The flow spec member vlan_tci is in network order. Hence comparisons
should be made again network order values.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Oddly, GENMASK() requires signed bit numbers, so that it can compare
them for < 0. If passed an unsigned type, we get warnings about the
test never being true.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrew Lunn says:

====================
net: dsa: Fix C=1 W=1 warnings

Mostly not using __be16 when decoding packet contents.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/tag_qca.c:48:15: warning: incorrect type in assignment (different base types)
net/dsa/tag_qca.c:48:15:    expected unsigned short [usertype]
net/dsa/tag_qca.c:48:15:    got restricted __be16 [usertype]
net/dsa/tag_qca.c:68:13: warning: incorrect type in assignment (different base types)
net/dsa/tag_qca.c:68:13:    expected restricted __be16 [usertype] hdr
net/dsa/tag_qca.c:68:13:    got int
net/dsa/tag_qca.c:71:16: warning: restricted __be16 degrades to integer
net/dsa/tag_qca.c:81:17: warning: restricted __be16 degrades to integer
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/tag_mtk.c:84:13: warning: incorrect type in assignment (different base types)
net/dsa/tag_mtk.c:84:13:    expected restricted __be16 [usertype] hdr
net/dsa/tag_mtk.c:84:13:    got int
net/dsa/tag_mtk.c:94:17: warning: restricted __be16 degrades to integer

The result of a ntohs() is not __be16, but u16.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/tag_lan9303.c:76:24: warning: incorrect type in assignment (different base types)
net/dsa/tag_lan9303.c:76:24:    expected unsigned short [usertype]
net/dsa/tag_lan9303.c:76:24:    got restricted __be16 [usertype]
net/dsa/tag_lan9303.c:80:24: warning: incorrect type in assignment (different base types)
net/dsa/tag_lan9303.c:80:24:    expected unsigned short [usertype]
net/dsa/tag_lan9303.c:80:24:    got restricted __be16 [usertype]
net/dsa/tag_lan9303.c:106:31: warning: restricted __be16 degrades to integer
net/dsa/tag_lan9303.c:111:24: warning: cast to restricted __be16
net/dsa/tag_lan9303.c:111:24: warning: cast to restricted __be16
net/dsa/tag_lan9303.c:111:24: warning: cast to restricted __be16
net/dsa/tag_lan9303.c:111:24: warning: cast to restricted __be16

Make use of __be16 where appropriate to fix these warnings.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

cpu_to_be16 returns a __be16 value. So what it is assigned to needs to
have the same type to avoid warnings.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dsa/slave.c:505:13: warning: incorrect type in initializer (different address spaces)
net/dsa/slave.c:505:13:    expected void const [noderef] <asn:3> *__vpp_verify
net/dsa/slave.c:505:13:    got struct pcpu_sw_netstats *

Add the needed _percpu property to prevent this warning.
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vladimir Oltean says:

====================
Phylink integration improvements for Felix DSA driver

This is an overhaul of the Felix switch driver's phylink operations.

Patches 1, 3, 4 and 5 are cleanup, patch 2 is adding a new feature and
and patch 6 is adaptation to the new format of an existing phylink API
(mac_link_up).

Changes since v2:
- Replaced "PHYLINK" with "phylink".
- Rewrote commit message of patch 5/6.

Changes since v1:
- Now using phy_clear_bits and phy_set_bits instead of plain writes to
  MII_BMCR. This combines former patches 1/7 and 6/7 into a single new
  patch 1/6.
- Updated commit message of patch 5/6.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Phylink now requires that parameters established through
auto-negotiation be written into the MAC at the time of the
mac_link_up() callback. In the case of felix, that means taking the port
out of reset, setting the correct timers for PAUSE frames, and
enabling/disabling TX flow control.

This patch also splits the inband and noinband configuration of the
vsc9959 PCS (currently found in a function called "init") into 2
different functions, which have a nomenclature closer to phylink:
"config", for inband setup, and "link_up", for noinband (forced) setup.

This is necessary as a preparation step for giving up control of the PCS
to phylink, which will be done in further patch series.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Phylink uses the .mac_an_restart method to offer the user an
implementation of the "ethtool -r" behavior, when the media-side auto
negotiation can be restarted by the local MAC PCS. This is the case for
fiber modes 1000Base-X and 2500Base-X (IEEE clause 37) that don't have
an Ethernet PHY connected locally, and the media is connected to the MAC
PCS directly.

On the other hand, the Cisco SGMII and USXGMII standards also have an
auto negotiation mechanism based on IEEE 802.3 clause 37 (their
respective specs require a MAC PCS and a PHY PCS to implement the same
state machine, which is described in IEEE 802.3 "Auto-Negotiation Figure
37-6"), so the ability to restart auto-negotiation is intrinsically
symmetrical (the MAC PCS can do it too).

However, it appears that not all SGMII/USXGMII PHYs have logic to
restart the MDI-side auto-negotiation process when they detect a
transition of the SGMII link from data mode to configuration mode.
Some do (VSC8234) and some don't (AR8033, MV88E1111). IEEE and/or Cisco
specification wordings to not help to prove whether propagating the "AN
restart" event from MII side ("mr_restart_an") to MDI side
("mr_restart_negotiation") is required behavior - neither of them
specifies any mandatory interaction between the clause 37 AN state
machine from Figure 37-6 and the clause 28 AN state machine from Figure
28-18.

Therefore, even if a certain behavior could be proven as being required,
real-life SGMII/USXGMII PHYs are inconsistent enough that a clause 37 AN
restart cannot be used by phylink to reliably trigger a media-side
renegotiation, when the user requests it via ethtool.

The only remaining use that the .mac_an_restart callback might possibly
have, given what we know now, is to implement some silicon quirks, but
so far that has proven to not be necessary.

So remove this code for now, since it never gets called and we don't
foresee any circumstance in which it might be, either.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

state->speed holds a value of 10, 100, 1000 or 2500, but
SYS_MAC_FC_CFG_FC_LINK_SPEED expects a value in the range 0, 1, 2 or 3.

So set the correct speed encoding into this register.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In VSC9959, the PCS is the one who performs rate adaptation (symbol
duplication) to the speed negotiated by the PHY. The MAC is unaware of
that and must remain configured for gigabit. If it is configured at
OCELOT_SPEED_10 or OCELOT_SPEED_100, it'll start transmitting PAUSE
frames out of control and never recover, _even if_ we then reconfigure
it at OCELOT_SPEED_1000 afterwards.

This patch fixes a bug that luckily did not have any functional impact.
We were writing 10, 100, 1000 etc into this 2-bit field in
DEV_CLOCK_CFG, but the hardware expects values in the range 0, 1, 2, 3.
So all speed values were getting truncated to 0, which is
OCELOT_SPEED_2500, and which also appears to be fine.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Ping tested:

  [   11.808455] mscc_felix 0000:00:00.5 swp0: Link is Up - 1Gbps/Full - flow control rx/tx
  [   11.816497] IPv6: ADDRCONF(NETDEV_CHANGE): swp0: link becomes ready

  [root@LS1028ARDB ~] # ethtool -s swp0 advertise 0x4
  [   18.844591] mscc_felix 0000:00:00.5 swp0: Link is Down
  [   22.048337] mscc_felix 0000:00:00.5 swp0: Link is Up - 100Mbps/Half - flow control off

  [root@LS1028ARDB ~] # ip addr add 192.168.1.1/24 dev swp0

  [root@LS1028ARDB ~] # ping 192.168.1.2
  PING 192.168.1.2 (192.168.1.2): 56 data bytes
  (...)
  ^C--- 192.168.1.2 ping statistics ---
  3 packets transmitted, 3 packets received, 0% packet loss
  round-trip min/avg/max = 0.383/0.611/1.051 ms

  [root@LS1028ARDB ~] # ethtool -s swp0 advertise 0x10
  [  355.637747] mscc_felix 0000:00:00.5 swp0: Link is Down
  [  358.788034] mscc_felix 0000:00:00.5 swp0: Link is Up - 1Gbps/Half - flow control off

  [root@LS1028ARDB ~] # ping 192.168.1.2
  PING 192.168.1.2 (192.168.1.2): 56 data bytes
  (...)
  ^C
  --- 192.168.1.2 ping statistics ---
  16 packets transmitted, 16 packets received, 0% packet loss
  round-trip min/avg/max = 0.301/0.384/1.138 ms
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

The driver appears to write to BMCR_SPEED and BMCR_DUPLEX, fields which
are read-only, since they are actually configured through the
vendor-specific IF_MODE (0x14) register.

But the reason we're writing back the read-only values of MII_BMCR is to
alter these writable fields:

BMCR_RESET
BMCR_LOOPBACK
BMCR_ANENABLE
BMCR_PDOWN
BMCR_ISOLATE
BMCR_ANRESTART

In particular, the only field which is really relevant to this driver is
BMCR_ANENABLE. Clarify that intention by spelling it out, using
phy_set_bits and phy_clear_bits.

The driver also made a few writes to BMCR_RESET and BMCR_ANRESTART which
are unnecessary and may temporarily disrupt the link to the PHY. Remove
them.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Vaibhav Gupta says:

====================
qlogic: use generic power management

Linux Kernel Mentee: Remove Legacy Power Management.

The purpose of this patch series is to remove legacy power management callbacks
from qlogic ethernet drivers.

The callbacks performing suspend() and resume() operations are still calling
pci_save_state(), pci_set_power_state(), etc. and handling the power management
themselves, which is not recommended.

The conversion requires the removal of the those function calls and change the
callback definition accordingly and make use of dev_pm_ops structure.

All patches are compile-tested only.

V2: Fix unused variable warning in v1.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

With legacy PM, drivers themselves were responsible for managing the
device's power states and taking care of register states. And they use PCI
helper functions to do it.

After upgrading to the generic structure, PCI core will take care of
required tasks and drivers should do only device-specific operations.

.suspend() calls __qlcnic_shutdown, which then calls qlcnic_82xx_shutdown;
.resume()  calls __qlcnic_resume,   which then calls qlcnic_82xx_resume;

Both ...82xx..() are define in
drivers/net/ethernet/qlogic/qlcnic/qlcnic_hw.c and are used only in
drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c.

Hence upgrade them and remove PCI function calls, like pci_save_state() and
pci_enable_wake(), inside them

Compile-tested only.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

With legacy PM, drivers themselves were responsible for managing the
device's power states and takes care of register states. And they use PCI
helper functions to do it.

After upgrading to the generic structure, PCI core will take care of
required tasks and drivers should do only device-specific operations.

In this driver:
netxen_nic_resume() calls netxen_nic_attach_func() which then invokes PCI
helper functions like pci_enable_device(), pci_set_power_state() and
pci_restore_state(). Other function:
 - netxen_io_slot_reset()
also calls netxen_nic_attach_func().

Also, netxen_io_slot_reset() returns specific value based on the return value
of netxen_nic_attach_func() as whole. Thus, cannot simply move some piece of
code from netxen_nic_attach_func() to it.

Hence, define a new function netxen_nic_attach_late_func() to do the tasks
which has to be done after PCI helper functions have done their job.

Now, netxen_nic_attach_func() invokes netxen_nic_attach_late_func(), thus
netxen_io_slot_reset() behaves normally.
And, netxen_nic_resume() calls netxen_nic_attach_late_func() to avoid PCI
helper functions calls.

Compile-tested only.
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Private structure members live_ports, on_ports, rx_ports, tx_ports are
initialized but not used anywhere. Let's remove them.
Suggested-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The DSA subsystem moved to phylink and adjust_link() became deprecated in
the process. This patch removes adjust_link from the KSZ DSA switches and
adds phylink_mac_link_up() and phylink_mac_link_down().
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Reviewed-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Florian Westphal says:

====================
mptcp: add REUSEADDR/REUSEPORT/V6ONLY setsockopt support

restarting an mptcp-patched sshd yields following error:

  sshd: error: Bind to port 22 on 0.0.0.0 failed: Address already in use.
  sshd: error: setsockopt IPV6_V6ONLY: Operation not supported
  sshd: error: Bind to port 22 on :: failed: Address already in use.
  sshd: fatal: Cannot bind any address.

This series adds support for the needed setsockopts:

First patch skips the generic SOL_SOCKET handler for MPTCP:
in mptcp case, the setsockopt needs to alter the tcp socket, not the mptcp
parent socket.

Second patch adds minimal SOL_SOCKET support: REUSEPORT and REUSEADDR.
Rest is still handled by the generic SOL_SOCKET code.

Last patch adds IPV6ONLY support.  This makes ipv6 work for openssh:
It creates two listening sockets, before this patch, binding the ipv6
socket will fail because the port is already bound by the ipv4 one.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Without this, Opensshd fails to open an ipv6 socket listening
socket:
  error: setsockopt IPV6_V6ONLY: Operation not supported
  error: Bind to port 22 on :: failed: Address already in use.

Opensshd opens an ipv4 and and ipv6 listening socket, but because
IPV6_V6ONLY setsockopt fails, the port number is already in use.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

This will e.g. make 'sshd restart' work when MPTCP is used, as we will
now set this option on the listener socket instead of only the mptcp
socket (where it has no effect).

We still need to copy the setting to the master socket so that a
subsequent getsockopt() returns the expected value.
Reported-by: Christoph Paasch <cpaasch@apple.com>
Suggested-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

setsockopt(mptcp_fd, SOL_SOCKET, ...)...  appears to work (returns 0),
but it has no effect -- this is because the MPTCP layer never has a
chance to copy the settings to the subflow socket.

Skip the generic handling for the mptcp case and instead call the
mptcp specific handler instead for SOL_SOCKET too.

Next patch adds more specific handling for SOL_SOCKET to mptcp.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Before, clang version 9 threw errors such as: error:
use of GNU old-style field designator extension [-Werror,-Wgnu-designator]
                { tstamp: true, swtstamp: true }
                  ^~~~~~~
                  .tstamp =
Fix these warnings in tools/testing/selftests/net in the same manner as
commit 121e357a ("selftests/harness: Update named initializer syntax").
N.B. rxtimestamp.c is the only affected file in the directory.
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Sudarsana Reddy Kalluru says:

====================
bnx2x: Perform IdleChk dump.

Idlechk test verifies that the chip is in idle state. If there are any
errors, Idlechk dump would capture the same. This data will help in
debugging the device related issues.
The patch series adds driver support for dumping IdleChk data during the
debug dump collection.
Patch (1) adds register definitions required in this implementation.
Patch (2) adds the implementation for Idlechk tests.
Patch (3) adds driver changes to invoke Idlechk implementation.

Changes from previous version:
-------------------------------
v3: Combined the test data creation and implementation to a single patch.
v2: Addressed issues reported by kernel test robot.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The patch adds driver changes to perform Idlechk dump during the debug
data collection.
Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch populates a database of idlechk tests (registers and
predicates) and performs the idlechk using this data.
Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The patch adds register definitions required for Idlechk implementation.
Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf-next 2020-07-04

The following pull-request contains BPF updates for your *net-next* tree.

We've added 73 non-merge commits during the last 17 day(s) which contain
a total of 106 files changed, 5233 insertions(+), 1283 deletions(-).

The main changes are:

1) bpftool ability to show PIDs of processes having open file descriptors
   for BPF map/program/link/BTF objects, relying on BPF iterator progs
   to extract this info efficiently, from Andrii Nakryiko.

2) Addition of BPF iterator progs for dumping TCP and UDP sockets to
   seq_files, from Yonghong Song.

3) Support access to BPF map fields in struct bpf_map from programs
   through BTF struct access, from Andrey Ignatov.

4) Add a bpf_get_task_stack() helper to be able to dump /proc/*/stack
   via seq_file from BPF iterator progs, from Song Liu.

5) Make SO_KEEPALIVE and related options available to bpf_setsockopt()
   helper, from Dmitry Yakunin.

6) Optimize BPF sk_storage selection of its caching index, from Martin
   KaFai Lau.

7) Removal of redundant synchronize_rcu()s from BPF map destruction which
   has been a historic leftover, from Alexei Starovoitov.

8) Several improvements to test_progs to make it easier to create a shell
   loop that invokes each test individually which is useful for some CIs,
   from Jesper Dangaard Brouer.

9) Fix bpftool prog dump segfault when compiled without skeleton code on
   older clang versions, from John Fastabend.

10) Bunch of cleanups and minor improvements, from various others.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Matteo Croce says:

====================
mvpp2: XDP support

Add XDP support to mvpp2. This series converts the driver to the
page_pool API for RX buffer management, and adds native XDP support.

XDP support comes with extack error reporting and statistics as well.

These are the performance numbers, as measured by Sven:

SKB fwd page pool:
Rx bps     390.38 Mbps
Rx pps     762.46 Kpps

XDP fwd:
Rx bps     1.39 Gbps
Rx pps     2.72 Mpps

XDP Drop:
eth0: 12.9 Mpps
eth1: 4.1 Mpps
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Add ethtool statistics for XDP.
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the transmit part of XDP support, which includes:
- support for XDP_TX in mvpp2_xdp()
- .ndo_xdp_xmit hook for AF_XDP and XDP_REDIRECT with mvpp2 as destination

mvpp2_xdp_submit_frame() is a generic function which is called by
mvpp2_xdp_xmit_back() when doing XDP_TX, and by mvpp2_xdp_xmit when
doing AF_XDP or XDP_REDIRECT target.

The buffer allocation has been reworked to be able to map the buffers
as DMA_FROM_DEVICE or DMA_BIDIRECTIONAL depending if native XDP is
in use or not.
Co-developed-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add XDP native support.
By now only XDP_DROP, XDP_PASS and XDP_REDIRECT
verdicts are supported.
Co-developed-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Use the page_pool API for memory management.
This is a prerequisite for native XDP support.
Tested-by: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In mvpp2_swf_bm_pool_init_percpu(), a reference to a struct
mvpp2_bm_pool is obtained traversing multiple structs, when a
local variable already points to the same object.

Fix it and, while at it, give the variable a meaningful name.
Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the options --ipv4, --ipv6 to specify running over ipv4 and/or
ipv6. If neither is specified, then run both.
Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Alex Elder says:

====================
net: ipa: fix HOLB timer register use

The function ipa_reg_init_hol_block_timer_val() generates the value
to write into the HOL_BLOCK_TIMER endpoint configuration register,
to represent a given timeout value (in microseconds).  It only
supports a timer value of 0 though, in part because that's
sufficient, but mainly because there was some confusion about
how the register is formatted in newer hardware.

I got clarification about the register format, so this series fixes
ipa_reg_init_hol_block_timer_val() to work for any supported delay
value.

The delay is based on the IPA core clock, so determining the value
to write for a given period requires access to the current core
clock rate.  So the first patch just creates a new function to
provide that.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

For IPA v4.2, the exact interpretation of the register that defines
the timeout for avoiding head-of-line blocking was a little unclear.
We're only assigning a 0 timeout to it right now, so that wasn't
very important.  But now that I know how it's supposed to work, I'm
fixing it.

The register represents a tick counter, where each tick is equal to
128 IPA core clock cycles.  For IPA v3.5.1, the register contains
a simple counter value.  But for IPA v4.2, the register contains two
fields, base and scale, which approximate the tick counter as:
    ticks = base << scale
The base and scale values to use for a given tick count are computed
using clever bit operations, and measures are taken to make the
resulting time period as close as possible to that requested.

There's no need for ipa_endpoint_init_hol_block_timer() to return
an error, so change its return type to void.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Create a new function that returns the current rate of the IPA core
clock.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>