Merge tag 'docs-6.6' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "Documentation work keeps chugging along; this includes:

   - Work from Carlos Bilbao to integrate rustdoc output into the
     generated HTML documentation. This took some work to figure out how
     to do it without slowing the docs build and without creating people
     who don't have Rust installed, but Carlos got there

   - Move the loongarch and mips architecture documentation under
     Documentation/arch/

   - Some more maintainer documentation from Jakub

  ... plus the usual assortment of updates, translations, and fixes"

* tag 'docs-6.6' of git://git.lwn.net/linux: (56 commits)
  Docu: genericirq.rst: fix irq-example
  input: docs: pxrc: remove reference to phoenix-sim
  Documentation: serial-console: Fix literal block marker
  docs/mm: remove references to hmm_mirror ops and clean typos
  docs/zh_CN: correct regi_chg(),regi_add() to region_chg(),region_add()
  Documentation: Fix typos
  Documentation/ABI: Fix typos
  scripts: kernel-doc: fix macro handling in enums
  scripts: kernel-doc: parse DEFINE_DMA_UNMAP_[ADDR|LEN]
  Documentation: riscv: Update boot image header since EFI stub is supported
  Documentation: riscv: Add early boot document
  Documentation: arm: Add bootargs to the table of added DT parameters
  docs: kernel-parameters: Refer to the correct bitmap function
  doc: update params of memhp_default_state=
  docs: Add book to process/kernel-docs.rst
  docs: sparse: fix invalid link addresses
  docs: vfs: clean up after the iterate() removal
  docs: Add a section on surveys to the researcher guidelines
  docs: move mips under arch
  docs: move loongarch under arch
  ...

26 files changed, 762 insertions, 20 deletions

diff --git a/Documentation/arch/arm/arm.rst b/Documentation/arch/arm/arm.rst
index 99d660fdf73fde..7b41b89dd9bd0b 100644
--- a/Documentation/arch/arm/arm.rst
+++ b/Documentation/arch/arm/arm.rst
@@ -141,7 +141,7 @@ ST506 hard drives
   `*configure` harddrive set to 2). I've got an internal 20MB and a great
   big external 5.25" FH 64MB drive (who could ever want more :-) ).
 
-  I've just got 240K/s off it (a dd with bs=128k); thats about half of what
+  I've just got 240K/s off it (a dd with bs=128k); that's about half of what
   RiscOS gets; but it's a heck of a lot better than the 50K/s I was getting
   last week :-)
 
diff --git a/Documentation/arch/arm/ixp4xx.rst b/Documentation/arch/arm/ixp4xx.rst
index a57235616294a3..17aafc610908f9 100644
--- a/Documentation/arch/arm/ixp4xx.rst
+++ b/Documentation/arch/arm/ixp4xx.rst
@@ -78,9 +78,9 @@ IXP4xx provides two methods of accessing PCI memory space:
 1) A direct mapped window from 0x48000000 to 0x4bffffff (64MB).
    To access PCI via this space, we simply ioremap() the BAR
    into the kernel and we can use the standard read[bwl]/write[bwl]
-   macros. This is the preffered method due to speed but it
+   macros. This is the preferred method due to speed but it
    limits the system to just 64MB of PCI memory. This can be
-   problamatic if using video cards and other memory-heavy devices.
+   problematic if using video cards and other memory-heavy devices.
 
 2) If > 64MB of memory space is required, the IXP4xx can be
    configured to use indirect registers to access PCI This allows
diff --git a/Documentation/arch/arm/sunxi/clocks.rst b/Documentation/arch/arm/sunxi/clocks.rst
index 23bd03f3e21f4e..dfe6d48872107c 100644
--- a/Documentation/arch/arm/sunxi/clocks.rst
+++ b/Documentation/arch/arm/sunxi/clocks.rst
@@ -5,7 +5,7 @@ Frequently asked questions about the sunxi clock system
 This document contains useful bits of information that people tend to ask
 about the sunxi clock system, as well as accompanying ASCII art when adequate.
 
-Q: Why is the main 24MHz oscillator gatable? Wouldn't that break the
+Q: Why is the main 24MHz oscillator gateable? Wouldn't that break the
    system?
 
 A: The 24MHz oscillator allows gating to save power. Indeed, if gated
diff --git a/Documentation/arch/arm/swp_emulation.rst b/Documentation/arch/arm/swp_emulation.rst
index 6a608a9c371588..bf205e3de36ec4 100644
--- a/Documentation/arch/arm/swp_emulation.rst
+++ b/Documentation/arch/arm/swp_emulation.rst
@@ -1,7 +1,7 @@
 Software emulation of deprecated SWP instruction (CONFIG_SWP_EMULATE)
 ---------------------------------------------------------------------
 
-ARMv6 architecture deprecates use of the SWP/SWPB instructions, and recommeds
+ARMv6 architecture deprecates use of the SWP/SWPB instructions, and recommends
 moving to the load-locked/store-conditional instructions LDREX and STREX.
 
 ARMv7 multiprocessing extensions introduce the ability to disable these
diff --git a/Documentation/arch/arm/tcm.rst b/Documentation/arch/arm/tcm.rst
index 1dc6c39220f98a..7ce17a248af91f 100644
--- a/Documentation/arch/arm/tcm.rst
+++ b/Documentation/arch/arm/tcm.rst
@@ -71,7 +71,7 @@ in <asm/tcm.h>. Using this interface it is possible to:
 
 - Have the remaining TCM RAM added to a special
   allocation pool with gen_pool_create() and gen_pool_add()
-  and provice tcm_alloc() and tcm_free() for this
+  and provide tcm_alloc() and tcm_free() for this
   memory. Such a heap is great for things like saving
   device state when shutting off device power domains.
 
diff --git a/Documentation/arch/arm/uefi.rst b/Documentation/arch/arm/uefi.rst
index baebe688a00641..2b7ad9bd7cd224 100644
--- a/Documentation/arch/arm/uefi.rst
+++ b/Documentation/arch/arm/uefi.rst
@@ -50,7 +50,7 @@ The stub populates the FDT /chosen node with (and the kernel scans for) the
 following parameters:
 
 ==========================  ======   ===========================================
-Name                        Size     Description
+Name                        Type     Description
 ==========================  ======   ===========================================
 linux,uefi-system-table     64-bit   Physical address of the UEFI System Table.
 
@@ -67,4 +67,6 @@ linux,uefi-mmap-desc-ver    32-bit   Version of the mmap descriptor format.
 
 kaslr-seed                  64-bit   Entropy used to randomize the kernel image
                                      base address location.
+
+bootargs                    String   Kernel command line
 ==========================  ======   ===========================================
diff --git a/Documentation/arch/arm/vlocks.rst b/Documentation/arch/arm/vlocks.rst
index a40a1742110bce..737aa8661a211a 100644
--- a/Documentation/arch/arm/vlocks.rst
+++ b/Documentation/arch/arm/vlocks.rst
@@ -155,7 +155,7 @@ the basic algorithm:
    optimisation.
 
    If there are too many CPUs to read the currently_voting array in
-   one transaction then multiple transations are still required.  The
+   one transaction then multiple transactions are still required.  The
    implementation uses a simple loop of word-sized loads for this
    case.  The number of transactions is still fewer than would be
    required if bytes were loaded individually.
diff --git a/Documentation/arch/arm64/acpi_object_usage.rst b/Documentation/arch/arm64/acpi_object_usage.rst
index 1da22200fdf8fe..06d8a87971ef0d 100644
--- a/Documentation/arch/arm64/acpi_object_usage.rst
+++ b/Documentation/arch/arm64/acpi_object_usage.rst
@@ -45,7 +45,7 @@ APMT   Signature Reserved (signature == "APMT")
 
        **Arm Performance Monitoring Table**
 
-       This table describes the properties of PMU support implmented by
+       This table describes the properties of PMU support implemented by
        components in the system.
 
 BERT   Section 18.3 (signature == "BERT")
diff --git a/Documentation/arch/arm64/arm-acpi.rst b/Documentation/arch/arm64/arm-acpi.rst
index 94274a8d84cf0a..a46c34fa96044c 100644
--- a/Documentation/arch/arm64/arm-acpi.rst
+++ b/Documentation/arch/arm64/arm-acpi.rst
@@ -99,7 +99,7 @@ to replace the kernel.
 
 When a Linux driver or subsystem is first implemented using ACPI, it by
 definition ends up requiring a specific version of the ACPI specification
--- it's baseline.  ACPI firmware must continue to work, even though it may
+-- its baseline.  ACPI firmware must continue to work, even though it may
 not be optimal, with the earliest kernel version that first provides support
 for that baseline version of ACPI.  There may be a need for additional drivers,
 but adding new functionality (e.g., CPU power management) should not break
diff --git a/Documentation/arch/index.rst b/Documentation/arch/index.rst
index c9a209878cf389..84b80255b85166 100644
--- a/Documentation/arch/index.rst
+++ b/Documentation/arch/index.rst
@@ -13,9 +13,9 @@ implementation.
    arm/index
    arm64/index
    ia64/index
-   ../loongarch/index
+   loongarch/index
    m68k/index
-   ../mips/index
+   mips/index
    nios2/index
    openrisc/index
    parisc/index
diff --git a/Documentation/arch/loongarch/booting.rst b/Documentation/arch/loongarch/booting.rst
new file mode 100644
index 00000000000000..91eccd410478d6
--- /dev/null
+++ b/Documentation/arch/loongarch/booting.rst
@@ -0,0 +1,42 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================
+Booting Linux/LoongArch
+=======================
+
+:Author: Yanteng Si <siyanteng@loongson.cn>
+:Date:   18 Nov 2022
+
+Information passed from BootLoader to kernel
+============================================
+
+LoongArch supports ACPI and FDT. The information that needs to be passed
+to the kernel includes the memmap, the initrd, the command line, optionally
+the ACPI/FDT tables, and so on.
+
+The kernel is passed the following arguments on `kernel_entry` :
+
+      - a0 = efi_boot: `efi_boot` is a flag indicating whether
+        this boot environment is fully UEFI-compliant.
+
+      - a1 = cmdline: `cmdline` is a pointer to the kernel command line.
+
+      - a2 = systemtable: `systemtable` points to the EFI system table.
+        All pointers involved at this stage are in physical addresses.
+
+Header of Linux/LoongArch kernel images
+=======================================
+
+Linux/LoongArch kernel images are EFI images. Being PE files, they have
+a 64-byte header structured like::
+
+	u32	MZ_MAGIC                /* "MZ", MS-DOS header */
+	u32	res0 = 0                /* Reserved */
+	u64	kernel_entry            /* Kernel entry point */
+	u64	_end - _text            /* Kernel image effective size */
+	u64	load_offset             /* Kernel image load offset from start of RAM */
+	u64	res1 = 0                /* Reserved */
+	u64	res2 = 0                /* Reserved */
+	u64	res3 = 0                /* Reserved */
+	u32	LINUX_PE_MAGIC          /* Magic number */
+	u32	pe_header - _head       /* Offset to the PE header */
diff --git a/Documentation/arch/loongarch/features.rst b/Documentation/arch/loongarch/features.rst
new file mode 100644
index 00000000000000..ebacade3ea454e
--- /dev/null
+++ b/Documentation/arch/loongarch/features.rst
@@ -0,0 +1,3 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. kernel-feat:: $srctree/Documentation/features loongarch
diff --git a/Documentation/arch/loongarch/index.rst b/Documentation/arch/loongarch/index.rst
new file mode 100644
index 00000000000000..c779bfa00c05b7
--- /dev/null
+++ b/Documentation/arch/loongarch/index.rst
@@ -0,0 +1,22 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+LoongArch Architecture
+======================
+
+.. toctree::
+   :maxdepth: 2
+   :numbered:
+
+   introduction
+   booting
+   irq-chip-model
+
+   features
+
+.. only::  subproject and html
+
+   Indices
+   =======
+
+   * :ref:`genindex`
diff --git a/Documentation/arch/loongarch/introduction.rst b/Documentation/arch/loongarch/introduction.rst
new file mode 100644
index 00000000000000..49135d451ced9a
--- /dev/null
+++ b/Documentation/arch/loongarch/introduction.rst
@@ -0,0 +1,390 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=========================
+Introduction to LoongArch
+=========================
+
+LoongArch is a new RISC ISA, which is a bit like MIPS or RISC-V. There are
+currently 3 variants: a reduced 32-bit version (LA32R), a standard 32-bit
+version (LA32S) and a 64-bit version (LA64). There are 4 privilege levels
+(PLVs) defined in LoongArch: PLV0~PLV3, from high to low. Kernel runs at PLV0
+while applications run at PLV3. This document introduces the registers, basic
+instruction set, virtual memory and some other topics of LoongArch.
+
+Registers
+=========
+
+LoongArch registers include general purpose registers (GPRs), floating point
+registers (FPRs), vector registers (VRs) and control status registers (CSRs)
+used in privileged mode (PLV0).
+
+GPRs
+----
+
+LoongArch has 32 GPRs ( ``$r0`` ~ ``$r31`` ); each one is 32-bit wide in LA32
+and 64-bit wide in LA64. ``$r0`` is hard-wired to zero, and the other registers
+are not architecturally special. (Except ``$r1``, which is hard-wired as the
+link register of the BL instruction.)
+
+The kernel uses a variant of the LoongArch register convention, as described in
+the LoongArch ELF psABI spec, in :ref:`References <loongarch-references>`:
+
+================= =============== =================== ============
+Name              Alias           Usage               Preserved
+                                                      across calls
+================= =============== =================== ============
+``$r0``           ``$zero``       Constant zero       Unused
+``$r1``           ``$ra``         Return address      No
+``$r2``           ``$tp``         TLS/Thread pointer  Unused
+``$r3``           ``$sp``         Stack pointer       Yes
+``$r4``-``$r11``  ``$a0``-``$a7`` Argument registers  No
+``$r4``-``$r5``   ``$v0``-``$v1`` Return value        No
+``$r12``-``$r20`` ``$t0``-``$t8`` Temp registers      No
+``$r21``          ``$u0``         Percpu base address Unused
+``$r22``          ``$fp``         Frame pointer       Yes
+``$r23``-``$r31`` ``$s0``-``$s8`` Static registers    Yes
+================= =============== =================== ============
+
+.. Note::
+    The register ``$r21`` is reserved in the ELF psABI, but used by the Linux
+    kernel for storing the percpu base address. It normally has no ABI name,
+    but is called ``$u0`` in the kernel. You may also see ``$v0`` or ``$v1``
+    in some old code,however they are deprecated aliases of ``$a0`` and ``$a1``
+    respectively.
+
+FPRs
+----
+
+LoongArch has 32 FPRs ( ``$f0`` ~ ``$f31`` ) when FPU is present. Each one is
+64-bit wide on the LA64 cores.
+
+The floating-point register convention is the same as described in the
+LoongArch ELF psABI spec:
+
+================= ================== =================== ============
+Name              Alias              Usage               Preserved
+                                                         across calls
+================= ================== =================== ============
+``$f0``-``$f7``   ``$fa0``-``$fa7``  Argument registers  No
+``$f0``-``$f1``   ``$fv0``-``$fv1``  Return value        No
+``$f8``-``$f23``  ``$ft0``-``$ft15`` Temp registers      No
+``$f24``-``$f31`` ``$fs0``-``$fs7``  Static registers    Yes
+================= ================== =================== ============
+
+.. Note::
+    You may see ``$fv0`` or ``$fv1`` in some old code, however they are
+    deprecated aliases of ``$fa0`` and ``$fa1`` respectively.
+
+VRs
+----
+
+There are currently 2 vector extensions to LoongArch:
+
+- LSX (Loongson SIMD eXtension) with 128-bit vectors,
+- LASX (Loongson Advanced SIMD eXtension) with 256-bit vectors.
+
+LSX brings ``$v0`` ~ ``$v31`` while LASX brings ``$x0`` ~ ``$x31`` as the vector
+registers.
+
+The VRs overlap with FPRs: for example, on a core implementing LSX and LASX,
+the lower 128 bits of ``$x0`` is shared with ``$v0``, and the lower 64 bits of
+``$v0`` is shared with ``$f0``; same with all other VRs.
+
+CSRs
+----
+
+CSRs can only be accessed from privileged mode (PLV0):
+
+================= ===================================== ==============
+Address           Full Name                             Abbrev Name
+================= ===================================== ==============
+0x0               Current Mode Information              CRMD
+0x1               Pre-exception Mode Information        PRMD
+0x2               Extension Unit Enable                 EUEN
+0x3               Miscellaneous Control                 MISC
+0x4               Exception Configuration               ECFG
+0x5               Exception Status                      ESTAT
+0x6               Exception Return Address              ERA
+0x7               Bad (Faulting) Virtual Address        BADV
+0x8               Bad (Faulting) Instruction Word       BADI
+0xC               Exception Entrypoint Address          EENTRY
+0x10              TLB Index                             TLBIDX
+0x11              TLB Entry High-order Bits             TLBEHI
+0x12              TLB Entry Low-order Bits 0            TLBELO0
+0x13              TLB Entry Low-order Bits 1            TLBELO1
+0x18              Address Space Identifier              ASID
+0x19              Page Global Directory Address for     PGDL
+                  Lower-half Address Space
+0x1A              Page Global Directory Address for     PGDH
+                  Higher-half Address Space
+0x1B              Page Global Directory Address         PGD
+0x1C              Page Walk Control for Lower-          PWCL
+                  half Address Space
+0x1D              Page Walk Control for Higher-         PWCH
+                  half Address Space
+0x1E              STLB Page Size                        STLBPS
+0x1F              Reduced Virtual Address Configuration RVACFG
+0x20              CPU Identifier                        CPUID
+0x21              Privileged Resource Configuration 1   PRCFG1
+0x22              Privileged Resource Configuration 2   PRCFG2
+0x23              Privileged Resource Configuration 3   PRCFG3
+0x30+n (0≤n≤15)   Saved Data register                   SAVEn
+0x40              Timer Identifier                      TID
+0x41              Timer Configuration                   TCFG
+0x42              Timer Value                           TVAL
+0x43              Compensation of Timer Count           CNTC
+0x44              Timer Interrupt Clearing              TICLR
+0x60              LLBit Control                         LLBCTL
+0x80              Implementation-specific Control 1     IMPCTL1
+0x81              Implementation-specific Control 2     IMPCTL2
+0x88              TLB Refill Exception Entrypoint       TLBRENTRY
+                  Address
+0x89              TLB Refill Exception BAD (Faulting)   TLBRBADV
+                  Virtual Address
+0x8A              TLB Refill Exception Return Address   TLBRERA
+0x8B              TLB Refill Exception Saved Data       TLBRSAVE
+                  Register
+0x8C              TLB Refill Exception Entry Low-order  TLBRELO0
+                  Bits 0
+0x8D              TLB Refill Exception Entry Low-order  TLBRELO1
+                  Bits 1
+0x8E              TLB Refill Exception Entry High-order TLBEHI
+                  Bits
+0x8F              TLB Refill Exception Pre-exception    TLBRPRMD
+                  Mode Information
+0x90              Machine Error Control                 MERRCTL
+0x91              Machine Error Information 1           MERRINFO1
+0x92              Machine Error Information 2           MERRINFO2
+0x93              Machine Error Exception Entrypoint    MERRENTRY
+                  Address
+0x94              Machine Error Exception Return        MERRERA
+                  Address
+0x95              Machine Error Exception Saved Data    MERRSAVE
+                  Register
+0x98              Cache TAGs                            CTAG
+0x180+n (0≤n≤3)   Direct Mapping Configuration Window n DMWn
+0x200+2n (0≤n≤31) Performance Monitor Configuration n   PMCFGn
+0x201+2n (0≤n≤31) Performance Monitor Overall Counter n PMCNTn
+0x300             Memory Load/Store WatchPoint          MWPC
+                  Overall Control
+0x301             Memory Load/Store WatchPoint          MWPS
+                  Overall Status
+0x310+8n (0≤n≤7)  Memory Load/Store WatchPoint n        MWPnCFG1
+                  Configuration 1
+0x311+8n (0≤n≤7)  Memory Load/Store WatchPoint n        MWPnCFG2
+                  Configuration 2
+0x312+8n (0≤n≤7)  Memory Load/Store WatchPoint n        MWPnCFG3
+                  Configuration 3
+0x313+8n (0≤n≤7)  Memory Load/Store WatchPoint n        MWPnCFG4
+                  Configuration 4
+0x380             Instruction Fetch WatchPoint          FWPC
+                  Overall Control
+0x381             Instruction Fetch WatchPoint          FWPS
+                  Overall Status
+0x390+8n (0≤n≤7)  Instruction Fetch WatchPoint n        FWPnCFG1
+                  Configuration 1
+0x391+8n (0≤n≤7)  Instruction Fetch WatchPoint n        FWPnCFG2
+                  Configuration 2
+0x392+8n (0≤n≤7)  Instruction Fetch WatchPoint n        FWPnCFG3
+                  Configuration 3
+0x393+8n (0≤n≤7)  Instruction Fetch WatchPoint n        FWPnCFG4
+                  Configuration 4
+0x500             Debug Register                        DBG
+0x501             Debug Exception Return Address        DERA
+0x502             Debug Exception Saved Data Register   DSAVE
+================= ===================================== ==============
+
+ERA, TLBRERA, MERRERA and DERA are sometimes also known as EPC, TLBREPC, MERREPC
+and DEPC respectively.
+
+Basic Instruction Set
+=====================
+
+Instruction formats
+-------------------
+
+LoongArch instructions are 32 bits wide, belonging to 9 basic instruction
+formats (and variants of them):
+
+=========== ==========================
+Format name Composition
+=========== ==========================
+2R          Opcode + Rj + Rd
+3R          Opcode + Rk + Rj + Rd
+4R          Opcode + Ra + Rk + Rj + Rd
+2RI8        Opcode + I8 + Rj + Rd
+2RI12       Opcode + I12 + Rj + Rd
+2RI14       Opcode + I14 + Rj + Rd
+2RI16       Opcode + I16 + Rj + Rd
+1RI21       Opcode + I21L + Rj + I21H
+I26         Opcode + I26L + I26H
+=========== ==========================
+
+Rd is the destination register operand, while Rj, Rk and Ra ("a" stands for
+"additional") are the source register operands. I8/I12/I14/I16/I21/I26 are
+immediate operands of respective width. The longer I21 and I26 are stored
+in separate higher and lower parts in the instruction word, denoted by the "L"
+and "H" suffixes.
+
+List of Instructions
+--------------------
+
+For brevity, only instruction names (mnemonics) are listed here; please see the
+:ref:`References <loongarch-references>` for details.
+
+
+1. Arithmetic Instructions::
+
+    ADD.W SUB.W ADDI.W ADD.D SUB.D ADDI.D
+    SLT SLTU SLTI SLTUI
+    AND OR NOR XOR ANDN ORN ANDI ORI XORI
+    MUL.W MULH.W MULH.WU DIV.W DIV.WU MOD.W MOD.WU
+    MUL.D MULH.D MULH.DU DIV.D DIV.DU MOD.D MOD.DU
+    PCADDI PCADDU12I PCADDU18I
+    LU12I.W LU32I.D LU52I.D ADDU16I.D
+
+2. Bit-shift Instructions::
+
+    SLL.W SRL.W SRA.W ROTR.W SLLI.W SRLI.W SRAI.W ROTRI.W
+    SLL.D SRL.D SRA.D ROTR.D SLLI.D SRLI.D SRAI.D ROTRI.D
+
+3. Bit-manipulation Instructions::
+
+    EXT.W.B EXT.W.H CLO.W CLO.D SLZ.W CLZ.D CTO.W CTO.D CTZ.W CTZ.D
+    BYTEPICK.W BYTEPICK.D BSTRINS.W BSTRINS.D BSTRPICK.W BSTRPICK.D
+    REVB.2H REVB.4H REVB.2W REVB.D REVH.2W REVH.D BITREV.4B BITREV.8B BITREV.W BITREV.D
+    MASKEQZ MASKNEZ
+
+4. Branch Instructions::
+
+    BEQ BNE BLT BGE BLTU BGEU BEQZ BNEZ B BL JIRL
+
+5. Load/Store Instructions::
+
+    LD.B LD.BU LD.H LD.HU LD.W LD.WU LD.D ST.B ST.H ST.W ST.D
+    LDX.B LDX.BU LDX.H LDX.HU LDX.W LDX.WU LDX.D STX.B STX.H STX.W STX.D
+    LDPTR.W LDPTR.D STPTR.W STPTR.D
+    PRELD PRELDX
+
+6. Atomic Operation Instructions::
+
+    LL.W SC.W LL.D SC.D
+    AMSWAP.W AMSWAP.D AMADD.W AMADD.D AMAND.W AMAND.D AMOR.W AMOR.D AMXOR.W AMXOR.D
+    AMMAX.W AMMAX.D AMMIN.W AMMIN.D
+
+7. Barrier Instructions::
+
+    IBAR DBAR
+
+8. Special Instructions::
+
+    SYSCALL BREAK CPUCFG NOP IDLE ERTN(ERET) DBCL(DBGCALL) RDTIMEL.W RDTIMEH.W RDTIME.D
+    ASRTLE.D ASRTGT.D
+
+9. Privileged Instructions::
+
+    CSRRD CSRWR CSRXCHG
+    IOCSRRD.B IOCSRRD.H IOCSRRD.W IOCSRRD.D IOCSRWR.B IOCSRWR.H IOCSRWR.W IOCSRWR.D
+    CACOP TLBP(TLBSRCH) TLBRD TLBWR TLBFILL TLBCLR TLBFLUSH INVTLB LDDIR LDPTE
+
+Virtual Memory
+==============
+
+LoongArch supports direct-mapped virtual memory and page-mapped virtual memory.
+
+Direct-mapped virtual memory is configured by CSR.DMWn (n=0~3), it has a simple
+relationship between virtual address (VA) and physical address (PA)::
+
+ VA = PA + FixedOffset
+
+Page-mapped virtual memory has arbitrary relationship between VA and PA, which
+is recorded in TLB and page tables. LoongArch's TLB includes a fully-associative
+MTLB (Multiple Page Size TLB) and set-associative STLB (Single Page Size TLB).
+
+By default, the whole virtual address space of LA32 is configured like this:
+
+============ =========================== =============================
+Name         Address Range               Attributes
+============ =========================== =============================
+``UVRANGE``  ``0x00000000 - 0x7FFFFFFF`` Page-mapped, Cached, PLV0~3
+``KPRANGE0`` ``0x80000000 - 0x9FFFFFFF`` Direct-mapped, Uncached, PLV0
+``KPRANGE1`` ``0xA0000000 - 0xBFFFFFFF`` Direct-mapped, Cached, PLV0
+``KVRANGE``  ``0xC0000000 - 0xFFFFFFFF`` Page-mapped, Cached, PLV0
+============ =========================== =============================
+
+User mode (PLV3) can only access UVRANGE. For direct-mapped KPRANGE0 and
+KPRANGE1, PA is equal to VA with bit30~31 cleared. For example, the uncached
+direct-mapped VA of 0x00001000 is 0x80001000, and the cached direct-mapped
+VA of 0x00001000 is 0xA0001000.
+
+By default, the whole virtual address space of LA64 is configured like this:
+
+============ ====================== ======================================
+Name         Address Range          Attributes
+============ ====================== ======================================
+``XUVRANGE`` ``0x0000000000000000 - Page-mapped, Cached, PLV0~3
+             0x3FFFFFFFFFFFFFFF``
+``XSPRANGE`` ``0x4000000000000000 - Direct-mapped, Cached / Uncached, PLV0
+             0x7FFFFFFFFFFFFFFF``
+``XKPRANGE`` ``0x8000000000000000 - Direct-mapped, Cached / Uncached, PLV0
+             0xBFFFFFFFFFFFFFFF``
+``XKVRANGE`` ``0xC000000000000000 - Page-mapped, Cached, PLV0
+             0xFFFFFFFFFFFFFFFF``
+============ ====================== ======================================
+
+User mode (PLV3) can only access XUVRANGE. For direct-mapped XSPRANGE and
+XKPRANGE, PA is equal to VA with bits 60~63 cleared, and the cache attribute
+is configured by bits 60~61 in VA: 0 is for strongly-ordered uncached, 1 is
+for coherent cached, and 2 is for weakly-ordered uncached.
+
+Currently we only use XKPRANGE for direct mapping and XSPRANGE is reserved.
+
+To put this in action: the strongly-ordered uncached direct-mapped VA (in
+XKPRANGE) of 0x00000000_00001000 is 0x80000000_00001000, the coherent cached
+direct-mapped VA (in XKPRANGE) of 0x00000000_00001000 is 0x90000000_00001000,
+and the weakly-ordered uncached direct-mapped VA (in XKPRANGE) of 0x00000000
+_00001000 is 0xA0000000_00001000.
+
+Relationship of Loongson and LoongArch
+======================================
+
+LoongArch is a RISC ISA which is different from any other existing ones, while
+Loongson is a family of processors. Loongson includes 3 series: Loongson-1 is
+the 32-bit processor series, Loongson-2 is the low-end 64-bit processor series,
+and Loongson-3 is the high-end 64-bit processor series. Old Loongson is based on
+MIPS, while New Loongson is based on LoongArch. Take Loongson-3 as an example:
+Loongson-3A1000/3B1500/3A2000/3A3000/3A4000 are MIPS-compatible, while Loongson-
+3A5000 (and future revisions) are all based on LoongArch.
+
+.. _loongarch-references:
+
+References
+==========
+
+Official web site of Loongson Technology Corp. Ltd.:
+
+  http://www.loongson.cn/
+
+Developer web site of Loongson and LoongArch (Software and Documentation):
+
+  http://www.loongnix.cn/
+
+  https://github.com/loongson/
+
+  https://loongson.github.io/LoongArch-Documentation/
+
+Documentation of LoongArch ISA:
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/LoongArch-Vol1-v1.02-CN.pdf (in Chinese)
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/LoongArch-Vol1-v1.02-EN.pdf (in English)
+
+Documentation of LoongArch ELF psABI:
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/LoongArch-ELF-ABI-v2.00-CN.pdf (in Chinese)
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/LoongArch-ELF-ABI-v2.00-EN.pdf (in English)
+
+Linux kernel repository of Loongson and LoongArch:
+
+  https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson.git
diff --git a/Documentation/arch/loongarch/irq-chip-model.rst b/Documentation/arch/loongarch/irq-chip-model.rst
new file mode 100644
index 00000000000000..7988f41923639d
--- /dev/null
+++ b/Documentation/arch/loongarch/irq-chip-model.rst
@@ -0,0 +1,160 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======================================
+IRQ chip model (hierarchy) of LoongArch
+=======================================
+
+Currently, LoongArch based processors (e.g. Loongson-3A5000) can only work together
+with LS7A chipsets. The irq chips in LoongArch computers include CPUINTC (CPU Core
+Interrupt Controller), LIOINTC (Legacy I/O Interrupt Controller), EIOINTC (Extended
+I/O Interrupt Controller), HTVECINTC (Hyper-Transport Vector Interrupt Controller),
+PCH-PIC (Main Interrupt Controller in LS7A chipset), PCH-LPC (LPC Interrupt Controller
+in LS7A chipset) and PCH-MSI (MSI Interrupt Controller).
+
+CPUINTC is a per-core controller (in CPU), LIOINTC/EIOINTC/HTVECINTC are per-package
+controllers (in CPU), while PCH-PIC/PCH-LPC/PCH-MSI are controllers out of CPU (i.e.,
+in chipsets). These controllers (in other words, irqchips) are linked in a hierarchy,
+and there are two models of hierarchy (legacy model and extended model).
+
+Legacy IRQ model
+================
+
+In this model, IPI (Inter-Processor Interrupt) and CPU Local Timer interrupt go
+to CPUINTC directly, CPU UARTS interrupts go to LIOINTC, while all other devices
+interrupts go to PCH-PIC/PCH-LPC/PCH-MSI and gathered by HTVECINTC, and then go
+to LIOINTC, and then CPUINTC::
+
+     +-----+     +---------+     +-------+
+     | IPI | --> | CPUINTC | <-- | Timer |
+     +-----+     +---------+     +-------+
+                      ^
+                      |
+                 +---------+     +-------+
+                 | LIOINTC | <-- | UARTs |
+                 +---------+     +-------+
+                      ^
+                      |
+                +-----------+
+                | HTVECINTC |
+                +-----------+
+                 ^         ^
+                 |         |
+           +---------+ +---------+
+           | PCH-PIC | | PCH-MSI |
+           +---------+ +---------+
+             ^     ^           ^
+             |     |           |
+     +---------+ +---------+ +---------+
+     | PCH-LPC | | Devices | | Devices |
+     +---------+ +---------+ +---------+
+          ^
+          |
+     +---------+
+     | Devices |
+     +---------+
+
+Extended IRQ model
+==================
+
+In this model, IPI (Inter-Processor Interrupt) and CPU Local Timer interrupt go
+to CPUINTC directly, CPU UARTS interrupts go to LIOINTC, while all other devices
+interrupts go to PCH-PIC/PCH-LPC/PCH-MSI and gathered by EIOINTC, and then go to
+to CPUINTC directly::
+
+          +-----+     +---------+     +-------+
+          | IPI | --> | CPUINTC | <-- | Timer |
+          +-----+     +---------+     +-------+
+                       ^       ^
+                       |       |
+                +---------+ +---------+     +-------+
+                | EIOINTC | | LIOINTC | <-- | UARTs |
+                +---------+ +---------+     +-------+
+                 ^       ^
+                 |       |
+          +---------+ +---------+
+          | PCH-PIC | | PCH-MSI |
+          +---------+ +---------+
+            ^     ^           ^
+            |     |           |
+    +---------+ +---------+ +---------+
+    | PCH-LPC | | Devices | | Devices |
+    +---------+ +---------+ +---------+
+         ^
+         |
+    +---------+
+    | Devices |
+    +---------+
+
+ACPI-related definitions
+========================
+
+CPUINTC::
+
+  ACPI_MADT_TYPE_CORE_PIC;
+  struct acpi_madt_core_pic;
+  enum acpi_madt_core_pic_version;
+
+LIOINTC::
+
+  ACPI_MADT_TYPE_LIO_PIC;
+  struct acpi_madt_lio_pic;
+  enum acpi_madt_lio_pic_version;
+
+EIOINTC::
+
+  ACPI_MADT_TYPE_EIO_PIC;
+  struct acpi_madt_eio_pic;
+  enum acpi_madt_eio_pic_version;
+
+HTVECINTC::
+
+  ACPI_MADT_TYPE_HT_PIC;
+  struct acpi_madt_ht_pic;
+  enum acpi_madt_ht_pic_version;
+
+PCH-PIC::
+
+  ACPI_MADT_TYPE_BIO_PIC;
+  struct acpi_madt_bio_pic;
+  enum acpi_madt_bio_pic_version;
+
+PCH-MSI::
+
+  ACPI_MADT_TYPE_MSI_PIC;
+  struct acpi_madt_msi_pic;
+  enum acpi_madt_msi_pic_version;
+
+PCH-LPC::
+
+  ACPI_MADT_TYPE_LPC_PIC;
+  struct acpi_madt_lpc_pic;
+  enum acpi_madt_lpc_pic_version;
+
+References
+==========
+
+Documentation of Loongson-3A5000:
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-3A5000-usermanual-1.02-CN.pdf (in Chinese)
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-3A5000-usermanual-1.02-EN.pdf (in English)
+
+Documentation of Loongson's LS7A chipset:
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-7A1000-usermanual-2.00-CN.pdf (in Chinese)
+
+  https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-7A1000-usermanual-2.00-EN.pdf (in English)
+
+.. Note::
+    - CPUINTC is CSR.ECFG/CSR.ESTAT and its interrupt controller described
+      in Section 7.4 of "LoongArch Reference Manual, Vol 1";
+    - LIOINTC is "Legacy I/OInterrupts" described in Section 11.1 of
+      "Loongson 3A5000 Processor Reference Manual";
+    - EIOINTC is "Extended I/O Interrupts" described in Section 11.2 of
+      "Loongson 3A5000 Processor Reference Manual";
+    - HTVECINTC is "HyperTransport Interrupts" described in Section 14.3 of
+      "Loongson 3A5000 Processor Reference Manual";
+    - PCH-PIC/PCH-MSI is "Interrupt Controller" described in Section 5 of
+      "Loongson 7A1000 Bridge User Manual";
+    - PCH-LPC is "LPC Interrupts" described in Section 24.3 of
+      "Loongson 7A1000 Bridge User Manual".
diff --git a/Documentation/arch/mips/booting.rst b/Documentation/arch/mips/booting.rst
new file mode 100644
index 00000000000000..7c18a4eab48b62
--- /dev/null
+++ b/Documentation/arch/mips/booting.rst
@@ -0,0 +1,28 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+BMIPS DeviceTree Booting
+------------------------
+
+  Some bootloaders only support a single entry point, at the start of the
+  kernel image.  Other bootloaders will jump to the ELF start address.
+  Both schemes are supported; CONFIG_BOOT_RAW=y and CONFIG_NO_EXCEPT_FILL=y,
+  so the first instruction immediately jumps to kernel_entry().
+
+  Similar to the arch/arm case (b), a DT-aware bootloader is expected to
+  set up the following registers:
+
+         a0 : 0
+
+         a1 : 0xffffffff
+
+         a2 : Physical pointer to the device tree block (defined in chapter
+         II) in RAM.  The device tree can be located anywhere in the first
+         512MB of the physical address space (0x00000000 - 0x1fffffff),
+         aligned on a 64 bit boundary.
+
+  Legacy bootloaders do not use this convention, and they do not pass in a
+  DT block.  In this case, Linux will look for a builtin DTB, selected via
+  CONFIG_DT_*.
+
+  This convention is defined for 32-bit systems only, as there are not
+  currently any 64-bit BMIPS implementations.
diff --git a/Documentation/arch/mips/features.rst b/Documentation/arch/mips/features.rst
new file mode 100644
index 00000000000000..1973d729b29a98
--- /dev/null
+++ b/Documentation/arch/mips/features.rst
@@ -0,0 +1,3 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. kernel-feat:: $srctree/Documentation/features mips
diff --git a/Documentation/arch/mips/index.rst b/Documentation/arch/mips/index.rst
new file mode 100644
index 00000000000000..037f85a08fe3bf
--- /dev/null
+++ b/Documentation/arch/mips/index.rst
@@ -0,0 +1,21 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+MIPS-specific Documentation
+===========================
+
+.. toctree::
+   :maxdepth: 2
+   :numbered:
+
+   booting
+   ingenic-tcu
+
+   features
+
+.. only::  subproject and html
+
+   Indices
+   =======
+
+   * :ref:`genindex`
diff --git a/Documentation/arch/mips/ingenic-tcu.rst b/Documentation/arch/mips/ingenic-tcu.rst
new file mode 100644
index 00000000000000..2ce4cb1314dc4a
--- /dev/null
+++ b/Documentation/arch/mips/ingenic-tcu.rst
@@ -0,0 +1,71 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============================================
+Ingenic JZ47xx SoCs Timer/Counter Unit hardware
+===============================================
+
+The Timer/Counter Unit (TCU) in Ingenic JZ47xx SoCs is a multi-function
+hardware block. It features up to eight channels, that can be used as
+counters, timers, or PWM.
+
+- JZ4725B, JZ4750, JZ4755 only have six TCU channels. The other SoCs all
+  have eight channels.
+
+- JZ4725B introduced a separate channel, called Operating System Timer
+  (OST). It is a 32-bit programmable timer. On JZ4760B and above, it is
+  64-bit.
+
+- Each one of the TCU channels has its own clock, which can be reparented to three
+  different clocks (pclk, ext, rtc), gated, and reclocked, through their TCSR register.
+
+    - The watchdog and OST hardware blocks also feature a TCSR register with the same
+      format in their register space.
+    - The TCU registers used to gate/ungate can also gate/ungate the watchdog and
+      OST clocks.
+
+- Each TCU channel works in one of two modes:
+
+    - mode TCU1: channels cannot work in sleep mode, but are easier to
+      operate.
+    - mode TCU2: channels can work in sleep mode, but the operation is a bit
+      more complicated than with TCU1 channels.
+
+- The mode of each TCU channel depends on the SoC used:
+
+    - On the oldest SoCs (up to JZ4740), all of the eight channels operate in
+      TCU1 mode.
+    - On JZ4725B, channel 5 operates as TCU2, the others operate as TCU1.
+    - On newest SoCs (JZ4750 and above), channels 1-2 operate as TCU2, the
+      others operate as TCU1.
+
+- Each channel can generate an interrupt. Some channels share an interrupt
+  line, some don't, and this changes between SoC versions:
+
+    - on older SoCs (JZ4740 and below), channel 0 and channel 1 have their
+      own interrupt line; channels 2-7 share the last interrupt line.
+    - On JZ4725B, channel 0 has its own interrupt; channels 1-5 share one
+      interrupt line; the OST uses the last interrupt line.
+    - on newer SoCs (JZ4750 and above), channel 5 has its own interrupt;
+      channels 0-4 and (if eight channels) 6-7 all share one interrupt line;
+      the OST uses the last interrupt line.
+
+Implementation
+==============
+
+The functionalities of the TCU hardware are spread across multiple drivers:
+
+===========  =====
+clocks       drivers/clk/ingenic/tcu.c
+interrupts   drivers/irqchip/irq-ingenic-tcu.c
+timers       drivers/clocksource/ingenic-timer.c
+OST          drivers/clocksource/ingenic-ost.c
+PWM          drivers/pwm/pwm-jz4740.c
+watchdog     drivers/watchdog/jz4740_wdt.c
+===========  =====
+
+Because various functionalities of the TCU that belong to different drivers
+and frameworks can be controlled from the same registers, all of these
+drivers access their registers through the same regmap.
+
+For more information regarding the devicetree bindings of the TCU drivers,
+have a look at Documentation/devicetree/bindings/timer/ingenic,tcu.yaml.
diff --git a/Documentation/arch/openrisc/openrisc_port.rst b/Documentation/arch/openrisc/openrisc_port.rst
index 657ac4af7be6ab..1565b9546e38d7 100644
--- a/Documentation/arch/openrisc/openrisc_port.rst
+++ b/Documentation/arch/openrisc/openrisc_port.rst
@@ -106,7 +106,7 @@ History
 	a much improved version with changes all around.
 
 10-04-2004	Matjaz Breskvar (phoenix@bsemi.com)
-	alot of bugfixes all over.
+	a lot of bugfixes all over.
 	ethernet support, functional http and telnet servers.
 	running many standard linux apps.
 
@@ -114,7 +114,7 @@ History
 	port to 2.6.x
 
 30-11-2004	Matjaz Breskvar (phoenix@bsemi.com)
-	lots of bugfixes and enhancments.
+	lots of bugfixes and enhancements.
 	added opencores framebuffer driver.
 
 09-10-2010    Jonas Bonn (jonas@southpole.se)
diff --git a/Documentation/arch/s390/vfio-ap.rst b/Documentation/arch/s390/vfio-ap.rst
index bb3f4c4e288563..929ee1c1c94007 100644
--- a/Documentation/arch/s390/vfio-ap.rst
+++ b/Documentation/arch/s390/vfio-ap.rst
@@ -422,7 +422,7 @@ Configure the guest's AP resources
 Configuring the AP resources for a KVM guest will be performed when the
 VFIO_GROUP_NOTIFY_SET_KVM notifier callback is invoked. The notifier
 function is called when userspace connects to KVM. The guest's AP resources are
-configured via it's APCB by:
+configured via its APCB by:
 
 * Setting the bits in the APM corresponding to the APIDs assigned to the
   vfio_ap mediated device via its 'assign_adapter' interface.
diff --git a/Documentation/arch/x86/boot.rst b/Documentation/arch/x86/boot.rst
index cdbca15a4fc238..f5d2f2414de8b6 100644
--- a/Documentation/arch/x86/boot.rst
+++ b/Documentation/arch/x86/boot.rst
@@ -1105,7 +1105,7 @@ The kernel command line should not be located below the real-mode
 code, nor should it be located in high memory.
 
 
-Sample Boot Configuartion
+Sample Boot Configuration
 =========================
 
 As a sample configuration, assume the following layout of the real
diff --git a/Documentation/arch/x86/buslock.rst b/Documentation/arch/x86/buslock.rst
index 31ec0ef7808683..4c5a4822eeb70b 100644
--- a/Documentation/arch/x86/buslock.rst
+++ b/Documentation/arch/x86/buslock.rst
@@ -32,7 +32,7 @@ mechanisms to detect split locks and bus locks.
 --------------------------------------
 
 Beginning with the Tremont Atom CPU split lock operations may raise an
-Alignment Check (#AC) exception when a split lock operation is attemped.
+Alignment Check (#AC) exception when a split lock operation is attempted.
 
 #DB exception for bus lock detection
 ------------------------------------
diff --git a/Documentation/arch/x86/mds.rst b/Documentation/arch/x86/mds.rst
index 5d4330be200f98..e73fdff62c0aa1 100644
--- a/Documentation/arch/x86/mds.rst
+++ b/Documentation/arch/x86/mds.rst
@@ -60,7 +60,7 @@ needed for exploiting MDS requires:
    data
 
 The existence of such a construct in the kernel cannot be excluded with
-100% certainty, but the complexity involved makes it extremly unlikely.
+100% certainty, but the complexity involved makes it extremely unlikely.
 
 There is one exception, which is untrusted BPF. The functionality of
 untrusted BPF is limited, but it needs to be thoroughly investigated
diff --git a/Documentation/arch/x86/sgx.rst b/Documentation/arch/x86/sgx.rst
index 2bcbffacbed559..d90796adc2ec88 100644
--- a/Documentation/arch/x86/sgx.rst
+++ b/Documentation/arch/x86/sgx.rst
@@ -245,7 +245,7 @@ SGX will likely become unusable because the memory available to SGX is
 limited. However, while this may be fatal to SGX, the rest of the kernel
 is unlikely to be impacted and should continue to work.
 
-As a result, when this happpens, user should stop running any new
+As a result, when this happens, user should stop running any new
 SGX workloads, (or just any new workloads), and migrate all valuable
 workloads. Although a machine reboot can recover all EPC memory, the bug
 should be reported to Linux developers.
diff --git a/Documentation/arch/xtensa/atomctl.rst b/Documentation/arch/xtensa/atomctl.rst
index 1ecbd0ba9a2e6f..75d1741694304a 100644
--- a/Documentation/arch/xtensa/atomctl.rst
+++ b/Documentation/arch/xtensa/atomctl.rst
@@ -23,7 +23,7 @@ doing a Cached (WB) transaction and use the Memory RCW for un-cached
 operations.
 
 For systems without an coherent cache controller, non-MX, we always
-use the memory controllers RCW, thought non-MX controlers likely
+use the memory controllers RCW, though non-MX controllers likely
 support the Internal Operation.
 
 CUSTOMER-WARNING: