TI CPTS IP is used as part of TI OMAP CPSW driver, but it's also
present as part of NETCP on TI Keystone 2 SoCs. So, It's required
to enable build of CPTS for both this drivers and this can be
achieved by allowing CPTS to be built separately.

Hence, allow cpts to be built separately and convert it to be
a module as both CPSW and NETCP drives can be built as modules.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Switch to readl/writel_relaxed() APIs, because this is recommended
API and the CPTS IP is reused on Keystone 2 SoCs
where LE/BE modes are supported.
Signed-off-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Acked-by: NRichard Cochran <richardcochran@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Michael Chan says:

====================
bnxt_en: Add interface to support RDMA driver.

This series adds an interface to support a brand new RDMA driver bnxt_re.
The first step is to re-arrange some code so that pci_enable_msix() can
be called during pci probe.  The purpose is to allow the RDMA driver to
initialize and stay initialized whether the netdev is up or down.

Then we make some changes to VF resource allocation so that there is
enough resources to support RDMA.

Finally the last patch adds a simple interface to allow the RDMA driver to
probe and register itself with any bnxt_en devices that support RDMA.
Once registered, the RDMA driver can request MSIX, send fw messages, and
receive some notifications.

v2: Fixed kbuild test robot warnings.

David, please consider this series for net-next.  Thanks.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since the network driver and RDMA driver operate on the same PCI function,
we need to create an interface to allow the RDMA driver to share resources
with the network driver.

1. Create a new bnxt_en_dev struct which will be returned by
bnxt_ulp_probe() upon success.  After that, all calls from the RDMA driver
to bnxt_en will pass a pointer to this struct.

2. This struct contains additional function pointers to register, request
msix, send fw messages, register for async events.

3. If the RDMA driver wants to enable RDMA on the function, it needs to
call the function pointer bnxt_register_device().  A ulp_ops structure
is passed for RCU protected upcalls from bnxt_en to the RDMA driver.

4. The RDMA driver can call firmware APIs using the bnxt_send_fw_msg()
function pointer.

5. 1 stats context is reserved when the RDMA driver registers.  MSIX
and completion rings are reserved when the RDMA driver calls
bnxt_request_msix() function pointer.

6. When the RDMA driver calls bnxt_unregister_device(), all RDMA resources
will be cleaned up.

v2: Fixed 2 uninitialized variable warnings.
Signed-off-by: NSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The driver register function with firmware consists of passing version
information and registering for async events.  To support the RDMA driver,
the async events that we need to register may change.  Separate the
driver register function into 2 parts so that we can just update the
async events for the RDMA driver.
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the device supports RDMA, we'll setup network default rings so that
there are enough minimum resources for RDMA, if possible.  However, the
user can still increase network rings to the max if he wants.  The actual
RDMA resources won't be reserved until the RDMA driver registers.

v2: Fix compile warning when BNXT_CONFIG_SRIOV is not set.
Signed-off-by: NSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All available remaining completion rings not used by the PF should be
made available for the VFs so that there are enough rings in the VF to
support RDMA.  The earlier workaround code of capping the rings by the
statistics context is removed.

When SRIOV is disabled, call a new function bnxt_restore_pf_fw_resources()
to restore FW resources.  Later on we need to add some logic to account
for RDMA resources.
Signed-off-by: NSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that MSIX is enabled in bnxt_init_one(), resources may be allocated by
the RDMA driver before the network device is opened.  So we cannot do
function reset in bnxt_open() which will clear all the resources.

The proper place to do function reset now is in bnxt_init_one().
If we get AER, we'll do function reset as well.
Signed-off-by: NSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To better support the new RDMA driver, we need to move pci_enable_msix()
from bnxt_open() to bnxt_init_one().  This way, MSIX vectors are available
to the RDMA driver whether the network device is up or down.

Part of the existing bnxt_setup_int_mode() function is now refactored into
a new bnxt_init_int_mode().  bnxt_init_int_mode() is called during
bnxt_init_one() to enable MSIX.  The remaining logic in
bnxt_setup_int_mode() to map the IRQs to the completion rings is called
during bnxt_open().

v2: Fixed compile warning when CONFIG_BNXT_SRIOV is not set.
Signed-off-by: NSomnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

By refactoring existing code into this new function.  The new function
will be used in subsequent patches.

v2: Fixed compile warning when CONFIG_BNXT_SRIOV is not set.
Signed-off-by: NMichael Chan <michael.chan@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Paolo noticed a cache line miss in UDP recvmsg() to access
sk_rxhash, sharing a cache line with sk_drops.

sk_drops might be heavily incremented by cpus handling a flood targeting
this socket.

We might place sk_drops on a separate cache line, but lets try
to avoid wasting 64 bytes per socket just for this, since we have
other bottlenecks to take care of.

sock_rps_record_flow() should only access sk_rxhash for connected
flows.

Testing sk_state for TCP_ESTABLISHED covers most of the cases for
connected sockets, for a zero cost, since system calls using
sock_rps_record_flow() also access sk->sk_prot which is on the
same cache line.

A follow up patch will provide a static_key (Jump Label) since most
hosts do not even use RFS.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch changes tun.c to call netif_receive_skb instead of netif_rx
when a packet is received (if CONFIG_4KSTACKS is not enabled to avoid
stack exhaustion). The difference between the two is that netif_rx queues
the packet into the backlog, and netif_receive_skb proccesses the packet
in the current context.

This patch is required for syzkaller [1] to collect coverage from packet
receive paths, when a packet being received through tun (syzkaller collects
coverage per process in the process context).

As mentioned by Eric this change also speeds up tun/tap. As measured by
Peter it speeds up his closed-loop single-stream tap/OVS benchmark by
about 23%, from 700k packets/second to 867k packets/second.

A similar patch was introduced back in 2010 [2, 3], but the author found
out that the patch doesn't help with the task he had in mind (for cgroups
to shape network traffic based on the original process) and decided not to
go further with it. The main concern back then was about possible stack
exhaustion with 4K stacks.

[1] https://github.com/google/syzkaller

[2] https://www.spinics.net/lists/netdev/thrd440.html#130570

[3] https://www.spinics.net/lists/netdev/msg130570.htmlSigned-off-by: NAndrey Konovalov <andreyknvl@google.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Joe Perches says:

====================
irda: w83977af_ir: Neatening

Originally on top of Arnd's overly long udelay patches because I
noticed a misindented block.  That's now already fixed along with some
other whitespace problems.  These patches are the remainder style
issues from my original series.

Even though I haven't turned on the netwinder in a box in the
garage in who knows how long, if this device is still used somewhere,
might as well neaten the code too.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use more common logging style, standardize function output logging use.

Miscellanea:

o Add and use pr_fmt
o Convert printks to pr_<level>
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Neaten function declaration and definition arguments.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add braces where appropriate and remove an unnecessary else.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Convert pointer comparisons to NULL.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use a more typical vertical spacing style.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add spaces around operators.
git diff -w shows no differences.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove leading and trailing whitespace.
git diff -w shows no differences.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull sparc fix from David Miller:
 "A use-before-NULL-check from Dan Carpenter"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  dbri: move dereference after check for NULL

We accidentally introduced a dereference before the NULL check in
xmit_descs() as part of silencing a GCC warning.

Fixes: 16f46050 ("dbri: Fix compiler warning")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pull networking fixes from David Miller:

 1) When dcbnl_cee_fill() fails to be able to push a new netlink
    attribute, it return 0 instead of an error code. From Pan Bian.

 2) Two suffix handling fixes to FIB trie code, from Alexander Duyck.

 3) bnxt_hwrm_stat_ctx_alloc() goes through all the trouble of setting
    and maintaining a return code 'rc' but fails to actually return it.
    Also from Pan Bian.

 4) ping socket ICMP handler needs to validate ICMP header length, from
    Kees Cook.

 5) caif_sktinit_module() has this interesting logic:

        int err = sock_register(...);
        if (!err)
                return err;
        return 0;

    Just return sock_register()'s return value directly which is the
    only possible correct thing to do.

 6) Two bnx2x driver fixes from Yuval Mintz, return a reasonable
    estimate from get_ringparam() ethtool op when interface is down and
    avoid trying to use UDP port based tunneling on 577xx chips.

 7) Fix ep93xx_eth crash on module unload from Florian Fainelli.

 8) Missing uapi exports, from Stephen Hemminger.

 9) Don't schedule work from sk_destruct(), because the socket will be
    freed upon return from that function. From Herbert Xu.

10) Buggy drivers, of which we know there is at least one, can send a
    huge packet into the TCP stack but forget to set the gso_size in the
    SKB, which causes all kinds of problems.

    Correct this when it happens, and emit a one-time warning with the
    device name included so that it can be diagnosed more easily.

    From Marcelo Ricardo Leitner.

11) virtio-net does DMA off the stack causes hiccups with VMAP_STACK,
    fix from Andy Lutomirski.

12) Fix fec driver compilation with CONFIG_M5272, from Nikita
    Yushchenko.

13) mlx5 fixes from Kamal Heib, Saeed Mahameed, and Mohamad Haj Yahia.
    (erroneously flushing queues on error, module parameter validation,
    etc)

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (34 commits)
  net/mlx5e: Change the SQ/RQ operational state to positive logic
  net/mlx5e: Don't flush SQ on error
  net/mlx5e: Don't notify HW when filling the edge of ICO SQ
  net/mlx5: Fix query ISSI flow
  net/mlx5: Remove duplicate pci dev name print
  net/mlx5: Verify module parameters
  net: fec: fix compile with CONFIG_M5272
  be2net: Add DEVSEC privilege to SET_HSW_CONFIG command.
  virtio-net: Fix DMA-from-the-stack in virtnet_set_mac_address()
  tcp: warn on bogus MSS and try to amend it
  uapi glibc compat: fix outer guard of net device flags enum
  net: stmmac: clear reset value of snps, wr_osr_lmt/snps, rd_osr_lmt before writing
  netlink: Do not schedule work from sk_destruct
  uapi: export nf_log.h
  uapi: export tc_skbmod.h
  net: ep93xx_eth: Do not crash unloading module
  bnx2x: Prevent tunnel config for 577xx
  bnx2x: Correct ringparam estimate when DOWN
  isdn: hisax: set error code on failure
  net: bnx2x: fix improper return value
  ...

The shmem hole punching with fallocate(FALLOC_FL_PUNCH_HOLE) does not
want to race with generating new pages by faulting them in.

However, the wait-queue used to delay the page faulting has a serious
problem: the wait queue head (in shmem_fallocate()) is allocated on the
stack, and the code expects that "wake_up_all()" will make sure that all
the queue entries are gone before the stack frame is de-allocated.

And that is not at all necessarily the case.

Yes, a normal wake-up sequence will remove the wait-queue entry that
caused the wakeup (see "autoremove_wake_function()"), but the key
wording there is "that caused the wakeup".  When there are multiple
possible wakeup sources, the wait queue entry may well stay around.

And _particularly_ in a page fault path, we may be faulting in new pages
from user space while we also have other things going on, and there may
well be other pending wakeups.

So despite the "wake_up_all()", it's not at all guaranteed that all list
entries are removed from the wait queue head on the stack.

Fix this by introducing a new wakeup function that removes the list
entry unconditionally, even if the target process had already woken up
for other reasons.  Use that "synchronous" function to set up the
waiters in shmem_fault().

This problem has never been seen in the wild afaik, but Dave Jones has
reported it on and off while running trinity.  We thought we fixed the
stack corruption with the blk-mq rq_list locking fix (commit
7fe31130: "blk-mq: update hardware and software queues for sleeping
alloc"), but it turns out there was _another_ stack corruptor hiding
in the trinity runs.

Vegard Nossum (also running trinity) was able to trigger this one fairly
consistently, and made us look once again at the shmem code due to the
faults often being in that area.

Reported-and-tested-by: Vegard Nossum <vegard.nossum@oracle.com>.
Reported-by: NDave Jones <davej@codemonkey.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Saeed Mahameed says:

====================
Mellanox 100G mlx5 fixes 2016-12-04

Some bug fixes for mlx5 core and mlx5e driver.

v1->v2:
 - replace "uint" with "unsigned int"
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When using the negative logic (i.e. FLUSH state), after the RQ/SQ reopen
we will have a time interval that the RQ/SQ is not really ready and the
state indicates that its not in FLUSH state because the initial SQ/RQ struct
memory starts as zeros.
Now we changed the state to indicate if the SQ/RQ is opened and we will
set the READY state after finishing preparing all the SQ/RQ resources.

Fixes: 6e8dd6d6 ("net/mlx5e: Don't wait for SQ completions on close")
Fixes: f2fde18c ("net/mlx5e: Don't wait for RQ completions on close")
Signed-off-by: NMohamad Haj Yahia <mohamad@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are doing SQ descriptors cleanup in driver.

Fixes: 6e8dd6d6 ("net/mlx5e: Don't wait for SQ completions on close")
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to do this a couple of steps ahead anyway.

Fixes: d3c9bc27 ("net/mlx5e: Added ICO SQs")
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In old FWs query ISSI command is not supported and for some of those FWs
it might fail with status other than "MLX5_CMD_STAT_BAD_OP_ERR".

In such case instead of failing the driver load, we will treat any FW
status other than 0 for Query ISSI FW command as ISSI not supported and
assume ISSI=0 (most basic driver/FW interface).

In case of driver syndrom (query ISSI failure by driver) we will fail
driver load.

Fixes: f62b8bb8 ('net/mlx5: Extend mlx5_core to support ConnectX-4
Ethernet functionality')
Signed-off-by: NKamal Heib <kamalh@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove duplicate pci dev name printing from mlx5_core_warn/dbg.

Fixes: 5a788398 ('net/mlx5_core: Improve mlx5 messages')
Signed-off-by: NKamal Heib <kamalh@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Verify the mlx5_core module parameters by making sure that they are in
the expected range and if they aren't restore them to their default
values.

Fixes: 9603b61d ('mlx5: Move pci device handling from mlx5_ib to mlx5_core')
Signed-off-by: NKamal Heib <kamalh@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch introduces the RX checksum function to check the
status of the hardware calculated checksum and its error and
appropriately convey status to the upper stack in skb->ip_summed
field.

In hardware, we only support checksum for the following
protocols:
1) IPv4,
2) TCP(over IPv4 or IPv6),
3) UDP(over IPv4 or IPv6),
4) SCTP(over IPv4 or IPv6)
but we support many L3(IPv4, IPv6, MPLS, PPPoE etc) and
L4(TCP, UDP, GRE, SCTP, IGMP, ICMP etc.) protocols.

Hardware limitation:
Our present hardware RX Descriptor lacks L3/L4 checksum
"Status & Error" bit (which usually can be used to indicate whether
checksum was calculated by the hardware and if there was any error
encountered during checksum calculation).

Software workaround:
We do get info within the RX descriptor about the kind of
L3/L4 protocol coming in the packet and the error status. These
errors might not just be checksum errors but could be related to
version, length of IPv4, UDP, TCP etc.
Because there is no-way of knowing if it is a L3/L4 error due
to bad checksum or any other L3/L4 error, we will not (cannot)
convey hardware checksum status(CHECKSUM_UNNECESSARY) for such
cases to upper stack and will not maintain the RX L3/L4 checksum
counters as well.
Signed-off-by: NSalil Mehta <salil.mehta@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 80cca775 ("net: fec: cache statistics while device is down")
introduced unconditional statistics-related actions.

However, when driver is compiled with CONFIG_M5272, staticsics-related
definitions do not exist, which results into build errors.

Fix that by adding explicit handling of !defined(CONFIG_M5272) case.

Fixes: 80cca775 ("net: fec: cache statistics while device is down")
Signed-off-by: NNikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

OPCODE_COMMON_GET_FN_PRIVILEGES is returning only DEVSEC
privilege (Unrestricted Administrative Privilege) for Lancer NIC functions.
So, driver is failing SET_HSW_CONFIG command, as DEVSEC privilege was not
set in the privilege bitmap. This patch fixes the problem by setting DEVSEC
privilege in SET_HSW_CONFIG’s privilege bitmap.
Signed-off-by: NVenkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Signed-off-by: NSuresh Reddy <suresh.reddy@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With CONFIG_VMAP_STACK=y, virtnet_set_mac_address() can be passed a
pointer to the stack and it will OOPS.  Copy the address to the heap
to prevent the crash.

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Laura Abbott <labbott@redhat.com>
Reported-by: zbyszek@in.waw.pl
Signed-off-by: NAndy Lutomirski <luto@kernel.org>
Acked-by: NJason Wang <jasowang@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The budget split function requires the phy speed to be known.
While ndo open a phy speed identification is postponed till the
moment link is up. Hence, move it to appropriate callback, when link
is up.
Reported-by: NGrygorii Strashko <grygorii.strashko@ti.com>
Fixes: 8feb0a19 ("net: ethernet: ti: cpsw: split tx budget according between channels")
Signed-off-by: NIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Neal Cardwell says:
 If I am reading the code correctly, then I would have two concerns:
 1) Has that been tested? That seems like an extremely dramatic
    decrease in cwnd. For example, if the cwnd is 80, and there are 40
    ACKs, and half the ACKs are ECE marked, then my back-of-the-envelope
    calculations seem to suggest that after just 11 ACKs the cwnd would be
    down to a minimal value of 2 [..]
 2) That seems to contradict another passage in the draft [..] where it
    sazs:
       Just as specified in [RFC3168], DCTCP does not react to congestion
       indications more than once for every window of data.

Neal is right.  Fortunately we don't have to complicate this by testing
vs. current rtt estimate, we can just revert the patch.

Normal stack already handles this for us: receiving ACKs with ECE
set causes a call to tcp_enter_cwr(), from there on the ssthresh gets
adjusted and prr will take care of cwnd adjustment.

Fixes: 47805667 ("dctcp: update cwnd on congestion event")
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Acked-by: NNeal Cardwell <ncardwell@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Vivien Didelot says:

====================
net: dsa: mv88e6xxx: rework reset and PPU code

Old Marvell chips (like 88E6060) don't have a PHY Polling Unit (PPU).

Next chips (like 88E6185) have a PPU, which has exclusive access to the
PHY registers, thus must be disabled before access.

Newer chips (like 88E6352) have an indirect mechanism to access the PHY
registers whenever, thus loose control over the PPU (always enabled).

Here's a summary:

Model | PPU? | Has PPU ctrl?  | PPU state readable? | PHY access
----- | ---- | -------------- | ------------------- | ----------
 6060 | no   | no             | no                  | direct
 6185 | yes  | yes, PPUEn bit | yes, PPUState 2-bit | direct w/ PPU dis.
 6352 | yes  | no             | yes, PPUState 1-bit | indirect
 6390 | yes  | no             | yes, InitState bit  | indirect

Depending on the PPU control, a switch may have to restart the PPU when
resetting the switch. Once the switch is reset, we must wait for the PPU
state to be active polling again before accessing the registers.

For that purpose, add new operations to the chips to enable/disable the
PPU, and execute software reset. With these new ops in place, rework the
switch reset code and finally get rid of the MV88E6XXX_FLAG_PPU* flags.

Changes in v3:
  - consider 6097 as 6352 (no PPU ops and use mv88e6352_g1_reset).

Changes in v2:
  - wait in ppu/reset ops so that ppu_polling is not needed anymore.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some Marvell chips can enable/disable the PPU on demand. This is needed
to access the PHY registers when there is no indirection mechanism.

Add two new ppu_enable and ppu_disable ops to describe this and finally
get rid of the MV88E6XXX_FLAG_PPU* flags.
Signed-off-by: NVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>