rust: add regulator consumer abstraction

.clippy.toml

@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0
+
+check-private-items = true
+
+disallowed-macros = [
+    # The `clippy::dbg_macro` lint only works with `std::dbg!`, thus we simulate
+    # it here, see: https://github.com/rust-lang/rust-clippy/issues/11303.
+    { path = "kernel::dbg", reason = "the `dbg!` macro is intended as a debugging tool" },
+]

.gitignore

@@ -103,6 +103,7 @@ modules.order
 # We don't want to ignore the following even if they are dot-files
 #
 !.clang-format
+!.clippy.toml
 !.cocciconfig
 !.editorconfig
 !.get_maintainer.ignore

Documentation/arch/arm/mem_alignment.rst

@@ -12,7 +12,7 @@ ones.
 
 Of course this is a bad idea to rely on the alignment trap to perform
 unaligned memory access in general.  If those access are predictable, you
-are better to use the macros provided by include/asm/unaligned.h.  The
+are better to use the macros provided by include/linux/unaligned.h.  The
 alignment trap can fixup misaligned access for the exception cases, but at
 a high performance cost.  It better be rare.
 

Documentation/arch/arm64/silicon-errata.rst

@@ -146,6 +146,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A715     | #2645198        | ARM64_ERRATUM_2645198       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Cortex-A715     | #3456084        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A720     | #3456091        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A725     | #3456106        | ARM64_ERRATUM_3194386       |
@@ -186,6 +188,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-N2     | #3324339        | ARM64_ERRATUM_3194386       |
 +----------------+-----------------+-----------------+-----------------------------+
+| ARM            | Neoverse-N3     | #3456111        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-V1     | #1619801        | N/A                         |
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Neoverse-V1     | #3324341        | ARM64_ERRATUM_3194386       |
@@ -289,3 +293,5 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | Microsoft      | Azure Cobalt 100| #2253138        | ARM64_ERRATUM_2253138       |
 +----------------+-----------------+-----------------+-----------------------------+
+| Microsoft      | Azure Cobalt 100| #3324339        | ARM64_ERRATUM_3194386       |
++----------------+-----------------+-----------------+-----------------------------+

Documentation/core-api/folio_queue.rst

@@ -0,0 +1,212 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+===========
+Folio Queue
+===========
+
+:Author: David Howells <[email protected]>
+
+.. Contents:
+
+ * Overview
+ * Initialisation
+ * Adding and removing folios
+ * Querying information about a folio
+ * Querying information about a folio_queue
+ * Folio queue iteration
+ * Folio marks
+ * Lockless simultaneous production/consumption issues
+
+
+Overview
+========
+
+The folio_queue struct forms a single segment in a segmented list of folios
+that can be used to form an I/O buffer.  As such, the list can be iterated over
+using the ITER_FOLIOQ iov_iter type.
+
+The publicly accessible members of the structure are::
+
+	struct folio_queue {
+		struct folio_queue *next;
+		struct folio_queue *prev;
+		...
+	};
+
+A pair of pointers are provided, ``next`` and ``prev``, that point to the
+segments on either side of the segment being accessed.  Whilst this is a
+doubly-linked list, it is intentionally not a circular list; the outward
+sibling pointers in terminal segments should be NULL.
+
+Each segment in the list also stores:
+
+ * an ordered sequence of folio pointers,
+ * the size of each folio and
+ * three 1-bit marks per folio,
+
+but hese should not be accessed directly as the underlying data structure may
+change, but rather the access functions outlined below should be used.
+
+The facility can be made accessible by::
+
+	#include <linux/folio_queue.h>
+
+and to use the iterator::
+
+	#include <linux/uio.h>
+
+
+Initialisation
+==============
+
+A segment should be initialised by calling::
+
+	void folioq_init(struct folio_queue *folioq);
+
+with a pointer to the segment to be initialised.  Note that this will not
+necessarily initialise all the folio pointers, so care must be taken to check
+the number of folios added.
+
+
+Adding and removing folios
+==========================
+
+Folios can be set in the next unused slot in a segment struct by calling one
+of::
+
+	unsigned int folioq_append(struct folio_queue *folioq,
+				   struct folio *folio);
+
+	unsigned int folioq_append_mark(struct folio_queue *folioq,
+					struct folio *folio);
+
+Both functions update the stored folio count, store the folio and note its
+size.  The second function also sets the first mark for the folio added.  Both
+functions return the number of the slot used.  [!] Note that no attempt is made
+to check that the capacity wasn't overrun and the list will not be extended
+automatically.
+
+A folio can be excised by calling::
+
+	void folioq_clear(struct folio_queue *folioq, unsigned int slot);
+
+This clears the slot in the array and also clears all the marks for that folio,
+but doesn't change the folio count - so future accesses of that slot must check
+if the slot is occupied.
+
+
+Querying information about a folio
+==================================
+
+Information about the folio in a particular slot may be queried by the
+following function::
+
+	struct folio *folioq_folio(const struct folio_queue *folioq,
+				   unsigned int slot);
+
+If a folio has not yet been set in that slot, this may yield an undefined
+pointer.  The size of the folio in a slot may be queried with either of::
+
+	unsigned int folioq_folio_order(const struct folio_queue *folioq,
+					unsigned int slot);
+
+	size_t folioq_folio_size(const struct folio_queue *folioq,
+				 unsigned int slot);
+
+The first function returns the size as an order and the second as a number of
+bytes.
+
+
+Querying information about a folio_queue
+========================================
+
+Information may be retrieved about a particular segment with the following
+functions::
+
+	unsigned int folioq_nr_slots(const struct folio_queue *folioq);
+
+	unsigned int folioq_count(struct folio_queue *folioq);
+
+	bool folioq_full(struct folio_queue *folioq);
+
+The first function returns the maximum capacity of a segment.  It must not be
+assumed that this won't vary between segments.  The second returns the number
+of folios added to a segments and the third is a shorthand to indicate if the
+segment has been filled to capacity.
+
+Not that the count and fullness are not affected by clearing folios from the
+segment.  These are more about indicating how many slots in the array have been
+initialised, and it assumed that slots won't get reused, but rather the segment
+will get discarded as the queue is consumed.
+
+
+Folio marks
+===========
+
+Folios within a queue can also have marks assigned to them.  These marks can be
+used to note information such as if a folio needs folio_put() calling upon it.
+There are three marks available to be set for each folio.
+
+The marks can be set by::
+
+	void folioq_mark(struct folio_queue *folioq, unsigned int slot);
+	void folioq_mark2(struct folio_queue *folioq, unsigned int slot);
+	void folioq_mark3(struct folio_queue *folioq, unsigned int slot);
+
+Cleared by::
+
+	void folioq_unmark(struct folio_queue *folioq, unsigned int slot);
+	void folioq_unmark2(struct folio_queue *folioq, unsigned int slot);
+	void folioq_unmark3(struct folio_queue *folioq, unsigned int slot);
+
+And the marks can be queried by::
+
+	bool folioq_is_marked(const struct folio_queue *folioq, unsigned int slot);
+	bool folioq_is_marked2(const struct folio_queue *folioq, unsigned int slot);
+	bool folioq_is_marked3(const struct folio_queue *folioq, unsigned int slot);
+
+The marks can be used for any purpose and are not interpreted by this API.
+
+
+Folio queue iteration
+=====================
+
+A list of segments may be iterated over using the I/O iterator facility using
+an ``iov_iter`` iterator of ``ITER_FOLIOQ`` type.  The iterator may be
+initialised with::
+
+	void iov_iter_folio_queue(struct iov_iter *i, unsigned int direction,
+				  const struct folio_queue *folioq,
+				  unsigned int first_slot, unsigned int offset,
+				  size_t count);
+
+This may be told to start at a particular segment, slot and offset within a
+queue.  The iov iterator functions will follow the next pointers when advancing
+and prev pointers when reverting when needed.
+
+
+Lockless simultaneous production/consumption issues
+===================================================
+
+If properly managed, the list can be extended by the producer at the head end
+and shortened by the consumer at the tail end simultaneously without the need
+to take locks.  The ITER_FOLIOQ iterator inserts appropriate barriers to aid
+with this.
+
+Care must be taken when simultaneously producing and consuming a list.  If the
+last segment is reached and the folios it refers to are entirely consumed by
+the IOV iterators, an iov_iter struct will be left pointing to the last segment
+with a slot number equal to the capacity of that segment.  The iterator will
+try to continue on from this if there's another segment available when it is
+used again, but care must be taken lest the segment got removed and freed by
+the consumer before the iterator was advanced.
+
+It is recommended that the queue always contain at least one segment, even if
+that segment has never been filled or is entirely spent.  This prevents the
+head and tail pointers from collapsing.
+
+
+API Function Reference
+======================
+
+.. kernel-doc:: include/linux/folio_queue.h

Documentation/core-api/index.rst

@@ -37,6 +37,7 @@ Library functionality that is used throughout the kernel.
    kref
    cleanup
    assoc_array
+   folio_queue
    xarray
    maple_tree
    idr

Documentation/core-api/unaligned-memory-access.rst

@@ -203,7 +203,7 @@ Avoiding unaligned accesses
 ===========================
 
 The easiest way to avoid unaligned access is to use the get_unaligned() and
-put_unaligned() macros provided by the <asm/unaligned.h> header file.
+put_unaligned() macros provided by the <linux/unaligned.h> header file.
 
 Going back to an earlier example of code that potentially causes unaligned
 access::

Documentation/devicetree/bindings/net/xlnx,axi-ethernet.yaml

@@ -34,6 +34,7 @@ properties:
       and length of the AXI DMA controller IO space, unless
       axistream-connected is specified, in which case the reg
       attribute of the node referenced by it is used.
+    minItems: 1
     maxItems: 2
 
   interrupts:
@@ -181,7 +182,7 @@ examples:
         clock-names = "s_axi_lite_clk", "axis_clk", "ref_clk", "mgt_clk";
         clocks = <&axi_clk>, <&axi_clk>, <&pl_enet_ref_clk>, <&mgt_clk>;
         phy-mode = "mii";
-        reg = <0x00 0x40000000 0x00 0x40000>;
+        reg = <0x40000000 0x40000>;
         xlnx,rxcsum = <0x2>;
         xlnx,rxmem = <0x800>;
         xlnx,txcsum = <0x2>;

Documentation/devicetree/bindings/sound/davinci-mcasp-audio.yaml

@@ -102,7 +102,7 @@ properties:
     default: 2
 
   interrupts:
-    anyOf:
+    oneOf:
       - minItems: 1
         items:
           - description: TX interrupt

Documentation/devicetree/bindings/sound/qcom,sm8250.yaml

@@ -30,6 +30,7 @@ properties:
           - qcom,apq8096-sndcard
           - qcom,qcm6490-idp-sndcard
           - qcom,qcs6490-rb3gen2-sndcard
+          - qcom,qrb4210-rb2-sndcard
           - qcom,qrb5165-rb5-sndcard
           - qcom,sc7180-qdsp6-sndcard
           - qcom,sc8280xp-sndcard

Documentation/devicetree/bindings/sound/renesas,rsnd.yaml

@@ -302,7 +302,7 @@ allOf:
         reg-names:
           items:
             enum:
-              - scu
+              - sru
               - ssi
               - adg
   # for Gen2/Gen3

Documentation/driver-api/wmi.rst

@@ -7,12 +7,11 @@ WMI Driver API
 The WMI driver core supports a more modern bus-based interface for interacting
 with WMI devices, and an older GUID-based interface. The latter interface is
 considered to be deprecated, so new WMI drivers should generally avoid it since
-it has some issues with multiple WMI devices and events sharing the same GUIDs
-and/or notification IDs. The modern bus-based interface instead maps each
-WMI device to a :c:type:`struct wmi_device <wmi_device>`, so it supports
-WMI devices sharing GUIDs and/or notification IDs. Drivers can then register
-a :c:type:`struct wmi_driver <wmi_driver>`, which will be bound to compatible
-WMI devices by the driver core.
+it has some issues with multiple WMI devices sharing the same GUID.
+The modern bus-based interface instead maps each WMI device to a
+:c:type:`struct wmi_device <wmi_device>`, so it supports WMI devices sharing the
+same GUID. Drivers can then register a :c:type:`struct wmi_driver <wmi_driver>`
+which will be bound to compatible WMI devices by the driver core.
 
 .. kernel-doc:: include/linux/wmi.h
    :internal:

Documentation/gpu/drm-kms-helpers.rst

@@ -181,7 +181,7 @@ Bridge Operations
 Bridge Connector Helper
 -----------------------
 
-.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_bridge_connector.c
    :doc: overview
 
 
@@ -204,7 +204,7 @@ MIPI-DSI bridge operation
 Bridge Connector Helper Reference
 ---------------------------------
 
-.. kernel-doc:: drivers/gpu/drm/drm_bridge_connector.c
+.. kernel-doc:: drivers/gpu/drm/display/drm_bridge_connector.c
    :export:
 
 Panel-Bridge Helper Reference

Documentation/networking/napi.rst

@@ -144,9 +144,8 @@ IRQ should only be unmasked after a successful call to napi_complete_done():
 
 napi_schedule_irqoff() is a variant of napi_schedule() which takes advantage
 of guarantees given by being invoked in IRQ context (no need to
-mask interrupts). Note that PREEMPT_RT forces all interrupts
-to be threaded so the interrupt may need to be marked ``IRQF_NO_THREAD``
-to avoid issues on real-time kernel configurations.
+mask interrupts). napi_schedule_irqoff() will fall back to napi_schedule() if
+IRQs are threaded (such as if ``PREEMPT_RT`` is enabled).
 
 Instance to queue mapping
 -------------------------