When setting a device online, both subdrivers have the same code to
program the HW trap and Isolation mode. Move that code into a single
place.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When napi_complete_done() returns false, the NAPI instance is still
active and we can keep the IRQ disabled a little longer.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qdio.h recently gained a new helper macro that handles wrap-around on a
QDIO queue, consistently use it across all of qeth.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For IQD devices with Multi-Write support, we can defer the queue-flush
further and transmit multiple IO buffers with a single TX doorbell.
The same-target restriction still applies.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Without this patch, a command bit in the supported commands mask is only
ever set to unsupported during set online. If a command is ever marked as
unsupported (e.g. because of error during qeth_l2_vnicc_query_cmds),
subsequent successful initialization (offline/online) would not bring it
back.

Fixes: caa1f0b1 ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Smatch discovered the use of uninitialized variable sup_cmds
in error paths.

Fixes: caa1f0b1 ("s390/qeth: add VNICC enable/disable support")
Signed-off-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

The QIB parm area is 128 bytes long. Current code consistently misuses
an _entirely unrelated_ QDIO constant, merely because it has the same
value. Stop doing so.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NBenjamin Block <bblock@linux.ibm.com>
Reviewed-by: NJens Remus <jremus@linux.ibm.com>
Signed-off-by: NVasily Gorbik <gor@linux.ibm.com>

The dev_kfree_skb() function performs also input parameter validation.
Thus the test around the shown calls is not needed.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

IQD devices offer limited support for bulking: all frames in a TX buffer
need to have the same target. qeth_iqd_may_bulk() implements this
constraint, and allows us to defer the TX doorbell until
(a) the buffer is full (since each buffer needs its own doorbell), or
(b) the entire TX queue is full, or
(b) we reached the BQL limit.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Each TX buffer may contain multiple skbs. So just accumulate the sent
byte count in the buffer struct, and later use the same count when
completing the buffer.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This allows the stack to bulk-free our TX-completed skbs.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Due to their large MTU and potentially low utilization of TX buffers,
IQD devices in particular require fast TX recycling. This makes them
a prime candidate for a TX NAPI path in qeth.

qeth_tx_poll() uses the recently introduced qdio_inspect_queue() helper
to poll the TX queue for completed buffers. To avoid hogging the CPU for
too long, we yield to the stack after completing an entire queue's worth
of buffers.
While IQD is expected to transfer its buffers synchronously (and thus
doesn't support TX interrupts), a timer covers for the odd case where a
TX buffer doesn't complete synchronously. Currently this timer should
only ever fire for
(1) the mcast queue,
(2) the occasional race, where the NAPI poll code observes an update to
    queue->used_buffers while the TX doorbell hasn't been issued yet.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This consolidates the SW statistics code, and improves it to
(1) account for the header overhead of each segment on a TSO skb,
(2) count dangling packets as in-error (during eg. shutdown), and
(3) only count offloads when the skb was successfully transmitted.

We also count each segment of an TSO skb as one packet - except for
tx_dropped, to be consistent with dev->tx_dropped.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit d4c08afa ("s390/qeth: streamline SNMP cmd code") removed
the bounds checking for req_len, under the assumption that the check in
qeth_alloc_cmd() would suffice.

But that code path isn't sufficiently robust to handle a user-provided
data_length, which could overflow (when adding the cmd header overhead)
before being checked against QETH_BUFSIZE. We end up allocating just a
tiny iob, and the subsequent copy_from_user() writes past the end of
that iob.

Special-case this path and add a coarse bounds check, to protect against
maliciuous requests. This let's the subsequent code flow do its normal
job and precise checking, without risk of overflow.

Fixes: d4c08afa ("s390/qeth: streamline SNMP cmd code")
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

lcs passes an intparm when calling ccw_device_*(), even though lcs_irq()
later makes no use of this.

To reduce the confusion, consistently pass 0 as intparm instead.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ctcm passes an intparm when calling ccw_device_*(), even though
ctcm_irq_handler() later makes no use of this.

To reduce the confusion, consistently pass 0 as intparm instead.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NSebastian Ott <sebott@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have logic to determine the desired promisc mode in _each_ code path.
Change things around so that there is a clean split between
(a) high-level code that selects the new mode, and (b) implementations
of the various mechanisms to program this mode.

This also keeps qeth_promisc_to_bridge() from polluting the debug logs
on each RX modeset.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When processing the reply for a vnicc cmd, there's no need to remember
which specific sub-cmd type we initially sent. The reply itself contains
all the needed information.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Except for card->read_cmd, every cmd we issue now passes through
qeth_send_control_data() and allocates a qeth_reply struct. The way we
use this struct requires additional refcounting, and pointer tracking.

Clean up things by moving most of qeth_reply's content into the main
cmd struct. This keeps things in one place, saves us the additional
refcounting and simplifies the overall code flow.
A nice little benefit is that we can now match incoming replies against
the pending requests themselves, without caching the requests' seqnos.

The qeth_reply struct stays around for a little bit longer in a shrunk
form, to avoid touching every single callback.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Current code releases the cmd struct after its initial IO has completed.
Any reply processing is done independently, using a separate qeth_reply
struct.
In preparation for merging the cmd and reply structs together, take an
additional reference on the cmd object so that it stays around all the
way until qeth_send_control_data() returns.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

qeth_snmp_command_cb() is the only cmd callback that pulls the reply's
data length from a low-level transport header field. This requires
additional complexity (ie. reply->offset) to make the header accessible
to what is supposed to be a pure IPA cmd callback.

Adapter cmds have a length field in their sub-cmd header, get the data
length from there instead.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When an cmd IO completes in qeth_irq(), calculate how much data was
processed by the device and pass this value to the cmd's callback.

This allows cmds that retrieve data from the device to check whether
sufficient data was received, so we do that in qeth_read_conf_data_cb().
Suggested-by: NJens Remus <jremus@linux.ibm.com>
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rather than fumbling with hard-coded offsets, use the proper struct to
access the retrieved RCD information.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Callbacks for a cmd reply run outside the protection of card->lock, to
allow for additional cmds to be issued & enqueued in parallel.

When qeth_send_control_data() bails out for a cmd without having
received a reply (eg. due to timeout), its callback may concurrently be
processing a reply that just arrived. In this case, the callback
potentially accesses a stale reply->reply_param area that eg. was
on-stack and has already been released.

To avoid this race, add some locking so that qeth_send_control_data()
can (1) wait for a concurrently running callback, and (2) zap any
pending callback that still wants to run.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>

Mark switch cases where we are expecting to fall through.

This patch fixes the following warnings (Building: s390):

drivers/s390/net/ctcm_fsms.c: In function ‘ctcmpc_chx_attnbusy’:
drivers/s390/net/ctcm_fsms.c:1703:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (grp->changed_side == 1) {
      ^
drivers/s390/net/ctcm_fsms.c:1707:2: note: here
  case MPCG_STATE_XID0IOWAIX:
  ^~~~

drivers/s390/net/ctcm_mpc.c: In function ‘ctc_mpc_alloc_channel’:
drivers/s390/net/ctcm_mpc.c:358:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (callback)
      ^
drivers/s390/net/ctcm_mpc.c:360:2: note: here
  case MPCG_STATE_XID0IOWAIT:
  ^~~~

drivers/s390/net/ctcm_mpc.c: In function ‘mpc_action_timeout’:
drivers/s390/net/ctcm_mpc.c:1469:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if ((fsm_getstate(rch->fsm) == CH_XID0_PENDING) &&
      ^
drivers/s390/net/ctcm_mpc.c:1472:2: note: here
  default:
  ^~~~~~~
drivers/s390/net/ctcm_mpc.c: In function ‘mpc_send_qllc_discontact’:
drivers/s390/net/ctcm_mpc.c:2087:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (grp->estconnfunc) {
      ^
drivers/s390/net/ctcm_mpc.c:2092:2: note: here
  case MPCG_STATE_FLOWC:
  ^~~~

drivers/s390/net/qeth_l2_main.c: In function ‘qeth_l2_process_inbound_buffer’:
drivers/s390/net/qeth_l2_main.c:328:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
    if (IS_OSN(card)) {
       ^
drivers/s390/net/qeth_l2_main.c:337:3: note: here
   default:
   ^~~~~~~
Reviewed-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGustavo A. R. Silva <gustavo@embeddedor.com>

In preparation for unifying the skb_frag and bio_vec, use the fine
accessors which already exist and use skb_frag_t instead of
struct skb_frag_struct.
Signed-off-by: NMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The cast type currently gets selected in .ndo_start_xmit, and is then
piped through several layers until it's stored into the HW header.
Push the selection down into qeth_l?_fill_header() to (1) reduce the
number of xmit-wide parameters, and (2) merge the two route validation
checks into just one.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As follow-up to commit 0cd6783d ("s390/qeth: check dst entry before use"),
consolidate the dst_check() logic into a single helper and add a wrapper
around the cast type selection.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use napi_gro_receive() to pass up all types of packets that a L3 device
may receive.
1) For proper L2 packets received by the IQD sniffer, this is the
   obvious thing to do.
2) For af_iucv (which doesn't provide a GRO assist), the GRO code will
   transparently fall back to netif_receive_skb(). So there's no need to
   special-case this traffic in our code.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

De-duplicate the pm callback implementations from the two sub-drivers,
replacing them with core helpers that delegate to the .set_online and
.set_offline callbacks.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Apply some cleanups to qeth_snmp_command() and its callback:
1. when accessing the user data, use the proper struct instead of
   hard-coded offsets. Also copy the request data straight into the
   allocated cmd, skipping the extra memdup_user() to a tmp buffer.
2. capping the request length is no longer needed, the same check gets
   applied at a base level in qeth_alloc_cmd().
3. clean up some duplicated (and misindented) trace statements.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that all cmds are dynamically allocated, the code for static cmd
buffers can go away entirely. Resulting in a nice reduction of
code/data size & complexity, while removing the risk that
qeth_clear_cmd_buffers() releases cmds that are still in-flight.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The base MPC cmds are the last remaining user of the static cmd buffers.
Port them over to use dynamic allocation, and stop backing the write
channel's cmd buffers with pages.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The VNICC code is somewhat quirky in that it defers the whole cmd setup
to a common helper qeth_l2_vnicc_request(). Some of the cmd specifics
are then passed in via parameter, while others are simply hard-coded.

Split the whole machinery up into the usual format: one helper that
allocates the cmd & fills in the common fields, while all the cmd
originators take care of their sub-cmd type specific work.
This makes it much easier to calculate the cmd's precise length, and
reduces code complexity.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: NAlexandra Winter <wintera@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new wrapper that allocates DIAG cmds of the right size, and fills
in the common fields.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch converts the adapter, assist and bridgeport cmd paths to
dynamic allocation. Most of the work is about re-organizing the cmd
headers, calculating the correct cmd length, and filling in the right
value in the sub-cmd's length field.

Since we now also set the correct length for cmds that are not reflected
by a fixed struct (ie SNMP), we can remove the work-around from
qeth_snmp_command().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For code that uses qeth_send_simple_setassparms_prot(), we currently
can't differentiate whether the cmd should contain (1) no parameter, or
(2) a 4-byte parameter with value 0.
At the moment this doesn't cause any trouble. But when using dynamically
allocated cmds, we need to know whether to allocate & transmit an
additional 4 bytes of zeroes.
So instead of the raw parameter value, pass a parameter pointer
(or NULL) to qeth_send_simple_setassparms_prot().
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch reduces the usage of the write channel's static cmd buffers,
by dynamically allocating all simple IPA cmds (eg. STARTLAN, SETVMAC).
It also converts the OSN path.

Doing so requires some changes to how we calculate the cmd length.
Currently when building IPA cmds, we're quite generous in how much data
we send down to the device (basically the size of the biggest cmd we
know). This is no real concern at the moment, since the static cmd
buffers are backed with zeroed pages. But for dynamic allocations, the
exact length matters. So this patch also adds the needed length
calculations to each cmd path.

Commands that have multiple subtypes (eg. SETADP) of differing length
will be converted with follow-up patches.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We statically allocate 8 cmd buffers on the read channel, when the only
IO left that's still using them is the long-running READ.
Replace this with a single allocated cmd, that gets restarted whenever
the READ completed.

This introduces refcounting for allocated cmds, so that the READ cmd can
survive the IO completion.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The current IDX sequence first sends one WRITE cmd to activate the
device, and then sends a second cmd that READs the response.

Using qeth_alloc_cmd(), we can combine this into a single IO with two
command-chained CCWs.
Signed-off-by: NJulian Wiedmann <jwi@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>