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A new ioctl, KVM_PPC_GET_HTAB_FD, returns a file descriptor. Reads on
this fd return the contents of the HPT (hashed page table), writes
create and/or remove entries in the HPT. There is a new capability,
KVM_CAP_PPC_HTAB_FD, to indicate the presence of the ioctl. The ioctl
takes an argument structure with the index of the first HPT entry to
read out and a set of flags. The flags indicate whether the user is
intending to read or write the HPT, and whether to return all entries
or only the "bolted" entries (those with the bolted bit, 0x10, set in
the first doubleword).
This is intended for use in implementing qemu's savevm/loadvm and for
live migration. Therefore, on reads, the first pass returns information
about all HPTEs (or all bolted HPTEs). When the first pass reaches the
end of the HPT, it returns from the read. Subsequent reads only return
information about HPTEs that have changed since they were last read.
A read that finds no changed HPTEs in the HPT following where the last
read finished will return 0 bytes.
The format of the data provides a simple run-length compression of the
invalid entries. Each block of data starts with a header that indicates
the index (position in the HPT, which is just an array), the number of
valid entries starting at that index (may be zero), and the number of
invalid entries following those valid entries. The valid entries, 16
bytes each, follow the header. The invalid entries are not explicitly
represented.
Signed-off-by: Paul Mackerras <paulus@samba.org>
[agraf: fix documentation]
Signed-off-by: Alexander Graf <agraf@suse.de>
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V3: make it a flag
V2: make the toggle per-port
Fast leave allows bridge to immediately stops the multicast
traffic on the port receives IGMP Leave when IGMP snooping is enabled,
no timeouts are observed.
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <amwang@redhat.com>
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Add and use #defines for PCI-X Capability registers and fields.
Note that the PCI-X Capability has a different layout for
type 0 (endpoint) and type 1 (bridge) devices.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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A mfc entry can be static or not (added via the mroute_sk socket). The patch
reports MFC_STATIC flag into rtm_protocol by setting rtm_protocol to
RTPROT_STATIC or RTPROT_MROUTED.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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These statistics can be checked only via /proc/net/ip_mr_cache or
SIOCGETSGCNT[_IN6] and thus only for the table RT_TABLE_DEFAULT.
Advertising them via rtnetlink allows to get statistics for all cache entries,
whatever the table is.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch advertise the MC_FORWARDING status for IPv4 and IPv6.
This field is readonly, only multicast engine in the kernel updates it.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pablo Neira Ayuso says:
====================
* Remove limitation in the maximum number of supported sets in ipset.
Now ipset automagically increments the number of slots in the array
of sets by 64 new spare slots, from Jozsef Kadlecsik.
* Partially remove the generic queue infrastructure now that ip_queue
is gone. Its only client is nfnetlink_queue now, from Florian
Westphal.
* Add missing attribute policy checkings in ctnetlink, from Florian
Westphal.
* Automagically kill conntrack entries that use the wrong output
interface for the masquerading case in case of routing changes,
from Jozsef Kadlecsik.
* Two patches two improve ct object traceability. Now ct objects are
always placed in any of the existing lists. This allows us to dump
the content of unconfirmed and dying conntracks via ctnetlink as
a way to provide more instrumentation in case you suspect leaks,
from myself.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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Historically tun supported two modes of operation:
- in default mode, a small number of packets would get queued
at the device, the rest would be queued in qdisc
- in one queue mode, all packets would get queued at the device
This might have made sense up to a point where we made the
queue depth for both modes the same and set it to
a huge value (500) so unless the consumer
is stuck the chance of losing packets is small.
Thus in practice both modes behave the same, but the
default mode has some problems:
- if packets are never consumed, fragments are never orphaned
which cases a DOS for sender using zero copy transmit
- overrun errors are hard to diagnose: fifo error is incremented
only once so you can not distinguish between
userspace that is stuck and a transient failure,
tcpdump on the device does not show any traffic
Userspace solves this simply by enabling IFF_ONE_QUEUE
but there seems to be little point in not doing the
right thing for everyone, by default.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch adds a new operation to dump the content of the dying and
unconfirmed lists.
Under some situations, the global conntrack counter can be inconsistent
with the number of entries that we can dump from the conntrack table.
The way to resolve this is to allow dumping the content of the unconfirmed
and dying lists, so far it was not possible to look at its content.
This provides some extra instrumentation to resolve problematic situations
in which anyone suspects memory leaks.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"This is mostly about unbreaking architectures that took the UAPI
changes in the v3.7 cycle, plus misc fixes."
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf kvm: Fix building perf kvm on non x86 arches
perf kvm: Rename perf_kvm to perf_kvm_stat
perf: Make perf build for x86 with UAPI disintegration applied
perf powerpc: Use uapi/unistd.h to fix build error
tools: Pass the target in descend
tools: Honour the O= flag when tool build called from a higher Makefile
tools: Define a Makefile function to do subdir processing
x86: Export asm/{svm.h,vmx.h,perf_regs.h}
perf tools: Fix strbuf_addf() when the buffer needs to grow
perf header: Fix numa topology printing
perf, powerpc: Fix hw breakpoints returning -ENOSPC
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
Conflicts:
drivers/net/wireless/iwlwifi/pcie/tx.c
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* linus/master: (1428 commits)
futex: avoid wake_futex() for a PI futex_q
watchdog: using u64 in get_sample_period()
writeback: put unused inodes to LRU after writeback completion
mm: vmscan: check for fatal signals iff the process was throttled
Revert "mm: remove __GFP_NO_KSWAPD"
proc: check vma->vm_file before dereferencing
UAPI: strip the _UAPI prefix from header guards during header installation
include/linux/bug.h: fix sparse warning related to BUILD_BUG_ON_INVALID
Linux 3.7-rc7
powerpc/eeh: Do not invalidate PE properly
ALSA: hda - Fix build without CONFIG_PM
of/address: sparc: Declare of_iomap as an extern function for sparc again
PM / QoS: fix wrong error-checking condition
bnx2x: remove redundant warning log
vxlan: fix command usage in its doc
8139cp: revert "set ring address before enabling receiver"
MPI: Fix compilation on MIPS with GCC 4.4 and newer
MIPS: Fix crash that occurs when function tracing is enabled
MIPS: Merge overlapping bootmem ranges
jbd: Fix lock ordering bug in journal_unmap_buffer()
...
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If a driver supports P2P GO powersave, allow it to
set the new feature flags for it and allow userspace
to configure the parameters for it. This can be done
at GO startup and later changed with SET_BSS.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Add support for reporting and calculating VHT MCSes.
Note that I'm not completely sure that the bitrate
calculations are correct, nor that they can't be
simplified.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Change nl80211 to support specifying a VHT (or HT)
using the control channel frequency (as before) and
new attributes for the channel width and first and
second center frequency. The old channel type is of
course still supported for HT.
Also change the cfg80211 channel definition struct
to support these by adding the relevant fields to
it (and removing the _type field.)
This also adds new helper functions:
- cfg80211_chandef_create to create a channel def
struct given the control channel and channel type,
- cfg80211_chandef_identical to check if two channel
definitions are identical
- cfg80211_chandef_compatible to check if the given
channel definitions are compatible, and return the
wider of the two
This isn't entirely complete, but that doesn't matter
until we have a driver using it. In particular, it's
missing
- regulatory checks on the usable bandwidth (if that
even makes sense)
- regulatory TX power (database can't deal with it)
- a proper channel compatibility calculation for the
new channel types
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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As mwifiex (and mac80211 in the software case) are the
only drivers actually implementing remain-on-channel
with channel type, userspace can't be relying on it.
This is the case, as it's used only for P2P operations
right now.
Rather than adding a flag to tell userspace whether or
not it can actually rely on it, simplify all the code
by removing the ability to use different channel types.
Leave only the validation of the attribute, so that if
we extend it again later (with the needed capability
flag), it can't break userspace sending invalid data.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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This patch adds extension to V4L2 api. A new ioctl VIDIOC_EXPBUF is added. The
ioctl is used to export an mmap buffer as a DMABUF file descriptor.
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Adds DMABUF memory type to v4l framework. Also adds the related file
descriptor in v4l2_plane and v4l2_buffer.
[original work in the PoC for buffer sharing]
Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Sumit Semwal <sumit.semwal@ti.com>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
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Add register definitions used in several Exar PCI/PCIe UARTs
Signed-off-by: Matt Schulte <matts@commtech-fastcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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PCIe UARTs
Add support for new devices: Exar's XR17V35x family of multi-port PCIe UARTs.
Signed-off-by: Matt Schulte <matts@commtech-fastcom.com>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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This patch add the support of 6RD tunnels management via netlink.
Note that netdev_state_change() is now called when 6RD parameters are updated.
6RD parameters are updated only if there is at least one 6RD attribute.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This patch provides extensions to VXLAN for supporting Distributed
Overlay Virtual Ethernet (DOVE) networks. The patch includes:
+ a dove flag per VXLAN device to enable DOVE extensions
+ ARP reduction, whereby a bridge-connected VXLAN tunnel endpoint
answers ARP requests from the local bridge on behalf of
remote DOVE clients
+ route short-circuiting (aka L3 switching). Known destination IP
addresses use the corresponding destination MAC address for
switching rather than going to a (possibly remote) router first.
+ netlink notification messages for forwarding table and L3 switching
misses
Changes since v2
- combined bools into "u32 flags"
- replaced loop with !is_zero_ether_addr()
Signed-off-by: David L Stevens <dlstevens@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Make perf build for x86 once the UAPI disintegration patches for that arch
have been applied by adding the appropriate -I flags - in the right order -
and then converting some #includes that use ../.. notation to find main kernel
headerfiles to use <asm/foo.h> and <linux/foo.h> instead.
Note that -Iarch/foo/include/uapi is present _before_ -Iarch/foo/include.
This makes sure we get the userspace version of the pt_regs struct. Ideally,
we wouldn't have the latter -I flag at all, but unfortunately we want
asm/svm.h and asm/vmx.h in builtin-kvm.c and these aren't part of the UAPI -
at least not for x86. I wonder if the bits outside of the __KERNEL__ guards
*should* be transferred there.
I note also that perf seems to do its dependency handling manually by listing
all the header files it might want to use in LIB_H in the Makefile. Can this
be changed to use -MD?
Note that to do make this work, we need to export and UAPI disintegrate
linux/hw_breakpoint.h, which I think should've been exported previously so that
perf can access the bits. We have to do this in the same patch to maintain
bisectability.
Signed-off-by: David Howells <dhowells@redhat.com>
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The NL80211_CMD_TDLS_OPER command was previously used only for userspace
request for the kernel code to perform TDLS operations. However, there
are also cases where the driver may need to request operations from
userspace, e.g., when using security on the AP path. Add a new cfg80211
function for generating a TDLS operation event for drivers to request a
new link to be set up (NL80211_TDLS_SETUP) or an existing link to be
torn down (NL80211_TDLS_TEARDOWN). Drivers can optionally use these
events, e.g., based on noticing data traffic being sent to a peer
station that is seen with good signal strength.
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Minor line offset auto-merges.
Signed-off-by: David S. Miller <davem@davemloft.net>
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This is mostly a revert of 01dc52ebdf47 ("oom: remove deprecated oom_adj")
from Davidlohr Bueso.
It reintroduces /proc/pid/oom_adj for backwards compatibility with earlier
kernels. It simply scales the value linearly when /proc/pid/oom_score_adj
is written.
The major difference is that its scheduled removal is no longer included
in Documentation/feature-removal-schedule.txt. We do warn users with a
single printk, though, to suggest the more powerful and supported
/proc/pid/oom_score_adj interface.
Reported-by: Artem S. Tashkinov <t.artem@lycos.com>
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Conflicts:
net/ipv6/netfilter/nf_conntrack_l3proto_ipv6.c
Minor conflict due to some IS_ENABLED conversions done
in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
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The kernel uses some default metric when routes are managed. For example, a
static route added with a metric set to 0 is inserted in the kernel with
metric 1024 (IP6_RT_PRIO_USER).
It is useful for routing daemons to know these values, to be able to set routes
without interfering with what the kernel does.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Some devices provides the actual timestamp (hid_dg_scan_time in win8 ones)
computed by the hardware itself. This value is global to the frame and is
not specific to the multitouch protocol.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Henrik Rydberg <rydberg@euromail.se>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next
John W. Linville says:
====================
Included is a Bluetooth pull -- Gustavo says:
"These are the Bluetooth bits for inclusion in 3.8, there is basically one big
thing here which is the High Speed patches from Andrei, he did a lot of work on
A2MP and management of AMP devices. The rest are mostly clean up and bug
fixes."
Also included is an NFC pull -- Samuel says:
"With this one we have:
- pn544 p2p support.
- pn544 physical and HCI layers separation. We are getting the pn544 driver
ready to support non i2c physical layers.
- LLCP SNL (Service Name Lookup). This is the NFC p2p service discovery
protocol.
- LLCP datagram sockets (connection less) support.
- IDR library usage for NFC devices indexes assignement.
- NFC netlink extension for setting and getting LLCP link characteristics.
- Various code style fixes and cleanups spread over the pn533, LLCP, HCI and
pn544 code."
There are a couple of mac80211 pulls as well -- Johannes says:
"Please pull my mac80211-next tree to get the first round of new features
for 3.8. We have:
* finally, the mac80211 multi-channel work
* scan improvements:
- bg scan
- scan flush
- forced AP scan
* cfg80211 tracing
* a bit of new code to allow implementing SAE (secure authentication of
equals) in managed mode
Along with a few random improvements, features and fixes."
and...
"Please pull from mac80211-next (per below pull request) to get a few
updates. Most important is probably the fix for the WDS regression that
my previous pull request introduced. Other than that, I have some
tracing code, two mesh updates and a change to allow drivers to
calculate the AES CMAC subkeys without having to implement the GF_mulx
operation themselves."
On top of that are the usual updates to iwlwifi, ath9k, rt2x00,
brcmfmac, mwifiex, and a few others here and there. Of note is the
addition of the ar5523 driver, ported from an original FreeBSD driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
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This parameter was missing in the dump.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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IPv6 tunnels can have three mode: 4in6, 6in6 and xin6.
This information was missing in the netlink message.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This is Linux bridge implementation of root port guard.
If BPDU is received from a leaf (edge) port, it should not
be elected as root port.
Why would you want to do this?
If using STP on a bridge and the downstream bridges are not fully
trusted; this prevents a hostile guest for rerouting traffic.
Why not just use netfilter?
Netfilter does not track of follow spanning tree decisions.
It would be difficult and error prone to try and mirror STP
resolution in netfilter module.
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This is Linux bridge implementation of STP protection
(Cisco BPDU guard/Juniper BPDU block). BPDU block disables
the bridge port if a STP BPDU packet is received.
Why would you want to do this?
If running Spanning Tree on bridge, hostile devices on the network
may send BPDU and cause network failure. Enabling bpdu block
will detect and stop this.
How to recover the port?
The port will be restarted if link is brought down, or
removed and reattached. For example:
# ip li set dev eth0 down; ip li set dev eth0 up
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Expose bridge port parameter over netlink. By switching to a nested
message, this can be used for other bridge parameters.
This changes IFLA_PROTINFO attribute from one byte to a full nested
set of attributes. This is safe for application interface because the
old message used IFLA_PROTINFO and new one uses
IFLA_PROTINFO | NLA_F_NESTED.
The code adapts to old format requests, and therefore stays
compatible with user mode RSTP daemon. Since the type field
for nested and unnested attributes are different, and the old
code in libnetlink doesn't do the mask, it is also safe to use
with old versions of bridge monitor command.
Note: although mode is only a boolean, treating it as a
full byte since in the future someone will probably want to add more
values (like macvlan has).
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This pulls in the 3.7-rc5 fixes into tty-next to make it easier to test.
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git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless-next into for-davem
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This patch introduces a new knob ndisc_notify. If enabled, the kernel
will transmit an unsolicited neighbour advertisement on link-layer address
change to update the neighbour tables of the corresponding hosts more quickly.
This is the equivalent to arp_notify in ipv4 world.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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wpa_supplicant will do OBSS scan for drivers that implement
auth/assoc API. Drivers that implement nl80211 connect API
(rather than auth/assoc) may need wpa_supplicant to do this
as well.
Add a new feature flag to inform it (wpa_s) that a driver
needs wpa_supplicant to do OBSS scans.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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Conflicts:
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
Minor conflict between the BCM_CNIC define removal in net-next
and a bug fix added to net. Based upon a conflict resolution
patch posted by Stephen Rothwell.
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is usefull for daemons that monitor link event to have the full parameters of
these interfaces when a rtnl message is sent.
It allows also to dump them via rtnetlink.
It is based on what is done for GRE tunnels.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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It is usefull for daemons that monitor link event to have the full parameters of
these interfaces when a rtnl message is sent.
It allows also to dump them via rtnetlink.
It is based on what is done for GRE tunnels.
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fix the wanxl firmware to include missing constants such as PARITY_NONE. It
should be #including the linux/hdlc/ioctl.h header.
To make this work, we also have to guard parts of ioctl.h with !__ASSEMBLY__.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
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According to the PCIe 3.0 spec, PCI_EXP_LNKCAP2_SLS_2_5GB is
1st bit of PCI_EXP_LNKCAP2 register, not 0th bit. So, the bit
definition of supported link speed vector should be fixed.
[bhelgaas: change "Current" to "Supported"]
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
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Revert commit 03a7beb55b9f ("epoll: support for disabling items, and a
self-test app") pending resolution of the issues identified by Michael
Kerrisk, copied below.
We'll revisit this for 3.8.
: I've taken a look at this patch as it currently stands in 3.7-rc1, and
: done a bit of testing. (By the way, the test program
: tools/testing/selftests/epoll/test_epoll.c does not compile...)
:
: There are one or two places where the behavior seems a little strange,
: so I have a question or two at the end of this mail. But other than
: that, I want to check my understanding so that the interface can be
: correctly documented.
:
: Just to go though my understanding, the problem is the following
: scenario in a multithreaded application:
:
: 1. Multiple threads are performing epoll_wait() operations,
: and maintaining a user-space cache that contains information
: corresponding to each file descriptor being monitored by
: epoll_wait().
:
: 2. At some point, a thread wants to delete (EPOLL_CTL_DEL)
: a file descriptor from the epoll interest list, and
: delete the corresponding record from the user-space cache.
:
: 3. The problem with (2) is that some other thread may have
: previously done an epoll_wait() that retrieved information
: about the fd in question, and may be in the middle of using
: information in the cache that relates to that fd. Thus,
: there is a potential race.
:
: 4. The race can't solved purely in user space, because doing
: so would require applying a mutex across the epoll_wait()
: call, which would of course blow thread concurrency.
:
: Right?
:
: Your solution is the EPOLL_CTL_DISABLE operation. I want to
: confirm my understanding about how to use this flag, since
: the description that has accompanied the patches so far
: has been a bit sparse
:
: 0. In the scenario you're concerned about, deleting a file
: descriptor means (safely) doing the following:
: (a) Deleting the file descriptor from the epoll interest list
: using EPOLL_CTL_DEL
: (b) Deleting the corresponding record in the user-space cache
:
: 1. It's only meaningful to use this EPOLL_CTL_DISABLE in
: conjunction with EPOLLONESHOT.
:
: 2. Using EPOLL_CTL_DISABLE without using EPOLLONESHOT in
: conjunction is a logical error.
:
: 3. The correct way to code multithreaded applications using
: EPOLL_CTL_DISABLE and EPOLLONESHOT is as follows:
:
: a. All EPOLL_CTL_ADD and EPOLL_CTL_MOD operations should
: should EPOLLONESHOT.
:
: b. When a thread wants to delete a file descriptor, it
: should do the following:
:
: [1] Call epoll_ctl(EPOLL_CTL_DISABLE)
: [2] If the return status from epoll_ctl(EPOLL_CTL_DISABLE)
: was zero, then the file descriptor can be safely
: deleted by the thread that made this call.
: [3] If the epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY,
: then the descriptor is in use. In this case, the calling
: thread should set a flag in the user-space cache to
: indicate that the thread that is using the descriptor
: should perform the deletion operation.
:
: Is all of the above correct?
:
: The implementation depends on checking on whether
: (events & ~EP_PRIVATE_BITS) == 0
: This replies on the fact that EPOLL_CTL_AD and EPOLL_CTL_MOD always
: set EPOLLHUP and EPOLLERR in the 'events' mask, and EPOLLONESHOT
: causes those flags (as well as all others in ~EP_PRIVATE_BITS) to be
: cleared.
:
: A corollary to the previous paragraph is that using EPOLL_CTL_DISABLE
: is only useful in conjunction with EPOLLONESHOT. However, as things
: stand, one can use EPOLL_CTL_DISABLE on a file descriptor that does
: not have EPOLLONESHOT set in 'events' This results in the following
: (slightly surprising) behavior:
:
: (a) The first call to epoll_ctl(EPOLL_CTL_DISABLE) returns 0
: (the indicator that the file descriptor can be safely deleted).
: (b) The next call to epoll_ctl(EPOLL_CTL_DISABLE) fails with EBUSY.
:
: This doesn't seem particularly useful, and in fact is probably an
: indication that the user made a logic error: they should only be using
: epoll_ctl(EPOLL_CTL_DISABLE) on a file descriptor for which
: EPOLLONESHOT was set in 'events'. If that is correct, then would it
: not make sense to return an error to user space for this case?
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paton J. Lewis" <palewis@adobe.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
The tx data offset of packet mmap tx ring used to be :
(TPACKET2_HDRLEN - sizeof(struct sockaddr_ll))
The problem is that, with SOCK_RAW socket, the payload (14 bytes after
the beginning of the user data) is misaligned.
This patch allows to let the user gives an offset for it's tx data if
he desires.
Set sock option PACKET_TX_HAS_OFF to 1, then specify in each frame of
your tx ring tp_net for SOCK_DGRAM, or tp_mac for SOCK_RAW.
Signed-off-by: Paul Chavent <paul.chavent@onera.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This command triggers a new callback: set_mcast_rate(). It enables
the user to change the rate used to send multicast frames for vif
configured as IBSS or MESH_POINT
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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