This ensures that the pvid which is stored in __le16 format is converted
to the CPU format. This will fix comparison issues on Big Endian
platforms.

Change-ID: I92c80d1315dc2a0f9f095d5a0c48d461beb052ed
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

On Big Endian platforms we would incorrectly calculate the wrong switch
id since we did not properly convert the le16 value into CPU format.
Caught by sparse.

Change-ID: I69a2f9fa064a0a91691f7d0e6fcc206adceb8e36
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch refactors the '%*ph' printk format specifier to instead use
the print_hex_dump function, as recommended by the '%*ph' documentation.
This produces better/more standardized output.

Change-ID: Id56700b4e8abc40ff8c04bc8379e7df04cb4d6fd
Signed-off-by: NAlan Brady <alan.brady@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch fixes a bug introduced with the addition of the per queue
ITR feature support in ethtool.  With that addition, there were
functions added which converted the ITR settings to binary values.
The IS_ENABLED macros that run on those values check whether a bit
is set or not and with the value being binary, the bit check always
returned ITR disabled which prevents any updating of the ITR rate.
This patch fixes the problem by changing the functions to return the
current ITR value instead and renaming it to better reflect
its function.  These functions now provide a value which will be
accurately asessed and update the ITR as intended.

Change-ID: I14f1d088d052e27f652aaa3113e186415ddea1fc
Signed-off-by: NCarolyn Wyborny <carolyn.wyborny@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Add a comment to reduce confusion.

Change-ID: I3d5819c0f3f5174680442ae54398a073d4a61f4f
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

When the i40evf_remove() calls netdev close, the device doesn't actually
close - it schedules the work for the watchdog to perform. Since we're
stopping the watchdog, this work doesn't get done. However, we're
resetting the part, so we can free resources after the reset request has
gone through. This plugs a memory leak.

Change-ID: Id5335dcaf76ce00d2a4c3d26e9faf711d7f051cf
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This call is made just prior to running i40e_link_event. In
i40e_link_event, we set hw->phy.get_link_info to true just prior to
calling i40e_get_link_status, which conveniently runs
i40e_update_link_info for us. Thus, we are running i40e_update_link_info
twice, which seems like something we don't need to do...

Change-ID: I36467a570f44b7546d218c99e134ff97c2709315
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds a call to the mac_address_write admin q function during
power down to update the PRTPM_SAH/SAL registers with the MC_MAG_EN bit
thus enabling multicast magic packet wakeup.

A FW workaround is needed to write the multicast magic wake up enable
bit in the PRTPM_SAH register. The FW expects the mac address write
admin q cmd to be called first with one of the WRITE_TYPE_LAA flags
and then with the multicast relevant flags.

*Note: This solution only works for X722 devices currently. A PFR will
clear the previously mentioned bit by default, but X722 has support for a
WOL_PRESERVE_ON_PFR flag which prevents the bit from being cleared. Once
other devices support this flag, this solution should work as well.

Change-ID: I51bd5b8535bd9051c2676e27c999c1657f786827
Signed-off-by: NJoshua Hay <joshua.a.hay@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

There exists a bug in which the driver is unable to exit overflow
promiscuous mode after having added "too many" mac filters.  It is
expected that after triggering overflow promiscuous, removing the
failed/extra filters should then disable overflow promiscuous mode.

The bug exists because we were intentionally skipping the sync_vsi_filter
path in cases where we were removing failed filters since they shouldn't
have been added to the firmware in the first place, however we still
need to go through the sync_vsi_filter code path to determine whether or
not it is ok to exit overflow promiscuous mode.  This patch fixes the
bug by making sure we go through the sync_vsi_filter path in cases of
failed filters.

Change-ID: I634d249ca3e5fa50729553137c295e73e7722143
Signed-off-by: NAlan Brady <alan.brady@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch makes it so that we don't need to bother with clearing the
memory out for the descriptor rings.  The general idea is to only free
buffers associated with buffers in use which are located between the
next_to_clean and next_to_use or next_to_alloc values.  Everything outside
of those regions can be safely ignored since they should have no buffers
associated with them.

The advantage to doing things this way is that is should speed up bring-up
and tear-down of the rings.  Specifically we can avoid the 512 or more
cycles required to memset the rings in tear-down.  In the bring-up phase we
then clear the memory as a part of initialization.  The general idea is
that the clearing in initialization can act as a prefetch of sorts for the
buffer info structures so they are in the local CPU when we go to populate
them.  This should help to improve overall time needed to perform a
suspend/resume.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds build_skb support to the Rx path.  There are several
advantages to this change.

1.  It avoids the memcpy and skb->head allocation for small packets which
    improves performance by about 5% in my tests.
2.  It avoids the memcpy, skb->head allocation, and eth_get_headlen
    for larger packets improving performance by about 10% in my tests.
3.  For VXLAN packets it allows the full header to be in skb->data which
    improves the performance by as much as 30% in some of my tests.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Since there are potential drawbacks to the new Rx allocation approach I
thought it best to add a "chicken bit" so that we can turn the feature off
if in the event that a problem is found.

It also provides a means of validating the legacy Rx path in the event that
we are forced to fall back.  At some point in the future when we are
convinced we don't need it anymore we might be able to drop the legacy-rx
flag.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds support for providing a buffer with headroom and tailroom
to allow for shared info, NET_SKB_PAD, and NET_IP_ALIGN.  With this
combined with the DMA changes we can start using build_skb to build frames
around an incoming Rx buffer instead of having to memcpy the headers.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

We are going to be expanding the number of Rx paths in the driver.  Instead
of duplicating all that code I am pulling it apart into separate functions
so that we don't have so much code duplication.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This change makes it so that we use the length of the packet instead of the
DD status bit to determine if a new descriptor is ready to be processed.
The obvious advantage is that it cuts down on reads as we don't really even
need the DD bit if going from a 0 to a non-zero value on size is enough to
inform us that the packet has been completed.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

In order to support build_skb with jumbo frames it will be necessary to use
3K buffers for the Rx path with 8K pages backing them.  This is needed on
architectures that implement 4K pages because we can't support 2K buffers
plus padding in a 4K page.

In the case of systems that support page sizes larger than 4K the 3K
attribute will only be applied to FCoE as we can fall back to using just 2K
buffers and adding the padding.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Batch the page count updates instead of doing them one at a time.  By doing
this we can improve the overall performance as the atomic increment
operations can be expensive due to the fact that on x86 they are locked
operations which can cause stalls.  By doing bulk updates we can
consolidate the stall which should help to improve the overall receive
performance.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Acked-by: NJohn Fastabend <john.r.fastabend@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch adds support for DMA_ATTR_SKIP_CPU_SYNC and
DMA_ATTR_WEAK_ORDERING.  By enabling both of these for the Rx path we are
able to see performance improvements on architectures that implement either
one due to the fact that page mapping and unmapping only has to sync what
is actually being used instead of the entire buffer.  In addition by
enabling the weak ordering attribute enables a performance improvement for
architectures that can associate a memory ordering with a DMA buffer such
as Sparc.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

On some platforms, syncing a buffer for DMA is expensive. Rather than
sync the whole 2K receive buffer, only synchronise the length of the
frame, which will typically be the MTU, or a much smaller TCP ACK.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch consolidates the code for the ixgbe driver so that it is more
inline with what is already in igb.  The general idea is to just
consolidate functions that represent logical steps in the Rx process so we
can later update them more easily.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Update the driver version to reflect the new devices that it
supports.
Signed-off-by: NMark Rustad <mark.d.rustad@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Since dcbnl_ops is global, it should be prefixed by ixgbe_
Signed-off-by: NStephen Hemminger <sthemmin@microsoft.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Though not advertised through ethtool, if the link partner advertises a
2.5Gb or 5Gb connection, and the adapter supports it, allow the speed to be
used.
Signed-off-by: NTony Nguyen <anthony.l.nguyen@intel.com>
Tested-by: NKrishneil Singh <krishneil.k.singh@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Ethtool support needs to save more PHY information. The
added information includes FEC capabilities and 25G link
types. Without this change it is possible to lose 25G or
FEC settings by using ethtool.

Change-ID: Ie42255b1e901ffbf9583b8c46466a54894114280
Signed-off-by: NHenry Tieman <henry.w.tieman@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Refactor how we add new filters to firmware to avoid a race condition
that can occur due to removing filters from the hash temporarily.

To understand the race condition, suppose that you have a number of MAC
filters, but have not yet added any VLANs. Now, add two VLANs in rapid
succession. A possible resulting flow would look something like the
following:

(1) lock hash for add VLAN
(2) add the new MAC/VLAN combos for each current MAC filter
(3) unlock hash
(4) lock hash for filter sync
(5) notice that we have a VLAN, so prepare to update all MAC filters
    with VLAN=-1 to be VLAN=0.
(6) move NEW and REMOVE filters to temporary list
(7) unlock hash
(8) lock hash for add VLAN
(9) add new MAC/VLAN combos. Notice that no MAC filters are currently in
    the hash list, so we don't add any VLANs <--- BUG!
(10) unlock hash
(11) sync the temporary lists to firmware
(12) lock hash for post-sync
(13) move the temporary elements back to the main list
....

Because we take filters out of the main hash into temporary lists, we
introduce a narrow window where it is possible that other callers to the
list will not see some of the filters which were previously added but
have not yet been finalized. This results in sometimes dropping VLAN
additions, and could also result in failing to add a MAC address on the
newly added VLAN.

One obvious way to avoid this race condition would be to lock the entire
firmware process. Unfortunately this does not work because adminq
firmware commands take a mutex which results in a sleep while atomic
BUG(). So, we can't use the simplest approach.

An alternative approach is to simply not remove the filters from the
hash list while adding. Instead, add an i40e_new_mac_filter structure
which we will use to track added filters. This avoids the need to remove
the filter from the hash list. We'll store a pointer to the original
i40e_mac_filter, along with our own copy of the state.

We won't update the state directly, so as to avoid race with other code
that may modify the state while under the lock. We are safe to read
f->macaddr and f->vlan since these only change in two locations. The
first is on filter creation, which must have already occurred. The
second is inside i40e_correct_vlan_filters which was previously run
after creation of this object and can't be run again until after. Thus,
we should be safe to read the MAC address and VLAN while outside the
lock.

We also aren't going to run into a use-after-free issue because the only
place where we free filters is when they are marked FAILED or when we
remove them inside the sync subtask. Since the subtask has its own
critical flag to prevent duplicate runs, we know this won't happen. We
also know that the only location to transition a filter from NEW to
FAILED is inside the subtask also, so we aren't worried about that
either.

Use the wrapper i40e_new_mac_filter for additions, and once we've
finalized the addition to firmware, we will update the filter state
inside a lock, and then free the wrapper structure.

In order to avoid a possible race condition with filter deletion, we
won't update the original filter state unless it is still
I40E_FILTER_NEW when we finish the firmware sync.

This approach is more complex, but avoids race conditions related to
filters being temporarily removed from the list. We do not need the same
behavior for deletion because we always unconditionally removed the
filters from the list regardless of the firmware status.

Change-Id: I14b74bc2301f8e69433fbe77ebca532db20c5317
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Fix a bug where we modified the mac_filter_hash while outside a lock,
when handling addition of broadcast filters.

Normally, we add filters to firmware by batching the additions into
lists and issuing 1 update for every few filters. Broadcast filters are
handled differently, by instead setting the broadcast promiscuous mode
flags. In order to make sure the 1<->1 mapping of filters in our
addition array lined up with filters in the hlist tmp_add_list, we had
to remove the filter and move it back to the main hash. However, we
didn't do this under lock, which could cause consistency problems for
the list.

Fix this by updating i40e_update_filter_state logic so that it knows to
avoid broadcast filters. This ensures that we don't have to remove the
filter separately, and can put it back using the normal flow.

Change-ID: Id288fade80b3e3a9a54b68cc249188cb95147518
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The intent of this message was to indicate to a user that we might have
missed a timestamp event for a valid packet. The original method of
detecting the missed events relied on waiting until all 4 registers were
filled.

A recent commit d55458c0cd7a5 ("i40e: replace PTP Rx timestamp hang
logic") replaced this logic with much better detection
scheme that could detect a stalled Rx timestamp register even when other
registers were still functional.

The new logic means that a message will be displayed almost as soon as
a timestamp for a dropped frame occurs. This new logic highlights that
the hardware will attempt timestamp for frames which it later decides to
drop. The most prominent example is when a multicast PTP frame is
received on a multicast address that we are not subscribed to.

Because the hardware initiates the Rx timestamp as soon as possible, it
will latch an RXTIME register, but then drop the packet.

This results in users being confused by the message as they are not
expecting to see dropped timestamp messages unless their application
also indicates that timestamps were missing.

Resolve this by reducing the severity and frequency of the displayed
message. We now only print the message if 3 or 4 of the RXTIME registers
are stalled and get cleared within the same watchdog event. This ensures
that the common case does not constantly display the message.
Additionally, since the message is likely not as meaningful to most
users, reduce the message to a dev_dbg instead of a dev_warn.

Users can still get a count of the number of timestamps dropped by
reading the ethtool statistics value, if necessary.

Change-ID: I35494442226a444c418dfb4f91a3070d06c8435c
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Store the FEC status bits from the link up event into the
hw_link_info structure.

Change-ID: I9a7b256f6dfb0dce89c2f503075d0d383526832e
Signed-off-by: NHenry Tieman <henry.w.tieman@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Currently i40e_bus_info has PCI device and function info only and log
messages print device number as bus number. Added field to provide bus
number info and modified log statements to print bus, device and
function information.

Change-ID: I811617cee2714cc0d6bade8d369f57040990756f
Signed-off-by: NSudheer Mogilappagari <sudheer.mogilappagari@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The function i40e_client_prepare() can never return an error. So make it
void and quit checking its return value.

Change-ID: I9ff311e2324dde329eb68648efb2c94aaff856db
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Signed-off-by: NBimmy Pujari <bimmy.pujari@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The original comment implies that the only location where the raw_packet
buffer will be freed is in i40e_clean_tx_ring() which is incorrect. In
fact this isn't even the normal case. Update the comment explaining
where the memory is freed.

Change-ID: Ie0defc35ed1c3af183f81fdc60b6d783707a5595
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Reorganize the i40e_pull_tail() logic, doing it in i40e_add_rx_frag()
where it's cheaper.  The igb driver does this the same way.

Also renames i40e_page_is_reserved() to reflect what it actually
tests.

Change-ID: Icd9cc507aae1fcdc02308b3a09034111b4c24071
Signed-off-by: NScott Peterson <scott.d.peterson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

This patch reduces the size of struct i40e_rx_buffer by one pointer,
and makes the i40e driver a little more consistent with the igb driver
in terms of packets that span buffers.

We do this by moving the skb field from struct i40e_rx_buffer to
struct i40e_ring. We pass the skb we already have (or NULL if we
don't) to i40e_fetch_rx_buffer(), which skips the skb allocation if we
already have one for this packet.

Change-ID: I4ad48a531844494ba0c5d8e1a62209a057f661b0
Signed-off-by: NScott Peterson <scott.d.peterson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

On packet RX, we perform a DMA sync for CPU before passing the
packet up.  Here we limit that sync to the actual length of the
incoming packet, rather than always syncing the entire buffer.

Change-ID: I626aaf6c37275a8ce9e81efcaa773f327b331487
Signed-off-by: NScott Peterson <scott.d.peterson@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

The iWarp client cannot continue until this operation has been completed
by the PF driver. Sleep (with timeout) until the reply from the PF
driver has been received.

Change-ID: I5dc41b857bba32d0218b7ce167b5da122dadf349
Signed-off-by: NMitch Williams <mitch.a.williams@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

We can avoid the minor bit of work by calling check params after we
check for the client instance, since we're about to return early in
cases where we do not have a client.

Change-ID: I56f8ea2ba48d4f571fa331c9ace50819a022fa1c
Signed-off-by: NJacob Keller <jacob.e.keller@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot's of code, we also remove one lock
operation in fast path, and allow GRO to do its job.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In linux-4.5, busy polling was implemented in core
NAPI stack, meaning that all custom implementation can
be removed from drivers.

Not only we remove lot's of code, we also remove one lock
operation in fast path, and allow GRO to do its job.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to the resolution of the register controlling interrupt rate
limiting, setting certain values for the interrupt rate limit make it
appear as though the limiting is not completely accurate.  The problem
is that the interrupt rate limit is getting rounded down to the nearest
multiple of 4.  This patch fixes the problem by adding some feedback to
the user as to the actual interrupt rate limit being used when it
differs from the requested limit.  Without this patch setting interrupt
rate limits may appear to behave inaccurately.

Change-ID: I3093cf3f2d437d35a4c4f4bb5af5ce1b85ab21b7
Signed-off-by: NAlan Brady <alan.brady@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>