c1cd1e01fe 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>
2017-07-20 09:36:15 -05:00
Rob Herring 0d638a07d3 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>
2017-07-18 17:09:18 -05:00
Frank Rowand 7a12f45989 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>
2017-06-22 11:19:09 -05:00
XuYing 261c73f3f6 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>
2017-01-09 14:21:23 -06:00
Geliang Tang 30965eeab5 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>
2017-01-04 14:01:28 -06:00
Alan Tull 39a842e22c 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>
2016-11-10 17:03:35 +01:00