All of the survey data is (currently) per channel anyway,
so having the word "channel" in the name does nothing. In
the next patch I'll introduce global data to the survey,
where the word "channel" is actually confusing.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When hw acceleration is enabled, the GENERATE_IV or PUT_IV_SPACE flags
only require headroom space. Therefore, the tailroom-needed counter can
safely be decremented for most drivers.
The older incarnation of this patch (ca34e3b5) assumed that the above
holds true for all drivers. As reported by Christopher Chavez and
researched by Christian Lamparter and Larry Finger, this isn't a valid
assumption for p54 and cw1200.
Drivers that still require tailroom for ICV/MIC even when HW encryption
is enabled can use IEEE80211_KEY_FLAG_RESERVE_TAILROOM to indicate it.
Signed-off-by: Ido Yariv <idox.yariv@intel.com>
Cc: Christopher Chavez <chrischavez@gmx.us>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Merge mac80211.git to get some changes that would otherwise
cause conflicts with new changes coming here.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The patch "40a11ca mac80211: check if channels allow 80 MHz for VHT
probe requests" considered disabled channels as VHT enabled, and
mistakenly sent out probe-requests with the VHT IE.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Put the group names into the userspace API header file so that
userspace clients can use symbolic names from there instead of
hardcoding the actual names. This doesn't really change much,
but seems somewhat cleaner.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
With the wiphy::features flag being used up this patch adds a
new field wiphy::ext_features. Considering extensibility this
new field is declared as a byte array. This extensible flag is
exposed to user-space by NL80211_ATTR_EXT_FEATURES.
Cc: Avinash Patil <patila@marvell.com>
Signed-off-by: Gautam (Gautam Kumar) Shukla <gautams@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The flag is no longer used (and hasn't been for a long time)
since trying to track authentication (and make decisions based
on state) was just causing issues all over - see commit
95de817b90.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This reverts commit ca34e3b5c8.
It turns out that the p54 and cw2100 drivers assume that there's
tailroom even when they don't say they really need it. However,
there's currently no way for them to explicitly say they do need
it, so for now revert this.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=90331.
Cc: stable@vger.kernel.org
Fixes: ca34e3b5c8 ("mac80211: Fix accounting of the tailroom-needed counter")
Reported-by: Christopher Chavez <chrischavez@gmx.us>
Bisected-by: Larry Finger <Larry.Finger@lwfinger.net>
Debugged-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
dot11MulticastTransmittedFrameCount should be updated according
to the DA, which might be different from A1. Checking A1 results
in the counter being 0 in case of station, as to-DS data frames
use A1 for the BSSID.
This behaviour is defined in state machines, specifically in the
sta_tx_dcf_3.1d(10) description of 802.11-2012.
Signed-off-by: Eliad Peller <eliad@wizery.com>
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
David Binderman reports that the conditions in the first loop
are the wrong way around - checking the array contents before
the size.
Instead of leaving the empty loop there and reordering the two
checks unify it into a single loop that skips over non-matches
and exits after the first match.
Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
On minstrel_ht, the size of the per-sta struct is almost 18k, making it
an order-3 allocation.
A few fields inside the per-rate statistics are bigger than they need to
be. This patch reduces the size enough to cut down the per-sta struct to
about 13k (order-2 allocation).
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Some network cards (Intel) produce per-channel regdomains and rely on
cfg80211 to merge rules as needed. This hits the max rules limit and
fails.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
An attribute NL80211_ATTR_SOCKET_OWNER can be set by the scan initiator.
If present, the attribute will cause the scan to be stopped if the client
dies.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Because of possible races when accessing sched_scan_req pointer in
rdev, the sched_scan_req is converted to RCU pointer.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If there are no interfaces up, there is no reason
to continue the reconfig flow.
The current code might end up calling driver
callbacks (e.g. resume(), reconfig_complete())
while the driver is already stopped.
Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The ht_oper variable is assigned a value, but never used in
ieee80211_parse_ch_switch_ie(). Remove it.
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Commit e1a0c6b ("mac80211: stop toggling IEEE80211_HT_CAP_SUP_WIDTH_20_40")
mistakenly removed the actual update of sta->sta.bandwidth.
Refactor ieee80211_sta_cur_vht_bw() into multiple functions
(calculate caps-bw and chandef-bw separately, and min them
with cur_max_bandwidth).
On ht chanwidth action frame set only cur_max_bandwidth
(according to the sta capabilities) and recalc the sta bw.
Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In beacons, handle the Country IE even if no Power Constraint IE
is present, and, capability wise, also in case that the Radio
Measurements capability is enabled.
In cases where the Country IE should be handled and that the
Power Constraint IE is not present, the Country IE alone will
set the power limit (and not both Country and Power Constraint
IEs).
Signed-off-by: Moshe Benji <moshe.benji@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
HT override configurations was ignored when choosing the channel
(until now, the override configuration affected only the
capabilities shown in the IEs).
The override configurations received only on association time,
so in this case we should determine the channel again.
Signed-off-by: Chaya Rachel Ivgi <chaya.rachel.ivgi@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When writing the code to allow per-station GTKs, I neglected to
take into account the management frame keys (index 4 and 5) when
freeing the station and only added code to free the first four
data frame keys.
Fix this by iterating the array of keys over the right length.
Cc: stable@vger.kernel.org
Fixes: e31b82136d ("cfg80211/mac80211: allow per-station GTKs")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The custom-reg handling function can currently only add flags to a given
channel. This results in stale flags being left applied. In some cases
a channel was disabled and even the orig_flags were changed to reflect
this.
Previously the API was designed for a single invocation before wiphy
registration, so this didn't matter. The previous approach doesn't scale
well to self-managed regulatory devices, particularly when a more
permissive regdom is applied after a restrictive one.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If a device has self-managed regulatory, insist on returning the wiphy
specific regdomain if a wiphy-idx is specified. The global regdomain is
meaningless for such devices.
Also add an attribute for self-managed devices, so usermode can
distinguish them as such.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add a new regulatory flag that allows a driver to manage regdomain
changes/updates for its own wiphy.
A self-managed wiphys only employs regulatory information obtained from
the FW and driver and does not use other cfg80211 sources like
beacon-hints, country-code IEs and hints from other devices on the same
system. Conversely, a self-managed wiphy does not share its regulatory
hints with other devices in the system. If a system contains several
devices, one or more of which are self-managed, there might be
contradictory regulatory settings between them. Usage of flag is
generally discouraged. Only use it if the FW/driver is incompatible
with non-locally originated hints.
A new API lets the driver send a complete regdomain, to be applied on
its wiphy only.
After a wiphy-specific regdomain change takes place, usermode will get
a new type of change notification. The regulatory core also takes care
enforce regulatory restrictions, in case some interfaces are on
forbidden channels.
Signed-off-by: Jonathan Doron <jonathanx.doron@intel.com>
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
If a wiphy-idx is specified, the kernel will return the wiphy specific
regdomain, if such exists. Otherwise return the global regdom.
When no wiphy-idx is specified, return the global regdomain as well as
all wiphy-specific regulatory domains in the system, via a new nested
list of attributes.
Add a new attribute for each wiphy-specific regdomain, for usermode to
identify it as such.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Instead of sending peer candidate events just once, send them as long
as the peer remains in the LISTEN state in the peering state machine,
when userspace is implementing the peering manager.
Userspace may silence the events from a peer by progressing the state
machine or by setting the link state to BLOCKED.
Fixes the problem that a mesh peering process won't be fired again after
the previous first peering trial fails due to like air propagation error
if the peering is managed by user space such as wpa_supplicant.
This patch works with another patch for wpa_supplicant described here
which fires a peering process again triggered by the notice from kernel.
http://lists.shmoo.com/pipermail/hostap/2014-November/031235.html
Signed-off-by: Kenzoh Nishikawa <Kenzoh.Nishikawa@jp.sony.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The call to cfg80211_ch_switch_notify() should be at the end of the
ieee80211_chswitch_post_beacon() function, because it should only be
sent if everything succeeded.
Fixes: d04b5ac9e7 ("cfg80211/mac80211: allow any interface to send channel switch notifications")
Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When using IBSS in HT mode, we always get NSS=1
in rc_update callback. Force NSS recalculation when
rates updated and notify driver that NSS changed.
Signed-off-by: Janusz Dziedzic <janusz.dziedzic@tieto.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In order to let drivers have more dynamic U-APSD support,
move the enablement flag to the virtual interface driver
flags. This lets drivers not only set it up differently
for different interfaces, but also enable/disable on the
fly if needed.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The power level might have been set, but as the interface was idle
it might not have taken effect yet. Ask the driver to check the
power level when starting up an AP so that in this case the correct
power level is used in case the device/driver can only set it when
the interface is actually active.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Since multicast frames are marked as no-ack, using
IEEE80211_TX_STAT_ACK to check if they have been
successfully transmitted by the driver is incorrect
since a driver can choose to ignore transmission status
for no-ack frames. This results in incorrect accounting
for such frames.
To fix this issue, this patch introduces a new flag
that can be used by drivers to indicate error-free
transmission of no-ack frames.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
[add a note about not setting the flag for non-no-ack frames]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Move IEEE80211_TX_CTL_PS_RESPONSE to info->control.flags since
this is used only in the TX path (by ath9k). This frees up
a bit which can be used for other purposes.
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
It allows to identify the wlan kind of device for the user application,
e.g.:
# ip -d link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 promiscuity 0
2: enp0s25: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN mode DEFAULT group default qlen 1000
link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff promiscuity 0
3: wlp3s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP mode DEFAULT group default qlen 1000
link/ether XX:XX:XX:XX:XX:XX brd ff:ff:ff:ff:ff:ff promiscuity 0
wlan
Signed-off-by: Vadim Kochan <vadim4j@gmail.com>
Acked-by: Marcel Holtmann <marcel@holtmann.org>
[make wireless_link_ops const]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Ad-hoc requires beaconing for regulatory purposes. Validate that the
channel is valid for beaconing, and not only enabled.
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Reviewed-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This can happen and there is no point in added more
detection code lower in the stack. Catching these in one
single point (cfg80211) is enough. Stop WARNING about this
case.
This fixes:
https://bugzilla.kernel.org/show_bug.cgi?id=89001
Cc: stable@vger.kernel.org
Fixes: 2f1c6c572d ("cfg80211: process non country IE conflicting first")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
When the channel switch has been made, a vif is now using
the channel context which was reserved. When that happens,
we need to update the channel context since its parameters
may change.
I hit a case in which I switched to a 40Mhz channel but the
reserved channel context was still on 20Mhz. The rate control
would try to send 40Mhz packets on a 20Mhz channel context and
that made iwlwifi's firmware unhappy.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The code assigns a constant value (a pointer to a static variable)
to an RCU pointer, which results in a sparse warning:
reg.c:112:10: warning: cast adds address space to expression (<asn:4>)
Suppress this warning by using __force.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
In the already-set and intersect case of a driver-hint, the previous
wiphy regdomain was not freed before being reset with a copy of the
cfg80211 regdomain.
Cc: stable@vger.kernel.org
Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Acked-by: Luis R. Rodriguez <mcgrof@suse.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The VHT supported channel width field is a two bit integer, not a
bitfield. cfg80211_chandef_usable() was interpreting it incorrectly and
ended up rejecting 160 MHz channel width if the driver indicated support
for both 160 and 80+80 MHz channels.
Cc: stable@vger.kernel.org (3.16+)
Fixes: 3d9d1d6656 ("nl80211/cfg80211: support VHT channel configuration")
(however, no real drivers had 160 MHz support it until 3.16)
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
As multicast-frames can't be fragmented, "dot11MulticastReceivedFrameCount"
stopped being incremented after the use-after-free fix. Furthermore, the
RX-LED will be triggered by every multicast frame (which wouldn't happen
before) which wouldn't allow the LED to rest at all.
Fixes https://bugzilla.kernel.org/show_bug.cgi?id=89431 which also had the
patch.
Cc: stable@vger.kernel.org
Fixes: b8fff407a1 ("mac80211: fix use-after-free in defragmentation")
Signed-off-by: Andreas Müller <goo@stapelspeicher.org>
[rewrite commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Avoid a case where we would access uninitialized stack data if the AP
advertises HT support without 40MHz channel support.
Cc: stable@vger.kernel.org
Fixes: f3000e1b43 ("mac80211: fix broken use of VHT/20Mhz with some APs")
Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Add ephy parameter to rtl8168g.
Also change the common function of rtl8168g from "rtl_hw_start_8168g_1" to
"rtl_hw_start_8168g". And function "rtl_hw_start_8168g_1" is used for
setting rtl8168g hardware parameters.
Following is the explanation of what hardware parameter change for.
rtl8168g may erroneous judge the PCIe signal quality and show the error bit
on PCI configuration space when in PCIe low power mode.
The following ephy parameters are for above issue.
{ 0x00, 0x0000, 0x0008 }
{ 0x0c, 0x37d0, 0x0820 }
{ 0x1e, 0x0000, 0x0001 }
rtl8168g may return to PCIe L0 from PCIe L0s low power mode too slow.
The following ephy parameter is for above issue.
{ 0x19, 0x8000, 0x0000 }
Signed-off-by: Chunhao Lin <hau@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For ports of the switch that we define as "fixed PHYs" such as MoCA, we
would have our Port 7 special handling that would allow us to assert the
link status indication.
For other ports, such as e.g: RGMII_1 connected to a cable modem, we
would rely on whatever the bootloader has left configured, which is a
bad assumption to make, we really need to force the link status
indication here.
Fixes: 246d7f773c ("net: dsa: add Broadcom SF2 switch driver")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Alexander Duyck says:
====================
arch: Add lightweight memory barriers for coherent memory access
These patches introduce two new primitives for synchronizing cache coherent
memory writes and reads. These two new primitives are:
dma_rmb()
dma_wmb()
The first patch cleans up some unnecessary overhead related to the
definition of read_barrier_depends, smp_read_barrier_depends, and comments
related to the barrier.
The second patch adds the primitives for the applicable architectures and
asm-generic.
The third patch adds the barriers to r8169 which turns out to be a good
example of where the new barriers might be useful as they have full
rmb()/wmb() barriers ordering accesses to the descriptors and the DescOwn
bit.
The fourth patch adds support for coherent_rmb() to the Intel fm10k, igb,
and ixgbe drivers. Testing with the ixgbe driver has shown a processing
time reduction of at least 7ns per 64B frame on a Core i7-4930K.
This patch series is essentially the v7 for:
v4-7: Add lightweight memory barriers for coherent memory access
v3: Add lightweight memory barriers fast_rmb() and fast_wmb()
v2: Introduce load_acquire() and store_release()
v1: Introduce read_acquire()
The key changes in this patch series versus the earlier patches are:
v7 resubmit:
- Added Acked-by: Ben Herrenschmidt from v5 to dma_rmb/wmb patch
- No code changes from previous set, still applies cleanly and builds.
v7:
- Dropped test/debug patch that was accidentally slipped in
v6:
- Replaced "memory based device I/O" with "consistent memory" in
docs
- Added reference to DMA-API.txt to explain consistent memory
v5:
- Renamed barriers dma_rmb and dma_wmb
- Undid smp_wmb changes in x86 and PowerPC
- Defined smp_rmb as __lwsync for SMP case on PowerPC
v4:
- Renamed barriers coherent_rmb and coherent_wmb
- Added smp_lwsync for use in smp_load_acquire/smp_store_release
v3:
- Moved away from acquire()/store() and instead focused on barriers
- Added cleanup of read_barrier_depends
- Added change in r8169 to fix cur_tx/DescOwn ordering
- Simplified changes to just replacing/moving barriers in r8169
- Added update to documentation with code example
v2:
- Renamed read_acquire() to be consistent with smp_load_acquire()
- Changed barrier used to be consistent with smp_load_acquire()
- Updated PowerPC code to use __lwsync based on IBM article
- Added store_release() as this is a viable use case for drivers
- Added r8169 patch which is able to fully use primitives
- Added fm10k/igb/ixgbe patch which is able to test performance
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This change makes it so that dma_rmb is used when reading the Rx
descriptor. The advantage of dma_rmb is that it allows for a much
lower cost barrier on x86, powerpc, arm, and arm64 architectures than a
traditional memory barrier when dealing with reads that only have to
synchronize to coherent memory.
In addition I have updated the code so that it just checks to see if any
bits have been set instead of just the DD bit since the DD bit will always
be set as a part of a descriptor write-back so we just need to check for a
non-zero value being present at that memory location rather than just
checking for any specific bit. This allows the code itself to appear much
cleaner and allows the compiler more room to optimize.
Cc: Matthew Vick <matthew.vick@intel.com>
Cc: Don Skidmore <donald.c.skidmore@intel.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The r8169 use a pair of wmb() calls when setting up the descriptor rings.
The first is to synchronize the descriptor data with the descriptor status,
and the second is to synchronize the descriptor status with the use of the
MMIO doorbell to notify the device that descriptors are ready. This can
come at a heavy price on some systems, and is not really necessary on
systems such as x86 as a simple barrier() would suffice to order store/store
accesses. As such we can replace the first memory barrier with
dma_wmb() to reduce the cost for these accesses.
In addition the r8169 uses a rmb() to prevent compiler optimization in the
cleanup paths, however by moving the barrier down a few lines and replacing
it with a dma_rmb() we should be able to use it to guarantee
descriptor accesses do not occur until the device has updated the DescOwn
bit from its end.
One last change I made is to move the update of cur_tx in the xmit path to
after the wmb. This way we can guarantee the device and all CPUs should
see the DescOwn update before they see the cur_tx value update.
Cc: Realtek linux nic maintainers <nic_swsd@realtek.com>
Cc: Francois Romieu <romieu@fr.zoreil.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There are a number of situations where the mandatory barriers rmb() and
wmb() are used to order memory/memory operations in the device drivers
and those barriers are much heavier than they actually need to be. For
example in the case of PowerPC wmb() calls the heavy-weight sync
instruction when for coherent memory operations all that is really needed
is an lsync or eieio instruction.
This commit adds a coherent only version of the mandatory memory barriers
rmb() and wmb(). In most cases this should result in the barrier being the
same as the SMP barriers for the SMP case, however in some cases we use a
barrier that is somewhere in between rmb() and smp_rmb(). For example on
ARM the rmb barriers break down as follows:
Barrier Call Explanation
--------- -------- ----------------------------------
rmb() dsb() Data synchronization barrier - system
dma_rmb() dmb(osh) data memory barrier - outer sharable
smp_rmb() dmb(ish) data memory barrier - inner sharable
These new barriers are not as safe as the standard rmb() and wmb().
Specifically they do not guarantee ordering between coherent and incoherent
memories. The primary use case for these would be to enforce ordering of
reads and writes when accessing coherent memory that is shared between the
CPU and a device.
It may also be noted that there is no dma_mb(). Most architectures don't
provide a good mechanism for performing a coherent only full barrier without
resorting to the same mechanism used in mb(). As such there isn't much to
be gained in trying to define such a function.
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: Michael Neuling <mikey@neuling.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: David Miller <davem@davemloft.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is meant to cleanup the handling of read_barrier_depends and
smp_read_barrier_depends. In multiple spots in the kernel headers
read_barrier_depends is defined as "do {} while (0)", however we then go
into the SMP vs non-SMP sections and have the SMP version reference
read_barrier_depends, and the non-SMP define it as yet another empty
do/while.
With this commit I went through and cleaned out the duplicate definitions
and reduced the number of definitions down to 2 per header. In addition I
moved the 50 line comments for the macro from the x86 and mips headers that
defined it as an empty do/while to those that were actually defining the
macro, alpha and blackfin.
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Florian Fainelli says:
====================
net: dsa: two small bug fixes
Here are two small fixes for the DSA slave interface creation code:
- first patch fixes a null pointer de-reference with an invalid PHY
device pointer while calling phy_connect_direct()
- second path propagates the dsa_slave_phy_setup() error code down to
its caller: dsa_slave_create
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
In case we cannot attach to our slave netdevice PHY, error out and
propagate that error up to the caller: dsa_slave_create().
Fixes: 0d8bcdd383 ("net: dsa: allow for more complex PHY setups")
Signed-off-by: Andrey Volkov <andrey.volkov@nexvision.fr>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
