Merge tag 'docs-4.19' of git://git.lwn.net/linux

Pull documentation update from Jonathan Corbet:
 "This was a moderately busy cycle for docs, with the usual collection
  of small fixes and updates.

  We also have new ktime_get_*() docs from Arnd, some kernel-doc fixes,
  a new set of Italian translations (non so se vale la pena, ma non fa
  male - speriamo bene), and some extensive early memory-management
  documentation improvements from Mike Rapoport"

* tag 'docs-4.19' of git://git.lwn.net/linux: (52 commits)
  Documentation: corrections to console/console.txt
  Documentation: add ioctl number entry for v4l2-subdev.h
  Remove gendered language from management style documentation
  scripts/kernel-doc: Escape all literal braces in regexes
  docs/mm: add description of boot time memory management
  docs/mm: memblock: add overview documentation
  docs/mm: memblock: add kernel-doc description for memblock types
  docs/mm: memblock: add kernel-doc comments for memblock_add[_node]
  docs/mm: memblock: update kernel-doc comments
  mm/memblock: add a name for memblock flags enumeration
  docs/mm: bootmem: add overview documentation
  docs/mm: bootmem: add kernel-doc description of 'struct bootmem_data'
  docs/mm: bootmem: fix kernel-doc warnings
  docs/mm: nobootmem: fixup kernel-doc comments
  mm/bootmem: drop duplicated kernel-doc comments
  Documentation: vm.txt: Adding 'nr_hugepages_mempolicy' parameter description.
  doc:it_IT: translation for kernel-hacking
  docs: Fix the reference labels in Locking.rst
  doc: tracing: Fix a typo of trace_stat
  mm: Introduce new type vm_fault_t
  ...

1 files changed, 13 insertions, 3 deletions

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 5a67e409d370..f3ade2f6b65b 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4136,6 +4136,8 @@
 			This parameter controls whether the Speculative Store
 			Bypass optimization is used.
 
+			On x86 the options are:
+
 			on      - Unconditionally disable Speculative Store Bypass
 			off     - Unconditionally enable Speculative Store Bypass
 			auto    - Kernel detects whether the CPU model contains an
@@ -4151,12 +4153,20 @@
 			seccomp - Same as "prctl" above, but all seccomp threads
 				  will disable SSB unless they explicitly opt out.
 
-			Not specifying this option is equivalent to
-			spec_store_bypass_disable=auto.
-
 			Default mitigations:
 			X86:	If CONFIG_SECCOMP=y "seccomp", otherwise "prctl"
 
+			On powerpc the options are:
+
+			on,auto - On Power8 and Power9 insert a store-forwarding
+				  barrier on kernel entry and exit. On Power7
+				  perform a software flush on kernel entry and
+				  exit.
+			off	- No action.
+
+			Not specifying this option is equivalent to
+			spec_store_bypass_disable=auto.
+
 	spia_io_base=	[HW,MTD]
 	spia_fio_base=
 	spia_pedr=