The current code assumes that a tx_skbuff entry has been cleared
by stmmac_tx_clean() before stmmac_xmit()/stmmac_tso_xmit()
assigns a new skb to that entry. However, since we never check
the current value before overwriting it, it is theoretically
possible that a non-NULL value is overwritten.
Add WARN_ONs to verify that each entry in tx_skbuff is NULL
before it is assigned a new value.
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
tx_skbuff is initialized to NULL in init_dma_tx_desc_rings(), which is
called from ndo_open().
stmmac_tx_clean() frees any non-NULL skb, and sets the tx_skbuff
entry to NULL. Hence, there is no need to set skbuff entries to NULL
in stmmac_xmit()/stmmac_tso_xmit(), and doing so falsely gives the
reader the impression that it is needed.
Do not clear tx_skbuff entries in stmmac_xmit()/stmmac_tso_xmit().
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The DMA engine in dwmac4 can segment a large TSO packet to several
smaller packets of (max) size Maximum Segment Size (MSS).
The DMA engine fetches and saves the MSS via a context descriptor.
This context decriptor has to be provided to each tx DMA channel.
To ensure that this is done, move struct member mss from stmmac_priv
to stmmac_tx_queue.
stmmac_reset_queues_param() now also resets mss, together with other
queue parameters, so reset of mss value can be removed from
stmmac_resume().
init_dma_tx_desc_rings() now also resets mss, together with other
queue parameters, so reset of mss value can be removed from
stmmac_open().
This fixes tx queue timeouts for dwmac4, with DT property
snps,tx-queues-to-use > 1, when running iperf3 with multiple threads.
Fixes: ce736788e8 ("net: stmmac: adding multiple buffers for TX")
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use %*ph format to print small buffer as hex string.
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Antonio Cardace <anto.cardace@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jiri Pirko says:
====================
net: Expose KVD linear parts as resources
Arkadi says:
Expose the KVD linear partitions via the devlink resource interface. This
will give the user the ability to control the linear memory division.
---
v1->v2:
- patch1:
- fixed u64 division error reported by kbuildbot
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for calculating occupancy for separate kvdl parts.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for dynamic partition set via the resource interface.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The linear part of the KVD memory is sub-divided into multiple parts. This
patch exposes this internal partitions via the resource interface.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After adding size validation logic into core cleanup is required.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently the size validation is done via a cb, which is unneeded. The
size validation can be moved to core. The next patch will perform cleanup.
Signed-off-by: Arkadi Sharshevsky <arkadis@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kirill Tkhai says:
====================
net: Get rid of net_mutex and simplify cleanup_list queueing
[1/3] kills net_mutex and makes net_sem be taken for write instead.
This is made to take less locks (1 instead of 2) for the time
before all pernet_operations are converted.
[2-3/3] simplifies dead net cleanup queueing, and makes llist api
be used for that.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When llist_add() returns false, cleanup_net() hasn't made its
llist_del_all(), while the work has already been scheduled
by the first queuer. So, we may skip queue_work() in this case.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This simplifies cleanup queueing and makes cleanup lists
to use llist primitives. Since llist has its own cmpxchg()
ordering, cleanup_list_lock is not more need.
Also, struct llist_node is smaller, than struct list_head,
so we save some bytes in struct net with this patch.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We take net_mutex, when there are !async pernet_operations
registered, and read locking of net_sem is not enough. But
we may get rid of taking the mutex, and just change the logic
to write lock net_sem in such cases. This obviously reduces
the number of lock operations, we do.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Supplementary TX descriptors were not being accounted for, which
was resulting in an overflow of the hardware device's transmit
queue. Keep track of those descriptors now when determining
how many entries remain on the TX queue.
Signed-off-by: Thomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull networking fixes from David Miller:
1) Prevent index integer overflow in ptr_ring, from Jason Wang.
2) Program mvpp2 multicast filter properly, from Mikulas Patocka.
3) The bridge brport attribute file is write only and doesn't have a
->show() method, don't blindly invoke it. From Xin Long.
4) Inverted mask used in genphy_setup_forced(), from Ingo van Lil.
5) Fix multiple definition issue with if_ether.h UAPI header, from
Hauke Mehrtens.
6) Fix GFP_KERNEL usage in atomic in RDS protocol code, from Sowmini
Varadhan.
7) Revert XDP redirect support from thunderx driver, it is not
implemented properly. From Jesper Dangaard Brouer.
8) Fix missing RTNL protection across some tipc operations, from Ying
Xue.
9) Return the correct IV bytes in the TLS getsockopt code, from Boris
Pismenny.
10) Take tclassid into consideration properly when doing FIB rule
matching. From Stefano Brivio.
11) cxgb4 device needs more PCI VPD quirks, from Casey Leedom.
12) TUN driver doesn't align frags properly, and we can end up doing
unaligned atomics on misaligned metadata. From Eric Dumazet.
13) Fix various crashes found using DEBUG_PREEMPT in rmnet driver, from
Subash Abhinov Kasiviswanathan.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (56 commits)
tg3: APE heartbeat changes
mlxsw: spectrum_router: Do not unconditionally clear route offload indication
net: qualcomm: rmnet: Fix possible null dereference in command processing
net: qualcomm: rmnet: Fix warning seen with 64 bit stats
net: qualcomm: rmnet: Fix crash on real dev unregistration
sctp: remove the left unnecessary check for chunk in sctp_renege_events
rxrpc: Work around usercopy check
tun: fix tun_napi_alloc_frags() frag allocator
udplite: fix partial checksum initialization
skbuff: Fix comment mis-spelling.
dn_getsockoptdecnet: move nf_{get/set}sockopt outside sock lock
PCI/cxgb4: Extend T3 PCI quirk to T4+ devices
cxgb4: fix trailing zero in CIM LA dump
cxgb4: free up resources of pf 0-3
fib_semantics: Don't match route with mismatching tclassid
NFC: llcp: Limit size of SDP URI
tls: getsockopt return record sequence number
tls: reset the crypto info if copy_from_user fails
tls: retrun the correct IV in getsockopt
docs: segmentation-offloads.txt: add SCTP info
...
In commit cc1ea9ffadf7 ("tipc: eliminate struct tipc_subscriber") we
re-introduced an old bug on the error path in the function
tipc_topsrv_kern_subscr(). We now re-introduce the correction too.
Reported-by: syzbot+f62e0f2a0ef578703946@syzkaller.appspotmail.com
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kirill Tkhai says:
====================
Converting pernet_operations (part #2)
This patchset continues to review and to convert pernet_operations
to async. There are mostly ipv6, also some regular used netfilter
pernet_operations are involved. One more converted is cfg80211_pernet_ops.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations register and unregister
net::ipv4.iptable_filter table. Since there are
no packets in-flight at the time of exit method
is working, iptables rules should not be touched.
Also, pernet_operations should not send ipv4
packets each other. So, it's safe to mark them
async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_tables_net_ops and udplite6_net_ops create and destroy /proc entries.
xt_net_ops does nothing.
So, we are able to mark them async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Exit methods calls inet_frags_exit_net() with global ip6_frags
as argument. So, after we make the pernet_operations async,
a pair of exit methods may be called to iterate this hash table.
Since there is inet_frag_worker(), which already may work
in parallel with inet_frags_exit_net(), and it can make the same
cleanup, that inet_frags_exit_net() does, it's safe. So we may
mark these pernet_operations as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations register and unregister tables
and lists for packets forwarding. All of the entities
are per-net. Init methods makes simple initializations,
and since net is not visible for foreigners at the time
it is working, it can't race with anything. Exit method
is executed when there are only local devices, and there
mustn't be packets in-flight. Also, it looks like no one
pernet_operations want to send ipv6 packets to foreign
net. The same reasons are for ipv6_addr_label_ops and
ip6_segments_ops. So, we are able to mark all them as
async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create sysctl tables and
initialize net::xfrm.xfrm6_dst_ops used for routing.
It doesn't look like another pernet_operations send
ipv6 packets to foreign net namespaces, so it should
be safe to mark the pernet_operations as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy /proc entries.
ip6_fl_purge() makes almost the same actions as timer
ip6_fl_gc_timer does, and as it can be executed in parallel
with ip6_fl_purge(), two parallel ip6_fl_purge() may be
executed. So, we can mark it async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations only register and unregister /proc
entries, so it's possible to mark them async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy sysctl tables.
They are not touched by another net pernet_operations.
So, it's possible to execute them in parallel with others.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy net::ipv6.tcp_sk
socket, which is used in tcp_v6_send_response() only. It looks
like foreign pernet_operations don't want to set ipv6 connection
inside destroyed net, so this socket may be created in destroyed
in parallel with anything else. inet_twsk_purge() is also safe
for that, as described in patch for tcp_sk_ops. So, it's possible
to mark them as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations register and unregister
net::ipv6.fib6_rules_ops, which are used for
routing. It looks like there are no pernet_operations,
which send ipv6 packages to another net, so we
are able to mark them as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net->ipv6.peers is dereferenced in three places via inet_getpeer_v6(),
and it's used to handle skb. All the users of inet_getpeer_v6() do not
look like be able to be called from foreign net pernet_operations, so
we may mark them as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy /proc entries
and safely may be converted and safely may be mark as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy net::ipv6.icmp_sk
socket, used to send ICMP or error reply.
Nobody can dereference the socket to handle a packet before
net is initialized, as there is no routing; nobody can do
that in parallel with exit, as all of devices are moved
to init_net or destroyed and there are no packets it-flight.
So, it's possible to mark these pernet_operations as async.
The same for ndisc_net_ops and for igmp6_net_ops. The last
one also creates and destroys /proc entries.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
These pernet_operations create and destroy /proc entries,
populate and depopulate net::rules_ops and multiroute table.
All the structures are pernet, and they are not touched
by foreign net pernet_operations. So, it's possible to mark
them async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch finishes converting pernet_operations
registered in net/wireless directory.
These pernet_operations have only exit method,
which moves devices to init_net. This action
is not pernet_operations-specific, and function
cfg80211_switch_netns() may be called all time
during the system life. All necessary protection
against concurrent cfg80211_pernet_exit() is made
by rtnl_lock(). So, cfg80211_pernet_ops is able
to be marked as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
init method initializes sysctl defaults, allocates
percpu arrays and creates /proc entries.
exit method reverts the above.
There are no pernet_operations, which are interested
in the above entities of foreign net namespace, so
inet6_net_ops are able to be marked as async.
Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In ungraceful host shutdown or driver crash case BMC connectivity is
lost. APE firmware is missing the driver state in this
case to keep the BMC connectivity alive.
This patch has below change to address this issue.
Heartbeat mechanism with APE firmware. This heartbeat mechanism
is needed to notify the APE firmware about driver state.
This patch also has the change in wait time for APE event from
1ms to 20ms as there can be some delay in getting response.
v2: Drop inline keyword as per David suggestion.
Signed-off-by: Prashant Sreedharan <prashant.sreedharan@broadcom.com>
Signed-off-by: Satish Baddipadige <satish.baddipadige@broadcom.com>
Signed-off-by: Siva Reddy Kallam <siva.kallam@broadcom.com>
Acked-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The ADVERTISED_Asym_Pause bit was being improperly set when both
rx and tx pause were enabled. When rx and tx are both enabled, only
the ADVERTISED_Pause bit is supposed to be set.
Signed-off-by: Jake Moroni <mail@jakemoroni.com>
Acked-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The *while* loop in this function can be turned into a normal *for* loop.
And getting rid of the single return point saves us a few more LoCs...
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Martin Blumenstingl says:
====================
dwmac-meson8b: small cleanup
This is a follow-up to my previous series "dwmac-meson8b: clock fixes for
Meson8b" from [0].
during the review of that series it was found that the clock registration
could be simplified. now that the previous series has landed we can start
cleaning up the clock registration.
the goal of this series is to simplify the code in the dwmac-meson8b
driver. no functional changes are intended.
I have tested this on my Khadas VIM2 (GXM SoC, with RGMII PHY) and my
Endless Mini (EC-100, Meson8b SoC with RMII PHY, .dts support is not part
of mainline yet). no problems were found.
[0] http://lists.infradead.org/pipermail/linux-amlogic/2018-January/006143.html
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
The common clock framework needs access to the "clock configuration"
structs during runtime.
However, only the common clock framework should access these. Ensure
this by moving the configuration structs out of struct meson8b_dwmac,
so only meson8b_init_rgmii_tx_clk() and the common clock framework know
about these configurations.
Suggested-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Acked-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Nothing in the dwmac-meson8b driver (except .probe itself) requires the
platform_device anymore after .probe has finished. Replace it with a
pointer to struct device since this is what the functions inside the
driver are actually accessing.
No functional changes.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To goal of this patch is to simplify the registration of the RGMII TX
clock (and it's parent clocks). This is achieved by:
- introducing the meson8b_dwmac_register_clk helper-function to remove
code duplication when registering a single clock (this saves a few
lines since we have 4 clocks internally)
- using devm_add_action_or_reset to disable the RGMII TX clock
automatically when needed. This also allows us to re-use the standard
stmmac_pltfr_remove function.
- devm_kasprintf() and devm_kstrdup() are not used anymore to generate
the clock name (these are replaced by a variable on the stack) because
the common clock framework already uses kstrdup() internally.
No functional changes intended.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When mlxsw replaces (or deletes) a route it removes the offload
indication from the replaced route. This is problematic for IPv4 routes,
as the offload indication is stored in the fib_info which is usually
shared between multiple routes.
Instead of unconditionally clearing the offload indication, only clear
it if no other route is using the fib_info.
Fixes: 3984d1a89f ("mlxsw: spectrum_router: Provide offload indication using nexthop flags")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alexander Petrovskiy <alexpe@mellanox.com>
Tested-by: Alexander Petrovskiy <alexpe@mellanox.com>
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Subash Abhinov Kasiviswanathan says:
====================
net: qualcomm: rmnet: Fix issues with CONFIG_DEBUG_PREEMPT enabled
Patch 1 and 2 fixes issues identified when CONFIG_DEBUG_PREEMPT was
enabled. These involve APIs which were called in invalid contexts.
Patch 3 is a null derefence fix identified by code inspection.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
If a command packet with invalid mux id is received, the packet would
not have a valid endpoint. This invalid endpoint maybe dereferenced
leading to a crash. Identified by manual code inspection.
Fixes: 3352e6c457 ("net: qualcomm: rmnet: Convert the muxed endpoint to hlist")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
With CONFIG_DEBUG_PREEMPT enabled, a crash with the following call
stack was observed when removing a real dev which had rmnet devices
attached to it.
To fix this, remove the netdev_upper link APIs and instead use the
existing information in rmnet_port and rmnet_priv to get the
association between real and rmnet devs.
BUG: sleeping function called from invalid context
in_atomic(): 0, irqs_disabled(): 0, pid: 5762, name: ip
Preemption disabled at:
[<ffffff9d49043564>] debug_object_active_state+0xa4/0x16c
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
Modules linked in:
PC is at ___might_sleep+0x13c/0x180
LR is at ___might_sleep+0x17c/0x180
[<ffffff9d48ce0924>] ___might_sleep+0x13c/0x180
[<ffffff9d48ce09c0>] __might_sleep+0x58/0x8c
[<ffffff9d49d6253c>] mutex_lock+0x2c/0x48
[<ffffff9d48ed4840>] kernfs_remove_by_name_ns+0x48/0xa8
[<ffffff9d48ed6ec8>] sysfs_remove_link+0x30/0x58
[<ffffff9d49b05840>] __netdev_adjacent_dev_remove+0x14c/0x1e0
[<ffffff9d49b05914>] __netdev_adjacent_dev_unlink_lists+0x40/0x68
[<ffffff9d49b08820>] netdev_upper_dev_unlink+0xb4/0x1fc
[<ffffff9d494a29f0>] rmnet_dev_walk_unreg+0x6c/0xc8
[<ffffff9d49b00b40>] netdev_walk_all_lower_dev_rcu+0x58/0xb4
[<ffffff9d494a30fc>] rmnet_config_notify_cb+0xf4/0x134
[<ffffff9d48cd21b4>] raw_notifier_call_chain+0x58/0x78
[<ffffff9d49b028a4>] call_netdevice_notifiers_info+0x48/0x78
[<ffffff9d49b0b568>] rollback_registered_many+0x230/0x3c8
[<ffffff9d49b0b738>] unregister_netdevice_many+0x38/0x94
[<ffffff9d49b1e110>] rtnl_delete_link+0x58/0x88
[<ffffff9d49b201dc>] rtnl_dellink+0xbc/0x1cc
[<ffffff9d49b2355c>] rtnetlink_rcv_msg+0xb0/0x244
[<ffffff9d49b5230c>] netlink_rcv_skb+0xb4/0xdc
[<ffffff9d49b204f4>] rtnetlink_rcv+0x34/0x44
[<ffffff9d49b51af0>] netlink_unicast+0x1ec/0x294
[<ffffff9d49b51fdc>] netlink_sendmsg+0x320/0x390
[<ffffff9d49ae6858>] sock_sendmsg+0x54/0x60
[<ffffff9d49ae6f94>] ___sys_sendmsg+0x298/0x2b0
[<ffffff9d49ae98f8>] SyS_sendmsg+0xb4/0xf0
[<ffffff9d48c83770>] el0_svc_naked+0x24/0x28
Fixes: ceed73a2cf ("drivers: net: ethernet: qualcomm: rmnet: Initial implementation")
Fixes: 60d58f971c ("net: qualcomm: rmnet: Implement bridge mode")
Signed-off-by: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
_port_ is already known to be a valid index in the callers [1]. So
these checks are unnecessary.
[1] https://lkml.org/lkml/2018/2/16/469
Addresses-Coverity-ID: 1465287
Addresses-Coverity-ID: 1465291
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Because READ_ONCE() now implies smp_read_barrier_depends(), the
smp_read_barrier_depends() in __ptr_ring_consume() is redundant;
this commit removes it and updates the comments.
Signed-off-by: Andrea Parri <parri.andrea@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: <linux-kernel@vger.kernel.org>
Cc: <netdev@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
