The napi_alloc_frag_align() will guarantee that a correctly align
buffer address is returned. So use this function to simplify the buffer
alloc and avoid the unnecessary memory waste.
Signed-off-by: NKevin Hao <haokexin@gmail.com>
Reviewed-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Fix the following coccicheck warnings:

./drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:1651:36-38: WARNING
!A || A && B is equivalent to !A || B.
Reported-by: NAbaci Robot <abaci@linux.alibaba.com>
Signed-off-by: NJiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/1612260157-128026-1-git-send-email-jiapeng.chong@linux.alibaba.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Check if the interface is indeed connected to a MAC before trying to
close the DPMAC object representing it. Without this check we end up
working with a NULL pointer.

Fixes: d87e6063 ("dpaa2-mac: export MAC counters even when in TYPE_FIXED")
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20210111171802.1826324-1-ciorneiioana@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Declare Rx VLAN filtering as supported and user-changeable only when
there are VLAN filtering entries available on the DPNI object. Even
then, rx-vlan-filtering is by default disabled.
Also, populate the .ndo_vlan_rx_add_vid() and .ndo_vlan_rx_kill_vid()
callbacks for adding and removing a specific VLAN from the VLAN table.
Signed-off-by: NIonut-robert Aron <ionut-robert.aron@nxp.com>
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20210111170725.1818218-1-ciorneiioana@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

The MC firmware takes these PAUSE/ASYM_PAUSE flags provided by the
driver, transforms them back into rx/tx pause enablement status and
applies them to hardware. We are not losing information by this
transformation, thus remove the comment.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The dpaa2-eth driver has phylink integration only if the connected dpmac
object is in TYPE_PHY (aka the PCS/PHY etc link status is managed by
Linux instead of the firmware). The check is thus unnecessary because
the code path that reaches the .mac_link_up() callback is only with
TYPE_PHY dpmac objects.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The fsl_mc_get_endpoint() function now returns -EPROBE_DEFER when the
dpmac device was not yet discovered by the fsl-mc bus. When this
happens, pass the error code up so that we can retry the probe at a
later time.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

If the network interface object is connected to a MAC of TYPE_FIXED, the
link status management is handled exclusively by the firmware. This does
not mean that the driver cannot access the MAC counters and export them
in ethtool.

For this to happen, we open the attached dpmac device and keep a pointer
to it in priv->mac. Because of this, all the checks in the driver of the
following form 'if (priv->mac)' have to be updated to actually check
the dpmac attribute and not rely on the presence of a non-NULL value.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Split up the initialization phase of the dpmac object from actually
configuring the phylink instance, connecting to it and configuring the
MAC. This is done so that even though the dpni object is connected to a
dpmac which has link management handled by the firmware we are still
able to export the MAC counters.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Introduce xdp_prepare_buff utility routine to initialize per-descriptor
xdp_buff fields (e.g. xdp_buff pointers). Rely on xdp_prepare_buff() in
all XDP capable drivers.
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NAlexander Duyck <alexanderduyck@fb.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NShay Agroskin <shayagr@amazon.com>
Acked-by: NMartin Habets <habetsm.xilinx@gmail.com>
Acked-by: NCamelia Groza <camelia.groza@nxp.com>
Acked-by: NMarcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/bpf/45f46f12295972a97da8ca01990b3e71501e9d89.1608670965.git.lorenzo@kernel.orgSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

Introduce xdp_init_buff utility routine to initialize xdp_buff fields
const over NAPI iterations (e.g. frame_sz or rxq pointer). Rely on
xdp_init_buff in all XDP capable drivers.
Signed-off-by: NLorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Reviewed-by: NAlexander Duyck <alexanderduyck@fb.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>
Acked-by: NShay Agroskin <shayagr@amazon.com>
Acked-by: NMartin Habets <habetsm.xilinx@gmail.com>
Acked-by: NCamelia Groza <camelia.groza@nxp.com>
Acked-by: NMarcin Wojtas <mw@semihalf.com>
Link: https://lore.kernel.org/bpf/7f8329b6da1434dc2b05a77f2e800b29628a8913.1608670965.git.lorenzo@kernel.orgSigned-off-by: NAlexei Starovoitov <ast@kernel.org>

This patch fixes an error condition triggered when the code path which
transmits a S/G frame descriptor when the skb's headroom is not enough
for DPAA2's needs.

We are greated with a splat like the one below when a SGT structure is
recycled and that is because even though a dma_unmap is performed on the
Tx confirmation path, the unmap is not done with the proper size.

[  714.464927] WARNING: CPU: 13 PID: 0 at drivers/iommu/io-pgtable-arm.c:281 __arm_lpae_map+0x2d4/0x30c
(...)
[  714.465343] Call trace:
[  714.465348]  __arm_lpae_map+0x2d4/0x30c
[  714.465353]  __arm_lpae_map+0x114/0x30c
[  714.465357]  __arm_lpae_map+0x114/0x30c
[  714.465362]  __arm_lpae_map+0x114/0x30c
[  714.465366]  arm_lpae_map+0xf4/0x180
[  714.465373]  arm_smmu_map+0x4c/0xc0
[  714.465379]  __iommu_map+0x100/0x2bc
[  714.465385]  iommu_map_atomic+0x20/0x30
[  714.465391]  __iommu_dma_map+0xb0/0x110
[  714.465397]  iommu_dma_map_page+0xb8/0x120
[  714.465404]  dma_map_page_attrs+0x1a8/0x210
[  714.465413]  __dpaa2_eth_tx+0x384/0xbd0 [fsl_dpaa2_eth]
[  714.465421]  dpaa2_eth_tx+0x84/0x134 [fsl_dpaa2_eth]
[  714.465427]  dev_hard_start_xmit+0x10c/0x2b0
[  714.465433]  sch_direct_xmit+0x1a0/0x550
(...)

The dpaa2-eth driver uses an area of software annotations to transmit
necessary information from the Tx path to the Tx confirmation one. This
SWA structure has a different layout for each kind of frame that we are
dealing with: linear, S/G or XDP.

The commit referenced was incorrectly setting up the 'sgt_size' field
for the S/G type of SWA even though we are dealing with a linear skb
here.

Fixes: d70446ee ("dpaa2-eth: send a scatter-gather FD instead of realloc-ing")
Reported-by: NDaniel Thompson <daniel.thompson@linaro.org>
Tested-by: NDaniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201211171607.108034-1-ciorneiioana@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Add an 'of_node_put()' call when a tested device node is not available.

Fixes: 94ae899b ("dpaa2-mac: add PCS support through the Lynx module")
Signed-off-by: NChristophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201206151339.44306-1-christophe.jaillet@wanadoo.frSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Add napi_id to the xdp_rxq_info structure, and make sure the XDP
socket pick up the napi_id in the Rx path. The napi_id is used to find
the corresponding NAPI structure for socket busy polling.
Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NIlias Apalodimas <ilias.apalodimas@linaro.org>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NTariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-7-bjorn.topel@gmail.com

The dpaa2 driver depends on devlink, so it should select
NET_DEVLINK in order to fix compile errors, such as:

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.o: in function `dpaa2_eth_rx_err':
dpaa2-eth.c:(.text+0x3cec): undefined reference to `devlink_trap_report'
drivers/net/ethernet/freescale/dpaa2/dpaa2-eth-devlink.o: in function `dpaa2_eth_dl_info_get':
dpaa2-eth-devlink.c:(.text+0x160): undefined reference to `devlink_info_driver_name_put'

Fixes: ceeb03ad ("dpaa2-eth: add basic devlink support")
Signed-off-by: NEzequiel Garcia <ezequiel@collabora.com>
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201123163553.1666476-1-ciorneiioana@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Remove usage of magic numbers.
Signed-off-by: NChristian Eggers <ceggers@arri.de>
Cc: Ioana Ciornei <ioana.ciornei@nxp.com>
Cc: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Cc: Yangbo Lu <yangbo.lu@nxp.com>
Reviewed-by: NVladimir Oltean <olteanv@gmail.com>
Reviewed-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

Explicitly enable the FSL_XGMAC_MDIO Kconfig option in order to have
MDIO access to internal and external PHYs.

Fixes: 71947923 ("dpaa2-eth: add MAC/PHY support through phylink")
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Link: https://lore.kernel.org/r/20201119145106.712761-1-ciorneiioana@gmail.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>

Add support for the new group of devlink traps - PARSER_ERROR_DROPS.
This consists of registering the array of parser error drops supported,
controlling their action through the .trap_group_action_set() callback
and reporting an erroneous skb received on the error queue
appropriately.
DPAA2 devices do not support controlling the action of independent
parser error traps, thus the .trap_action_set() callback just returns an
EOPNOTSUPP while .trap_group_action_set() actually notifies the hardware
what it should do with a frame marked as having a header error.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add basic support in dpaa2-eth for devlink. For the moment, just
register the device with devlink, add the corresponding devlink port and
implement the .info_get() callback.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a null-check for _pcs_, but it is being dereferenced
prior to this null-check. So, if _pcs_ can actually be null,
then there is a potential null pointer dereference that should
be fixed by null-checking _pcs_ before being dereferenced.

Addresses-Coverity-ID: 1497159 ("Dereference before null check")
Fixes: 94ae899b ("dpaa2-mac: add PCS support through the Lynx module")
Signed-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When SHARED_FS is enabled on a DPNI object the flow steering tables are
shared between all the traffic classes. Modify the driver so that we
only add a new flow steering entry on the TC#0 when this new option is
enabled.
Signed-off-by: NIonut-robert Aron <ionut-robert.aron@nxp.com>
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The call to dpaa2_eth_link_state_update() is a leftover from the time
when on DPAA2 platforms the PHYs were started at boot time so when an
ifconfig was issued on the associated interface, the link status needed
to be checked directly from the ndo_open() callback.
This is not needed anymore since we are now properly integrated with the
PHY layer thus a link interrupt will come directly from the PHY
eventually without the need to call the sync function.
Fix this up by removing the call to dpaa2_eth_link_state_update().
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is no need to check if both the MDIO controller node and its
child node, the PCS device, are available since there is no chance that
the child node would be enabled when the parent it's not.
Suggested-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When adding the support for TBF offload, the improper command version
was added even though the command format is for the V2 of
dpni_set_tx_shaping(). This does not affect the functionality of TBF
since the only change between these two versions is the addition of the
exceeded parameters which are not used in TBF. Still, fix the bug so
that we keep things in sync.

Fixes: 39344a89 ("dpaa2-eth: add API for Tx shaping")
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As part of the W=1 cleanups for ethernet, a million [*] driver
comments had to be cleaned up to get the W=1 compilation to
succeed. This change finally makes the drivers/net/ethernet tree
compile with W=1 set on the command line. NOTE: The kernel uses
kdoc style (see Documentation/process/kernel-doc.rst) when
documenting code, not doxygen or other styles.

After this patch the x86_64 build has no warnings from W=1, however
scripts/kernel-doc says there are 1545 more warnings in source files, that
I need to develop a script to fix in a followup patch.

The errors fixed here are all kdoc of a few classes, with a few outliers:
In file included from drivers/net/ethernet/qlogic/netxen/netxen_nic_hw.c:10:
drivers/net/ethernet/qlogic/netxen/netxen_nic.h:1193:18: warning: ‘FW_DUMP_LEVELS’ defined but not used [-Wunused-const-variable=]
 1193 | static const u32 FW_DUMP_LEVELS[] = { 0x3, 0x7, 0xf, 0x1f, 0x3f, 0x7f, 0xff };
      |                  ^~~~~~~~~~~~~~
... repeats 4 times...
drivers/net/ethernet/sun/cassini.c:2084:24: warning: suggest braces around empty body in an ‘else’ statement [-Wempty-body]
 2084 |    RX_USED_ADD(page, i);
drivers/net/ethernet/natsemi/ns83820.c: In function ‘phy_intr’:
drivers/net/ethernet/natsemi/ns83820.c:603:6: warning: variable ‘tbisr’ set but not used [-Wunused-but-set-variable]
  603 |  u32 tbisr, tanar, tanlpar;
      |      ^~~~~
drivers/net/ethernet/natsemi/ns83820.c: In function ‘ns83820_get_link_ksettings’:
drivers/net/ethernet/natsemi/ns83820.c:1207:11: warning: variable ‘tanar’ set but not used [-Wunused-but-set-variable]
 1207 |  u32 cfg, tanar, tbicr;
      |           ^~~~~
drivers/net/ethernet/packetengines/yellowfin.c:1063:18: warning: variable ‘yf_size’ set but not used [-Wunused-but-set-variable]
 1063 |   int data_size, yf_size;
      |                  ^~~~~~~

Normal kdoc fixes:
warning: Function parameter or member 'x' not described in 'y'
warning: Excess function parameter 'x' description in 'y'
warning: Cannot understand <string> on line <NNN> - I thought it was a doc line

[*] - ok it wasn't quite a million, but it felt like it.
Signed-off-by: NJesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Include PCS support in the dpaa2-eth driver by integrating it with the
new Lynx PCS module. There is not much to talk about in terms of changes
needed in the dpaa2-eth driver since the only steps necessary are to
find the MDIO device representing the PCS, register it to the Lynx PCS
module and then let phylink know if its existence also.
After this, the PCS callbacks will be treated directly by Lynx, without
interraction from dpaa2-eth's part.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

sg_init_table zeroes its first argument, so the allocation of that argument
doesn't have to.

the semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,n,flags;
@@

x =
- kcalloc
+ kmalloc_array
  (n,sizeof(struct scatterlist),flags)
...
sg_init_table(x,n)
// </smpl>
Signed-off-by: NJulia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix below sparse warning in dpmac.c.
warning: cast to restricted __le64
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add PTP sync packet one-step timestamping support.
Before egress, one-step timestamping enablement needs,

- Enabling timestamp and FAS (Frame Annotation Status) in
  dpni buffer layout.

- Write timestamp to frame annotation and set PTP bit in
  FAS to mark as one-step timestamping event.

- Enabling one-step timestamping by dpni_set_single_step_cfg()
  API, with offset provided to insert correction time on frame.
  The offset must respect all MAC headers, VLAN tags and other
  protocol headers accordingly. The correction field update can
  consider delays up to one second. So PTP frame needs to be
  filtered and parsed, and written timestamp into Sync frame
  originTimestamp field.

The operation of API dpni_set_single_step_cfg() has to be done
when no one-step timestamping frames are in flight. So we have
to make sure the last one-step timestamping frame has already
been transmitted on hardware before starting to send the current
one. The resolution is,

- Utilize skb->cb[0] to mark timestamping request per packet.
  If it is one-step timestamping PTP sync packet, queue to skb queue.
  If not, transmit immediately.

- Schedule a work to transmit skbs in skb queue.

- mutex lock is used to ensure the last one-step timestamping packet
  has already been transmitted on hardware through TX confirmation queue
  before transmitting current packet.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is a preparation for next hardware one-step timestamping
support. For DPAA2, the one step timestamping configuration on
hardware registers has to be done when there is no one-step timestamping
packet in flight. So we will have to use workqueue and skb queue
for such packets transmitting, to make sure waiting the last packet has
already been sent on hardware, and starting to transmit the current one.

So the tx timestamping flag in private data may not reflect the actual
request for the one-step timestamping packets of skb queue. This also
affects skb headroom allocation. Let's use skb->cb[0] to mark the
timestamping request for each skb.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Invoke dpaa2_eth_enable_tx_tstamp() once in code after building FD,
rather than calling it in dpaa2_eth_build_single_fd(),
dpaa2_eth_build_sg_fd_single_buf(), and dpaa2_eth_build_sg_fd().
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Define a global ptp_qoriq structure pointer, and export to use.
The ptp clock operations will be used in dpaa2-eth driver.
For example, supporting one step timestamping needs to write
current time to hardware frame annotation before sending and
then hardware inserts the delay time on frame during sending.
So in driver, at least clock gettime operation will be needed
to make sure right time is written to hardware frame annotation
for one step timestamping.
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch is to add APIs of 1588 single step timestamping.

- dpni_set_single_step_cfg
- dpni_get_single_step_cfg
Signed-off-by: NYangbo Lu <yangbo.lu@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NQinglang Miao <miaoqinglang@huawei.com>
Reviewed-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some static functions in the dpaa2-eth driver don't have the dpaa2_eth_
prefix and this is becoming an inconvenience when looking at, for
example, a perf top output and trying to determine easily which entries
are dpaa2-eth related. Ammend this by adding the prefix to all the
functions.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some static functions in the dpaa2-eth driver don't have the dpaa2_eth_
prefix and this is becoming an inconvenience when looking at, for
example, a perf top output and trying to determine easily which entries
are dpaa2-eth related. Ammend this by adding the prefix to all the
functions.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some static functions in the dpaa2-eth driver don't have the dpaa2_eth_
prefix and this is becoming an inconvenience when looking at, for
example, a perf top output and trying to determine easily which entries
are dpaa2-eth related. Ammend this by adding the prefix to all the
functions.
Signed-off-by: NIoana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>

Fix smatch warning:

drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c:2419
 alloc_channel() warn: passing zero to 'ERR_PTR'

setup_dpcon() should return ERR_PTR(err) instead of zero in error
handling case.

Fixes: d7f5a9d8 ("dpaa2-eth: defer probe on object allocate")
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver calls napi_schedule_irqoff() from a context where, in RT,
hardirqs are not disabled, since the IRQ handler is force-threaded.

In the call path of this function, __raise_softirq_irqoff() is modifying
its per-CPU mask of pending softirqs that must be processed, using
or_softirq_pending(). The or_softirq_pending() function is not atomic,
but since interrupts are supposed to be disabled, nobody should be
preempting it, and the operation should be safe.

Nonetheless, when running with hardirqs on, as in the PREEMPT_RT case,
it isn't safe, and the pending softirqs mask can get corrupted,
resulting in softirqs being lost and never processed.

To have common code that works with PREEMPT_RT and with mainline Linux,
we can use plain napi_schedule() instead. The difference is that
napi_schedule() (via __napi_schedule) also calls local_irq_save, which
disables hardirqs if they aren't already. But, since they already are
disabled in non-RT, this means that in practice we don't see any
measurable difference in throughput or latency with this patch.
Signed-off-by: NJiafei Pan <Jiafei.Pan@nxp.com>
Signed-off-by: NVladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>