linux-toradex.git/arch/cris/include/asm, branch v4.8-rc2

tree wide: get rid of __GFP_REPEAT for order-0 allocations part I

2016-06-25T00:23:52+00:00

This is the third version of the patchset previously sent [1].  I have
basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get
rid of superfluous gfp flags" which went through dm tree.  I am sending
it now because it is tree wide and chances for conflicts are reduced
considerably when we want to target rc2.  I plan to send the next step
and rename the flag and move to a better semantic later during this
release cycle so we will have a new semantic ready for 4.8 merge window
hopefully.

Motivation:

While working on something unrelated I've checked the current usage of
__GFP_REPEAT in the tree.  It seems that a majority of the usage is and
always has been bogus because __GFP_REPEAT has always been about costly
high order allocations while we are using it for order-0 or very small
orders very often.  It seems that a big pile of them is just a
copy&paste when a code has been adopted from one arch to another.

I think it makes some sense to get rid of them because they are just
making the semantic more unclear.  Please note that GFP_REPEAT is
documented as

* __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt

* _might_ fail.  This depends upon the particular VM implementation.
  while !costly requests have basically nofail semantic.  So one could
  reasonably expect that order-0 request with __GFP_REPEAT will not loop
  for ever.  This is not implemented right now though.

I would like to move on with __GFP_REPEAT and define a better semantic
for it.

  $ git grep __GFP_REPEAT origin/master | wc -l
  111
  $ git grep __GFP_REPEAT | wc -l
  36

So we are down to the third after this patch series.  The remaining
places really seem to be relying on __GFP_REPEAT due to large allocation
requests.  This still needs some double checking which I will do later
after all the simple ones are sorted out.

I am touching a lot of arch specific code here and I hope I got it right
but as a matter of fact I even didn't compile test for some archs as I
do not have cross compiler for them.  Patches should be quite trivial to
review for stupid compile mistakes though.  The tricky parts are usually
hidden by macro definitions and thats where I would appreciate help from
arch maintainers.

[1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org

This patch (of 19):

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.  Yet we
have the full kernel tree with its usage for apparently order-0
allocations.  This is really confusing because __GFP_REPEAT is
explicitly documented to allow allocation failures which is a weaker
semantic than the current order-0 has (basically nofail).

Let's simply drop __GFP_REPEAT from those places.  This would allow to
identify place which really need allocator to retry harder and formulate
a more specific semantic for what the flag is supposed to do actually.

Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Cc: "David S. Miller" 
Cc: "H. Peter Anvin" 
Cc: "James E.J. Bottomley" 
Cc: "Theodore Ts'o" 
Cc: Andy Lutomirski 
Cc: Benjamin Herrenschmidt 
Cc: Catalin Marinas 
Cc: Chen Liqin 
Cc: Chris Metcalf  [for tile]
Cc: Guan Xuetao 
Cc: Heiko Carstens 
Cc: Helge Deller 
Cc: Ingo Molnar 
Cc: Jan Kara 
Cc: John Crispin 
Cc: Lennox Wu 
Cc: Ley Foon Tan 
Cc: Martin Schwidefsky 
Cc: Matt Fleming 
Cc: Ralf Baechle 
Cc: Rich Felker 
Cc: Russell King 
Cc: Thomas Gleixner 
Cc: Vineet Gupta 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2016-03-19T17:05:34+00:00

Pull networking updates from David Miller:
 "Highlights:

   1) Support more Realtek wireless chips, from Jes Sorenson.

   2) New BPF types for per-cpu hash and arrap maps, from Alexei
      Starovoitov.

   3) Make several TCP sysctls per-namespace, from Nikolay Borisov.

   4) Allow the use of SO_REUSEPORT in order to do per-thread processing
   of incoming TCP/UDP connections.  The muxing can be done using a
   BPF program which hashes the incoming packet.  From Craig Gallek.

   5) Add a multiplexer for TCP streams, to provide a messaged based
      interface.  BPF programs can be used to determine the message
      boundaries.  From Tom Herbert.

   6) Add 802.1AE MACSEC support, from Sabrina Dubroca.

   7) Avoid factorial complexity when taking down an inetdev interface
      with lots of configured addresses.  We were doing things like
      traversing the entire address less for each address removed, and
      flushing the entire netfilter conntrack table for every address as
      well.

   8) Add and use SKB bulk free infrastructure, from Jesper Brouer.

   9) Allow offloading u32 classifiers to hardware, and implement for
      ixgbe, from John Fastabend.

  10) Allow configuring IRQ coalescing parameters on a per-queue basis,
      from Kan Liang.

  11) Extend ethtool so that larger link mode masks can be supported.
      From David Decotigny.

  12) Introduce devlink, which can be used to configure port link types
      (ethernet vs Infiniband, etc.), port splitting, and switch device
      level attributes as a whole.  From Jiri Pirko.

  13) Hardware offload support for flower classifiers, from Amir Vadai.

  14) Add "Local Checksum Offload".  Basically, for a tunneled packet
      the checksum of the outer header is 'constant' (because with the
      checksum field filled into the inner protocol header, the payload
      of the outer frame checksums to 'zero'), and we can take advantage
      of that in various ways.  From Edward Cree"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1548 commits)
  bonding: fix bond_get_stats()
  net: bcmgenet: fix dma api length mismatch
  net/mlx4_core: Fix backward compatibility on VFs
  phy: mdio-thunder: Fix some Kconfig typos
  lan78xx: add ndo_get_stats64
  lan78xx: handle statistics counter rollover
  RDS: TCP: Remove unused constant
  RDS: TCP: Add sysctl tunables for sndbuf/rcvbuf on rds-tcp socket
  net: smc911x: convert pxa dma to dmaengine
  team: remove duplicate set of flag IFF_MULTICAST
  bonding: remove duplicate set of flag IFF_MULTICAST
  net: fix a comment typo
  ethernet: micrel: fix some error codes
  ip_tunnels, bpf: define IP_TUNNEL_OPTS_MAX and use it
  bpf, dst: add and use dst_tclassid helper
  bpf: make skb->tc_classid also readable
  net: mvneta: bm: clarify dependencies
  cls_bpf: reset class and reuse major in da
  ldmvsw: Checkpatch sunvnet.c and sunvnet_common.c
  ldmvsw: Add ldmvsw.c driver code
  ...

ipv4: Update parameters for csum_tcpudp_magic to their original types

2016-03-14T03:55:13+00:00

This patch updates all instances of csum_tcpudp_magic and
csum_tcpudp_nofold to reflect the types that are usually used as the source
inputs.  For example the protocol field is populated based on nexthdr which
is actually an unsigned 8 bit value.  The length is usually populated based
on skb->len which is an unsigned integer.

This addresses an issue in which the IPv6 function csum_ipv6_magic was
generating a checksum using the full 32b of skb->len while
csum_tcpudp_magic was only using the lower 16 bits.  As a result we could
run into issues when attempting to adjust the checksum as there was no
protocol agnostic way to update it.

With this change the value is still truncated as many architectures use
"(len + proto) << 8", however this truncation only occurs for values
greater than 16776960 in length and as such is unlikely to occur as we stop
the inner headers at ~64K in size.

I did have to make a few minor changes in the arm, mn10300, nios2, and
score versions of the function in order to support these changes as they
were either using things such as an OR to combine the protocol and length,
or were using ntohs to convert the length which would have truncated the
value.

I also updated a few spots in terms of whitespace and type differences for
the addresses.  Most of this was just to make sure all of the definitions
were in sync going forward.

Signed-off-by: Alexander Duyck 
Signed-off-by: David S. Miller

PCI: Move pci_dma_* helpers to common code

2016-03-07T16:40:02+00:00

For a long time all architectures implement the pci_dma_* functions using
the generic DMA API, and they all use the same header to do so.

Move this header, pci-dma-compat.h, to include/linux and include it from
the generic pci.h instead of having each arch duplicate this include.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Bjorn Helgaas

dma-mapping: always provide the dma_map_ops based implementation

2016-01-21T01:09:18+00:00

Move the generic implementation to  now that all
architectures support it and remove the HAVE_DMA_ATTR Kconfig symbol now
that everyone supports them.

[valentinrothberg@gmail.com: remove leftovers in Kconfig]
Signed-off-by: Christoph Hellwig 
Cc: "David S. Miller" 
Cc: Aurelien Jacquiot 
Cc: Chris Metcalf 
Cc: David Howells 
Cc: Geert Uytterhoeven 
Cc: Haavard Skinnemoen 
Cc: Hans-Christian Egtvedt 
Cc: Helge Deller 
Cc: James Hogan 
Cc: Jesper Nilsson 
Cc: Koichi Yasutake 
Cc: Ley Foon Tan 
Cc: Mark Salter 
Cc: Mikael Starvik 
Cc: Steven Miao 
Cc: Vineet Gupta 
Cc: Christian Borntraeger 
Cc: Joerg Roedel 
Cc: Sebastian Ott 
Signed-off-by: Valentin Rothberg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

cris: convert to dma_map_ops

2016-01-21T01:09:18+00:00

Signed-off-by: Christoph Hellwig 
Cc: Mikael Starvik 
Cc: Jesper Nilsson 
Cc: Christian Borntraeger 
Cc: Joerg Roedel 
Cc: Sebastian Ott 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

CRIS: Drop code related to obsolete or unused kconfigs

2015-11-02T19:03:05+00:00

Drop all code related to Kconfigs that don't exist.
Fix one Kconfig where it was actually typo:ed (ETRAX_KGB_PORT2)
Drop content related to CRIS v32 SoCs from etraxgpio.h headerfile,
all use of GPIO for both ETRAX FS and ARTPEC-3 should now be through
standard gpiolib instead.

Signed-off-by: Jesper Nilsson

CRIS v32: remove old GPIO and LEDs code

2015-11-02T19:03:05+00:00

Since we now have a gpiolib driver, remove this code:

The gpio-etraxfs driver (along with things like gpio-keys-polled for
polling support) replaces the GIO driver implementations in mach-a3 and
mach-fs.  The various generic external chip drivers replace the "virtual
gpio" parts.

The generic gpio-leds driver replaces the LED handling.

Signed-off-by: Rabin Vincent 
Signed-off-by: Jesper Nilsson

Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile

2015-10-04T15:31:13+00:00

Pull strscpy string copy function implementation from Chris Metcalf.

Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.

The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.

strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result.  To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.

strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string.  Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated.  It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.

strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG.  It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.

So why did I waffle about this for so long?

Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.

And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.

So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches.  Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.

* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
  tile: use global strscpy() rather than private copy
  string: provide strscpy()
  Make asm/word-at-a-time.h available on all architectures

CRIS: fix switch_mm() lockdep splat

2015-09-04T22:56:50+00:00

With lockdep support implemented on CRISv32, we get the following splat.
switch_mm() can be called both from the scheduler() (with interrupts
disabled) and from flush_old_exec (via activate_mm()), with interrupts
enabled.  Fix it by disabling interrupts in activate_mm(), similar to
powerpc and hexagon.

 t======================================================
 [ INFO: HARDIRQ-safe -> HARDIRQ-unsafe lock order detected ]
 3.19.0-08802-g20bc9f1-dirty #323 Not tainted
 ------------------------------------------------------
 init/1 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire:
  (mmu_context_lock){+.+...}, at: [] switch_mm+0x22/0xc6

 and this task is already holding:
  (&rq->lock){-.-.-.}, at: [] __schedule+0x5e/0x648
 which would create a new lock dependency:
  (&rq->lock){-.-.-.} -> (mmu_context_lock){+.+...}

 but this new dependency connects a HARDIRQ-irq-safe lock:
  (&rq->lock){-.-.-.}
 ... which became HARDIRQ-irq-safe at:
   [] scheduler_tick+0x28/0x5e
   [] timer_interrupt+0x4e/0x6a
   [] handle_irq_event_percpu+0x54/0x13c
   [] generic_handle_irq+0x2a/0x36

 to a HARDIRQ-irq-unsafe lock:
  (mmu_context_lock){+.+...}
 ... which became HARDIRQ-irq-unsafe at:
 ...  [] __lock_acquire+0x8f8/0x1d9c
   [] switch_mm+0x22/0xc6
   [] flush_old_exec+0x500/0x5d4
   [] load_elf_phdrs+0x7a/0x84
   [] load_elf_binary+0x21c/0x13b4
   [] do_execve+0x22/0x2c
   [] ____call_usermodehelper+0x0/0x154
   [] ret_from_kernel_thread+0xe/0x14

 other info that might help us debug this:

  Possible interrupt unsafe locking scenario:

        CPU0                    CPU1
        ----                    ----
   lock(mmu_context_lock);
                                local_irq_disable();
                                lock(&rq->lock);
                                lock(mmu_context_lock);
   
     lock(&rq->lock);

  *** DEADLOCK ***

 1 lock held by init/1:
  #0:  (&rq->lock){-.-.-.}, at: [] __schedule+0x5e/0x648

 Call Trace:
 [] printk+0x0/0x4e
 [] print_shortest_lock_dependencies+0x0/0x15c
 [] print_stack_trace+0x0/0x88
 [] __lock_is_held+0x3e/0x5e
 [] lock_acquire+0x8a/0xcc
 [] _raw_spin_lock+0x44/0x7a
 [] switch_mm+0x22/0xc6
 [] __schedule+0x0/0x648
 [] schedule+0x36/0x7c
 [] trace_hardirqs_on+0x0/0x1e
 [] do_work_pending+0x30/0xd4
 [] _work_pending+0xe/0x12

Signed-off-by: Rabin Vincent 
Signed-off-by: Jesper Nilsson