Testing with RTL8822BE hardware, when available memory is low, we
frequently see a kernel panic and system freeze.

First, rtw_pci_rx_isr encounters a memory allocation failure (trimmed):

rx routine starvation
WARNING: CPU: 7 PID: 9871 at drivers/net/wireless/realtek/rtw88/pci.c:822 rtw_pci_rx_isr.constprop.25+0x35a/0x370 [rtwpci]
[ 2356.580313] RIP: 0010:rtw_pci_rx_isr.constprop.25+0x35a/0x370 [rtwpci]

Then we see a variety of different error conditions and kernel panics,
such as this one (trimmed):

rtw_pci 0000:02:00.0: pci bus timeout, check dma status
skbuff: skb_over_panic: text:00000000091b6e66 len:415 put:415 head:00000000d2880c6f data:000000007a02b1ea tail:0x1df end:0xc0 dev:<NULL>
------------[ cut here ]------------
kernel BUG at net/core/skbuff.c:105!
invalid opcode: 0000 [#1] SMP NOPTI
RIP: 0010:skb_panic+0x43/0x45

When skb allocation fails and the "rx routine starvation" is hit, the
function returns immediately without updating the RX ring. At this
point, the RX ring may continue referencing an old skb which was already
handed off to ieee80211_rx_irqsafe(). When it comes to be used again,
bad things happen.

This patch allocates a new, data-sized skb first in RX ISR. After
copying the data in, we pass it to the upper layers. However, if skb
allocation fails, we effectively drop the frame. In both cases, the
original, full size ring skb is reused.

In addition, to fixing the kernel crash, the RX routine should now
generally behave better under low memory conditions.

Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=204053Signed-off-by: Jian-Hong Pan <jian-hong@endlessm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

This sentinel tells the firmware loading process when to stop.

Reported-and-tested-by: syzbot+98156c174c5a2cad9f8f@syzkaller.appspotmail.com
Signed-off-by: Kevin Easton <kevin@guarana.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Arguments are supposed to be ordered high then low.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Yan-Hsuan Chuang <yhchuang@realtek.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

The variable rc is being initialized with a value that is never
read and it is being updated later with a new value that is returned.
The variable is redundant and can be replaced with a return 0 as
there are no other return points in this function.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

The variable ret is being initialized with a value that is never
read and it is being updated later with a new value. The
initialization is redundant and can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

The WiFi tx power of RTL8723BU is extremely low after booting. So
the WiFi scan gives very limited AP list and it always fails to
connect to the selected AP. This module only supports 1x1 antenna
and the antenna is switched to bluetooth due to some incorrect
register settings.

Compare with the vendor driver https://github.com/lwfinger/rtl8723bu,
we realized that the 8723bu's enable_rf() does the same thing as
rtw_btcoex_HAL_Initialize() in vendor driver. And it by default
sets the antenna path to BTC_ANT_PATH_BT which we verified it's
the cause of the wifi weak tx power. The vendor driver will set
the antenna path to BTC_ANT_PATH_PTA in the consequent btcoexist
mechanism, by the function halbtc8723b1ant_PsTdma.

This commit hand over the antenna control to PTA(Packet Traffic
Arbitration), which compares the weight of bluetooth/wifi traffic
then determine whether to continue current wifi traffic or not.
After PTA take control, The wifi signal will be back to normal and
the bluetooth scan can also work at the same time. However, the
btcoexist still needs to be handled under different circumstances.
If there's a BT connection established, the wifi still fails to
connect until BT disconnected.
Signed-off-by: Chris Chiu <chiu@endlessm.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Because we don't need to save the individual debugfs files and
directories, remove the local storage of them and just remove the entire
debugfs directory in a single call, making things a lot simpler.

Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Helmut Schaa <helmut.schaa@googlemail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

In contrast to the TX path, there is no need to separately read the transfer
status from the device after receiving RX data. Consequently, there is no
real STATUS_PENDING RX processing queue entry state.
Remove the unnecessary ENTRY_DATA_STATUS_PENDING flag checks from the RX path.
Also remove the misleading comment about reading RX status from device.
Suggested-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Soeren Moch <smoch@web.de>
Acked-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Explicitly return constants instead of variable (and rely on
it to be explicitly initialized), if the value is supposed
to be fixed anyways. Align it with the rest of the driver,
which does it the same way.
Signed-off-by: Enrico Weigelt <info@metux.net>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Signed-off-by: Roman Mashak <mrv@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The rest of Hyper-V code is using new types for UUID handling.
Convert hv_sock as well.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

John Hurley says:

====================
nfp: Offload MPLS actions

The module act_mpls has recently been added to the kernel. This allows the
manipulation of MPLS headers on packets including push, pop and modify.
Add these new actions and parameters to the intermediate representation
API for hardware offload. Follow this by implementing the offload of these
MPLS actions in the NFP driver.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Recent additions to the kernel include a TC action module to manipulate
MPLS headers on packets. Such actions are available to offload via the
flow_offload intermediate representation API.

Modify the NFP driver to allow the offload of MPLS set actions to
firmware. Set actions update the outermost MPLS header. The offload
includes a mask to specify which fields should be set.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Recent additions to the kernel include a TC action module to manipulate
MPLS headers on packets. Such actions are available to offload via the
flow_offload intermediate representation API.

Modify the NFP driver to allow the offload of MPLS pop actions to
firmware. The act_mpls TC module enforces that the next protocol is
supplied along with the pop action. Passing this to firmware allows it
to properly rebuild the underlying packet after the pop.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Recent additions to the kernel include a TC action module to manipulate
MPLS headers on packets. Such actions are available to offload via the
flow_offload intermediate representation API.

Modify the NFP driver to allow the offload of MPLS push actions to
firmware.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Simon Horman <simon.horman@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

A recent addition to TC actions is the ability to manipulate the MPLS
headers on packets.

In preparation to offload such actions to hardware, update the IR code to
accept and prepare the new actions.

Note that no driver currently impliments the MPLS dec_ttl action so this
is not included.
Signed-off-by: John Hurley <john.hurley@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The structure is too large to put on the stack, resulting in a
warning on 32-bit ARM:

drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c:59:5: error: stack frame size of 1344 bytes in function
      'mlx5e_open_xsk' [-Werror,-Wframe-larger-than=]

Use kvzalloc() instead.

Fixes: a038e9794541 ("net/mlx5e: Add XSK zero-copy support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Instead of using to_pci_dev + pci_get_drvdata,
use dev_get_drvdata to make code simpler.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/faraday/ftgmac100.c:777:13: error: 'skb_frag_t {aka struct bio_vec}' has no member named 'size'

Fallout from the skb_frag_t conversion to bio_vec, simply
use skb_frag_size().

Fixes: b8b576a1 ("net: Rename skb_frag_t size to bv_len")
Reported-by: René van Dorst <opensource@vdorst.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The hardware has been declared EOL by the vendor more than 5 years ago.
What's more relevant to the Linux kernel is that the quality of this driver
is not on par with many other mainline drivers.

Cc: Manish Chopra <manishc@marvell.com>
Message-id: <20190617074858.32467-1-bpoirier@suse.com>
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Matthew Wilcox says:

====================
Convert skb_frag_t to bio_vec

The skb_frag_t and bio_vec are fundamentally the same (page, offset,
length) tuple.  This patch series unifies the two, leaving the
skb_frag_t typedef in place.  This has the immediate advantage that
we already have iov_iter support for bvecs and don't need to add
support for iterating skbuffs.  It enables a long-term plan to use
bvecs more broadly within the kernel and should make network-storage
drivers able to do less work converting between skbuffs and biovecs.

It will consume more memory on 32-bit kernels.  If that proves
problematic, we can look at ways of addressing it.

v3: Rebase on latest Linus with net-next merged.
  - Reorder the uncontroversial 'Use skb accessors' patches first so you
    can apply just those two if you want to hold off on the full
    conversion.
  - Convert all the users of 'struct skb_frag_struct' to skb_frag_t.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

There are a lot of users of frag->page_offset, so use a union
to avoid converting those users today.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Improved compatibility with bvec
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

One step closer to turning the skb_frag_t into a bio_vec.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Match the layout of bio_vec.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

To increase commonality between block and net, we are going to replace
the skb_frag_t with the bio_vec.  This patch increases the size of
skb_frag_t on 32-bit machines from 8 bytes to 12 bytes.  The size is
unchanged on 64-bit machines.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge the combo uses of cpu_to_le32s and memcpy.
Use put_unaligned_le32 instead.
This simplifies the code.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch improves few aspects of rtl_rx, no functional change intended.

1. inline rtl8169_try_rx_copy
2. make pkt_size unsigned
3. use constant ETH_FCS_LEN instead of value 4
4. We just created the skb, so we don't need the checks in skb_put.
   Also we don't need the return value of skb_put.
   Set skb->tail and skb->len directly.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge the combo use of memcpy and le32_to_cpus.
Use get_unaligned_le32 instead.
This simplifies the code.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge the combo use of memcpy and le32_to_cpus.
Use get_unaligned_le32 instead.
This simplifies the code.
Signed-off-by: Chuhong Yuan <hslester96@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>