Make lib/textsearch.c usable as kernel-doc.
Add textsearch() function family to kernel-api documentation.
Fix kernel-doc warnings in <linux/textsearch.h>:
  ../include/linux/textsearch.h:65: warning: Incorrect use of kernel-doc format:
	* get_next_block - fetch next block of data
  ../include/linux/textsearch.h:82: warning: Incorrect use of kernel-doc format:
	* finish - finalize/clean a series of get_next_block() calls

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

When debugging recent kernels, people will see '(ptrval)' but there
isn't much information as to what that means. Briefly describe why it's
there.

Signed-off-by: Joel Stanley <joel@jms.id.au>
Acked-by: Tobin C. Harding <me@tobin.cc>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Move the idr kernel-doc to its own idr.rst file and add a few
paragraphs about how to use it.  Also add some more kernel-doc.

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>

Pull printk updates from Petr Mladek:

 - Add a console_msg_format command line option:

     The value "default" keeps the old "[time stamp] text\n" format. The
     value "syslog" allows to see the syslog-like "<log
     level>[timestamp] text" format.

     This feature was requested by people doing regression tests, for
     example, 0day robot. They want to have both filtered and full logs
     at hands.

 - Reduce the risk of softlockup:

     Pass the console owner in a busy loop.

     This is a new approach to the old problem. It was first proposed by
     Steven Rostedt on Kernel Summit 2017. It marks a context in which
     the console_lock owner calls console drivers and could not sleep.
     On the other side, printk() callers could detect this state and use
     a busy wait instead of a simple console_trylock(). Finally, the
     console_lock owner checks if there is a busy waiter at the end of
     the special context and eventually passes the console_lock to the
     waiter.

     The hand-off works surprisingly well and helps in many situations.
     Well, there is still a possibility of the softlockup, for example,
     when the flood of messages stops and the last owner still has too
     much to flush.

     There is increasing number of people having problems with
     printk-related softlockups. We might eventually need to get better
     solution. Anyway, this looks like a good start and promising
     direction.

 - Do not allow to schedule in console_unlock() called from printk():

     This reverts an older controversial commit. The reschedule helped
     to avoid softlockups. But it also slowed down the console output.
     This patch is obsoleted by the new console waiter logic described
     above. In fact, the reschedule made the hand-off less effective.

 - Deprecate "%pf" and "%pF" format specifier:

     It was needed on ia64, ppc64 and parisc64 to dereference function
     descriptors and show the real function address. It is done
     transparently by "%ps" and "pS" format specifier now.

     Sergey Senozhatsky found that all the function descriptors were in
     a special elf section and could be easily detected.

 - Remove printk_symbol() API:

     It has been obsoleted by "%pS" format specifier, and this change
     helped to remove few continuous lines and a less intuitive old API.

 - Remove redundant memsets:

     Sergey removed unnecessary memset when processing printk.devkmsg
     command line option.

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (27 commits)
  printk: drop redundant devkmsg_log_str memsets
  printk: Never set console_may_schedule in console_trylock()
  printk: Hide console waiter logic into helpers
  printk: Add console owner and waiter logic to load balance console writes
  kallsyms: remove print_symbol() function
  checkpatch: add pF/pf deprecation warning
  symbol lookup: introduce dereference_symbol_descriptor()
  parisc64: Add .opd based function descriptor dereference
  powerpc64: Add .opd based function descriptor dereference
  ia64: Add .opd based function descriptor dereference
  sections: split dereference_function_descriptor()
  openrisc: Fix conflicting types for _exext and _stext
  lib: do not use print_symbol()
  irq debug: do not use print_symbol()
  sysfs: do not use print_symbol()
  drivers: do not use print_symbol()
  x86: do not use print_symbol()
  unicore32: do not use print_symbol()
  sh: do not use print_symbol()
  mn10300: do not use print_symbol()
  ...

 - Move errseq.rst into core-api
 - Add errseq to the core-api index
 - Promote the header to a more prominent header type, otherwise we get three
   entries in the table of contents.
 - Reformat the table to look nicer and be a little more proportional in
   terms of horizontal width per bit (the SF bit is still disproportionately
   large, but there's no way to fix that).
 - Include errseq kernel-doc in the errseq.rst
 - Neaten some kernel-doc markup

Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/printk-formats.txt is a candidate for conversion to
ReStructuredText format. Some effort has already been made to do this
conversion even thought the suffix is currently .txt

Changes required to complete conversion

 - Move printk-formats.txt to core-api/printk-formats.rst
 - Add entry to Documentation/core-api/index.rst
 - Remove entry from Documentation/00-INDEX
 - Fix minor grammatical errors.
 - Order heading adornments as suggested by rst docs.
 - Use 'Passed by reference' uniformly.
 - Update pointer documentation around %px specifier.
 - Fix erroneous double backticks (to commas).
 - Remove extraneous double backticks (suggested by Jonathan Corbet).
 - Simplify documentation for kobject.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
[jc: downcased "kernel"]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Update kernel-doc notation in lib/uuid.c and then add UUID/GUID
function interfaces to kernel-api.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
[jc: tweaked the uuid_is_valid() kerneldoc]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Add sort() and list_sort() to the kernel API documentation in a
new "Sorting" section.

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Some functions from refcount_t API provide different
memory ordering guarantees that their atomic counterparts.
This adds a document outlining these differences (
Documentation/core-api/refcount-vs-atomic.rst) as well as
some other minor improvements.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

In code blocks, :c:func:`...` annotations don't result in
cross-references. Instead, they are rendered verbatim.  Remove these
broken annotations, and mark function calls with parentheses() again.

Fixes: 76d40fae1351 ("genericirq.rst: add cross-reference links and use monospaced fonts")
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>