Improve TX pool buffer accounting to prevent the producer
index from overruning the consumer. First, set the next free
index to an invalid value if it is in use. If next buffer
to be consumed is in use, drop the packet.

Finally, if the transmit fails for some other reason, roll
back the consumer index and set the free map entry to its original
value. This should also be done if the DMA map fails.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update TX and TX completion routines to account for TX pool
restructuring. TX routine first chooses the pool depending
on whether a packet is GSO or not, then uses it accordingly.

For the completion routine to know which pool it needs to use,
set the most significant bit of the correlator index to one
if the packet uses the TSO pool. On completion, unset the bit
and use the correlator index to release the buffer pool entry.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce function that initializes one TX pool. Use that to
create each pool entry in both the standard TX pool and TSO
pool arrays.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce function that frees one TX pool.  Use that to release
each pool in both the standard TX pool and TSO pool arrays.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Update TX pool reset routine to accommodate new TSO pool array. Introduce
a function that resets one TX pool, and use that function to initialize
each pool in both pool arrays.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The case in which we handle a reset from the state where the device is
closed seems to be bugged for all types of reset. For most types of reset
we currently exit the reset routine correctly, but don't set the state to
indicate that we are back in the "closed" state. For some specific cases,
we don't exit the reset routine at all and resetting will cause a closed
device to be opened.

This patch fixes the problem by unconditionally checking the reset_state
and correctly setting the adapter state before returning.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sorry, one of the patches I sent in an earlier series
has some dumb mistakes. One was that I had changed the
parameter for the errata workaround function but forgot
to make that change in the code that called it.

The second mistake was a forgotten return value at the end
of the function in case the workaround was not needed.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

TSO packets with one segment or with an MSS less than 224 can
cause errors on some backing devices, so disable GSO in those cases.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Some backing devices cannot handle small packets well,
so pad any small packets to avoid that. It was recommended
that the VNIC driver should not send packets smaller than the
minimum MTU value provided by firmware, so pad small packets
to be at least that long.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The extra four bytes of a VLAN packet was throwing off
TX buffer entry values used by the driver. Account for those
bytes when in buffer size and buffer entry calculations
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a VLAN tag is present in the Ethernet header, account
for that when providing the L2 header to firmware.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During a device failover or partition migration reset, it is not
necessary to disable the backing adapter since it should not be
running yet and its Command-Response Queue is closed. Sending
device commands during this time could result in an error or
timeout disrupting the reset process. In these cases, just halt
transmissions, clean up resources, and continue with reset.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a function to halt network operations and clean up any
unused or outstanding socket buffers. Then, during device close,
disable backing adapter before halting all queues and performing
cleanup. This ensures all backing device operations will be
stopped before the driver cleans up shared resources.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove some dead code now that RX pools are being cleaned. This
was included to wait until any pending RX queue interrupts are
processed, but NAPI polling should be disabled by this point.

Another minor change is to use the net device parameter for any
print functions instead of accessing it from the adapter structure.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a device reset fails for some reason, TX and RX queue resources
could be released. If a user attempts to open the device in this scenario,
it may result in a kernel panic as the driver tries to access this
memory. To fix this, include a check before device login that TX/RX
queues are still there before enabling the device. In addition, return a
value that can be checked in case of any errors to avoid waiting for a
completion that will never come.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's not necessary to report each time a queue is stopped and restarted
as an informational message. Change that to be a debug message so that
it can be observed if needed but not printed by default.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If the driver releases resources after a failed reset or some other
error, the driver might attempt to clean up and free memory that
isn't there anymore. Include some additional checks that RX/TX queues
along with their associated structures are still there before cleaning.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, buffers holding individual queue statistics are allocated
when the device is opened. If an ibmvnic interface is hotplugged or
initialized but never opened, an attempt to get statistics with
ethtool will result in a kernel panic.

Since the driver allocates a constant number, the maximum supported
queues, of buffers, these can be allocated during device probe and
freed when the device is hot-unplugged or the module is removed.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Sorry, the previous change introduced a race condition between
transmit completion processing and tracking TX descriptors. If a
completion is received before the number of descriptors is logged,
the number of descriptors will be add but not removed. After enough
times, this could halt the transmit queue forever.

Log the number of descriptors used by a transmit before sending.
I stress tested the fix on two different systems running over the
weekend without any issues.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The approach of one counter to rule them all when tracking the number
of active sub-crqs, pools, and napi has problems handling some failover
scenarios. This is due to the split in initializing the sub crqs,
pools and napi in different places and the placement of updating
the active counts.

This patch simplifies this by having a counter for tx and rx
sub-crqs, pools, and napi.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the recent change, transmissions that only needed
one descriptor were being missed. The result is that such
packets were tracked as outstanding transmissions but never
removed when its completion notification was received.

Fixes: ffc385b9 ("ibmvnic: Keep track of supplementary TX descriptors")
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The login buffer is released before the driver can perform
sanity checks between resources the driver requested and what
firmware will provide. Don't release the login buffer until
the sanity check is performed.

Fixes: 34f0f4e3 ("ibmvnic: Fix login buffer memory leaks")
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a failure occurs during initialization of the tx sub crq
irqs, we should branch to the cleanup of the tx irqs. The current
code branches to the rx irq cleanup and attempts to cleanup the
rx irqs which have not been initialized.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To avoid losing any stats when the number of sub-crqs change, allocate
the max number of stats buffers so a stats buffer exists all possible
sub-crqs.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In order to handle the number of rx sub crqs changing during a driver
reset, the ibmvnic driver also needs to update the number of napi.
To do this the code to init and free napi's is moved to their own
routines so they can be called during the reset process.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the driver resets it is possible that the number of tx/rx
sub-crqs can change. This patch handles this so that the driver does
not try to access non-existent sub-crqs.

The count for releasing sub crqs depends on the adapter state. The
active queue count is not set in probe, so if we are relasing in probe
state we use the request queue count.

Additionally, a parameter is added to release_sub_crqs() so that
we know if the h_call to free the sub-crq needs to be made. In
the reset path we have to do a reset of the main crq, which is
a free followed by a register of the main crq. The free of main
crq results in all of the sub crq's being free'ed. When updating
sub-crq count in the reset path we do not want to h_free the
sub-crqs, they are already free'ed.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Inpreparation for using the active scrq count to track more active
resources, move the setting of the active count to after initialization
occurs in initial driver init and during driver reset.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rename the tx/rx active pool variables to be tx/rx active scrq
counts. The tx/rx pools are per sub-crq so this is a more appropriate
name. This also is a preparatory step for using thiese variables
for handling updates to sub-crqs and napi based on the active
count.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

After introduction of commit d0869c00, there were some instances of
RX queue entries from a previous session (before the device was closed
and reopened) returned to the NAPI polling routine. Since the corresponding
socket buffers were freed, this resulted in a panic on reopen. Include
a check for a NULL skb here to avoid this.

Fixes: d0869c00 ("ibmvnic: Clean RX pool buffers during device close")
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Supplementary TX descriptors were not being accounted for, which
was resulting in an overflow of the hardware device's transmit
queue. Keep track of those descriptors now when determining
how many entries remain on the TX queue.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During device close or reset, there were some cases of outstanding
RX socket buffers not being freed. Include a function similar to the
one that already exists to clean TX socket buffers in this case.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If a RX buffer is returned to the client driver with an error, free the
corresponding socket buffer before continuing.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This memory is allocated during initialization but never freed,
so do that now.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

During device bringup, the driver exchanges login buffers with
firmware. These buffers contain information such number of TX
and RX queues alloted to the device, RX buffer size, etc. These
buffers weren't being properly freed on device reset or close.

We can free the buffer we send to firmware as soon as we get
a response. There is information in the response buffer that
the driver needs for normal operation so retain it until the
next reset or removal.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pushes back setting the carrier on until the end of the reset
code. This resolves a bug where a watchdog timer was detecting
that a TX queue had stalled before the adapter reset was complete.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Having these checks in ibmvnic_xmit causes problems with VLAN
tagging and balance-alb/tlb bonding modes. The restriction they
imposed can be removed.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When allocating RX or TX buffer pools, the driver needs to provide a
unique mapping ID to firmware for each pool. This value is assigned
using a counter which is incremented after a new pool is created. The
ID can be an integer ranging from 1-255. When migrating to a device
that requests a different number of queues, this value was not being
reset properly. As a result, after enough migrations, the counter
exceeded the upper bound and pool creation failed. This is fixed by
resetting the counter to one in this case.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

While handling a driver reset we get a H_CLOSED return trying
to send a CRQ event. When this occurs we need to queue up another
reset attempt. Without doing this we see instances where the driver
is left in a closed state because the reset failed and there is no
further attempts to reset the driver.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change will guard against a double free in the case that the
buffers were previously freed at some other time, such as during
a device reset. It resolves a kernel oops that occurred when changing
the VNIC device's MTU.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

At some point, a check was added to exit the polling routine during resets.
This makes sense for most reset conditions, but for a non-fatal error, we
expect the polling routine to continue running to properly clean up the rx
queues. This patch checks if we are performing a non-fatal reset and if we
are, continues normal polling operation.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>