Commit 23a12dde authored by Ingo Molnar's avatar Ingo Molnar
Browse files

Merge branch 'core/urgent' into x86/urgent, to pick up objtool fix

Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parents 98f76206 bcb6fb5d

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......@@ -323,7 +323,6 @@ ForEachMacros:
- 'protocol_for_each_card'
- 'protocol_for_each_dev'
- 'queue_for_each_hw_ctx'
- 'radix_tree_for_each_contig'
- 'radix_tree_for_each_slot'
- 'radix_tree_for_each_tagged'
- 'rbtree_postorder_for_each_entry_safe'
......
......@@ -119,6 +119,13 @@ Mark Brown <broonie@sirena.org.uk>
Mark Yao <markyao0591@gmail.com> <mark.yao@rock-chips.com>
Martin Kepplinger <martink@posteo.de> <martin.kepplinger@theobroma-systems.com>
Martin Kepplinger <martink@posteo.de> <martin.kepplinger@ginzinger.com>
Matthew Wilcox <willy@infradead.org> <matthew.r.wilcox@intel.com>
Matthew Wilcox <willy@infradead.org> <matthew@wil.cx>
Matthew Wilcox <willy@infradead.org> <mawilcox@linuxonhyperv.com>
Matthew Wilcox <willy@infradead.org> <mawilcox@microsoft.com>
Matthew Wilcox <willy@infradead.org> <willy@debian.org>
Matthew Wilcox <willy@infradead.org> <willy@linux.intel.com>
Matthew Wilcox <willy@infradead.org> <willy@parisc-linux.org>
Matthieu CASTET <castet.matthieu@free.fr>
Mauro Carvalho Chehab <mchehab@kernel.org> <mchehab@brturbo.com.br>
Mauro Carvalho Chehab <mchehab@kernel.org> <maurochehab@gmail.com>
......@@ -153,6 +160,11 @@ Peter Oruba <peter.oruba@amd.com>
Pratyush Anand <pratyush.anand@gmail.com> <pratyush.anand@st.com>
Praveen BP <praveenbp@ti.com>
Qais Yousef <qsyousef@gmail.com> <qais.yousef@imgtec.com>
Oleksij Rempel <linux@rempel-privat.de> <bug-track@fisher-privat.net>
Oleksij Rempel <linux@rempel-privat.de> <external.Oleksij.Rempel@de.bosch.com>
Oleksij Rempel <linux@rempel-privat.de> <fixed-term.Oleksij.Rempel@de.bosch.com>
Oleksij Rempel <linux@rempel-privat.de> <o.rempel@pengutronix.de>
Oleksij Rempel <linux@rempel-privat.de> <ore@pengutronix.de>
Rajesh Shah <rajesh.shah@intel.com>
Ralf Baechle <ralf@linux-mips.org>
Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
......
......@@ -199,7 +199,7 @@ Description:
What: /sys/bus/iio/devices/iio:deviceX/in_positionrelative_x_raw
What: /sys/bus/iio/devices/iio:deviceX/in_positionrelative_y_raw
KernelVersion: 4.18
KernelVersion: 4.19
Contact: linux-iio@vger.kernel.org
Description:
Relative position in direction x or y on a pad (may be
......
......@@ -5,7 +5,7 @@ Memory Hotplug
==============
:Created: Jul 28 2007
:Updated: Add description of notifier of memory hotplug: Oct 11 2007
:Updated: Add some details about locking internals: Aug 20 2018
This document is about memory hotplug including how-to-use and current status.
Because Memory Hotplug is still under development, contents of this text will
......@@ -392,6 +392,46 @@ Need more implementation yet....
- Notification completion of remove works by OS to firmware.
- Guard from remove if not yet.
Locking Internals
=================
When adding/removing memory that uses memory block devices (i.e. ordinary RAM),
the device_hotplug_lock should be held to:
- synchronize against online/offline requests (e.g. via sysfs). This way, memory
block devices can only be accessed (.online/.state attributes) by user
space once memory has been fully added. And when removing memory, we
know nobody is in critical sections.
- synchronize against CPU hotplug and similar (e.g. relevant for ACPI and PPC)
Especially, there is a possible lock inversion that is avoided using
device_hotplug_lock when adding memory and user space tries to online that
memory faster than expected:
- device_online() will first take the device_lock(), followed by
mem_hotplug_lock
- add_memory_resource() will first take the mem_hotplug_lock, followed by
the device_lock() (while creating the devices, during bus_add_device()).
As the device is visible to user space before taking the device_lock(), this
can result in a lock inversion.
onlining/offlining of memory should be done via device_online()/
device_offline() - to make sure it is properly synchronized to actions
via sysfs. Holding device_hotplug_lock is advised (to e.g. protect online_type)
When adding/removing/onlining/offlining memory or adding/removing
heterogeneous/device memory, we should always hold the mem_hotplug_lock in
write mode to serialise memory hotplug (e.g. access to global/zone
variables).
In addition, mem_hotplug_lock (in contrast to device_hotplug_lock) in read
mode allows for a quite efficient get_online_mems/put_online_mems
implementation, so code accessing memory can protect from that memory
vanishing.
Future Work
===========
......
......@@ -26,6 +26,7 @@ Offset Value Purpose
0x20 0xfcba0d10 (Magic cookie) AFTR
0x24 exynos_cpu_resume_ns AFTR
0x28 + 4*cpu 0x8 (Magic cookie, Exynos3250) AFTR
0x28 0x0 or last value during resume (Exynos542x) System suspend
2. Secure mode
......
......@@ -5,54 +5,23 @@ Boot time memory management
Early system initialization cannot use "normal" memory management
simply because it is not set up yet. But there is still need to
allocate memory for various data structures, for instance for the
physical page allocator. To address this, a specialized allocator
called the :ref:`Boot Memory Allocator <bootmem>`, or bootmem, was
introduced. Several years later PowerPC developers added a "Logical
Memory Blocks" allocator, which was later adopted by other
architectures and renamed to :ref:`memblock <memblock>`. There is also
a compatibility layer called `nobootmem` that translates bootmem
allocation interfaces to memblock calls.
physical page allocator.
The selection of the early allocator is done using
``CONFIG_NO_BOOTMEM`` and ``CONFIG_HAVE_MEMBLOCK`` kernel
configuration options. These options are enabled or disabled
statically by the architectures' Kconfig files.
* Architectures that rely only on bootmem select
``CONFIG_NO_BOOTMEM=n && CONFIG_HAVE_MEMBLOCK=n``.
* The users of memblock with the nobootmem compatibility layer set
``CONFIG_NO_BOOTMEM=y && CONFIG_HAVE_MEMBLOCK=y``.
* And for those that use both memblock and bootmem the configuration
includes ``CONFIG_NO_BOOTMEM=n && CONFIG_HAVE_MEMBLOCK=y``.
Whichever allocator is used, it is the responsibility of the
architecture specific initialization to set it up in
:c:func:`setup_arch` and tear it down in :c:func:`mem_init` functions.
A specialized allocator called ``memblock`` performs the
boot time memory management. The architecture specific initialization
must set it up in :c:func:`setup_arch` and tear it down in
:c:func:`mem_init` functions.
Once the early memory management is available it offers a variety of
functions and macros for memory allocations. The allocation request
may be directed to the first (and probably the only) node or to a
particular node in a NUMA system. There are API variants that panic
when an allocation fails and those that don't. And more recent and
advanced memblock even allows controlling its own behaviour.
.. _bootmem:
Bootmem
=======
when an allocation fails and those that don't.
(mostly stolen from Mel Gorman's "Understanding the Linux Virtual
Memory Manager" `book`_)
Memblock also offers a variety of APIs that control its own behaviour.
.. _book: https://www.kernel.org/doc/gorman/
.. kernel-doc:: mm/bootmem.c
:doc: bootmem overview
.. _memblock:
Memblock
========
Memblock Overview
=================
.. kernel-doc:: mm/memblock.c
:doc: memblock overview
......@@ -61,26 +30,6 @@ Memblock
Functions and structures
========================
Common API
----------
The functions that are described in this section are available
regardless of what early memory manager is enabled.
.. kernel-doc:: mm/nobootmem.c
Bootmem specific API
--------------------
These interfaces available only with bootmem, i.e when ``CONFIG_NO_BOOTMEM=n``
.. kernel-doc:: include/linux/bootmem.h
.. kernel-doc:: mm/bootmem.c
:functions:
Memblock specific API
---------------------
Here is the description of memblock data structures, functions and
macros. Some of them are actually internal, but since they are
documented it would be silly to omit them. Besides, reading the
......
......@@ -21,6 +21,7 @@ Core utilities
local_ops
workqueue
genericirq
xarray
flexible-arrays
librs
genalloc
......
.. SPDX-License-Identifier: GPL-2.0+
======
XArray
======
:Author: Matthew Wilcox
Overview
========
The XArray is an abstract data type which behaves like a very large array
of pointers. It meets many of the same needs as a hash or a conventional
resizable array. Unlike a hash, it allows you to sensibly go to the
next or previous entry in a cache-efficient manner. In contrast to a
resizable array, there is no need to copy data or change MMU mappings in
order to grow the array. It is more memory-efficient, parallelisable
and cache friendly than a doubly-linked list. It takes advantage of
RCU to perform lookups without locking.
The XArray implementation is efficient when the indices used are densely
clustered; hashing the object and using the hash as the index will not
perform well. The XArray is optimised for small indices, but still has
good performance with large indices. If your index can be larger than
``ULONG_MAX`` then the XArray is not the data type for you. The most
important user of the XArray is the page cache.
Each non-``NULL`` entry in the array has three bits associated with
it called marks. Each mark may be set or cleared independently of
the others. You can iterate over entries which are marked.
Normal pointers may be stored in the XArray directly. They must be 4-byte
aligned, which is true for any pointer returned from :c:func:`kmalloc` and
:c:func:`alloc_page`. It isn't true for arbitrary user-space pointers,
nor for function pointers. You can store pointers to statically allocated
objects, as long as those objects have an alignment of at least 4.
You can also store integers between 0 and ``LONG_MAX`` in the XArray.
You must first convert it into an entry using :c:func:`xa_mk_value`.
When you retrieve an entry from the XArray, you can check whether it is
a value entry by calling :c:func:`xa_is_value`, and convert it back to
an integer by calling :c:func:`xa_to_value`.
Some users want to store tagged pointers instead of using the marks
described above. They can call :c:func:`xa_tag_pointer` to create an
entry with a tag, :c:func:`xa_untag_pointer` to turn a tagged entry
back into an untagged pointer and :c:func:`xa_pointer_tag` to retrieve
the tag of an entry. Tagged pointers use the same bits that are used
to distinguish value entries from normal pointers, so each user must
decide whether they want to store value entries or tagged pointers in
any particular XArray.
The XArray does not support storing :c:func:`IS_ERR` pointers as some
conflict with value entries or internal entries.
An unusual feature of the XArray is the ability to create entries which
occupy a range of indices. Once stored to, looking up any index in
the range will return the same entry as looking up any other index in
the range. Setting a mark on one index will set it on all of them.
Storing to any index will store to all of them. Multi-index entries can
be explicitly split into smaller entries, or storing ``NULL`` into any
entry will cause the XArray to forget about the range.
Normal API
==========
Start by initialising an XArray, either with :c:func:`DEFINE_XARRAY`
for statically allocated XArrays or :c:func:`xa_init` for dynamically
allocated ones. A freshly-initialised XArray contains a ``NULL``
pointer at every index.
You can then set entries using :c:func:`xa_store` and get entries
using :c:func:`xa_load`. xa_store will overwrite any entry with the
new entry and return the previous entry stored at that index. You can
use :c:func:`xa_erase` instead of calling :c:func:`xa_store` with a
``NULL`` entry. There is no difference between an entry that has never
been stored to and one that has most recently had ``NULL`` stored to it.
You can conditionally replace an entry at an index by using
:c:func:`xa_cmpxchg`. Like :c:func:`cmpxchg`, it will only succeed if
the entry at that index has the 'old' value. It also returns the entry
which was at that index; if it returns the same entry which was passed as
'old', then :c:func:`xa_cmpxchg` succeeded.
If you want to only store a new entry to an index if the current entry
at that index is ``NULL``, you can use :c:func:`xa_insert` which
returns ``-EEXIST`` if the entry is not empty.
You can enquire whether a mark is set on an entry by using
:c:func:`xa_get_mark`. If the entry is not ``NULL``, you can set a mark
on it by using :c:func:`xa_set_mark` and remove the mark from an entry by
calling :c:func:`xa_clear_mark`. You can ask whether any entry in the
XArray has a particular mark set by calling :c:func:`xa_marked`.
You can copy entries out of the XArray into a plain array by calling
:c:func:`xa_extract`. Or you can iterate over the present entries in
the XArray by calling :c:func:`xa_for_each`. You may prefer to use
:c:func:`xa_find` or :c:func:`xa_find_after` to move to the next present
entry in the XArray.
Calling :c:func:`xa_store_range` stores the same entry in a range
of indices. If you do this, some of the other operations will behave
in a slightly odd way. For example, marking the entry at one index
may result in the entry being marked at some, but not all of the other
indices. Storing into one index may result in the entry retrieved by
some, but not all of the other indices changing.
Finally, you can remove all entries from an XArray by calling
:c:func:`xa_destroy`. If the XArray entries are pointers, you may wish
to free the entries first. You can do this by iterating over all present
entries in the XArray using the :c:func:`xa_for_each` iterator.
ID assignment
-------------
You can call :c:func:`xa_alloc` to store the entry at any unused index
in the XArray. If you need to modify the array from interrupt context,
you can use :c:func:`xa_alloc_bh` or :c:func:`xa_alloc_irq` to disable
interrupts while allocating the ID. Unlike :c:func:`xa_store`, allocating
a ``NULL`` pointer does not delete an entry. Instead it reserves an
entry like :c:func:`xa_reserve` and you can release it using either
:c:func:`xa_erase` or :c:func:`xa_release`. To use ID assignment, the
XArray must be defined with :c:func:`DEFINE_XARRAY_ALLOC`, or initialised
by passing ``XA_FLAGS_ALLOC`` to :c:func:`xa_init_flags`,
Memory allocation
-----------------
The :c:func:`xa_store`, :c:func:`xa_cmpxchg`, :c:func:`xa_alloc`,
:c:func:`xa_reserve` and :c:func:`xa_insert` functions take a gfp_t
parameter in case the XArray needs to allocate memory to store this entry.
If the entry is being deleted, no memory allocation needs to be performed,
and the GFP flags specified will be ignored.
It is possible for no memory to be allocatable, particularly if you pass
a restrictive set of GFP flags. In that case, the functions return a
special value which can be turned into an errno using :c:func:`xa_err`.
If you don't need to know exactly which error occurred, using
:c:func:`xa_is_err` is slightly more efficient.
Locking
-------
When using the Normal API, you do not have to worry about locking.
The XArray uses RCU and an internal spinlock to synchronise access:
No lock needed:
* :c:func:`xa_empty`
* :c:func:`xa_marked`
Takes RCU read lock:
* :c:func:`xa_load`
* :c:func:`xa_for_each`
* :c:func:`xa_find`
* :c:func:`xa_find_after`
* :c:func:`xa_extract`
* :c:func:`xa_get_mark`
Takes xa_lock internally:
* :c:func:`xa_store`
* :c:func:`xa_insert`
* :c:func:`xa_erase`
* :c:func:`xa_erase_bh`
* :c:func:`xa_erase_irq`
* :c:func:`xa_cmpxchg`
* :c:func:`xa_store_range`
* :c:func:`xa_alloc`
* :c:func:`xa_alloc_bh`
* :c:func:`xa_alloc_irq`
* :c:func:`xa_destroy`
* :c:func:`xa_set_mark`
* :c:func:`xa_clear_mark`
Assumes xa_lock held on entry:
* :c:func:`__xa_store`
* :c:func:`__xa_insert`
* :c:func:`__xa_erase`
* :c:func:`__xa_cmpxchg`
* :c:func:`__xa_alloc`
* :c:func:`__xa_set_mark`
* :c:func:`__xa_clear_mark`
If you want to take advantage of the lock to protect the data structures
that you are storing in the XArray, you can call :c:func:`xa_lock`
before calling :c:func:`xa_load`, then take a reference count on the
object you have found before calling :c:func:`xa_unlock`. This will
prevent stores from removing the object from the array between looking
up the object and incrementing the refcount. You can also use RCU to
avoid dereferencing freed memory, but an explanation of that is beyond
the scope of this document.
The XArray does not disable interrupts or softirqs while modifying
the array. It is safe to read the XArray from interrupt or softirq
context as the RCU lock provides enough protection.
If, for example, you want to store entries in the XArray in process
context and then erase them in softirq context, you can do that this way::
void foo_init(struct foo *foo)
{
xa_init_flags(&foo->array, XA_FLAGS_LOCK_BH);
}
int foo_store(struct foo *foo, unsigned long index, void *entry)
{
int err;
xa_lock_bh(&foo->array);
err = xa_err(__xa_store(&foo->array, index, entry, GFP_KERNEL));
if (!err)
foo->count++;
xa_unlock_bh(&foo->array);
return err;
}
/* foo_erase() is only called from softirq context */
void foo_erase(struct foo *foo, unsigned long index)
{
xa_lock(&foo->array);
__xa_erase(&foo->array, index);
foo->count--;
xa_unlock(&foo->array);
}
If you are going to modify the XArray from interrupt or softirq context,
you need to initialise the array using :c:func:`xa_init_flags`, passing
``XA_FLAGS_LOCK_IRQ`` or ``XA_FLAGS_LOCK_BH``.
The above example also shows a common pattern of wanting to extend the
coverage of the xa_lock on the store side to protect some statistics
associated with the array.
Sharing the XArray with interrupt context is also possible, either
using :c:func:`xa_lock_irqsave` in both the interrupt handler and process
context, or :c:func:`xa_lock_irq` in process context and :c:func:`xa_lock`
in the interrupt handler. Some of the more common patterns have helper
functions such as :c:func:`xa_erase_bh` and :c:func:`xa_erase_irq`.
Sometimes you need to protect access to the XArray with a mutex because
that lock sits above another mutex in the locking hierarchy. That does
not entitle you to use functions like :c:func:`__xa_erase` without taking
the xa_lock; the xa_lock is used for lockdep validation and will be used
for other purposes in the future.
The :c:func:`__xa_set_mark` and :c:func:`__xa_clear_mark` functions are also
available for situations where you look up an entry and want to atomically
set or clear a mark. It may be more efficient to use the advanced API
in this case, as it will save you from walking the tree twice.
Advanced API
============
The advanced API offers more flexibility and better performance at the
cost of an interface which can be harder to use and has fewer safeguards.
No locking is done for you by the advanced API, and you are required
to use the xa_lock while modifying the array. You can choose whether
to use the xa_lock or the RCU lock while doing read-only operations on
the array. You can mix advanced and normal operations on the same array;
indeed the normal API is implemented in terms of the advanced API. The
advanced API is only available to modules with a GPL-compatible license.
The advanced API is based around the xa_state. This is an opaque data
structure which you declare on the stack using the :c:func:`XA_STATE`
macro. This macro initialises the xa_state ready to start walking
around the XArray. It is used as a cursor to maintain the position
in the XArray and let you compose various operations together without
having to restart from the top every time.
The xa_state is also used to store errors. You can call
:c:func:`xas_error` to retrieve the error. All operations check whether
the xa_state is in an error state before proceeding, so there's no need
for you to check for an error after each call; you can make multiple
calls in succession and only check at a convenient point. The only
errors currently generated by the XArray code itself are ``ENOMEM`` and
``EINVAL``, but it supports arbitrary errors in case you want to call
:c:func:`xas_set_err` yourself.
If the xa_state is holding an ``ENOMEM`` error, calling :c:func:`xas_nomem`
will attempt to allocate more memory using the specified gfp flags and
cache it in the xa_state for the next attempt. The idea is that you take
the xa_lock, attempt the operation and drop the lock. The operation
attempts to allocate memory while holding the lock, but it is more
likely to fail. Once you have dropped the lock, :c:func:`xas_nomem`
can try harder to allocate more memory. It will return ``true`` if it
is worth retrying the operation (i.e. that there was a memory error *and*
more memory was allocated). If it has previously allocated memory, and
that memory wasn't used, and there is no error (or some error that isn't
``ENOMEM``), then it will free the memory previously allocated.
Internal Entries
----------------
The XArray reserves some entries for its own purposes. These are never
exposed through the normal API, but when using the advanced API, it's
possible to see them. Usually the best way to handle them is to pass them
to :c:func:`xas_retry`, and retry the operation if it returns ``true``.
.. flat-table::
:widths: 1 1 6
* - Name
- Test
- Usage
* - Node
- :c:func:`xa_is_node`
- An XArray node. May be visible when using a multi-index xa_state.
* - Sibling
- :c:func:`xa_is_sibling`
- A non-canonical entry for a multi-index entry. The value indicates
which slot in this node has the canonical entry.
* - Retry
- :c:func:`xa_is_retry`
- This entry is currently being modified by a thread which has the
xa_lock. The node containing this entry may be freed at the end
of this RCU period. You should restart the lookup from the head
of the array.
* - Zero
- :c:func:`xa_is_zero`
- Zero entries appear as ``NULL`` through the Normal API, but occupy
an entry in the XArray which can be used to reserve the index for
future use.
Other internal entries may be added in the future. As far as possible, they
will be handled by :c:func:`xas_retry`.
Additional functionality
------------------------
The :c:func:`xas_create_range` function allocates all the necessary memory
to store every entry in a range. It will set ENOMEM in the xa_state if
it cannot allocate memory.
You can use :c:func:`xas_init_marks` to reset the marks on an entry
to their default state. This is usually all marks clear, unless the
XArray is marked with ``XA_FLAGS_TRACK_FREE``, in which case mark 0 is set
and all other marks are clear. Replacing one entry with another using
:c:func:`xas_store` will not reset the marks on that entry; if you want
the marks reset, you should do that explicitly.
The :c:func:`xas_load` will walk the xa_state as close to the entry
as it can. If you know the xa_state has already been walked to the
entry and need to check that the entry hasn't changed, you can use
:c:func:`xas_reload` to save a function call.
If you need to move to a different index in the XArray, call
:c:func:`xas_set`. This resets the cursor to the top of the tree, which
will generally make the next operation walk the cursor to the desired
spot in the tree. If you want to move to the next or previous index,
call :c:func:`xas_next` or :c:func:`xas_prev`. Setting the index does
not walk the cursor around the array so does not require a lock to be
held, while moving to the next or previous index does.
You can search for the next present entry using :c:func:`xas_find`. This
is the equivalent of both :c:func:`xa_find` and :c:func:`xa_find_after`;
if the cursor has been walked to an entry, then it will find the next
entry after the one currently referenced. If not, it will return the
entry at the index of the xa_state. Using :c:func:`xas_next_entry` to
move to the next present entry instead of :c:func:`xas_find` will save
a function call in the majority of cases at the expense of emitting more
inline code.
The :c:func:`xas_find_marked` function is similar. If the xa_state has
not been walked, it will return the entry at the index of the xa_state,
if it is marked. Otherwise, it will return the first marked entry after
the entry referenced by the xa_state. The :c:func:`xas_next_marked`
function is the equivalent of :c:func:`xas_next_entry`.
When iterating over a range of the XArray using :c:func:`xas_for_each`
or :c:func:`xas_for_each_marked`, it may be necessary to temporarily stop
the iteration. The :c:func:`xas_pause` function exists for this purpose.
After you have done the necessary work and wish to resume, the xa_state
is in an appropriate state to continue the iteration after the entry
you last processed. If you have interrupts disabled while iterating,
then it is good manners to pause the iteration and reenable interrupts
every ``XA_CHECK_SCHED`` entries.
The :c:func:`xas_get_mark`, :c:func:`xas_set_mark` and
:c:func:`xas_clear_mark` functions require the xa_state cursor to have
been moved to the appropriate location in the xarray; they will do
nothing if you have called :c:func:`xas_pause` or :c:func:`xas_set`
immediately before.
You can call :c:func:`xas_set_update` to have a callback function
called each time the XArray updates a node. This is used by the page
cache workingset code to maintain its list of nodes which contain only
shadow entries.
Multi-Index Entries
-------------------
The XArray has the ability to tie multiple indices together so that
operations on one index affect all indices. For example, storing into
any index will change the value of the entry retrieved from any index.
Setting or clearing a mark on any index will set or clear the mark
on every index that is tied together. The current implementation
only allows tying ranges which are aligned powers of two together;
eg indices 64-127 may be tied together, but 2-6 may not be. This may
save substantial quantities of memory; for example tying 512 entries
together will save over 4kB.
You can create a multi-index entry by using :c:func:`XA_STATE_ORDER`
or :c:func:`xas_set_order` followed by a call to :c:func:`xas_store`.
Calling :c:func:`xas_load` with a multi-index xa_state will walk the
xa_state to the right location in the tree, but the return value is not
meaningful, potentially being an internal entry or ``NULL`` even when there
is an entry stored within the range. Calling :c:func:`xas_find_conflict`
will return the first entry within the range or ``NULL`` if there are no
entries in the range. The :c:func:`xas_for_each_conflict` iterator will
iterate over every entry which overlaps the specified range.
If :c:func:`xas_load` encounters a multi-index entry, the xa_index
in the xa_state will not be changed. When iterating over an XArray
or calling :c:func:`xas_find`, if the initial index is in the middle
of a multi-index entry, it will not be altered. Subsequent calls
or iterations will move the index to the first index in the range.
Each entry will only be returned once, no matter how many indices it
occupies.
Using :c:func:`xas_next` or :c:func:`xas_prev` with a multi-index xa_state
is not supported. Using either of these functions on a multi-index entry
will reveal sibling entries; these should be skipped over by the caller.
Storing ``NULL`` into any index of a multi-index entry will set the entry
at every index to ``NULL`` and dissolve the tie. Splitting a multi-index
entry into entries occupying smaller ranges is not yet supported.
Functions and structures
========================
.. kernel-doc:: include/linux/xarray.h
.. kernel-doc:: lib/xarray.c
......@@ -57,12 +57,17 @@ Boards with the Amlogic Meson AXG A113D SoC shall have the following properties:
Required root node property:
compatible: "amlogic,a113d", "amlogic,meson-axg";
Boards with the Amlogic Meson G12A S905D2 SoC shall have the following properties:
Required root node property:
compatible: "amlogic,g12a";
Board compatible values (alphabetically, grouped by SoC):
- "geniatech,atv1200" (Meson6)
- "minix,neo-x8" (Meson8)
- "endless,ec100" (Meson8b)
- "hardkernel,odroid-c1" (Meson8b)
- "tronfy,mxq" (Meson8b)
......@@ -101,6 +106,8 @@ Board compatible values (alphabetically, grouped by SoC):
- "amlogic,s400" (Meson axg a113d)
- "amlogic,u200" (Meson g12a s905d2)
Amlogic Meson Firmware registers Interface
------------------------------------------
......
......@@ -42,6 +42,14 @@ Raspberry Pi Compute Module
Required root node properties:
compatible = "raspberrypi,compute-module", "brcm,bcm2835";
Raspberry Pi Compute Module 3
Required root node properties:
compatible = "raspberrypi,3-compute-module", "brcm,bcm2837";
Raspberry Pi Compute Module 3 Lite
Required root node properties:
compatible = "raspberrypi,3-compute-module-lite", "brcm,bcm2837";
Raspberry Pi Zero
Required root node properties:
compatible = "raspberrypi,model-zero", "brcm,bcm2835";
......
NXP i.MX System Controller Firmware (SCFW)
--------------------------------------------------------------------
The System Controller Firmware (SCFW) is a low-level system function
which runs on a dedicated Cortex-M core to provide power, clock, and
resource management. It exists on some i.MX8 processors. e.g. i.MX8QM
(QM, QP), and i.MX8QX (QXP, DX).
The AP communicates with the SC using a multi-ported MU module found
in the LSIO subsystem. The current definition of this MU module provides
5 remote AP connections to the SC to support up to 5 execution environments
(TZ, HV, standard Linux, etc.). The SC side of this MU module interfaces
with the LSIO DSC IP bus. The SC firmware will communicate with this MU
using the MSI bus.
System Controller Device Node:
============================================================
The scu node with the following properties shall be under the /firmware/ node.
Required properties:
-------------------
- compatible: should be "fsl,imx-scu".
- mbox-names: should include "tx0", "tx1", "tx2", "tx3",
"rx0", "rx1", "rx2", "rx3".
- mboxes: List of phandle of 4 MU channels for tx and 4 MU channels
for rx. All 8 MU channels must be in the same MU instance.
Cross instances are not allowed. The MU instance can only
be one of LSIO MU0~M4 for imx8qxp and imx8qm. Users need
to make sure use the one which is not conflict with other
execution environments. e.g. ATF.
Note:
Channel 0 must be "tx0" or "rx0".
Channel 1 must be "tx1" or "rx1".
Channel 2 must be "tx2" or "rx2".
Channel 3 must be "tx3" or "rx3".
e.g.
mboxes = <&lsio_mu1 0 0
&lsio_mu1 0 1
&lsio_mu1 0 2
&lsio_mu1 0 3
&lsio_mu1 1 0
&lsio_mu1 1 1
&lsio_mu1 1 2
&lsio_mu1 1 3>;
See Documentation/devicetree/bindings/mailbox/fsl,mu.txt
for detailed mailbox binding.
i.MX SCU Client Device Node:
============================================================
Client nodes are maintained as children of the relevant IMX-SCU device node.
Power domain bindings based on SCU Message Protocol
------------------------------------------------------------
This binding for the SCU power domain providers uses the generic power
domain binding[2].
Required properties:
- compatible: Should be "fsl,scu-pd".
- #address-cells: Should be 1.
- #size-cells: Should be 0.
Required properties for power domain sub nodes:
- #power-domain-cells: Must be 0.
Optional Properties:
- reg: Resource ID of this power domain.
No exist means uncontrollable by user.
See detailed Resource ID list from:
include/dt-bindings/power/imx-rsrc.h
- power-domains: phandle pointing to the parent power domain.
Clock bindings based on SCU Message Protocol
------------------------------------------------------------
This binding uses the common clock binding[1].
Required properties:
- compatible: Should be "fsl,imx8qxp-clock".
- #clock-cells: Should be 1. Contains the Clock ID value.
- clocks: List of clock specifiers, must contain an entry for
each required entry in clock-names
- clock-names: Should include entries "xtal_32KHz", "xtal_24MHz"
The clock consumer should specify the desired clock by having the clock
ID in its "clocks" phandle cell.
See the full list of clock IDs from:
include/dt-bindings/clock/imx8qxp-clock.h
Pinctrl bindings based on SCU Message Protocol
------------------------------------------------------------
This binding uses the i.MX common pinctrl binding[3].
Required properties:
- compatible: Should be "fsl,imx8qxp-iomuxc".
Required properties for Pinctrl sub nodes:
- fsl,pins: Each entry consists of 3 integers which represents
the mux and config setting for one pin. The first 2
integers <pin_id mux_mode> are specified using a
PIN_FUNC_ID macro, which can be found in
<dt-bindings/pinctrl/pads-imx8qxp.h>.
The last integer CONFIG is the pad setting value like
pull-up on this pin.
Please refer to i.MX8QXP Reference Manual for detailed
CONFIG settings.
[1] Documentation/devicetree/bindings/clock/clock-bindings.txt
[2] Documentation/devicetree/bindings/power/power_domain.txt
[3] Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt
Example (imx8qxp):
-------------
lsio_mu1: mailbox@5d1c0000 {
...
#mbox-cells = <2>;
};
firmware {
scu {
compatible = "fsl,imx-scu";
mbox-names = "tx0", "tx1", "tx2", "tx3",
"rx0", "rx1", "rx2", "rx3";
mboxes = <&lsio_mu1 0 0
&lsio_mu1 0 1
&lsio_mu1 0 2
&lsio_mu1 0 3
&lsio_mu1 1 0
&lsio_mu1 1 1
&lsio_mu1 1 2
&lsio_mu1 1 3>;
clk: clk {
compatible = "fsl,imx8qxp-clk";
#clock-cells = <1>;
};
iomuxc {
compatible = "fsl,imx8qxp-iomuxc";
pinctrl_lpuart0: lpuart0grp {
fsl,pins = <
SC_P_UART0_RX_ADMA_UART0_RX 0x06000020
SC_P_UART0_TX_ADMA_UART0_TX 0x06000020
>;
};
...
};
imx8qx-pm {
compatible = "fsl,scu-pd";
#address-cells = <1>;
#size-cells = <0>;
pd_dma: dma-power-domain {
#power-domain-cells = <0>;
pd_dma_lpuart0: dma-lpuart0@57 {
reg = <SC_R_UART_0>;
#power-domain-cells = <0>;
power-domains = <&pd_dma>;
};
...
};
...
};
};
};
serial@5a060000 {
...
pinctrl-names = "default";
pinctrl-0 = <&pinctrl_lpuart0>;
clocks = <&clk IMX8QXP_UART0_CLK>,
<&clk IMX8QXP_UART0_IPG_CLK>;
clock-names = "per", "ipg";
power-domains = <&pd_dma_lpuart0>;
};
......@@ -57,6 +57,50 @@ i.MX6SLL EVK board
Required root node properties:
- compatible = "fsl,imx6sll-evk", "fsl,imx6sll";
i.MX6 Quad Plus SABRE Smart Device Board
Required root node properties:
- compatible = "fsl,imx6qp-sabresd", "fsl,imx6qp";
i.MX6 Quad Plus SABRE Automotive Board
Required root node properties:
- compatible = "fsl,imx6qp-sabreauto", "fsl,imx6qp";
i.MX6 DualLite SABRE Smart Device Board
Required root node properties:
- compatible = "fsl,imx6dl-sabresd", "fsl,imx6dl";
i.MX6 DualLite/Solo SABRE Automotive Board
Required root node properties:
- compatible = "fsl,imx6dl-sabreauto", "fsl,imx6dl";
i.MX6 SoloLite EVK Board
Required root node properties:
- compatible = "fsl,imx6sl-evk", "fsl,imx6sl";
i.MX6 UltraLite 14x14 EVK Board
Required root node properties:
- compatible = "fsl,imx6ul-14x14-evk", "fsl,imx6ul";
i.MX6 UltraLiteLite 14x14 EVK Board
Required root node properties:
- compatible = "fsl,imx6ull-14x14-evk", "fsl,imx6ull";
i.MX6 ULZ 14x14 EVK Board
Required root node properties:
- compatible = "fsl,imx6ulz-14x14-evk", "fsl,imx6ull", "fsl,imx6ulz";
i.MX6 SoloX SDB Board
Required root node properties:
- compatible = "fsl,imx6sx-sdb", "fsl,imx6sx";
i.MX6 SoloX Sabre Auto Board
Required root node properties:
- compatible = "fsl,imx6sx-sabreauto", "fsl,imx6sx";
i.MX7 SabreSD Board
Required root node properties:
- compatible = "fsl,imx7d-sdb", "fsl,imx7d";
Generic i.MX boards
-------------------
......
......@@ -8,6 +8,14 @@ HiKey960 Board
Required root node properties:
- compatible = "hisilicon,hi3660-hikey960", "hisilicon,hi3660";
Hi3670 SoC
Required root node properties:
- compatible = "hisilicon,hi3670";
HiKey970 Board
Required root node properties:
- compatible = "hisilicon,hi3670-hikey970", "hisilicon,hi3670";
Hi3798cv200 SoC
Required root node properties:
- compatible = "hisilicon,hi3798cv200";
......
......@@ -45,11 +45,15 @@ Optional Properties:
debug_messages - Map the Debug message region
- reg: register space corresponding to the debug_messages
- ti,system-reboot-controller: If system reboot can be triggered by SoC reboot
- ti,host-id: Integer value corresponding to the host ID assigned by Firmware
for identification of host processing entities such as virtual
machines
Example (K2G):
-------------
pmmc: pmmc {
compatible = "ti,k2g-sci";
ti,host-id = <2>;
mbox-names = "rx", "tx";
mboxes= <&msgmgr &msgmgr_proxy_pmmc_rx>,
<&msgmgr &msgmgr_proxy_pmmc_tx>;
......
......@@ -10,6 +10,7 @@ Required Properties:
- "mediatek,mt2712-apmixedsys", "syscon"
- "mediatek,mt6797-apmixedsys"
- "mediatek,mt7622-apmixedsys"
- "mediatek,mt7623-apmixedsys", "mediatek,mt2701-apmixedsys"
- "mediatek,mt8135-apmixedsys"
- "mediatek,mt8173-apmixedsys"
- #clock-cells: Must be 1
......
......@@ -8,6 +8,7 @@ Required Properties:
- compatible: Should be one of:
- "mediatek,mt2701-audsys", "syscon"
- "mediatek,mt7622-audsys", "syscon"
- "mediatek,mt7623-audsys", "mediatek,mt2701-audsys", "syscon"
- #clock-cells: Must be 1
The AUDSYS controller uses the common clk binding from
......
......@@ -8,6 +8,7 @@ Required Properties:
- compatible: Should be:
- "mediatek,mt2701-bdpsys", "syscon"
- "mediatek,mt2712-bdpsys", "syscon"
- "mediatek,mt7623-bdpsys", "mediatek,mt2701-bdpsys", "syscon"
- #clock-cells: Must be 1
The bdpsys controller uses the common clk binding from
......
......@@ -8,6 +8,7 @@ Required Properties:
- compatible: Should be:
- "mediatek,mt2701-ethsys", "syscon"
- "mediatek,mt7622-ethsys", "syscon"
- "mediatek,mt7623-ethsys", "mediatek,mt2701-ethsys", "syscon"
- #clock-cells: Must be 1
- #reset-cells: Must be 1
......
......@@ -9,6 +9,7 @@ Required Properties:
- compatible: Should be:
- "mediatek,mt2701-hifsys", "syscon"
- "mediatek,mt7622-hifsys", "syscon"
- "mediatek,mt7623-hifsys", "mediatek,mt2701-hifsys", "syscon"
- #clock-cells: Must be 1
The hifsys controller uses the common clk binding from
......
......@@ -9,6 +9,7 @@ Required Properties:
- "mediatek,mt2701-imgsys", "syscon"
- "mediatek,mt2712-imgsys", "syscon"
- "mediatek,mt6797-imgsys", "syscon"
- "mediatek,mt7623-imgsys", "mediatek,mt2701-imgsys", "syscon"
- "mediatek,mt8173-imgsys", "syscon"
- #clock-cells: Must be 1
......
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