expose bpf_map_lookup_elem(), bpf_map_update_elem(), bpf_map_delete_elem()
map accessors to eBPF programs
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

the current meaning of BPF_MAP_UPDATE_ELEM syscall command is:
either update existing map element or create a new one.
Initially the plan was to add a new command to handle the case of
'create new element if it didn't exist', but 'flags' style looks
cleaner and overall diff is much smaller (more code reused), so add 'flags'
attribute to BPF_MAP_UPDATE_ELEM command with the following meaning:
 #define BPF_ANY	0 /* create new element or update existing */
 #define BPF_NOEXIST	1 /* create new element if it didn't exist */
 #define BPF_EXIST	2 /* update existing element */

bpf_update_elem(fd, key, value, BPF_NOEXIST) call can fail with EEXIST
if element already exists.

bpf_update_elem(fd, key, value, BPF_EXIST) can fail with ENOENT
if element doesn't exist.

Userspace will call it as:
int bpf_update_elem(int fd, void *key, void *value, __u64 flags)
{
    union bpf_attr attr = {
        .map_fd = fd,
        .key = ptr_to_u64(key),
        .value = ptr_to_u64(value),
        .flags = flags;
    };

    return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}

First two bits of 'flags' are used to encode style of bpf_update_elem() command.
Bits 2-63 are reserved for future use.
Signed-off-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use of well known RSS key increases attack surface.
Switch to a random one, using generic helper so that all
ports share a common key.

Also provide ethtool -x support to fetch RSS key
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Amir Vadai <amirv@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RSS (Receive Side Scaling) typically uses Toeplitz hash and a 40 or 52 bytes
RSS key.

Some drivers use a constant (and well known key), some drivers use a random
key per port, making bonding setups hard to tune. Well known keys increase
attack surface, considering that number of queues is usually a power of two.

This patch provides infrastructure to help drivers doing the right thing.

netdev_rss_key_fill() should be used by drivers to initialize their RSS key,
even if they provide ethtool -X support to let user redefine the key later.

A new /proc/sys/net/core/netdev_rss_key file can be used to get the host
RSS key even for drivers not providing ethtool -x support, in case some
applications want to precisely setup flows to match some RX queues.

Tested:

myhost:~# cat /proc/sys/net/core/netdev_rss_key
11:63:99:bb:79:fb:a5:a7:07:45:b2:20:bf:02:42:2d:08:1a:dd:19:2b:6b:23:ac:56:28:9d:70:c3:ac:e8:16:4b:b7:c1:10:53:a4:78:41:36:40:74:b6:15:ca:27:44:aa:b3:4d:72

myhost:~# ethtool -x eth0
RX flow hash indirection table for eth0 with 8 RX ring(s):
    0:      0     1     2     3     4     5     6     7
RSS hash key:
11:63:99:bb:79:fb:a5:a7:07:45:b2:20:bf:02:42:2d:08:1a:dd:19:2b:6b:23:ac:56:28:9d:70:c3:ac:e8:16:4b:b7:c1:10:53:a4:78:41
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit e5a2c899.

	Commit e5a2c899 introduced an alternative_call, arch_fast_hash2,
that selects between __jhash2 and __intel_crc4_2_hash based on the
X86_FEATURE_XMM4_2.

	Unfortunately, the alternative_call system does not appear to be
suitable for use with C functions, as register usage is not handled
properly for the called functions.  The __jhash2 function in particular
clobbers registers that are not preserved when called via
alternative_call, resulting in a panic for direct callers of
arch_fast_hash2 on older CPUs lacking sse4_2.  It is possible that
__intel_crc4_2_hash works merely by chance because it uses fewer
registers.

	This commit was suggested as the source of the problem by Jesse
Gross <jesse@nicira.com>.
Signed-off-by: NJay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In free_area_init_core(), zone->managed_pages is set to an approximate
value for lowmem, and will be adjusted when the bootmem allocator frees
pages into the buddy system.

But free_area_init_core() is also called by hotadd_new_pgdat() when
hot-adding memory.  As a result, zone->managed_pages of the newly added
node's pgdat is set to an approximate value in the very beginning.

Even if the memory on that node has node been onlined,
/sys/device/system/node/nodeXXX/meminfo has wrong value:

  hot-add node2 (memory not onlined)
  cat /sys/device/system/node/node2/meminfo
  Node 2 MemTotal:       33554432 kB
  Node 2 MemFree:               0 kB
  Node 2 MemUsed:        33554432 kB
  Node 2 Active:                0 kB

This patch fixes this problem by reset node managed pages to 0 after
hot-adding a new node.

1. Move reset_managed_pages_done from reset_node_managed_pages() to
   reset_all_zones_managed_pages()
2. Make reset_node_managed_pages() non-static
3. Call reset_node_managed_pages() in hotadd_new_pgdat() after pgdat
   is initialized
Signed-off-by: NTang Chen <tangchen@cn.fujitsu.com>
Signed-off-by: NYasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: <stable@vger.kernel.org>	[3.16+]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Before describing bugs itself, I first explain definition of freepage.

 1. pages on buddy list are counted as freepage.
 2. pages on isolate migratetype buddy list are *not* counted as freepage.
 3. pages on cma buddy list are counted as CMA freepage, too.

Now, I describe problems and related patch.

Patch 1: There is race conditions on getting pageblock migratetype that
it results in misplacement of freepages on buddy list, incorrect
freepage count and un-availability of freepage.

Patch 2: Freepages on pcp list could have stale cached information to
determine migratetype of buddy list to go.  This causes misplacement of
freepages on buddy list and incorrect freepage count.

Patch 4: Merging between freepages on different migratetype of
pageblocks will cause freepages accouting problem.  This patch fixes it.

Without patchset [3], above problem doesn't happens on my CMA allocation
test, because CMA reserved pages aren't used at all.  So there is no
chance for above race.

With patchset [3], I did simple CMA allocation test and get below
result:

 - Virtual machine, 4 cpus, 1024 MB memory, 256 MB CMA reservation
 - run kernel build (make -j16) on background
 - 30 times CMA allocation(8MB * 30 = 240MB) attempts in 5 sec interval
 - Result: more than 5000 freepage count are missed

With patchset [3] and this patchset, I found that no freepage count are
missed so that I conclude that problems are solved.

On my simple memory offlining test, these problems also occur on that
environment, too.

This patch (of 4):

There are two paths to reach core free function of buddy allocator,
__free_one_page(), one is free_one_page()->__free_one_page() and the
other is free_hot_cold_page()->free_pcppages_bulk()->__free_one_page().
Each paths has race condition causing serious problems.  At first, this
patch is focused on first type of freepath.  And then, following patch
will solve the problem in second type of freepath.

In the first type of freepath, we got migratetype of freeing page
without holding the zone lock, so it could be racy.  There are two cases
of this race.

 1. pages are added to isolate buddy list after restoring orignal
    migratetype

    CPU1                                   CPU2

    get migratetype => return MIGRATE_ISOLATE
    call free_one_page() with MIGRATE_ISOLATE

                                grab the zone lock
                                unisolate pageblock
                                release the zone lock

    grab the zone lock
    call __free_one_page() with MIGRATE_ISOLATE
    freepage go into isolate buddy list,
    although pageblock is already unisolated

This may cause two problems.  One is that we can't use this page anymore
until next isolation attempt of this pageblock, because freepage is on
isolate buddy list.  The other is that freepage accouting could be wrong
due to merging between different buddy list.  Freepages on isolate buddy
list aren't counted as freepage, but ones on normal buddy list are
counted as freepage.  If merge happens, buddy freepage on normal buddy
list is inevitably moved to isolate buddy list without any consideration
of freepage accouting so it could be incorrect.

 2. pages are added to normal buddy list while pageblock is isolated.
    It is similar with above case.

This also may cause two problems.  One is that we can't keep these
freepages from being allocated.  Although this pageblock is isolated,
freepage would be added to normal buddy list so that it could be
allocated without any restriction.  And the other problem is same as
case 1, that it, incorrect freepage accouting.

This race condition would be prevented by checking migratetype again
with holding the zone lock.  Because it is somewhat heavy operation and
it isn't needed in common case, we want to avoid rechecking as much as
possible.  So this patch introduce new variable, nr_isolate_pageblock in
struct zone to check if there is isolated pageblock.  With this, we can
avoid to re-check migratetype in common case and do it only if there is
isolated pageblock or migratetype is MIGRATE_ISOLATE.  This solve above
mentioned problems.

Changes from v3:
Add one more check in free_one_page() that checks whether migratetype is
MIGRATE_ISOLATE or not. Without this, abovementioned case 1 could happens.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: NMinchan Kim <minchan@kernel.org>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Wen Congyang <wency@cn.fujitsu.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Heesub Shin <heesub.shin@samsung.com>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Cc: Ritesh Harjani <ritesh.list@gmail.com>
Cc: Gioh Kim <gioh.kim@lge.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Reallocation is only required for shrinking and expanding and both rely
on a mutex for synchronization and callers of rhashtable_init() are in
non atomic context. Therefore, no reason to continue passing allocation
hints through the API.

Instead, use GFP_KERNEL and add __GFP_NOWARN | __GFP_NORETRY to allow
for silent fall back to vzalloc() without the OOM killer jumping in as
pointed out by Eric Dumazet and Eric W. Biederman.
Signed-off-by: NThomas Graf <tgraf@suug.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We now allow up to 126 VFs. Note though that certain firmware
versions only allow up to 80 VFs. Moreover, old HCAs only support 64 VFs.
In these cases, we limit the maximum number of VFs to 64.
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Previously, the driver queried the firmware in order to get the number
of supported EQs. Under SRIOV, since this was done before the driver
notified the firmware how many VFs it actually needs, the firmware had
to take into account a worst case scenario and always allocated four EQs
per VF, where one was used for events while the others were used for completions.

Now, when the firmware supports the asymmetric allocation scheme, denoted
by exposing num_sys_eqs > 0 (--> MLX4_DEV_CAP_FLAG2_SYS_EQS), we use the
QUERY_FUNC command to query the firmware before enabling SRIOV. Thus we
can get more EQs and MSI-X vectors per function.

Moreover, when running in the new firmware/driver mode, the limitation
that the number of EQs should be a power of two is lifted.
Signed-off-by: NJack Morgenstein <jackm@dev.mellanox.co.il>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently mutex_is_held can only test locks in the that are global
since it takes no arguments.  This prevents rhashtable from being
used in places where locks are lock, e.g., per-namespace locks.

This patch adds a parent field to mutex_is_held and rhashtable_params
so that local locks can be used (and tested).
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The rhashtable function mutex_is_held is only used when PROVE_LOCKING
is enabled.  This patch makes the mutex_is_held field in rhashtable
optional depending on PROVE_LOCKING.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add helper macro for PHY drivers which do not do anything special in
module init/exit. This will allow us to eliminate a lot of boilerplate
code.
Signed-off-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the two functions which are now dead code.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch implements __dev_alloc_pages and __dev_alloc_page.  These are
meant to replace the __skb_alloc_pages and __skb_alloc_page functions.  The
reason for doing this is that it occurred to me that __skb_alloc_page is
supposed to be passed an sk_buff pointer, but it is NULL in all cases where
it is used.  Worse is that in the case of ixgbe it is passed NULL via the
sk_buff pointer in the rx_buffer info structure which means the compiler is
not correctly stripping it out.

The naming for these functions is based on dev_alloc_skb and __dev_alloc_skb.
There was originally a netdev_alloc_page, however that was passed a
net_device pointer and this function is not so I thought it best to follow
that naming scheme since that is the same difference between dev_alloc_skb
and netdev_alloc_skb.

In the case of anything greater than order 0 it is assumed that we want a
compound page so __GFP_COMP is set for all allocations as we expect a
compound page when assigning a page frag.

The other change in this patch is to exploit the behaviors of the page
allocator in how it handles flags.  So for example we can always set
__GFP_COMP and __GFP_MEMALLOC since they are ignored if they are not
applicable or are overridden by another flag.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

vlan was the only user of netif_copy_real_num_queues(),
but it no longer calls it after
commit 4af429d2 ("vlan: lockless transmit path").
So we can just remove it.

Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When processing received traffic, pass CHECKSUM_COMPLETE status to the
stack, with calculated checksum for non TCP/UDP packets (such
as GRE or ICMP).

Although the stack expects checksum which doesn't include the pseudo
header, the HW adds it. To address that, we are subtracting the pseudo
header checksum from the checksum value provided by the HW.

In the IPv6 case, we also compute/add the IP header checksum which
is not added by the HW for such packets.

Cc: Jerry Chu <hkchu@google.com>
Signed-off-by: NShani Michaeli <shanim@mellanox.com>
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

On a !PREEMPT kernel, attempting to use trace-cmd results in a soft
lockup:

 # trace-cmd record -e raw_syscalls:* -F false
 NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [trace-cmd:61]
 ...
 Call Trace:
  [<ffffffff8105b580>] ? __wake_up_common+0x90/0x90
  [<ffffffff81092e25>] wait_on_pipe+0x35/0x40
  [<ffffffff810936e3>] tracing_buffers_splice_read+0x2e3/0x3c0
  [<ffffffff81093300>] ? tracing_stats_read+0x2a0/0x2a0
  [<ffffffff812d10ab>] ? _raw_spin_unlock+0x2b/0x40
  [<ffffffff810dc87b>] ? do_read_fault+0x21b/0x290
  [<ffffffff810de56a>] ? handle_mm_fault+0x2ba/0xbd0
  [<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80
  [<ffffffff810951e2>] ? trace_buffer_lock_reserve+0x22/0x60
  [<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80
  [<ffffffff8112415d>] do_splice_to+0x6d/0x90
  [<ffffffff81126971>] SyS_splice+0x7c1/0x800
  [<ffffffff812d1edd>] tracesys_phase2+0xd3/0xd8

The problem is this: tracing_buffers_splice_read() calls
ring_buffer_wait() to wait for data in the ring buffers.  The buffers
are not empty so ring_buffer_wait() returns immediately.  But
tracing_buffers_splice_read() calls ring_buffer_read_page() with full=1,
meaning it only wants to read a full page.  When the full page is not
available, tracing_buffers_splice_read() tries to wait again with
ring_buffer_wait(), which again returns immediately, and so on.

Fix this by adding a "full" argument to ring_buffer_wait() which will
make ring_buffer_wait() wait until the writer has left the reader's
page, i.e.  until full-page reads will succeed.

Link: http://lkml.kernel.org/r/1415645194-25379-1-git-send-email-rabin@rab.in

Cc: stable@vger.kernel.org # 3.16+
Fixes: b1169cc6 ("tracing: Remove mock up poll wait function")
Signed-off-by: NRabin Vincent <rabin@rab.in>
Signed-off-by: NSteven Rostedt <rostedt@goodmis.org>

Tuning coalescing parameters on NIC can be really hard.

Servers can handle both bulk and RPC like traffic, with conflicting
goals : bulk flows want as big GRO packets as possible, RPC want minimal
latencies.

To reach big GRO packets on 10Gbe NIC, one can use :

ethtool -C eth0 rx-usecs 4 rx-frames 44

But this penalizes rpc sessions, with an increase of latencies, up to
50% in some cases, as NICs generally do not force an interrupt when
a packet with TCP Push flag is received.

Some NICs do not have an absolute timer, only a timer rearmed for every
incoming packet.

This patch uses a different strategy : Let GRO stack decides what do do,
based on traffic pattern.

Packets with Push flag wont be delayed.
Packets without Push flag might be held in GRO engine, if we keep
receiving data.

This new mechanism is off by default, and shall be enabled by setting
/sys/class/net/ethX/gro_flush_timeout to a value in nanosecond.

To fully enable this mechanism, drivers should use napi_complete_done()
instead of napi_complete().

Tested:
 Ran 200 netperf TCP_STREAM from A to B (10Gbe mlx4 link, 8 RX queues)

Without this feature, we send back about 305,000 ACK per second.

GRO aggregation ratio is low (811/305 = 2.65 segments per GRO packet)

Setting a timer of 2000 nsec is enough to increase GRO packet sizes
and reduce number of ACK packets. (811/19.2 = 42)

Receiver performs less calls to upper stacks, less wakes up.
This also reduces cpu usage on the sender, as it receives less ACK
packets.

Note that reducing number of wakes up increases cpu efficiency, but can
decrease QPS, as applications wont have the chance to warmup cpu caches
doing a partial read of RPC requests/answers if they fit in one skb.

B:~# sar -n DEV 1 10 | grep eth0 | tail -1
Average:         eth0 811269.80 305732.30 1199462.57  19705.72      0.00
0.00      0.50

B:~# echo 2000 >/sys/class/net/eth0/gro_flush_timeout

B:~# sar -n DEV 1 10 | grep eth0 | tail -1
Average:         eth0 811577.30  19230.80 1199916.51   1239.80      0.00
0.00      0.50
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All interrupts coming from MUIC were ignored because interrupt source
register was masked.

The Maxim 77693 has a "interrupt source" - a separate register and interrupts
which give information about PMIC block triggering the individual
interrupt (charger, topsys, MUIC, flash LED).

By default bootloader could initialize this register to "mask all"
value. In such case (observed on Trats2 board) MUIC interrupts won't be
generated regardless of their mask status. Regmap irq chip was unmasking
individual MUIC interrupts but the source was masked

Before introducing regmap irq chip this interrupt source was unmasked,
read and acked. Reading and acking is not necessary but unmasking is.

Fixes: 342d669c ("mfd: max77693: Handle IRQs using regmap")

Cc: <stable@vger.kernel.org>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

Now that both macvtap and tun are using skb_copy_datagram_iter, we
can kill the abomination that is skb_copy_datagram_const_iovec.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds skb_copy_datagram_iter, which is identical to
skb_copy_datagram_iovec except that it operates on iov_iter
instead of iovec.

Eventually all users of skb_copy_datagram_iovec should switch
over to iov_iter and then we can remove skb_copy_datagram_iovec.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Device can export MPLS GSO support in dev->mpls_features same way
it export vlan features in dev->vlan_features. So it is safe to
remove NETIF_F_GSO_MPLS redundant flag.
Signed-off-by: NPravin B Shelar <pshelar@nicira.com>

By default the arch_fast_hash hashing function pointers are initialized
to jhash(2). If during boot-up a CPU with SSE4.2 is detected they get
updated to the CRC32 ones. This dispatching scheme incurs a function
pointer lookup and indirect call for every hashing operation.

rhashtable as a user of arch_fast_hash e.g. stores pointers to hashing
functions in its structure, too, causing two indirect branches per
hashing operation.

Using alternative_call we can get away with one of those indirect branches.
Acked-by: NDaniel Borkmann <dborkman@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
Signed-off-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It is only used in net/ipv6/inet6_hashtables.c.

Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new GSO type, SKB_GSO_TUNNEL_REMCSUM, which indicates remote
checksum offload being done (in this case inner checksum must not
be offloaded to the NIC).

Added logic in __skb_udp_tunnel_segment to handle remote checksum
offload case.
Signed-off-by: NTom Herbert <therbert@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

File descriptors are always closed on exit :-)
Signed-off-by: NRasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

acpi_pci_get_bridge_handle() returns the ACPI handle for the bridge device
(either a host bridge or a PCI-to-PCI bridge) leading to a PCI bus.  But
SR-IOV virtual functions can be on a virtual bus with no bridge leading to
it.  Return a NULL acpi_handle in this case instead of trying to
dereference the NULL pointer to the bridge.

This fixes a NULL pointer dereference oops in pci_get_hp_params() when
adding SR-IOV VF devices on virtual buses.

[bhelgaas: changelog, add comment in code]
Fixes: 6cd33649 ("PCI: Add pci_configure_device() during enumeration")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=87591Reported-by: NChao Zhou <chao.zhou@intel.com>
Reported-by: NJoerg Roedel <joro@8bytes.org>
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

The string property read helpers will run off the end of the buffer if
it is handed a malformed string property. Rework the parsers to make
sure that doesn't happen. At the same time add new test cases to make
sure the functions behave themselves.

The original implementations of of_property_read_string_index() and
of_property_count_strings() both open-coded the same block of parsing
code, each with it's own subtly different bugs. The fix here merges
functions into a single helper and makes the original functions static
inline wrappers around the helper.

One non-bugfix aspect of this patch is the addition of a new wrapper,
of_property_read_string_array(). The new wrapper is needed by the
device_properties feature that Rafael is working on and planning to
merge for v3.19. The implementation is identical both with and without
the new static inline wrapper, so it just got left in to reduce the
churn on the header file.
Signed-off-by: NGrant Likely <grant.likely@linaro.org>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Darren Hart <darren.hart@intel.com>
Cc: <stable@vger.kernel.org>  # v3.3+: Drop selftest hunks that don't apply

Maximum length of AMPDU that an STA can receive in VHT.
length = 2 ^ (13 + max_ampdu_length_exp) - 1.
Signed-off-by: NEran Harary <eran.harary@intel.com>
Signed-off-by: NEmmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>

Yaogong replaces TCP out of order receive queue by an RB tree.

As netem already does a private skb->{next/prev/tstamp} union
with a 'struct rb_node', lets do this in a cleaner way.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Yaogong Wang <wygivan@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add code to issue CONFIG_DEV "get" firmware command.

This command is used in order to obtain certain parameters used for
supporting various RX checksumming options and vxlan UDP port.

The GET operation is allowed for VFs too.
Signed-off-by: NMatan Barak <matanb@mellanox.com>
Signed-off-by: NShani Michaeli <shanim@mellanox.com>
Signed-off-by: NOr Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

flow_limit in struct softnet_data is only read from local cpu
and can be moved to fill a hole, reducing softnet_data size by
64 bytes on x86_64

While we are at it, move output_queue, output_queue_tailp and
completion_queue, so that rx / tx paths touch a single cache line.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Author: David Jeffery <djeffery@redhat.com>
Changes to the basic direct I/O code have broken the raw driver when reading
to the end of a raw device.  Instead of returning a short read for a read that
extends partially beyond the device's end or 0 when at the end of the device,
these reads now return EIO.

The raw driver needs the same end of device handling as was added for normal
block devices.  Using blkdev_read_iter, which has the needed size checks,
prevents the EIO conditions at the end of the device.
Signed-off-by: NDavid Jeffery <djeffery@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Some drivers are unable to perform TX completions in a bound time.
They instead call skb_orphan()

Problem is skb_fclone_busy() has to detect this case, otherwise
we block TCP retransmits and can freeze unlucky tcp sessions on
mostly idle hosts.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Fixes: 1f3279ae ("tcp: avoid retransmits of TCP packets hanging in host queues")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 0a31bc97 ("mm: memcontrol: rewrite uncharge API") changed
page migration to uncharge the old page right away.  The page is locked,
unmapped, truncated, and off the LRU, but it could race with writeback
ending, which then doesn't unaccount the page properly:

test_clear_page_writeback()              migration
                                           wait_on_page_writeback()
  TestClearPageWriteback()
                                           mem_cgroup_migrate()
                                             clear PCG_USED
  mem_cgroup_update_page_stat()
    if (PageCgroupUsed(pc))
      decrease memcg pages under writeback

  release pc->mem_cgroup->move_lock

The per-page statistics interface is heavily optimized to avoid a
function call and a lookup_page_cgroup() in the file unmap fast path,
which means it doesn't verify whether a page is still charged before
clearing PageWriteback() and it has to do it in the stat update later.

Rework it so that it looks up the page's memcg once at the beginning of
the transaction and then uses it throughout.  The charge will be
verified before clearing PageWriteback() and migration can't uncharge
the page as long as that is still set.  The RCU lock will protect the
memcg past uncharge.

As far as losing the optimization goes, the following test results are
from a microbenchmark that maps, faults, and unmaps a 4GB sparse file
three times in a nested fashion, so that there are two negative passes
that don't account but still go through the new transaction overhead.
There is no actual difference:

 old:     33.195102545 seconds time elapsed       ( +-  0.01% )
 new:     33.199231369 seconds time elapsed       ( +-  0.03% )

The time spent in page_remove_rmap()'s callees still adds up to the
same, but the time spent in the function itself seems reduced:

     # Children      Self  Command        Shared Object       Symbol
 old:     0.12%     0.11%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
 new:     0.12%     0.08%  filemapstress  [kernel.kallsyms]   [k] page_remove_rmap
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: <stable@vger.kernel.org>	[3.17.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A follow-up patch would have changed the call signature.  To save the
trouble, just fold it instead.
Signed-off-by: NJohannes Weiner <hannes@cmpxchg.org>
Acked-by: NMichal Hocko <mhocko@suse.cz>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: <stable@vger.kernel.org>	[3.17.x]
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If an anonymous mapping is not allowed to fault thp memory and then
madvise(MADV_HUGEPAGE) is used after fault, khugepaged will never
collapse this memory into thp memory.

This occurs because the madvise(2) handler for thp, hugepage_madvise(),
clears VM_NOHUGEPAGE on the stack and it isn't stored in vma->vm_flags
until the final action of madvise_behavior().  This causes the
khugepaged_enter_vma_merge() to be a no-op in hugepage_madvise() when
the vma had previously had VM_NOHUGEPAGE set.

Fix this by passing the correct vma flags to the khugepaged mm slot
handler.  There's no chance khugepaged can run on this vma until after
madvise_behavior() returns since we hold mm->mmap_sem.

It would be possible to clear VM_NOHUGEPAGE directly from vma->vm_flags
in hugepage_advise(), but I didn't want to introduce special case
behavior into madvise_behavior().  I think it's best to just let it
always set vma->vm_flags itself.
Signed-off-by: NDavid Rientjes <rientjes@google.com>
Reported-by: NSuleiman Souhlal <suleiman@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Driver calling of_reserved_mem_device_init() might be interested if the
initialization has been successful or not, so add support for returning
error code.

This fixes a build warining caused by commit 7bfa5ab6 ("drivers:
dma-coherent: add initialization from device tree"), which has been
merged without this change and without fixing function return value.

Fixes: 7bfa5ab6 ("drivers: dma-coherent: add initialization from device tree")
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Josh Cartwright <joshc@codeaurora.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>