0day-ci / linux

If arg to "switch case" is determined and it's a consecutive numbers
(This is enum btrfs_wq_endio_type)
Compiler can create jump table to optimize logic

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

In worst case code do 4 comparison,
just add some new checks to switch check branch faster
now in worst case code do 3 comparison

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

By comparison logic if ret => 0 -> ret=0;
So lets cleanup compare logic

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

As code already know that (node->ref_mod > 0)
else if (node->ref_mod <= 0) - useless
So just leave 'else'

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

In worst case code do 8 comparison,
just add some new checks to switch check branch faster
now in worst case code do 5 comparison

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

In worst case code do 6 comparison,
just add some new checks to switch check branch faster
now in worst case code do 4 comparison

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

In worst case code do 4 comparison,
just add some new checks to switch check branch faster
now in worst case code do 3 comparison

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

In support of a soon to be published MFD driver using serdev to talk to
a supervisory processor that uses the CCITT-FALSE CRC16 variant in it's
protocol, this patch was tested successfully on an i.MX6 ARM platform.

Link: http://lkml.kernel.org/r/20170413142932.27287-1-andrew.smirnov@gmail.com
Signed-off-by: Andrey Vostrikov <andrey.vostrikov@cogentembedded.com>
Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Tested-by: Chris Healy <cphealy@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

The arch uses a verbatim copy of the asm-generic version and does not add
any own implementations to the header, so use asm-generic/fb.h instead of
duplicating code.

Link: http://lkml.kernel.org/r/20170517083545.2115-1-tklauser@distanz.ch
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Early in boot Linux patches memset and memcpy to branch to platform
optimized versions of these routines.  The NG4 (Niagra 4) versions are
currently used on all platforms starting from T4.  Recently, there were M7
optimized routines added into UEK4 but not into mainline yet.  So, even
with M7 optimized routines NG4 are still going to be used on T4, T5, M5,
and M6 processors.

While investigating how to improve initialization time of dentry_hashtable
which is 8G long on M6 ldom with 7T of main memory, I noticed that
memset() does not reset all the memory in this array, after studying the
code, I realized that NG4memset() branches use %icc register instead of
%xcc to check compare, so if value of length is over 32-bit long, which is
true for 8G array, these routines fail to work properly.

The fix is to replace all %icc with %xcc in these routines.  (Alternative
is to use %ncc, but this is misleading, as the code already has sparcv9
only instructions, and cannot be compiled on 32-bit).

This is important to fix this bug, because even older T4-4 can have 2T of
memory, and there are large memory proportional data structures in kernel
which can be larger than 4G in size.  The failing of memset() is silent
and corruption is hard to detect.

Link: http://lkml.kernel.org/r/1488432825-92126-2-git-send-email-pasha.tatashin@oracle.com
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Cc: David Miller <davem@davemloft.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

xt_alloc_table_info() basically opencodes kvmalloc() so use the library
function instead.

Link: http://lkml.kernel.org/r/20170531155145.17111-4-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

…functions"

This reverts commit 088a5ec.