RX buffer pools are disabled while awaiting a device
reset if firmware indicates that the resource is closed.

This patch fixes a bug where pools were not being
subsequently enabled after the device reset, causing
the device to become inoperable.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When handling a driver reset due to a failover of the backing
server on the vios, doing the netdev_notify_peers() can cause
network traffic to stall or halt. Remove the netdev notify call
for failover resets.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The IBM vNIC protocol provides support for the user to initiate
a failover from the client LPAR in case the current backing infrastructure
is deemed inadequate or in an error state.

Support for two H_VIOCTL sub-commands for vNIC devices are required
to implement this function. These commands are H_GET_SESSION_TOKEN
and H_SESSION_ERR_DETECTED.

"[H_GET_SESSION_TOKEN] is used to obtain a session token from a VNIC client
adapter.  This token is opaque to the caller and is intended to be used in
tandem with the SESSION_ERROR_DETECTED vioctl subfunction."

"[H_SESSION_ERR_DETECTED] is used to report that the currently active
backing device for a VNIC client adapter is behaving poorly, and that
the hypervisor should attempt to fail over to a different backing device,
if one is available."

To provide tools access to this functionality the vNIC driver creates a
sysfs file that, when written to, will send a request to pHyp to failover
to a different backing device.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Reviewed-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The object references of mii_phy_ops structures are only stored
in the ops field of a mii_phy_def structure. This ops field is of type
const. So, mii_phy_ops structures having similar properties can be
declared as const.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

emac_mdio_read_link() was not copying the requested phy settings
back into the emac driver's own phy api. This has caused a link
speed mismatch issue for the AR8035 as the emac driver kept
trying to connect with 10/100MBps on a 1GBit/s link.

This patch also unifies shared code between emac_setup_aneg()
and emac_mdio_setup_forced(). And furthermore it removes
a chunk of emac_mdio_init_phy(), that was copying the same
data into itself.
Signed-off-by: NChristian Lamparter <chunkeey@googlemail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fixes a problem where the AR8035 PHY can't be
detected on an Cisco Meraki MR24, if the ethernet cable is
not connected on boot.

Russell Senior provided steps to reproduce the issue:
|Disconnect ethernet cable, apply power, wait until device has booted,
|plug in ethernet, check for interfaces, no eth0 is listed.
|
|This appears to be a problem during probing of the AR8035 Phy chip.
|When ethernet has no link, the phy detection fails, and eth0 is not
|created. Plugging ethernet later has no effect, because there is no
|interface as far as the kernel is concerned. The relevant part of
|the boot log looks like this:
|this is the failing case:
|
|[    0.876611] /plb/opb/emac-rgmii@ef601500: input 0 in RGMII mode
|[    0.882532] /plb/opb/ethernet@ef600c00: reset timeout
|[    0.888546] /plb/opb/ethernet@ef600c00: can't find PHY!
|and the succeeding case:
|
|[    0.876672] /plb/opb/emac-rgmii@ef601500: input 0 in RGMII mode
|[    0.883952] eth0: EMAC-0 /plb/opb/ethernet@ef600c00, MAC 00:01:..
|[    0.890822] eth0: found Atheros 8035 Gigabit Ethernet PHY (0x01)

Based on the comment and the commit message of
commit 23fbb5a8 ("emac: Fix EMAC soft reset on 460EX/GT").
This is because the AR8035 PHY doesn't provide the TX Clock,
if the ethernet cable is not attached. This causes the reset
to timeout and the PHY detection code in emac_init_phy() is
unable to detect the AR8035 PHY. As a result, the emac driver
bails out early and the user left with no ethernet.

In order to stay compatible with existing configurations, the driver
tries the current reset approach at first. Only if the first attempt
timed out, it does perform one more retry with the clock temporarily
switched to the internal source for just the duration of the reset.

LEDE-Bug: #687 <https://bugs.lede-project.org/index.php?do=details&task_id=687>

Cc: Chris Blake <chrisrblake93@gmail.com>
Reported-by: NRussell Senior <russell@personaltelco.net>
Fixes: 23fbb5a8 ("emac: Fix EMAC soft reset on 460EX/GT")
Signed-off-by: NChristian Lamparter <chunkeey@googlemail.com>
Reviewed-by: NAndrew Lunn <andrew@lunn.ch>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Changing the mtu is currently not supported in the ibmvnic driver.

Implement .ndo_change_mtu in the driver so that attempting to use ifconfig
to change the mtu will fail and present the user with an error message.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The original author left the project and so far has not
responded to emails sent to the listed address.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the ibmvnic driver is resetting, we can just reset the sub crqs
instead of releasing all of their resources and re-allocting them.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When resetting the ibmvnic driver there is not a need to release
and re-allocate the resources for the tx and rx pools. These
resources can just be reset to avoid the re-allocations.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a driver reset operation occurs there is not a need to release
the CRQ resources and re-allocate them. Instead a reset of the CRQ
will suffice.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We do not want to process any receive frames if the ibmvnic_poll
routine is invoked while a reset is in process. Also, before
replenishing the rx pools in the ibmvnic_poll, we want to
make sure the adapter is not in the process of closing.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

If H_CLOSED is returned, halt RX buffer replenishment activity
until firmware sends a notification that the driver can reset.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch disables transmissions and reports carrier off if xmit
function returns that the hardware TX queue is closed. The driver can
then await a signal from firmware to determine the correct reset method.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Handle non-fatal error conditions. The process to do this when
resetting the driver is to just do __ibmvnic_close followed by
__ibmvnic_open.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A race condition occurs when closing the driver. Free'ing of skb's
can race between the close routine and ibmvnic_tx_interrupt. To fix
this we move the claenup of tx pools during close to after the
sub-CRQ interrupts are disabled.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Send gratuitous arp after any reset.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Handle case where phyp sends a failover after failing to send the
init crq.
Signed-off-by: NJohn Allen <jallen@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Track the state of ibmvnic napis. The driver can get into states where it
can be reset when napis are already disabled and attempting to disable them
again will cause the driver to hang.
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>

Current largesend and checksum offload feature in ibmveth driver,
 - Source VM sends the TCP packets with ip_summed field set as
   CHECKSUM_PARTIAL and TCP pseudo header checksum is placed in
   checksum field
 - CHECKSUM_PARTIAL flag in SKB will enable ibmveth driver to mark
   "no checksum" and "checksum good" bits in transmit buffer descriptor
   before the packet is delivered to pseries PowerVM Hypervisor
 - If ibmveth has largesend capability enabled, transmit buffer descriptors
   are market accordingly before packet is delivered to Hypervisor
   (along with mss value for packets with length > MSS)
 - Destination VM's ibmveth driver receives the packet with "checksum good"
   bit set and so, SKB's ip_summed field is set with CHECKSUM_UNNECESSARY
 - If "largesend" bit was on, mss value is copied from receive descriptor
   into SKB's gso_size and other flags are appropriately set for
   packets > MSS size
 - The packet is now successfully delivered up the stack in destination VM

The offloads described above works fine for TCP communication among VMs in
the same pseries server ( VM A <=> PowerVM Hypervisor <=> VM B )

We are now enabling support for OVS in pseries PowerVM environment. One of
our requirements is to have ibmveth driver configured in "Trunk" mode, when
they are used with OVS. This is because, PowerVM Hypervisor will no more
bridge the packets between VMs, instead the packets are delivered to
IO Server which hosts OVS to bridge them between VMs or to external
networks (flow shown below),
  VM A <=> PowerVM Hypervisor <=> IO Server(OVS) <=> PowerVM Hypervisor
                                                                   <=> VM B
In "IO server" the packet is received by inbound Trunk ibmveth and then
delivered to OVS, which is then bridged to outbound Trunk ibmveth (shown
below),
        Inbound Trunk ibmveth <=> OVS <=> Outbound Trunk ibmveth

In this model, we hit the following issues which impacted the VM
communication performance,

 - Issue 1: ibmveth doesn't support largesend and checksum offload features
   when configured as "Trunk". Driver has explicit checks to prevent
   enabling these offloads.

 - Issue 2: SYN packet drops seen at destination VM. When the packet
   originates, it has CHECKSUM_PARTIAL flag set and as it gets delivered to
   IO server's inbound Trunk ibmveth, on validating "checksum good" bits
   in ibmveth receive routine, SKB's ip_summed field is set with
   CHECKSUM_UNNECESSARY flag. This packet is then bridged by OVS (or Linux
   Bridge) and delivered to outbound Trunk ibmveth. At this point the
   outbound ibmveth transmit routine will not set "no checksum" and
   "checksum good" bits in transmit buffer descriptor, as it does so only
   when the ip_summed field is CHECKSUM_PARTIAL. When this packet gets
   delivered to destination VM, TCP layer receives the packet with checksum
   value of 0 and with no checksum related flags in ip_summed field. This
   leads to packet drops. So, TCP connections never goes through fine.

 - Issue 3: First packet of a TCP connection will be dropped, if there is
   no OVS flow cached in datapath. OVS while trying to identify the flow,
   computes the checksum. The computed checksum will be invalid at the
   receiving end, as ibmveth transmit routine zeroes out the pseudo
   checksum value in the packet. This leads to packet drop.

 - Issue 4: ibmveth driver doesn't have support for SKB's with frag_list.
   When Physical NIC has GRO enabled and when OVS bridges these packets,
   OVS vport send code will end up calling dev_queue_xmit, which in turn
   calls validate_xmit_skb.
   In validate_xmit_skb routine, the larger packets will get segmented into
   MSS sized segments, if SKB has a frag_list and if the driver to which
   they are delivered to doesn't support NETIF_F_FRAGLIST feature.

This patch addresses the above four issues, thereby enabling end to end
largesend and checksum offload support for better performance.

 - Fix for Issue 1 : Remove checks which prevent enabling TCP largesend and
   checksum offloads.
 - Fix for Issue 2 : When ibmveth receives a packet with "checksum good"
   bit set and if its configured in Trunk mode, set appropriate SKB fields
   using skb_partial_csum_set (ip_summed field is set with
   CHECKSUM_PARTIAL)
 - Fix for Issue 3: Recompute the pseudo header checksum before sending the
   SKB up the stack.
 - Fix for Issue 4: Linearize the SKBs with frag_list. Though we end up
   allocating buffers and copying data, this fix gives
   upto 4X throughput increase.

Note: All these fixes need to be dropped together as fixing just one of
them will lead to other issues immediately (especially for Issues 1,2 & 3).
Signed-off-by: NSivakumar Krishnasamy <ksiva@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add the missing unlock before return from function __ibmvnic_reset()
in the error handling case.

Fixes: ed651a10 ("ibmvnic: Updated reset handling")
Signed-off-by: NWei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Restart of the subqueue should occur outside of the loop processing
any tx buffers instead of doing this in the middle of the loop.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Map each RX SKB to the RX queue associated with the driver's RX SCRQ.
This should improve the RX CPU load balancing issues seen by the
performance team.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is not a need to stop processing skbs if we encounter a
skb that has a receive completion error.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move the check for the driver resetting to the first thing
in ibmvnic_xmit().
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When closing the ibmvnic driver we need to wait for any pending
sub crq entries to ensure they are handled.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When closing the ibmvnic driver, most notably during the reset
path, the tx pools need to be cleaned to ensure there are no
hanging skbs that need to be free'ed.

The need for this was found during debugging a loss of network
traffic after handling a driver reset. The underlying cause was
some skbs in the tx pool that were never free'ed. As a
result the upper network layers never tried a re-send since it
believed the driver still had the skb.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The napi structs allocated at drivier initializatio need to be
free'ed when releasing the drivers resources.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The ibmvnic driver has multiple handlers for resetting the driver
depending on the reason the reset is needed (failover, lpm,
fatal erors,...). All of the reset handlers do essentially the same
thing, this patch moves this work to a common reset handler.

By doing this we also allow the driver to better handle situations
where we can get a reset while handling a reset.

The updated reset handling works by adding a reset work item to the
list of resets and then scheduling work to perform the reset. This
step is necessary because we can receive a reset in interrupt context
and we want to handle the reset out of interrupt context.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Replace the is_closed flag in the ibmvnic adapter strcut with a
more comprehensive state field that tracks the current state of
the driver.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move all of the calls to initialize resources for the driver to
a separate routine.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The sub crq structures are initialized in interrupt context while
handling the response to crqs when negotiating capabilities for
the driver. The sub crqs do not need to be initialized at this point
and can be moved to being done from ibmvnic_init. Moving the init
of the sub crqs to ibmvnic_init also allows use to allocate the
memory with GFP_KERNEL instead of GFP_ATOMIC.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Split the sending of capability request crqs and the initialization
of sub crqs into their own routines. This is a first step to moving
the allocation of sub-crqs out of interrupt context.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an error is encountered during transmit we need to free the
skb instead of returning TX_BUSY.
Signed-off-by: NThomas Falcon <tlfalcon@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Validate that the napi structs exist before trying to disable them
at driver close.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Create a common routine for setting the link state for the vnic adapter.
This update moves the sending of the crq and waiting for the link state
response to a common place. The new routine also adds handling of
resending the crq in cases of getting a partial success response.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We should be initializing the stats token in the same place we
initialize the other resources for the driver.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When handling a fatal error in the driver, there can be additional
error information provided by the vios. This information is not
always present, so only retrieve the additional error information
when present.
Signed-off-by: NNathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch addresses a modification in the PAPR+ specification which now
defines a previously reserved value for vNIC capabilities. It indicates
whether the system firmware performs a VLAN header stripping on all VLAN
tagged received frames, in case it does, the behavior expected is for
the ibmvnic driver to be responsible for inserting the VLAN header.
Reported-by: NManvanthara B. Puttashankar <mputtash@in.ibm.com>
Signed-off-by: NMurilo Fossa Vicentini <muvic@linux.vnet.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>