1. 29 Aug, 2018 1 commit
    • Johan Hovold's avatar
      of: add helper to lookup compatible child node · 36156f92
      Johan Hovold authored
      Add of_get_compatible_child() helper that can be used to lookup
      compatible child nodes.
      Several drivers currently use of_find_compatible_node() to lookup child
      nodes while failing to notice that the of_find_ functions search the
      entire tree depth-first (from a given start node) and therefore can
      match unrelated nodes. The fact that these functions also drop a
      reference to the node they start searching from (e.g. the parent node)
      is typically also overlooked, something which can lead to use-after-free
      Signed-off-by: default avatarJohan Hovold <johan@kernel.org>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  2. 16 Jul, 2018 1 commit
  3. 07 Mar, 2018 1 commit
    • Frank Rowand's avatar
      of: cache phandle nodes to reduce cost of of_find_node_by_phandle() · 0b3ce78e
      Frank Rowand authored
      Create a cache of the nodes that contain a phandle property.  Use this
      cache to find the node for a given phandle value instead of scanning
      the devicetree to find the node.  If the phandle value is not found
      in the cache, of_find_node_by_phandle() will fall back to the tree
      scan algorithm.
      The cache is initialized in of_core_init().
      The cache is freed via a late_initcall_sync() if modules are not
      If the devicetree is created by the dtc compiler, with all phandle
      property values auto generated, then the size required by the cache
      could be 4 * (1 + number of phandles) bytes.  This results in an O(1)
      node lookup cost for a given phandle value.  Due to a concern that the
      phandle property values might not be consistent with what is generated
      by the dtc compiler, a mask has been added to the cache lookup algorithm.
      To maintain the O(1) node lookup cost, the size of the cache has been
      increased by rounding the number of entries up to the next power of
      The overhead of finding the devicetree node containing a given phandle
      value has been noted by several people in the recent past, in some cases
      with a patch to add a hashed index of devicetree nodes, based on the
      phandle value of the node.  One concern with this approach is the extra
      space added to each node.  This patch takes advantage of the phandle
      property values auto generated by the dtc compiler, which begin with
      one and monotonically increase by one, resulting in a range of 1..n
      for n phandle values.  This implementation should also provide a good
      reduction of overhead for any range of phandle values that are mostly
      in a monotonic range.
      Performance measurements by Chintan Pandya <cpandya@codeaurora.org>
      of several implementations of patches that are similar to this one
      suggest an expected reduction of boot time by ~400ms for his test
      system.  If the cache size was decreased to 64 entries, the boot
      time was reduced by ~340 ms.  The measurements were on a 4.9.73 kernel
      for arch/arm64/boot/dts/qcom/sda670-mtp.dts, contains 2371 nodes and
      814 phandle values.
      Reported-by: default avatarChintan Pandya <cpandya@codeaurora.org>
      Signed-off-by: default avatarFrank Rowand <frank.rowand@sony.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  4. 12 Feb, 2018 1 commit
    • Stephen Boyd's avatar
      of: Support parsing phandle argument lists through a nexus node · bd6f2fd5
      Stephen Boyd authored
      Platforms like 96boards have a standardized connector/expansion
      slot that exposes signals like GPIOs to expansion boards in an
      SoC agnostic way. We'd like the DT overlays for the expansion
      boards to be written once without knowledge of the SoC on the
      other side of the connector. This avoids the unscalable
      combinatorial explosion of a different DT overlay for each
      expansion board and SoC pair.
      We need a way to describe the GPIOs routed through the connector
      in an SoC agnostic way. Let's introduce nexus property parsing
      into the OF core to do this. This is largely based on the
      interrupt nexus support we already have. This allows us to remap
      a phandle list in a consumer node (e.g. reset-gpios) through a
      connector in a generic way (e.g. via gpio-map). Do this in a
      generic routine so that we can remap any sort of variable length
      phandle list.
      Taking GPIOs as an example, the connector would be a GPIO nexus,
      supporting the remapping of a GPIO specifier space to multiple
      GPIO providers on the SoC. DT would look as shown below, where
      'soc_gpio1' and 'soc_gpio2' are inside the SoC, 'connector' is an
      expansion port where boards can be plugged in, and
      'expansion_device' is a device on the expansion board.
      	soc {
      		soc_gpio1: gpio-controller1 {
      			#gpio-cells = <2>;
      		soc_gpio2: gpio-controller2 {
      			#gpio-cells = <2>;
      	connector: connector {
      		#gpio-cells = <2>;
      		gpio-map = <0 0 &soc_gpio1 1 0>,
      			   <1 0 &soc_gpio2 4 0>,
      			   <2 0 &soc_gpio1 3 0>,
      			   <3 0 &soc_gpio2 2 0>;
      		gpio-map-mask = <0xf 0x0>;
      		gpio-map-pass-thru = <0x0 0x1>
      	expansion_device {
      		reset-gpios = <&connector 2 GPIO_ACTIVE_LOW>;
      The GPIO core would use of_parse_phandle_with_args_map() instead
      of of_parse_phandle_with_args() and arrive at the same type of
      result, a phandle and argument list. The difference is that the
      phandle and arguments will be remapped through the nexus node to
      the underlying SoC GPIO controller node. In the example above,
      we would remap 'reset-gpios' from <&connector 2 GPIO_ACTIVE_LOW>
      to <&soc_gpio1 3 GPIO_ACTIVE_LOW>.
      Cc: Pantelis Antoniou <pantelis.antoniou@konsulko.com>
      Cc: Linus Walleij <linus.walleij@linaro.org>
      Cc: Mark Brown <broonie@kernel.org>
      Signed-off-by: default avatarStephen Boyd <stephen.boyd@linaro.org>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  5. 08 Jan, 2018 1 commit
  6. 02 Jan, 2018 1 commit
  7. 20 Nov, 2017 1 commit
  8. 18 Oct, 2017 1 commit
    • Frank Rowand's avatar
      of: overlay: remove a dependency on device node full_name · e0a58f3e
      Frank Rowand authored
      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: default avatarFrank Rowand <frank.rowand@sony.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  9. 16 Oct, 2017 2 commits
  10. 12 Oct, 2017 1 commit
    • Sergey Senozhatsky's avatar
      of: do not leak console options · db179e0d
      Sergey Senozhatsky authored
      Do not strdup() console options. It seems that the only reason for
      it to be strdup()-ed was a compilation warning: printk, UART and
      console drivers, for some reason, expect char pointer instead of
      const char pointer. So we can just pass `of_stdout_options', but
      need to cast it to char pointer. A better fix would be to change
      printk, console drivers and UART to accept const char `options';
      but that will take time - there are lots of drivers to update.
      The patch also fixes a possible memory leak: add_preferred_console()
      can fail, but we don't kfree() options.
      Signed-off-by: default avatarSergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Reviewed-by: default avatarPetr Mladek <pmladek@suse.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  11. 24 Jul, 2017 2 commits
  12. 18 Jul, 2017 1 commit
  13. 22 Jun, 2017 3 commits
  14. 01 Jun, 2017 1 commit
    • Sakari Ailus's avatar
      of: Move OF property and graph API from base.c to property.c · 1df09bc6
      Sakari Ailus authored
      base.c contains both core OF functions and increasingly other
      functionality such as accessing properties and graphs, including
      convenience functions. In the near future this would also include OF
      specific implementation of the fwnode property and graph APIs.
      Create driver/of/property.c to contain procedures for accessing and
      interpreting device tree properties. The procedures are moved from
      drivers/of/base.c, with no changes other than copying only the includes
      required by the moved procedures.
      Signed-off-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  15. 17 May, 2017 4 commits
  16. 04 May, 2017 1 commit
    • Rob Herring's avatar
      of: fix sparse warnings in of_find_next_cache_node · 91d96749
      Rob Herring authored
      sparse gives a warning that 'handle' is not a __be32:
      ../drivers/of/base.c:2261:61: warning: incorrect type in argument 1 (different base types)
      ../drivers/of/base.c:2261:61:    expected restricted __be32 const [usertype] *p
      ../drivers/of/base.c:2261:61:    got unsigned int const [usertype] *[assigned] handle
      We could just change the type, but the code can be improved by using
      of_parse_phandle instead of open coding it with of_get_property and
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  17. 03 Apr, 2017 1 commit
  18. 15 Feb, 2017 1 commit
  19. 09 Feb, 2017 1 commit
    • Qi Hou's avatar
      of: fix of_node leak caused in of_find_node_opts_by_path · 0549bde0
      Qi Hou authored
      During stepping down the tree, parent node is gotten first and its refcount is
      increased with of_node_get() in __of_get_next_child(). Since it just being used
      as tmp node, its refcount must be decreased with of_node_put() after traversing
      its child nodes.
      Or, its refcount will never be descreased to ZERO, then it will never be freed,
      as well as other related memory blocks.
      To fix this, decrease refcount of parent with of_node_put() after
      Signed-off-by: default avatarQi Hou <qi.hou@windriver.com>
      Acked-by: default avatarPeter Rosin <peda@axentia.se>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  20. 17 Jan, 2017 1 commit
  21. 03 Jan, 2017 1 commit
  22. 09 Dec, 2016 2 commits
  23. 18 Nov, 2016 1 commit
    • Sudeep Holla's avatar
      of: base: add support to get machine model name · e5269794
      Sudeep Holla authored
      Currently platforms/drivers needing to get the machine model name are
      replicating the same snippet of code. In some case, the OF reference
      counting is either missing or incorrect.
      This patch adds support to read the machine model name either using
      the "model" or the "compatible" property in the device tree root node
      to the core OF/DT code.
      This can be used to remove all the duplicate code snippets doing exactly
      same thing later.
      Cc: Rob Herring <robh+dt@kernel.org>
      Cc: Frank Rowand <frowand.list@gmail.com>
      Cc: Arnd Bergmann <arnd@arndb.de>
      Signed-off-by: Sudeep Holla's avatarSudeep Holla <sudeep.holla@arm.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  24. 11 Nov, 2016 1 commit
    • Hans de Goede's avatar
      Revert "console: don't prefer first registered if DT specifies stdout-path" · c6c7d83b
      Hans de Goede authored
      This reverts commit 05fd007e ("console: don't prefer first
      registered if DT specifies stdout-path").
      The reverted commit changes existing behavior on which many ARM boards
      rely.  Many ARM small-board-computers, like e.g.  the Raspberry Pi have
      both a video output and a serial console.  Depending on whether the user
      is using the device as a more regular computer; or as a headless device
      we need to have the console on either one or the other.
      Many users rely on the kernel behavior of the console being present on
      both outputs, before the reverted commit the console setup with no
      console= kernel arguments on an ARM board which sets stdout-path in dt
      would look like this:
        [root@localhost ~]# cat /proc/consoles
        ttyS0                -W- (EC p a)    4:64
        tty0                 -WU (E  p  )    4:1
      Where as after the reverted commit, it looks like this:
        [root@localhost ~]# cat /proc/consoles
        ttyS0                -W- (EC p a)    4:64
      This commit reverts commit 05fd007e ("console: don't prefer first
      registered if DT specifies stdout-path") restoring the original
      Fixes: 05fd007e ("console: don't prefer first registered if DT specifies stdout-path")
      Link: http://lkml.kernel.org/r/20161104121135.4780-2-hdegoede@redhat.com
      Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Rob Herring <robh+dt@kernel.org>
      Cc: Frank Rowand <frowand.list@gmail.com>
      Cc: Thorsten Leemhuis <regressions@leemhuis.info>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  25. 08 Oct, 2016 1 commit
    • Paul Burton's avatar
      console: don't prefer first registered if DT specifies stdout-path · 05fd007e
      Paul Burton authored
      If a device tree specifies a preferred device for kernel console output
      via the stdout-path or linux,stdout-path chosen node properties or the
      stdout alias then the kernel ought to honor it & output the kernel
      console to that device.  As it stands, this isn't the case.  Whilst we
      parse the stdout-path properties & set an of_stdout variable from
      of_alias_scan(), and use that from of_console_check() to determine
      whether to add a console device as a preferred console whilst
      registering it, we also prefer the first registered console if no other
      has been selected at the time of its registration.
      This means that if a console other than the one the device tree selects
      via stdout-path is registered first, we will switch to using it & when
      the stdout-path console is later registered the call to
      add_preferred_console() via of_console_check() is too late to do
      anything useful.  In practice this seems to mean that we switch to the
      dummy console device fairly early & see no further console output:
          Console: colour dummy device 80x25
          console [tty0] enabled
          bootconsole [ns16550a0] disabled
      Fix this by not automatically preferring the first registered console if
      one is specified by the device tree.  This allows consoles to be
      registered but not enabled, and once the driver for the console selected
      by stdout-path calls of_console_check() the driver will be added to the
      list of preferred consoles before any other console has been enabled.
      When that console is then registered via register_console() it will be
      enabled as expected.
      Link: http://lkml.kernel.org/r/20160809151937.26118-1-paul.burton@imgtec.com
      Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Cc: Paul Burton <paul.burton@imgtec.com>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
      Cc: Jiri Slaby <jslaby@suse.cz>
      Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
      Cc: Ivan Delalande <colona@arista.com>
      Cc: Thierry Reding <treding@nvidia.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: Jan Kara <jack@suse.com>
      Cc: Petr Mladek <pmladek@suse.com>
      Cc: Joe Perches <joe@perches.com>
      Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
      Cc: Rob Herring <robh+dt@kernel.org>
      Cc: Frank Rowand <frowand.list@gmail.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
  26. 15 Sep, 2016 2 commits
    • Richard Fitzgerald's avatar
      of: Add array read functions with min/max size limits · a67e9472
      Richard Fitzgerald authored
      Add a new set of array reading functions that take a minimum and
      maximum size limit and will fail if the property size is not within
      the size limits. This makes it more convenient for drivers that
      use variable-size DT arrays which must be bounded at both ends -
      data must be at least N entries but must not overflow the array
      it is being copied into. It is also more efficient than making this
      functionality out of existing public functions and avoids duplication.
      The existing array functions have been left in the API, since there
      are a very large number of clients of those functions and their
      existing functionality is still useful. This avoids turning a small
      API improvement into a major kernel rework.
      The old functions have been turned into mininmal static inlines calling
      the new functions. The old functions had no upper limit on the actual
      size of the dts entry, to preserve this functionality rather than keeping
      two near-identical implementations, if the new function is called with
      max=0 there is no limit on the size of the dts entry but only the min
      number of elements are read.
      Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.wolfsonmicro.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
    • Richard Fitzgerald's avatar
      of: Make of_find_property_value_of_size take a length range · 79ac5d31
      Richard Fitzgerald authored
      In preparation for adding variable-length array reads, change
      of_find_property_value_of_size so that it takes an optional
      maximum length. If the maximum is passed as 0, the behaviour is
      unchanged and it will return a property if it's >= the requested
      minimum length. If maximum is non-zero it will only return a
      property whose length is min <= l <= max.
      Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.wolfsonmicro.com>
      Signed-off-by: default avatarRob Herring <robh@kernel.org>
  27. 15 Aug, 2016 1 commit
  28. 09 Aug, 2016 1 commit
  29. 20 Jul, 2016 1 commit
  30. 18 Jul, 2016 1 commit
  31. 24 Jun, 2016 1 commit
    • Frank Rowand's avatar
      of: fix memory leak related to safe_name() · d9fc8807
      Frank Rowand authored
      Fix a memory leak resulting from memory allocation in safe_name().
      This patch fixes all call sites of safe_name().
      Mathieu Malaterre reported the memory leak on boot:
      On my PowerMac device-tree would generate a duplicate name:
      [    0.023043] device-tree: Duplicate name in PowerPC,G4@0, renamed to "l2-cache#1"
      in this case a newly allocated name is generated by `safe_name`. However
      in this case it is never deallocated.
      The bug was found using kmemleak reported as:
      unreferenced object 0xdf532e60 (size 32):
        comm "swapper", pid 1, jiffies 4294892300 (age 1993.532s)
        hex dump (first 32 bytes):
          6c 32 2d 63 61 63 68 65 23 31 00 dd e4 dd 1e c2  l2-cache#1......
          ec d4 ba ce 04 ec cc de 8e 85 e9 ca c4 ec cc 9e  ................
          [<c02d3350>] kvasprintf+0x64/0xc8
          [<c02d3400>] kasprintf+0x4c/0x5c
          [<c0453814>] safe_name.isra.1+0x80/0xc4
          [<c04545d8>] __of_attach_node_sysfs+0x6c/0x11c
          [<c075f21c>] of_core_init+0x8c/0xf8
          [<c0729594>] kernel_init_freeable+0xd4/0x208
          [<c00047e8>] kernel_init+0x24/0x11c
          [<c00158ec>] ret_from_kernel_thread+0x5c/0x64
      Link: https://bugzilla.kernel.org/show_bug.cgi?id=120331
      Signed-off-by: default avatarFrank Rowand <frank.rowand@am.sony.com>
      Reported-by: mathieu.malaterre@gmail.com
      Tested-by: default avatarMathieu Malaterre <mathieu.malaterre@gmail.com>
      Cc: stable@vger.kernel.org
      Signed-off-by: default avatarRob Herring <robh@kernel.org>