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601696 Commits
Author SHA1 Message Date
Luis R. Rodriguez dd951fc1b6 scripts: add Linux .cocciconfig for coccinelle
Coccinelle supports reading .cocciconfig, the order of precedence for
variables for .cocciconfig is as follows:

 o Your current user's home directory is processed first
 o Your directory from which spatch is called is processed next
 o The directory provided with the --dir option is processed last, if used

Since coccicheck runs through make, it naturally runs from the kernel
proper dir, as such the second rule above would be implied for picking up a
.cocciconfig when using 'make coccicheck'.

'make coccicheck' also supports using M= targets.If you do not supply
any M= target, it is assumed you want to target the entire kernel.
The kernel coccicheck script has:

    if [ "$KBUILD_EXTMOD" = "" ] ; then
        OPTIONS="--dir $srctree $COCCIINCLUDE"
    else
        OPTIONS="--dir $KBUILD_EXTMOD $COCCIINCLUDE"
    fi

KBUILD_EXTMOD is set when an explicit target with M= is used. For both cases
the spatch --dir argument is used, as such third rule applies when
whether M= is used or not, and when M= is used the target directory can
have its own .cocciconfig file. When M= is not passed as an argument to
coccicheck the target directory is the same as the directory from where
spatch was called.

If not using the kernel's coccicheck target, keep the above precedence order
logic of .cocciconfig reading. If using the kernel's coccicheck target,
override any of the kernel's .coccicheck's settings using SPFLAGS.

We help Coccinelle when used against Linux with a set of sensible defaults
options for Linux with our own Linux .cocciconfig. This hints to coccinelle
git can be used for 'git grep' queries over coccigrep. A timeout of 200
seconds should suffice for now.

The options picked up by coccinelle when reading a .cocciconfig do not appear
as arguments to spatch processes running on your system, to confirm what
options will be used by Coccinelle run:

  spatch --print-options-only

You can override with your own preferred index option by using SPFLAGS.
Coccinelle supports both glimpse and idutils. Glimpse had historically
provided the best performance, however recent benchmarks reveal idutils
is performing just as well. Due to some recent fixes however you however
will need at least coccinelle >= 1.0.6 if using idutils.

Coccinelle carries a script scripts/idutils_index.sh which creates the
idutils database with as follows:

    mkid -i C --output .id-utils.index

If using just "--use-idutils" coccinelle expects your idutils database to be
on the top level of the kernel as a file named ".id-utils.index". If you do
not use this you can symlink your database file to it, or you can specify the
database file following the "--use-idutils" argument. Examples:

    make SPFLAGS=--use-idutils coccicheck

This assumes you have $srctree/.id-utils.index, where $srctree is
the top level of the kernel.

    make SPFLAGS="--use-idutils /full-path/to/ID" coccicheck

Here you specify the full path of the idutils ID database. Using
.cocciconfig is possible, however given the order of precedence followed
by Coccinelle, and since the kernel now carries its own .cocciconfig,
you will need to use SPFLAGS to use idutils if desired.

v4:

o Recommend upgrade for using idutils with coccinelle due to some
  recent fixes.

o Refer to using --print-options-only for testing what options are
  picked up by .cocciconfig reading.

o Expand commit log considerably explaining *why* .cocconfig from
  two precedence rules are used when using coccicheck, and how to
  properly override these if needed.

o Expand Documentation/coccinelle.txt

v3: Expand commit log a bit more

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Luis R. Rodriguez 5c384dba97 coccicheck: replace --very-quiet with --quiet when debugging
When debugging (using --profile or --show-trying) you want to
avoid supressing output,  use --quiet instead. While at it, extend
documentation for SPFLAGS use.

For instance one can use:

$ export COCCI=scripts/coccinelle/misc/irqf_oneshot.cocci
$ make coccicheck DEBUG_FILE="poo.err" MODE=report SPFLAGS="--profile --show-trying" M=./drivers/mfd/arizona-irq.c

Expand Documentation/coccinelle.txt as well.

v4: expand Documentation/coccinelle.txt
v3: rebased, resolve conflicts, expand Documentation/coccinelle.txt
v2: use egrep instead of the *"=--option"* check, this doesn't work for
    disjunctions.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Luis R. Rodriguez be1fa90066 coccicheck: add support for DEBUG_FILE
Enable to capture stderr via a DEBUG_FILE variable passed to
coccicheck. You can now do:

$ rm -f cocci.err
$ export COCCI=scripts/coccinelle/free/kfree.cocci
$ make coccicheck MODE=report DEBUG_FILE=cocci.err
...
$ cat cocci.err

This will be come more useful once we add support to
use more things which would go into stderr, such as
profiling. That will be done separately in another
commit.

Expand Documentation/coccinelle.txt with details.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Luis R. Rodriguez c930a1b23b coccicheck: enable parmap support
Coccinelle has had parmap support since 1.0.2, this means
it supports --jobs, enabling built-in multithreaded functionality,
instead of needing one to script it out. Just look for --jobs
in the help output to determine if this is supported and use it
only if your number of processors detected is > 1.

If parmap is enabled also enable the load balancing to be dynamic, so
that if a thread finishes early we keep feeding it.

stderr is currently sent to /dev/null, addressing a way to capture
that will be addressed next.

If --jobs is not supported we fallback to the old mechanism.
We expect to deprecate the old mechanism as soon as we can get
confirmation all users are ready.

While at it propagate back into the shell script any coccinelle error
code. When used in serialized mode where all cocci files are run this
also stops processing if an error has occured. This lets us handle some
errors in coccinelle cocci files and if they bail out we should inspect
the errors. This will be more useful later to help annotate coccinelle
version dependency requirements. This will let you run only SmPL files
that your system supports.

Extend Documentation/coccinelle.txt as well.

As a small example, prior to this change, on an 8-core system:

Before:

$ export COCCI=scripts/coccinelle/free/kfree.cocci
$ time make coccicheck MODE=report
...

real    29m14.912s
user    103m1.796s
sys     0m4.464s

After:

real    16m22.435s
user    128m30.060s
sys     0m2.712s

v4:

o expand Documentation/coccinelle.txt to reflect parmap support info
o update commit log to reflect what we actually do now with stderr
o split out DEBUG_FILE use into another patch
o detect number of CPUs and if its 1 then skip parmap support,
  note that if you still support parmap, but have 1 CPU you will
  also go through the new branches, so the old complex multithreaded process
  is skipped as well.

v3:

o move USE_JOBS to avoid being overriden

v2:

o redirect coccinelle stderr to /dev/null by default and
  only if DEBUG_FILE is used do we pass it to a file
o fix typo of paramap/parmap

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Luis R. Rodriguez 8e826ad52b coccicheck: make SPFLAGS more useful
SPFLAGS is set early, it means that any heuristics done on
coccicheck cannot be overridden currently. Move SPFLAGS
after OPTIONS and set this at the end. This lets you override
any heuristics as coccinelle treats conflicts by only listening
to the last option that makes sense.

v3: this patch was added in the v3 series
v4: Update Documentation/coccinelle.txt explaining how
    SPFLAGS works as well.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Luis R. Rodriguez 13d9486533 coccicheck: move spatch binary check up
This has no functional changes. This is being done
to enable us to later use spatch binary for some
flag checking for certain features early on.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-22 12:13:39 +02:00
Wilfried Klaebe 15f6d33715 builddeb: really include objtool binary in headers package
On May 4th, Bjørn Mork provided patch 697bbc7b83 ("builddeb: include
objtool binary in headers package"). However, that one only works if
$srctree=$objtree, because the objtool binaries are not written to the
srctree, but to the objtree.

Signed-off-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de>
Fixes: 697bbc7b83 ("builddeb: include objtool binary in headers package")
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-07-19 11:19:27 +02:00
Yann Droneaud b7b2ee41f3 coccinelle: catch krealloc() on devm_*() allocated memory
krealloc() must not be used against devm_*() allocated
memory regions:

- if a bigger memory is to be allocated, krealloc() and
  __krealloc() could return a different pointer than the
  one given to them, creating a memory region which is not
  managed, thus it will not be automatically released on
  device removal.

- if a bigger memory is to be allocated, krealloc() could
  kfree() the managed memory region which is passed to it.
  The old pointer is left registered as a resource for the
  device. On device removal, this dangling pointer will be
  used and an unrelated memory region could be released.

- if the requested size is equal to 0, krealloc() can also
  just behave like kfree(). Here too, the old pointer is
  kept associated with the device. On device removal, this
  invalid pointer will be used and an unrelated memory
  region could be released.

For all these reasons, krealloc() must not be used on a
pointer returned by devm_*() functions.

Cc: Tejun Heo <tj@kernel.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-21 11:43:32 +02:00
Yann Droneaud a720c0644d coccinelle: recognize more devm_* memory allocation functions
Updates free/devm_free.cocci to recognize functions added by:

- commit 64c862a839 ('devres: add kernel standard devm_k.alloc functions')
- commit e31108cad3 ('devres: introduce API "devm_kstrdup"')
- commit 3046365bb4 ('devres: introduce API "devm_kmemdup')
- commit 43339bed70 ('devres: Add devm_get_free_pages API')
- commit 75f2a4ead5 ('devres: Add devm_kasprintf and devm_kvasprintf API')

See also Documentation/driver-model/devres.txt

Cc: Joe Perches <joe@perches.com>
Cc: Manish Badarkhe <badarkhe.manish@gmail.com>
Cc: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Cc: Eli Billauer <eli.billauer@gmail.com>
Cc: Himangi Saraogi <himangi774@gmail.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Wolfram Sang <w.sang@pengutronix.de>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-21 11:43:32 +02:00
Yann Droneaud 6dd9379e8f coccinelle: also catch kzfree() issues
Since commit 3ef0e5ba46 ('slab: introduce kzfree()'),
kfree() is no more the only function to be considered:
kzfree() should be recognized too.

In particular, kzfree() must not be called on memory
allocated through devm_*() functions.

Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Yann Droneaud <ydroneaud@opteya.com>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-21 11:43:32 +02:00
Deepa Dinamani 7a2358b381 coccicheck: Allow for overriding spatch flags
Documentation/coccinelle.txt suggests using the SPFLAGS
make variable to pass additional options to spatch.

Reorder the way SPFLAGS is added to FLAGS, to allow
for options in the SPFLAGS to override the default
--very-quiet option.

Similarly, rearrage the FLAGS for org or report mode.
This allows for overriding of the default --no-show-diff
option through SPFLAGS.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Gilles Muller <Gilles.Muller@lip6.fr>
Acked-by: Nicolas Palix <nicolas.palix@imag.fr>
Acked-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-20 22:08:13 +02:00
Vaishali Thakkar bf56cc04ef Coccinelle: noderef: Add new rules and correct the old rule
Add new rules to detect the cases where sizeof is used in
function calls as a argument.

Also, for the patch mode third rule should behave same as
second rule with arguments reversed. So, change that as well.

Signed-off-by: Vaishali Thakkar <vaishali.thakkar@oracle.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-06-20 17:20:13 +02:00
Linus Torvalds 1a695a905c Linux 4.7-rc1 2016-05-29 09:29:24 -07:00
George Spelvin e0ab7af9bd hash_string: Fix zero-length case for !DCACHE_WORD_ACCESS
The self-test was updated to cover zero-length strings; the function
needs to be updated, too.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Fixes: fcfd2fbf22 ("fs/namei.c: Add hashlen_string() function")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-29 07:33:47 -07:00
George Spelvin f2a031b66e Rename other copy of hash_string to hashlen_string
The original name was simply hash_string(), but that conflicted with a
function with that name in drivers/base/power/trace.c, and I decided
that calling it "hashlen_" was better anyway.

But you have to do it in two places.

[ This caused build errors for architectures that don't define
  CONFIG_DCACHE_WORD_ACCESS   - Linus ]

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Fixes: fcfd2fbf22 ("fs/namei.c: Add hashlen_string() function")
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 22:34:33 -07:00
Mikulas Patocka 037369b872 hpfs: implement the show_options method
The HPFS filesystem used generic_show_options to produce string that is
displayed in /proc/mounts.  However, there is a problem that the options
may disappear after remount.  If we mount the filesystem with option1
and then remount it with option2, /proc/mounts should show both option1
and option2, however it only shows option2 because the whole option
string is replaced with replace_mount_options in hpfs_remount_fs.

To fix this bug, implement the hpfs_show_options function that prints
options that are currently selected.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:50:24 -07:00
Mikulas Patocka 01d6e08711 affs: fix remount failure when there are no options changed
Commit c8f33d0bec ("affs: kstrdup() memory handling") checks if the
kstrdup function returns NULL due to out-of-memory condition.

However, if we are remounting a filesystem with no change to
filesystem-specific options, the parameter data is NULL.  In this case,
kstrdup returns NULL (because it was passed NULL parameter), although no
out of memory condition exists.  The mount syscall then fails with
ENOMEM.

This patch fixes the bug.  We fail with ENOMEM only if data is non-NULL.

The patch also changes the call to replace_mount_options - if we didn't
pass any filesystem-specific options, we don't call
replace_mount_options (thus we don't erase existing reported options).

Fixes: c8f33d0bec ("affs: kstrdup() memory handling")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org	# v4.1+
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:50:24 -07:00
Mikulas Patocka 44d51706b4 hpfs: fix remount failure when there are no options changed
Commit ce657611ba ("hpfs: kstrdup() out of memory handling") checks if
the kstrdup function returns NULL due to out-of-memory condition.

However, if we are remounting a filesystem with no change to
filesystem-specific options, the parameter data is NULL.  In this case,
kstrdup returns NULL (because it was passed NULL parameter), although no
out of memory condition exists.  The mount syscall then fails with
ENOMEM.

This patch fixes the bug.  We fail with ENOMEM only if data is non-NULL.

The patch also changes the call to replace_mount_options - if we didn't
pass any filesystem-specific options, we don't call
replace_mount_options (thus we don't erase existing reported options).

Fixes: ce657611ba ("hpfs: kstrdup() out of memory handling")
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:50:24 -07:00
Linus Torvalds 4029632c34 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull more MIPS updates from Ralf Baechle:
 "This is the secondnd batch of MIPS patches for 4.7. Summary:

  CPS:
   - Copy EVA configuration when starting secondary VPs.

  EIC:
   - Clear Status IPL.

  Lasat:
   - Fix a few off by one bugs.

  lib:
   - Mark intrinsics notrace.  Not only are the intrinsics
     uninteresting, it would cause infinite recursion.

  MAINTAINERS:
   - Add file patterns for MIPS BRCM device tree bindings.
   - Add file patterns for mips device tree bindings.

  MT7628:
   - Fix MT7628 pinmux typos.
   - wled_an pinmux gpio.
   - EPHY LEDs pinmux support.

  Pistachio:
   - Enable KASLR

  VDSO:
   - Build microMIPS VDSO for microMIPS kernels.
   - Fix aliasing warning by building with `-fno-strict-aliasing' for
     debugging but also tracing them might result in recursion.

  Misc:
   - Add missing FROZEN hotplug notifier transitions.
   - Fix clk binding example for varioius PIC32 devices.
   - Fix cpu interrupt controller node-names in the DT files.
   - Fix XPA CPU feature separation.
   - Fix write_gc0_* macros when writing zero.
   - Add inline asm encoding helpers.
   - Add missing VZ accessor microMIPS encodings.
   - Fix little endian microMIPS MSA encodings.
   - Add 64-bit HTW fields and fix its configuration.
   - Fix sigreturn via VDSO on microMIPS kernel.
   - Lots of typo fixes.
   - Add definitions of SegCtl registers and use them"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (49 commits)
  MIPS: Add missing FROZEN hotplug notifier transitions
  MIPS: Build microMIPS VDSO for microMIPS kernels
  MIPS: Fix sigreturn via VDSO on microMIPS kernel
  MIPS: devicetree: fix cpu interrupt controller node-names
  MIPS: VDSO: Build with `-fno-strict-aliasing'
  MIPS: Pistachio: Enable KASLR
  MIPS: lib: Mark intrinsics notrace
  MIPS: Fix 64-bit HTW configuration
  MIPS: Add 64-bit HTW fields
  MAINTAINERS: Add file patterns for mips device tree bindings
  MAINTAINERS: Add file patterns for mips brcm device tree bindings
  MIPS: Simplify DSP instruction encoding macros
  MIPS: Add missing tlbinvf/XPA microMIPS encodings
  MIPS: Fix little endian microMIPS MSA encodings
  MIPS: Add missing VZ accessor microMIPS encodings
  MIPS: Add inline asm encoding helpers
  MIPS: Spelling fix lets -> let's
  MIPS: VR41xx: Fix typo
  MIPS: oprofile: Fix typo
  MIPS: math-emu: Fix typo
  ...
2016-05-28 16:41:39 -07:00
Guenter Roeck d66492bce1 fs: fix binfmt_aout.c build error
Various builds (such as i386:allmodconfig) fail with

  fs/binfmt_aout.c:133:2: error: expected identifier or '(' before 'return'
  fs/binfmt_aout.c:134:1: error: expected identifier or '(' before '}' token

[ Oops. My bad, I had stupidly thought that "allmodconfig" covered this
  on x86-64 too, but it obviously doesn't.  Egg on my face.  - Linus ]

Fixes: 5d22fc25d4 ("mm: remove more IS_ERR_VALUE abuses")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28 16:34:59 -07:00
Linus Torvalds 7e0fb73c52 Merge branch 'hash' of git://ftp.sciencehorizons.net/linux
Pull string hash improvements from George Spelvin:
 "This series does several related things:

   - Makes the dcache hash (fs/namei.c) useful for general kernel use.

     (Thanks to Bruce for noticing the zero-length corner case)

   - Converts the string hashes in <linux/sunrpc/svcauth.h> to use the
     above.

   - Avoids 64-bit multiplies in hash_64() on 32-bit platforms.  Two
     32-bit multiplies will do well enough.

   - Rids the world of the bad hash multipliers in hash_32.

     This finishes the job started in commit 689de1d6ca ("Minimal
     fix-up of bad hashing behavior of hash_64()")

     The vast majority of Linux architectures have hardware support for
     32x32-bit multiply and so derive no benefit from "simplified"
     multipliers.

     The few processors that do not (68000, h8/300 and some models of
     Microblaze) have arch-specific implementations added.  Those
     patches are last in the series.

   - Overhauls the dcache hash mixing.

     The patch in commit 0fed3ac866 ("namei: Improve hash mixing if
     CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion.
     Replaced with a much more careful design that's simultaneously
     faster and better.  (My own invention, as there was noting suitable
     in the literature I could find.  Comments welcome!)

   - Modify the hash_name() loop to skip the initial HASH_MIX().  This
     would let us salt the hash if we ever wanted to.

   - Sort out partial_name_hash().

     The hash function is declared as using a long state, even though
     it's truncated to 32 bits at the end and the extra internal state
     contributes nothing to the result.  And some callers do odd things:

      - fs/hfs/string.c only allocates 32 bits of state
      - fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes

   - Modify bytemask_from_count to handle inputs of 1..sizeof(long)
     rather than 0..sizeof(long)-1.  This would simplify users other
     than full_name_hash"

  Special thanks to Bruce Fields for testing and finding bugs in v1.  (I
  learned some humbling lessons about "obviously correct" code.)

  On the arch-specific front, the m68k assembly has been tested in a
  standalone test harness, I've been in contact with the Microblaze
  maintainers who mostly don't care, as the hardware multiplier is never
  omitted in real-world applications, and I haven't heard anything from
  the H8/300 world"

* 'hash' of git://ftp.sciencehorizons.net/linux:
  h8300: Add <asm/hash.h>
  microblaze: Add <asm/hash.h>
  m68k: Add <asm/hash.h>
  <linux/hash.h>: Add support for architecture-specific functions
  fs/namei.c: Improve dcache hash function
  Eliminate bad hash multipliers from hash_32() and  hash_64()
  Change hash_64() return value to 32 bits
  <linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string()
  fs/namei.c: Add hashlen_string() function
  Pull out string hash to <linux/stringhash.h>
2016-05-28 16:15:25 -07:00
George Spelvin 4684fe9530 h8300: Add <asm/hash.h>
This will improve the performance of hash_32() and hash_64(), but due
to complete lack of multi-bit shift instructions on H8, performance will
still be bad in surrounding code.

Designing H8-specific hash algorithms to work around that is a separate
project.  (But if the maintainers would like to get in touch...)

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
2016-05-28 15:48:58 -04:00
George Spelvin 7b13277b68 microblaze: Add <asm/hash.h>
Microblaze is an FPGA soft core that can be configured various ways.

If it is configured without a multiplier, the standard __hash_32()
will require a call to __mulsi3, which is a slow software loop.

Instead, use a shift-and-add sequence for the constant multiply.
GCC knows how to do this, but it's not as clever as some.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Alistair Francis <alistair.francis@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
2016-05-28 15:48:58 -04:00
George Spelvin 14c44b95b3 m68k: Add <asm/hash.h>
This provides a multiply by constant GOLDEN_RATIO_32 = 0x61C88647
for the original mc68000, which lacks a 32x32-bit multiply instruction.

Yes, the amount of optimization effort put in is excessive. :-)

Shift-add chain found by Yevgen Voronenko's Hcub algorithm at
http://spiral.ece.cmu.edu/mcm/gen.html

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Philippe De Muyter <phdm@macq.eu>
Cc: linux-m68k@lists.linux-m68k.org
2016-05-28 15:48:57 -04:00
George Spelvin 468a942852 <linux/hash.h>: Add support for architecture-specific functions
This is just the infrastructure; there are no users yet.

This is modelled on CONFIG_ARCH_RANDOM; a CONFIG_ symbol declares
the existence of <asm/hash.h>.

That file may define its own versions of various functions, and define
HAVE_* symbols (no CONFIG_ prefix!) to suppress the generic ones.

Included is a self-test (in lib/test_hash.c) that verifies the basics.
It is NOT in general required that the arch-specific functions compute
the same thing as the generic, but if a HAVE_* symbol is defined with
the value 1, then equality is tested.

Signed-off-by: George Spelvin <linux@sciencehorizons.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Philippe De Muyter <phdm@macq.eu>
Cc: linux-m68k@lists.linux-m68k.org
Cc: Alistair Francis <alistai@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: uclinux-h8-devel@lists.sourceforge.jp
2016-05-28 15:48:31 -04:00