cpuidle: rearrange __cpuidle_register_device() to keep minimal exit points

This patch rearranges __cpuidle_register_device() a bit in order to
reduce the number of exit points in that function.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: merge two if() statements for checking error cases

Two checks cpuidle_idle_call() cause the same error code to be
returned if they fail, so merge them for clarity.

[rjw: Changelog]
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: reduce code duplication inside cpuidle_idle_call()

We are doing this twice in cpuidle_idle_call() routine:
	drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP

Would be better if we actually store this in a local variable and
use that. That reduces code duplication and likely makes this piece
of code run faster (in case the compiler wasn't able to optimize it
earlier)

[rjw: Cast the result of bitwise AND to bool explicitly using !!]
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: replace multiline statements with single line in cpuidle_idle_call()

Few statements in cpuidle_idle_call() are broken into multiple lines,
although that isn't really necessary. Convert those to single line.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: call cpuidle_get_driver() from after taking cpuidle_driver_lock

There are a few cpuidle_get_driver() calls that aren't made under
cpuidle_driver_lock which is incorrect.

Fix them by calling cpuidle_get_driver() after taking cpuidle_driver_lock.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: use drv instead of cpuidle_driver in show_current_driver()

Instances of "struct cpuidle_driver *" are consistently named as "drv"
in the cpuidle core except in show_current_driver().

Make that function use variable naming consistent with the rest of the
code.

[rjw: Changelog]
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: don't call poll_idle_init() for every cpu

poll_idle_init() just initializes drv->states[0] and so that is
required to be done only once for each driver.  Currently, it is
called from cpuidle_enable_device() which is called for every CPU
that the driver supports.  That is not required, so move it to a
better place and call it from __cpuidle_register_driver() so that
the initialization is carried out only once.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
cpuidle: remove cpuidle_unregister_governor()

cpuidle_unregister_governor() and cpuidle_replace_governor() aren't
used anymore and can be removed. They were used by cpufreq governors
earlier, but since the governors can't be compiled as modules any
more, these two functions aren't necessary.

Suggested-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
intel_idle: use CPU_TASKS_FROZEN instead of a numeric constant

Small fixup to use CPU_TASKS_FROZEN instead of 0xf.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'for-rafael' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq into pm-devfreq

Pull devfreq fixes from MyungJoo Ham.

* 'for-rafael' of git://git.kernel.org/pub/scm/linux/kernel/git/mzx/devfreq:
  PM / devfreq: create_freezable_workqueue() doesn't return an ERR_PTR
  PM / devfreq: Remove duplicate header file inclusion in exynos5_bus.c
  PM / devfreq: Use devm_* APIs in exynos5_bus.c
  PM / devfreq: Remove redundant platform_set_drvdata() in exynos5_bus.c
  PM / devfreq: Fix incorrect usage of IS_ERR_OR_NULL in exynos5_bus.c
Merge back earlier devfreq material for v3.13.
net: ipvs: sctp: do not recalc sctp csum when ports didn't change

Unlike UDP or TCP, we do not take the pseudo-header into
account in SCTP checksums. So in case port mapping is the
very same, we do not need to recalculate the whole SCTP
checksum in software, which is very expensive.

Also, similarly as in TCP, take into account when a private
helper mangled the packet. In that case, we also need to
recalculate the checksum even if ports might be same.

Thanks for feedback regarding skb->ip_summed checks from
Julian Anastasov; here's a discussion on these checks for
snat and dnat:

* For snat_handler(), we can see CHECKSUM_PARTIAL from
  virtual devices, and from LOCAL_OUT, otherwise it
  should be CHECKSUM_UNNECESSARY. In general, in snat it
  is more complex. skb contains the original route and
  ip_vs_route_me_harder() can change the route after
  snat_handler. So, for locally generated replies from
  local server we can not preserve the CHECKSUM_PARTIAL
  mode. It is an chicken or egg dilemma: snat_handler
  needs the device after rerouting (to check for
  NETIF_F_SCTP_CSUM), while ip_route_me_harder() wants
  the snat_handler() to put the new saddr for proper
  rerouting.

* For dnat_handler(), we should not see CHECKSUM_COMPLETE
  for SCTP, in fact the small set of drivers that support
  SCTP offloading return CHECKSUM_UNNECESSARY on correctly
  received SCTP csum. We can see CHECKSUM_PARTIAL from
  local stack or received from virtual drivers. The idea is
  that SCTP decides to avoid csum calculation if hardware
  supports offloading. IPVS can change the device after
  rerouting to real server but we can preserve the
  CHECKSUM_PARTIAL mode if the new device supports
  offloading too. This works because skb dst is changed
  before dnat_handler and we see the new device. So, checks
  in the 'if' part will decide whether it is ok to keep
  CHECKSUM_PARTIAL for the output. If the packet was with
  CHECKSUM_NONE, hence we deal with unknown checksum. As we
  recalculate the sum for IP header in all cases, it should
  be safe to use CHECKSUM_UNNECESSARY. We can forward wrong
  checksum in this case (without cp->app). In case of
  CHECKSUM_UNNECESSARY, the csum was valid on receive.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
tcp: temporarily disable Fast Open on SYN timeout

Fast Open currently has a fall back feature to address SYN-data being
dropped but it requires the middle-box to pass on regular SYN retry
after SYN-data. This is implemented in commit aab487435 ("net-tcp:
Fast Open client - detecting SYN-data drops")

However some NAT boxes will drop all subsequent packets after first
SYN-data and blackholes the entire connections.  An example is in
commit 356d7d8 "netfilter: nf_conntrack: fix tcp_in_window for Fast
Open".

The sender should note such incidents and fall back to use the regular
TCP handshake on subsequent attempts temporarily as well: after the
second SYN timeouts the original Fast Open SYN is most likely lost.
When such an event recurs Fast Open is disabled based on the number of
recurrences exponentially.

Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
octeon_mgmt: drop redundant mac address check

Checking if MAC address is valid using is_valid_ether_addr() is already done in
of_get_mac_address().

Signed-off-by: Luka Perkov <luka@openwrt.org>
Acked-by: David Daney <david.daney@cavium.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
mvneta: drop redundant mac address check

Checking if MAC address is valid using is_valid_ether_addr() is already done in
of_get_mac_address().

Signed-off-by: Luka Perkov <luka@openwrt.org>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
arc_emac: drop redundant mac address check

Checking if MAC address is valid using is_valid_ether_addr() is already done in
of_get_mac_address(). While at it, reorganize checking so it matches checks in
other drivers.

Signed-off-by: Luka Perkov <luka@openwrt.org>
CC: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
CC: David Miller <davem@davemloft.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
f2fs: change the method of calculating the number summary blocks

npages_for_summary_flush uses (SUMMARY_SIZE + 1) as the size of a f2fs_summary
while its actual size is  SUMMARY_SIZE. So the result sometimes is bigger than
actual number by one, which causes checkpoint can't be written into disk
contiguously, and sometimes summary blocks can't be compacted like they should.
Besides, when writing summary blocks into pages, if remain space in a page
isn't big enough for one f2fs_summary, it will be left unused, current code
seems not to take it into account.

Signed-off-by: Fan Li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
f2fs: check all ones or zeros bitmap with bitops for better mount performance

Previously, check_block_count check valid_map with bit data type in common
scenario that sit has all ones or zeros bitmap, it makes low mount performance.
So let's check the special bitmap with integer data type instead of the bit one.

v1-->v2:
 o use find_next_{zero_}bit_le for better performance and readable as Jaegeuk
   suggested.
 o use neat logogram in comment as Gu Zheng suggested.
 o search continuous ones or zeros for better performance when checking mixed
   bitmap.

Suggested-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Signed-off-by: Shu Tan <shu.tan@samsung.com>
Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
simplefb: fix unmapping fb during destruction

Unfortunately, fbdev does not create its own "struct device" for
framebuffers. Instead, it attaches to the device of the parent layer. This
has the side-effect that devm_* managed resources are not cleaned up on
framebuffer-destruction but rather during destruction of the
parent-device. In case of fbdev this might be too late, though.
remove_conflicting_framebuffer() may remove fbdev devices but keep the
parent device as it is.

Therefore, we now use plain ioremap() and unmap the framebuffer in the
fb_destroy() callback. Note that we must not free the device here as this
might race with the parent-device removal. Instead, we rely on
unregister_framebuffer() as barrier and we're safe.

Reported-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
simplefb: use write-combined remapping

Framebuffers shouldn't be cached and it is usually very uncommon to read
them. Therefore, use ioremap_wc() to get significant speed improvements on
systems which provide it. On all other systems it's aliased to
ioremap_nocache() which is also fine.

Reported-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Tested-by: Tom Gundersen <teg@jklm.no>
Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>