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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
Commit 3e7f7626fd ("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>
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>
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>
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>
