smc_ism_register_dmb() returns error codes set by the ISM driver which
are not guaranteed to be negative or in the errno range. Such values
would not be handled by ERR_PTR() and finally the return code will be
used as a memory address.
Fix that by using a valid negative errno value with ERR_PTR().

Fixes: 72b7f6c4 ("net/smc: unique reason code for exceeded max dmb count")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

The SMCD_DMBE_SIZES should include all valid DMBE buffer sizes, so the
correct value is 6 which means 1MB. With 7 the registration of an ISM
buffer would always fail because of the invalid size requested.
Fix that and set the value to 6.

Fixes: c6ba7c9b ("net/smc: add base infrastructure for SMC-D and ISM")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NJakub Kicinski <kuba@kernel.org>

When an SMC connection is created, and there is a problem to
create an RMB or DMB, the previously created send buffer is
thrown away as well including buffer descriptor freeing.
Make sure the connection no longer references the freed
buffer descriptor, otherwise bugs like this are possible:

[71556.835148] =============================================================================
[71556.835168] BUG kmalloc-128 (Tainted: G    B      OE    ): Poison overwritten
[71556.835172] -----------------------------------------------------------------------------

[71556.835179] INFO: 0x00000000d20894be-0x00000000aaef63e9 @offset=2724. First byte 0x0 instead of 0x6b
[71556.835215] INFO: Allocated in __smc_buf_create+0x184/0x578 [smc] age=0 cpu=5 pid=46726
[71556.835234]     ___slab_alloc+0x5a4/0x690
[71556.835239]     __slab_alloc.constprop.0+0x70/0xb0
[71556.835243]     kmem_cache_alloc_trace+0x38e/0x3f8
[71556.835250]     __smc_buf_create+0x184/0x578 [smc]
[71556.835257]     smc_buf_create+0x2e/0xe8 [smc]
[71556.835264]     smc_listen_work+0x516/0x6a0 [smc]
[71556.835275]     process_one_work+0x280/0x478
[71556.835280]     worker_thread+0x66/0x368
[71556.835287]     kthread+0x17a/0x1a0
[71556.835294]     ret_from_fork+0x28/0x2c
[71556.835301] INFO: Freed in smc_buf_create+0xd8/0xe8 [smc] age=0 cpu=5 pid=46726
[71556.835307]     __slab_free+0x246/0x560
[71556.835311]     kfree+0x398/0x3f8
[71556.835318]     smc_buf_create+0xd8/0xe8 [smc]
[71556.835324]     smc_listen_work+0x516/0x6a0 [smc]
[71556.835328]     process_one_work+0x280/0x478
[71556.835332]     worker_thread+0x66/0x368
[71556.835337]     kthread+0x17a/0x1a0
[71556.835344]     ret_from_fork+0x28/0x2c
[71556.835348] INFO: Slab 0x00000000a0744551 objects=51 used=51 fp=0x0000000000000000 flags=0x1ffff00000010200
[71556.835352] INFO: Object 0x00000000563480a1 @offset=2688 fp=0x00000000289567b2

[71556.835359] Redzone 000000006783cde2: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835363] Redzone 00000000e35b876e: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835367] Redzone 0000000023074562: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835372] Redzone 00000000b9564b8c: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835376] Redzone 00000000810c6362: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835380] Redzone 0000000065ef52c3: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835384] Redzone 00000000c5dd6984: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835388] Redzone 000000004c480f8f: bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb bb  ................
[71556.835392] Object 00000000563480a1: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[71556.835397] Object 000000009c479d06: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[71556.835401] Object 000000006e1dce92: 6b 6b 6b 6b 00 00 00 00 6b 6b 6b 6b 6b 6b 6b 6b  kkkk....kkkkkkkk
[71556.835405] Object 00000000227f7cf8: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[71556.835410] Object 000000009a701215: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[71556.835414] Object 000000003731ce76: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[71556.835418] Object 00000000f7085967: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b  kkkkkkkkkkkkkkkk
[71556.835422] Object 0000000007f99927: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b a5  kkkkkkkkkkkkkkk.
[71556.835427] Redzone 00000000579c4913: bb bb bb bb bb bb bb bb                          ........
[71556.835431] Padding 00000000305aef82: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[71556.835435] Padding 00000000b1cdd722: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[71556.835438] Padding 00000000c7568199: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[71556.835442] Padding 00000000fad4c4d4: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
[71556.835451] CPU: 0 PID: 47939 Comm: kworker/0:15 Tainted: G    B      OE     5.9.0-rc1uschi+ #54
[71556.835456] Hardware name: IBM 3906 M03 703 (LPAR)
[71556.835464] Workqueue: events smc_listen_work [smc]
[71556.835470] Call Trace:
[71556.835478]  [<00000000d5eaeb10>] show_stack+0x90/0xf8
[71556.835493]  [<00000000d66fc0f8>] dump_stack+0xa8/0xe8
[71556.835499]  [<00000000d61a511c>] check_bytes_and_report+0x104/0x130
[71556.835504]  [<00000000d61a57b2>] check_object+0x26a/0x2e0
[71556.835509]  [<00000000d61a59bc>] alloc_debug_processing+0x194/0x238
[71556.835514]  [<00000000d61a8c14>] ___slab_alloc+0x5a4/0x690
[71556.835519]  [<00000000d61a9170>] __slab_alloc.constprop.0+0x70/0xb0
[71556.835524]  [<00000000d61aaf66>] kmem_cache_alloc_trace+0x38e/0x3f8
[71556.835530]  [<000003ff80549bbc>] __smc_buf_create+0x184/0x578 [smc]
[71556.835538]  [<000003ff8054a396>] smc_buf_create+0x2e/0xe8 [smc]
[71556.835545]  [<000003ff80540c16>] smc_listen_work+0x516/0x6a0 [smc]
[71556.835549]  [<00000000d5f0f448>] process_one_work+0x280/0x478
[71556.835554]  [<00000000d5f0f6a6>] worker_thread+0x66/0x368
[71556.835559]  [<00000000d5f18692>] kthread+0x17a/0x1a0
[71556.835563]  [<00000000d6abf3b8>] ret_from_fork+0x28/0x2c
[71556.835569] INFO: lockdep is turned off.
[71556.835573] FIX kmalloc-128: Restoring 0x00000000d20894be-0x00000000aaef63e9=0x6b

[71556.835577] FIX kmalloc-128: Marking all objects used

Fixes: fd7f3a74 ("net/smc: remove freed buffer from list")
Reviewed-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

SMC tries to make use of SMCD first. If a problem shows up,
it tries to switch to SMCR. If the SMCD initializing problem shows
up after the SMCD connection has already been initialized, field
rx_off keeps the wrong SMCD value for SMCR, which results in corrupted
data at the receiver.
This patch adds an explicit (re-)setting of field rx_off to zero if the
connection uses SMCR.

Fixes: be244f28 ("net/smc: add SMC-D support in data transfer")
Reviewed-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When the maximum dmb buffer limit for an ism device is reached no more
dmb buffers can be registered. When this happens the reason code is set
to SMC_CLC_DECL_MEM indicating out-of-memory. This is the same reason
code that is used when no memory could be allocated for the new dmb
buffer.
This is confusing for users when they see this error but there is more
memory available. To solve this set a separate new reason code when the
maximum dmb limit exceeded.
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There is a current limit of 1920 registered dmb buffers per ISM device
for smc-d. One link group can contain 255 connections, each connection
is using one dmb buffer. When the connection is closed then the
registered buffer is held in a queue and is reused by the next
connection. When a link group is 'full' then another link group is
created and uses an own buffer pool. The link groups are added to a
list using list_add() which puts a new link group to the first position
in the list.
In the situation that many connections are opened (>1920) and a few of
them stay open while others are closed quickly we end up with at least 8
link groups. For a new connection a matching link group is looked up,
iterating over the list of link groups. The trailing 7 link groups
all have registered dmb buffers which could be reused, while the first
link group has only a few dmb buffers and then hit the 1920 limit.
Because the first link group is not full (255 connection limit not
reached) it is chosen and finally the connection falls back to TCP
because there is no dmb buffer available in this link group.
There are multiple ways to fix that: using list_add_tail() allows
to scan older link groups first for free buffers which ensures that
buffers are reused first. This fixes the problem for smc-r link groups
as well. For smc-d there is an even better way to address this problem
because smc-d does not have the 255 connections per link group limit.
So fix the problem for smc-d by allowing large link groups.

Fixes: c6ba7c9b ("net/smc: add base infrastructure for SMC-D and ISM")
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Two buffers are allocated for each SMC connection. Each buffer is
added to a buffer list after creation. When the second buffer
allocation fails, the first buffer is freed but not deleted from
the list. This might result in crashes when another connection picks
up the freed buffer later and starts to work with it.
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Fixes: 6511aad3 ("net/smc: change smc_buf_free function parameters")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The dma related ...sync_sg... functions check the link state before the
dma function is actually called. But the check in smc_link_usable()
allows links in ACTIVATING state which are not yet mapped to dma memory.
Under high load it may happen that the sync_sg functions are called for
such a link which results in an debug output like
   DMA-API: mlx5_core 0002:00:00.0: device driver tries to sync
   DMA memory it has not allocated [device address=0x0000000103370000]
   [size=65536 bytes]
To fix that introduce a helper to check for the link state ACTIVE and
use it where appropriate. And move the link state update to ACTIVATING
to the end of smcr_link_init() when most initial setup is done.
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Fixes: d854fcbf ("net/smc: add new link state and related helpers")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a new ib device is up smc will send an add link invitation to the
peer if needed. This is currently done with rudimentary flow control.
Under high workload these add link invitations can disturb other llc
flows because they arrive unexpected. Fix this by integrating the
invitations into the normal llc event flow and handle them as a flow.
While at it, check for already assigned requests in the flow before
the new add link request is assigned.
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Fixes: 1f90a05d ("net/smc: add smcr_port_add() and smcr_link_up() processing")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

In a link-down condition we notify the SMC server and expect that the
server will finally trigger the link clear processing on the client
side. This could fail when anything along this notification path goes
wrong. Clear the link as part of SMC client link-down processing to
prevent dangling links.
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Fixes: 541afa10 ("net/smc: add smcr_port_err() and smcr_link_down() processing")
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The similar smc_ib_devices spinlock has been converted to a mutex.
Protecting the smcd_dev_list by a mutex is possible as well. This
patch converts the smcd_dev_list spinlock to a mutex.

Fixes: c6ba7c9b ("net/smc: add base infrastructure for SMC-D and ISM")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Tests showed this BUG:
[572555.252867] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
[572555.252876] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 131031, name: smcapp
[572555.252879] INFO: lockdep is turned off.
[572555.252883] CPU: 1 PID: 131031 Comm: smcapp Tainted: G           O      5.7.0-rc3uschi+ #356
[572555.252885] Hardware name: IBM 3906 M03 703 (LPAR)
[572555.252887] Call Trace:
[572555.252896]  [<00000000ac364554>] show_stack+0x94/0xe8
[572555.252901]  [<00000000aca1f400>] dump_stack+0xa0/0xe0
[572555.252906]  [<00000000ac3c8c10>] ___might_sleep+0x260/0x280
[572555.252910]  [<00000000acdc0c98>] __mutex_lock+0x48/0x940
[572555.252912]  [<00000000acdc15c2>] mutex_lock_nested+0x32/0x40
[572555.252975]  [<000003ff801762d0>] mlx5_lag_get_roce_netdev+0x30/0xc0 [mlx5_core]
[572555.252996]  [<000003ff801fb3aa>] mlx5_ib_get_netdev+0x3a/0xe0 [mlx5_ib]
[572555.253007]  [<000003ff80063848>] smc_pnet_find_roce_resource+0x1d8/0x310 [smc]
[572555.253011]  [<000003ff800602f0>] __smc_connect+0x1f0/0x3e0 [smc]
[572555.253015]  [<000003ff80060634>] smc_connect+0x154/0x190 [smc]
[572555.253022]  [<00000000acbed8d4>] __sys_connect+0x94/0xd0
[572555.253025]  [<00000000acbef620>] __s390x_sys_socketcall+0x170/0x360
[572555.253028]  [<00000000acdc6800>] system_call+0x298/0x2b8
[572555.253030] INFO: lockdep is turned off.

Function smc_pnet_find_rdma_dev() might be called from
smc_pnet_find_roce_resource(). It holds the smc_ib_devices list
spinlock while calling infiniband op get_netdev(). At least for mlx5
the get_netdev operation wants mutex serialization, which conflicts
with the smc_ib_devices spinlock.
This patch switches the smc_ib_devices spinlock into a mutex to
allow sleeping when calling get_netdev().

Fixes: a4cf0443 ("smc: introduce SMC as an IB-client")
Signed-off-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There might be races in scenarios where both SMC link groups are on the
same system. Prevent that by creating separate wait queues for LLC flows
and messages. Switch to non-interruptable versions of wait_event() and
wake_up() for the llc flow waiter to make sure the waiters get control
sequentially. Fine tune the llc_flow_lock to include the assignment of
the message. Write to system log when an unexpected message was
dropped. And remove an extra indirection and use the existing local
variable lgr in smc_llc_enqueue().

Fixes: 555da9af ("net/smc: add event-based llc_flow framework")
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pre-fetch send buffer for the CDC validation message before entering the
send_lock. Without that the send call might fail with -EBUSY because
there are no free buffers and waiting for buffers is not possible under
send_lock.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Print to system log when SMC links are available or go down, link group
state changes or pnetids are applied to and removed from devices.
The log entries are triggered by either user configuration actions or
adapter activation/deactivation events and are not expected to happen
often. The entries help SMC users to keep track of the SMC link group
status and to detect when actions are needed (like to add replacements
for failed adapters).
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The link_uid of an SMC-R link is exchanged between SMC peers and its
value can be used for debugging purposes. Create a unique link_uid
during link initialization and use it in communication with SMC-R peers.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add helper smcr_lgr_link_deactivate_all() and eliminate duplicate code.
In smc_lgr_free(), clear the smc-r links before smc_lgr_free_bufs() is
called so buffers are already prepared for free. The usage of the soft
parameter in __smc_lgr_terminate() is no longer needed, smc_lgr_free()
can be called directly. smc_lgr_terminate_sched() and
smc_smcd_terminate() set lgr->freeing to indicate that the link group
will be freed soon to avoid unnecessary schedules of the free worker.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Allow to set the reason code for the link group termination, and set
meaningful values before termination processing is triggered. This
reason code is sent to the peer in the final delete link message.
When the LLC request or response layer receives a message type that was
not handled, drop a warning and terminate the link group.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

New connections must not be assigned to asymmetric links. Add asymmetric
link tagging using new link variable link_is_asym. The new helpers
smcr_lgr_set_type() and smcr_lgr_set_type_asym() are called to set the
state of the link group, and tag all links accordingly.
smcr_lgr_conn_assign_link() respects the link tagging and will not
assign new connections to links tagged as asymmetric link.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For new connections, assign a link from the link group, using some
simple load balancing.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add smc_llc_send_message_wait() which uses smc_wr_tx_send_wait() to send
an LLC message and waits for the message send to complete.
smc_llc_send_link_delete_all() calls the new function to send an
DELETE_LINK,ALL LLC message. The RFC states that the sender of this type
of message needs to wait for the completion event of the message
transmission and can terminate the link afterwards.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Call smc_cdc_msg_validate() when a CDC message with the failover
validation bit enabled was received. Validate that the sequence number
sent with the message is one we already have received. If not, messages
were lost and the connection is terminated using a new abort_work.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a connection is switched to a new link then a link validation
message must be sent to the peer over the new link, containing the
sequence number of the last CDC message that was sent over the old link.
The peer will validate if this sequence number is the same or lower then
the number he received, and abort the connection if messages were lost.
Add smcr_cdc_msg_send_validation() to send the message validation
message and call it when a connection was switched in
smc_switch_cursor().
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add smc_switch_conns() to switch all connections from a link that is
going down. Find an other link to switch the connections to, and
switch each connection to the new link. smc_switch_cursor() updates the
cursors of a connection to the state of the last successfully sent CDC
message. When there is no link to switch to, terminate the link group.
Call smc_switch_conns() when a link is going down.
And with the possibility that links of connections can switch adapt CDC
and TX functions to detect and handle link switches.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As SMC server, when a second link was deleted, trigger the setup of an
asymmetric link. Do this by enqueueing a local ADD_LINK message which
is processed by the LLC layer as if it were received from peer. Do the
same when a new IB port became active and a new link could be created.
smc_llc_srv_add_link_local() enqueues a local ADD_LINK message.
And smc_llc_srv_delete_link_local() is used the same way to enqueue a
local DELETE_LINK message. This is used when an IB port is no longer
active.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce a work that is scheduled when a new DELETE_LINK LLC request is
received. The work will call either the SMC client or SMC server
DELETE_LINK processing.
And use the LLC flow framework to process incoming DELETE_LINK LLC
messages, scheduling the llc_del_link_work for those events.
With these changes smc_lgr_forget() is only called by one function and
can be migrated into smc_lgr_cleanup_early().
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

First set of functions to process an ADD_LINK LLC request as an SMC
client. Find an alternate IB device, determine the new link group type
and get the index for the new link. Then ready the link, map the buffers
and send an ADD_LINK LLC response. If any error occurs, send a reject
LLC message and terminate the processing.
Add smc_llc_alloc_alt_link() to find a free link index for a new link,
depending on the new link group type.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Support for multiple links makes the former DELETE LINK processing
obsolete which sent one DELETE_LINK LLC message for each single link.
Remove this processing from smc_core.c.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the introduced link down processing in all places where the link
group is terminated and take down the affected link only.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Call smcr_port_err() when an IB event reports an inactive IB device.
smcr_port_err() calls smcr_link_down() for all affected links.
smcr_link_down() either triggers the local DELETE_LINK processing, or
sends an DELETE_LINK LLC message to the SMC server to initiate the
processing.
The old handler function smc_port_terminate() is removed.
Add helper smcr_link_down_cond() to take a link down conditionally, and
smcr_link_down_cond_sched() to schedule the link_down processing to a
work.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Call smcr_port_add() when an IB event reports a new active IB device.
smcr_port_add() will start a work which either triggers the local
ADD_LINK processing, or send an ADD_LINK LLC message to the SMC server
to initiate the processing.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The PNETID is needed to find an alternate link for a link group.
Save the PNETID of the link that is used to create the link group for
later device matching.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce llc_conf_mutex in the link group which is used to protect the
buffers and lgr states against parallel link reconfiguration.
This ensures that new connections do not start to register buffers with
the links of a link group when link creation or termination is running.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

All LLC sends are done from worker context only, so remove the prep
functions which were used to build the message before it was sent, and
add the function content into the respective send function
smc_llc_send_add_link() and smc_llc_send_delete_link().
Extend smc_llc_send_add_link() to include the qp_mtu value in the LLC
message, which is needed to establish a link after the initial link was
created. Extend smc_llc_send_delete_link() to contain a link_id and a
reason code for the link deletion in the LLC message, which is needed
when a specific link should be deleted.
And add the list of existing DELETE_LINK reason codes.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce support to map and register all current buffers for a new
link. smcr_buf_map_lgr() will map used buffers for a new link and
smcr_buf_reg_lgr() can be called to register used buffers on the
IB device of the new link.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With the support of multiple links that are created and cleared there
is a need to unmap one link from all current buffers. Add unmapping by
link and by rmb. And make smcr_link_clear() available to be called from
the LLC layer.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The CONFIRM_RKEY LLC processing handles all links in one LLC message.
Move the call to this processing out of smcr_link_reg_rmb() which does
processing per link, into smcr_lgr_reg_rmbs() which is responsible for
link group level processing. Move smcr_link_reg_rmb() into module
smc_core.c.
>From af_smc.c now call smcr_lgr_reg_rmbs() to register new rmbs on all
available links.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The connection layer in af_smc.c is now using the new LLC flow
framework, which made the link state DELETING obsolete. Remove the state
and the respective helpers.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce smc_rtoken_set() to set the rtoken for a new link to an
existing rmb whose rtoken is given, and smc_rtoken_set2() to set an
rtoken for a new link whose link_id is given.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Adapt smc_llc_do_delete_rkey() to use the LLC flow and support multiple
links when deleting the rkeys for rmb buffers at the peer.
Signed-off-by: NKarsten Graul <kgraul@linux.ibm.com>
Reviewed-by: NUrsula Braun <ubraun@linux.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>