Merge tag 'docs-5.10' of git://git.lwn.net/linux

Pull documentation updates from Jonathan Corbet:
 "As hoped, things calmed down for docs this cycle; fewer changes and
  almost no conflicts at all. This includes:

   - A reworked and expanded user-mode Linux document

   - Some simplifications and improvements for submitting-patches.rst

   - An emergency fix for (some) problems with Sphinx 3.x

   - Some welcome automarkup improvements to automatically generate
     cross-references to struct definitions and other documents

   - The usual collection of translation updates, typo fixes, etc"

* tag 'docs-5.10' of git://git.lwn.net/linux: (81 commits)
  gpiolib: Update indentation in driver.rst for code excerpts
  Documentation/admin-guide: tainted-kernels: Fix typo occured
  Documentation: better locations for sysfs-pci, sysfs-tagging
  docs: programming-languages: refresh blurb on clang support
  Documentation: kvm: fix a typo
  Documentation: Chinese translation of Documentation/arm64/amu.rst
  doc: zh_CN: index files in arm64 subdirectory
  mailmap: add entry for <[email protected]>
  doc: seq_file: clarify role of *pos in ->next()
  docs: trace: ring-buffer-design.rst: use the new SPDX tag
  Documentation: kernel-parameters: clarify "module." parameters
  Fix references to nommu-mmap.rst
  docs: rewrite admin-guide/sysctl/abi.rst
  docs: fb: Remove vesafb scrollback boot option
  docs: fb: Remove sstfb scrollback boot option
  docs: fb: Remove matroxfb scrollback boot option
  docs: fb: Remove framebuffer scrollback boot option
  docs: replace the old User Mode Linux HowTo with a new one
  Documentation/admin-guide: blockdev/ramdisk: remove use of "rdev"
  Documentation/admin-guide: README & svga: remove use of "rdev"
  ...

.gitignore

@@ -152,3 +152,6 @@ x509.genkey
 
 # Clang's compilation database file
 /compile_commands.json
+
+# Documentation toolchain
+sphinx_*/

.mailmap

@@ -197,6 +197,7 @@ Maciej W. Rozycki <[email protected]> <[email protected]>
 Marcin Nowakowski <[email protected]> <[email protected]>
 Marc Zyngier <[email protected]> <[email protected]>
 Mark Brown <[email protected]>
+Mark Starovoytov <[email protected]> <[email protected]>
 Mark Yao <[email protected]> <[email protected]>
 Martin Kepplinger <[email protected]> <[email protected]>
 Martin Kepplinger <[email protected]> <[email protected]>

Documentation/ABI/stable/sysfs-kernel-notes

@@ -0,0 +1,5 @@
+What:		/sys/kernel/notes
+Date:		July 2009
+Contact:	<[email protected]>
+Description:	The /sys/kernel/notes file contains the binary representation
+		of the running vmlinux's .notes section.

Documentation/PCI/index.rst

@@ -12,6 +12,7 @@ Linux PCI Bus Subsystem
    pciebus-howto
    pci-iov-howto
    msi-howto
+   sysfs-pci
    acpi-info
    pci-error-recovery
    pcieaer-howto

Documentation/admin-guide/README.rst

@@ -322,9 +322,9 @@ Compiling the kernel
    reboot, and enjoy!
 
    If you ever need to change the default root device, video mode,
-   ramdisk size, etc.  in the kernel image, use the ``rdev`` program (or
-   alternatively the LILO boot options when appropriate).  No need to
-   recompile the kernel to change these parameters.
+   etc. in the kernel image, use your bootloader's boot options
+   where appropriate.  No need to recompile the kernel to change
+   these parameters.
 
  - Reboot with the new kernel and enjoy.
 

Documentation/admin-guide/bcache.rst

@@ -5,11 +5,14 @@ A block layer cache (bcache)
 Say you've got a big slow raid 6, and an ssd or three. Wouldn't it be
 nice if you could use them as cache... Hence bcache.
 
-Wiki and git repositories are at:
+The bcache wiki can be found at:
+  https://bcache.evilpiepirate.org
 
-  - https://bcache.evilpiepirate.org
-  - http://evilpiepirate.org/git/linux-bcache.git
-  - https://evilpiepirate.org/git/bcache-tools.git
+This is the git repository of bcache-tools:
+  https://git.kernel.org/pub/scm/linux/kernel/git/colyli/bcache-tools.git/
+
+The latest bcache kernel code can be found from mainline Linux kernel:
+  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
 
 It's designed around the performance characteristics of SSDs - it only allocates
 in erase block sized buckets, and it uses a hybrid btree/log to track cached
@@ -41,17 +44,21 @@ in the cache it first disables writeback caching and waits for all dirty data
 to be flushed.
 
 Getting started:
-You'll need make-bcache from the bcache-tools repository. Both the cache device
+You'll need bcache util from the bcache-tools repository. Both the cache device
 and backing device must be formatted before use::
 
-  make-bcache -B /dev/sdb
-  make-bcache -C /dev/sdc
+  bcache make -B /dev/sdb
+  bcache make -C /dev/sdc
 
-make-bcache has the ability to format multiple devices at the same time - if
+`bcache make` has the ability to format multiple devices at the same time - if
 you format your backing devices and cache device at the same time, you won't
 have to manually attach::
 
-  make-bcache -B /dev/sda /dev/sdb -C /dev/sdc
+  bcache make -B /dev/sda /dev/sdb -C /dev/sdc
+
+If your bcache-tools is not updated to latest version and does not have the
+unified `bcache` utility, you may use the legacy `make-bcache` utility to format
+bcache device with same -B and -C parameters.
 
 bcache-tools now ships udev rules, and bcache devices are known to the kernel
 immediately.  Without udev, you can manually register devices like this::
@@ -188,7 +195,7 @@ D) Recovering data without bcache:
 If bcache is not available in the kernel, a filesystem on the backing
 device is still available at an 8KiB offset. So either via a loopdev
 of the backing device created with --offset 8K, or any value defined by
---data-offset when you originally formatted bcache with `make-bcache`.
+--data-offset when you originally formatted bcache with `bcache make`.
 
 For example::
 
@@ -210,7 +217,7 @@ E) Wiping a cache device
 
 After you boot back with bcache enabled, you recreate the cache and attach it::
 
-	host:~# make-bcache -C /dev/sdh2
+	host:~# bcache make -C /dev/sdh2
 	UUID:                   7be7e175-8f4c-4f99-94b2-9c904d227045
 	Set UUID:               5bc072a8-ab17-446d-9744-e247949913c1
 	version:                0
@@ -318,7 +325,7 @@ want for getting the best possible numbers when benchmarking.
 
    The default metadata size in bcache is 8k.  If your backing device is
    RAID based, then be sure to align this by a multiple of your stride
-   width using `make-bcache --data-offset`. If you intend to expand your
+   width using `bcache make --data-offset`. If you intend to expand your
    disk array in the future, then multiply a series of primes by your
    raid stripe size to get the disk multiples that you would like.
 

Documentation/admin-guide/blockdev/ramdisk.rst

@@ -6,7 +6,7 @@ Using the RAM disk block device with Linux
 
 	1) Overview
 	2) Kernel Command Line Parameters
-	3) Using "rdev -r"
+	3) Using "rdev"
 	4) An Example of Creating a Compressed RAM Disk
 
 
@@ -59,51 +59,27 @@ default is 4096 (4 MB).
 	rd_size
 		See ramdisk_size.
 
-3) Using "rdev -r"
-------------------
+3) Using "rdev"
+---------------
 
-The usage of the word (two bytes) that "rdev -r" sets in the kernel image is
-as follows. The low 11 bits (0 -> 10) specify an offset (in 1 k blocks) of up
-to 2 MB (2^11) of where to find the RAM disk (this used to be the size). Bit
-14 indicates that a RAM disk is to be loaded, and bit 15 indicates whether a
-prompt/wait sequence is to be given before trying to read the RAM disk. Since
-the RAM disk dynamically grows as data is being written into it, a size field
-is not required. Bits 11 to 13 are not currently used and may as well be zero.
-These numbers are no magical secrets, as seen below::
+"rdev" is an obsolete, deprecated, antiquated utility that could be used
+to set the boot device in a Linux kernel image.
 
-  ./arch/x86/kernel/setup.c:#define RAMDISK_IMAGE_START_MASK     0x07FF
-  ./arch/x86/kernel/setup.c:#define RAMDISK_PROMPT_FLAG          0x8000
-  ./arch/x86/kernel/setup.c:#define RAMDISK_LOAD_FLAG            0x4000
+Instead of using rdev, just place the boot device information on the
+kernel command line and pass it to the kernel from the bootloader.
 
-Consider a typical two floppy disk setup, where you will have the
-kernel on disk one, and have already put a RAM disk image onto disk #2.
+You can also pass arguments to the kernel by setting FDARGS in
+arch/x86/boot/Makefile and specify in initrd image by setting FDINITRD in
+arch/x86/boot/Makefile.
 
-Hence you want to set bits 0 to 13 as 0, meaning that your RAM disk
-starts at an offset of 0 kB from the beginning of the floppy.
-The command line equivalent is: "ramdisk_start=0"
+Some of the kernel command line boot options that may apply here are::
 
-You want bit 14 as one, indicating that a RAM disk is to be loaded.
-The command line equivalent is: "load_ramdisk=1"
-
-You want bit 15 as one, indicating that you want a prompt/keypress
-sequence so that you have a chance to switch floppy disks.
-The command line equivalent is: "prompt_ramdisk=1"
-
-Putting that together gives 2^15 + 2^14 + 0 = 49152 for an rdev word.
-So to create disk one of the set, you would do::
-
-	/usr/src/linux# cat arch/x86/boot/zImage > /dev/fd0
-	/usr/src/linux# rdev /dev/fd0 /dev/fd0
-	/usr/src/linux# rdev -r /dev/fd0 49152
+  ramdisk_start=N
+  ramdisk_size=M
 
 If you make a boot disk that has LILO, then for the above, you would use::
 
-	append = "ramdisk_start=0 load_ramdisk=1 prompt_ramdisk=1"
-
-Since the default start = 0 and the default prompt = 1, you could use::
-
-	append = "load_ramdisk=1"
-
+	append = "ramdisk_start=N ramdisk_size=M"
 
 4) An Example of Creating a Compressed RAM Disk
 -----------------------------------------------
@@ -151,12 +127,9 @@ f) Put the RAM disk image onto the floppy, after the kernel. Use an offset
 
 	dd if=/tmp/ram_image.gz of=/dev/fd0 bs=1k seek=400
 
-g) Use "rdev" to set the boot device, RAM disk offset, prompt flag, etc.
-   For prompt_ramdisk=1, load_ramdisk=1, ramdisk_start=400, one would
-   have 2^15 + 2^14 + 400 = 49552::
-
-	rdev /dev/fd0 /dev/fd0
-	rdev -r /dev/fd0 49552
+g) Make sure that you have already specified the boot information in
+   FDARGS and FDINITRD or that you use a bootloader to pass kernel
+   command line boot options to the kernel.
 
 That is it. You now have your boot/root compressed RAM disk floppy. Some
 users may wish to combine steps (d) and (f) by using a pipe.
@@ -167,11 +140,14 @@ users may wish to combine steps (d) and (f) by using a pipe.
 Changelog:
 ----------
 
+SEPT-2020 :
+
+                Removed usage of "rdev"
+
 10-22-04 :
 		Updated to reflect changes in command line options, remove
 		obsolete references, general cleanup.
 		James Nelson ([email protected])
 
-
 12-95 :
 		Original Document

Documentation/admin-guide/cgroup-v1/cpusets.rst

@@ -1,3 +1,5 @@
+.. _cpusets:
+
 =======
 CPUSETS
 =======

Documentation/admin-guide/kdump/kdump.rst

@@ -509,9 +509,12 @@ ELF32-format headers using the --elf32-core-headers kernel option on the
 dump kernel.
 
 You can also use the Crash utility to analyze dump files in Kdump
-format. Crash is available on Dave Anderson's site at the following URL:
+format. Crash is available at the following URL:
 
-   http://people.redhat.com/~anderson/
+   https://github.com/crash-utility/crash
+
+Crash document can be found at:
+   https://crash-utility.github.io/
 
 Trigger Kdump on WARN()
 =======================

Documentation/admin-guide/kernel-parameters.txt

@@ -591,7 +591,7 @@
 			some critical bits.
 
 	cma=nn[MG]@[start[MG][-end[MG]]]
-			[ARM,X86,KNL]
+			[KNL,CMA]
 			Sets the size of kernel global memory area for
 			contiguous memory allocations and optionally the
 			placement constraint by the physical address range of
@@ -940,7 +940,7 @@
 			Arch Perfmon v4 (Skylake and newer).
 
 	disable_ddw	[PPC/PSERIES]
-			Disable Dynamic DMA Window support. Use this if
+			Disable Dynamic DMA Window support. Use this
 			to workaround buggy firmware.
 
 	disable_ipv6=	[IPV6]
@@ -1019,15 +1019,15 @@
 			what data is available or for reverse-engineering.
 
 	dyndbg[="val"]		[KNL,DYNAMIC_DEBUG]
-	module.dyndbg[="val"]
+	<module>.dyndbg[="val"]
 			Enable debug messages at boot time.  See
 			Documentation/admin-guide/dynamic-debug-howto.rst
 			for details.
 
 	nopku		[X86] Disable Memory Protection Keys CPU feature found
 			in some Intel CPUs.
 
-	module.async_probe [KNL]
+	<module>.async_probe [KNL]
 			Enable asynchronous probe on this module.
 
 	early_ioremap_debug [KNL]
@@ -1956,7 +1956,7 @@
 			1 - Bypass the IOMMU for DMA.
 			unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH.
 
-	io7=		[HW] IO7 for Marvel based alpha systems
+	io7=		[HW] IO7 for Marvel-based Alpha systems
 			See comment before marvel_specify_io7 in
 			arch/alpha/kernel/core_marvel.c.
 
@@ -2177,7 +2177,7 @@
 	kgdbwait	[KGDB] Stop kernel execution and enter the
 			kernel debugger at the earliest opportunity.
 
-	kmac=		[MIPS] korina ethernet MAC address.
+	kmac=		[MIPS] Korina ethernet MAC address.
 			Configure the RouterBoard 532 series on-chip
 			Ethernet adapter MAC address.
 
@@ -2258,6 +2258,14 @@
 			[KVM,ARM] Allow use of GICv4 for direct injection of
 			LPIs.
 
+	kvm_cma_resv_ratio=n [PPC]
+			Reserves given percentage from system memory area for
+			contiguous memory allocation for KVM hash pagetable
+			allocation.
+			By default it reserves 5% of total system memory.
+			Format: <integer>
+			Default: 5
+
 	kvm-intel.ept=	[KVM,Intel] Disable extended page tables
 			(virtualized MMU) support on capable Intel chips.
 			Default is 1 (enabled)
@@ -2367,9 +2375,10 @@
 	lapic		[X86-32,APIC] Enable the local APIC even if BIOS
 			disabled it.
 
-	lapic=		[X86,APIC] "notscdeadline" Do not use TSC deadline
+	lapic=		[X86,APIC] Do not use TSC deadline
 			value for LAPIC timer one-shot implementation. Default
 			back to the programmable timer unit in the LAPIC.
+			Format: notscdeadline
 
 	lapic_timer_c2_ok	[X86,APIC] trust the local apic timer
 			in C2 power state.
@@ -2441,8 +2450,7 @@
 
 	memblock=debug	[KNL] Enable memblock debug messages.
 
-	load_ramdisk=	[RAM] List of ramdisks to load from floppy
-			See Documentation/admin-guide/blockdev/ramdisk.rst.
+	load_ramdisk=	[RAM] [Deprecated]
 
 	lockd.nlm_grace_period=P  [NFS] Assign grace period.
 			Format: <integer>
@@ -2579,8 +2587,8 @@
 			(machvec) in a generic kernel.
 			Example: machvec=hpzx1
 
-	machtype=	[Loongson] Share the same kernel image file between different
-			 yeeloong laptop.
+	machtype=	[Loongson] Share the same kernel image file between
+			different yeeloong laptops.
 			Example: machtype=lemote-yeeloong-2f-7inch
 
 	max_addr=nn[KMG]	[KNL,BOOT,ia64] All physical memory greater
@@ -3185,7 +3193,7 @@
 			register save and restore. The kernel will only save
 			legacy floating-point registers on task switch.
 
-	nohugeiomap	[KNL,X86,PPC] Disable kernel huge I/O mappings.
+	nohugeiomap	[KNL,X86,PPC,ARM64] Disable kernel huge I/O mappings.
 
 	nosmt		[KNL,S390] Disable symmetric multithreading (SMT).
 			Equivalent to smt=1.
@@ -3921,9 +3929,7 @@
 			Param: <number> - step/bucket size as a power of 2 for
 				statistical time based profiling.
 
-	prompt_ramdisk=	[RAM] List of RAM disks to prompt for floppy disk
-			before loading.
-			See Documentation/admin-guide/blockdev/ramdisk.rst.
+	prompt_ramdisk=	[RAM] [Deprecated]
 
 	prot_virt=	[S390] enable hosting protected virtual machines
 			isolated from the hypervisor (if hardware supports
@@ -3981,6 +3987,8 @@
 	ramdisk_size=	[RAM] Sizes of RAM disks in kilobytes
 			See Documentation/admin-guide/blockdev/ramdisk.rst.
 
+	ramdisk_start=	[RAM] RAM disk image start address
+
 	random.trust_cpu={on,off}
 			[KNL] Enable or disable trusting the use of the
 			CPU's random number generator (if available) to