user/sven/linux.git/drivers/of/dynamic.c, branch v5.15.27

of: Add missing 'Return' section in kerneldoc comments

2021-03-27T18:59:03Z

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 Cc: Mauro Carvalho Chehab Signed-off-by: Rob Herring Reviewed-by: Mauro Carvalho Chehab Link: https://lore.kernel.org/r/20210325164713.1296407-8-robh@kernel.org

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

2021-03-23T21:27:52Z

Fixes the following W=1 kernel build warning(s): drivers/of/dynamic.c:234: warning: Function parameter or member 'np' not described in 'of_attach_node' drivers/of/dynamic.c:286: warning: Function parameter or member 'np' not described in 'of_detach_node' drivers/of/dynamic.c:326: warning: Function parameter or member 'kobj' not described in 'of_node_release' drivers/of/dynamic.c:326: warning: Excess function parameter 'kref' description in 'of_node_release' Cc: Rob Herring Cc: Frank Rowand Cc: devicetree@vger.kernel.org Signed-off-by: Lee Jones Signed-off-by: Rob Herring Link: https://lore.kernel.org/r/20210318104036.3175910-3-lee.jones@linaro.org

driver core: Add fwnode link support

2020-12-09T18:10:21Z

Add support for creating supplier-consumer links between fwnodes. It is intended for internal use the driver core and generic firmware support code (eg. Device Tree, ACPI), so it is simple by design and the API provided is limited. Acked-by: Rob Herring Signed-off-by: Saravana Kannan Link: https://lore.kernel.org/r/20201121020232.908850-9-saravanak@google.com Signed-off-by: Greg Kroah-Hartman

of: of_detach_node() remove unneeded local return variable

2020-04-14T12:59:54Z

rc is unneeded, just return 0. Signed-off-by: Ding Xiang Signed-off-by: Rob Herring

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

2019-12-24T21:17:52Z

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 Cc: Michael Ellerman Cc: Segher Boessenkool Cc: Frank Rowand Acked-by: Sebastian Andrzej Siewior Reviewed-by: Frank Rowand Tested-by: Frank Rowand Signed-off-by: Rob Herring

of: Remove struct device_node.type pointer

2019-01-10T22:24:44Z

Now that all users of device_node.type pointer have been removed in favor of accessor functions, we can remove it. Cc: Frank Rowand Cc: devicetree@vger.kernel.org Signed-off-by: Rob Herring

of: __of_detach_node() - remove node from phandle cache

2018-12-21T18:42:36Z

Non-overlay dynamic devicetree node removal may leave the node in the phandle cache. Subsequent calls to of_find_node_by_phandle() will incorrectly find the stale entry. Remove the node from the cache. Add paranoia checks in of_find_node_by_phandle() as a second level of defense (do not return cached node if detached, do not add node to cache if detached). Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Reported-by: Michael Bringmann Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Frank Rowand Signed-off-by: Rob Herring

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

2018-11-09T06:12:17Z

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 , for example, "fc4ab000.". After applying the patch the name, in this example, for node restart@fc4ab000 is "fc4ab000.restart". Tested-by: Alan Tull Signed-off-by: Frank Rowand

of: overlay: add missing of_node_get() in __of_attach_node_sysfs

2018-11-09T06:10:53Z

There is a matching of_node_put() in __of_detach_node_sysfs() Remove misleading comment from function header comment for of_detach_node(). This patch may result in memory leaks from code that directly calls the dynamic node add and delete functions directly instead of using changesets. This commit should result in powerpc systems that dynamically allocate a node, then later deallocate the node to have a memory leak when the node is deallocated. The next commit will fix the leak. Tested-by: Alan Tull Acked-by: Michael Ellerman (powerpc) Signed-off-by: Frank Rowand

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

2018-11-09T06:10:35Z

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 Signed-off-by: Frank Rowand