Commit Graph

424 Commits

Author SHA1 Message Date
Karsten Graul 29bd73dba4 net/smc: send failover validation message
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:54:39 -07:00
Karsten Graul c6f02ebeea net/smc: switch connections to alternate link
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:54:39 -07:00
Karsten Graul f0ec4f1d32 net/smc: save state of last sent CDC message
When a link goes down and all connections of this link need to be
switched to an other link then the producer cursor and the sequence of
the last successfully sent CDC message must be known. Add the two fields
to the SMC connection and update it in the tx completion handler.
And to allow matching of sequences in error cases reset the seqno to the
old value in smc_cdc_msg_send() when the actual send failed.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 10:54:39 -07:00
Karsten Graul 4dadd151b2 net/smc: enqueue local LLC messages
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:08:07 -07:00
Karsten Graul 08ae27ddfb net/smc: delete link processing as SMC server
Add smc_llc_process_srv_delete_link() to process a DELETE_LINK request
as SMC server. When the request is to delete ALL links then terminate
the whole link group. If not, find the link to delete by its link_id,
send the DELETE_LINK request LLC message and wait for the response.
No matter if a response was received, clear the deleted link and update
the link group state.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:07:56 -07:00
Karsten Graul 9c4168789c net/smc: delete link processing as SMC client
Add smc_llc_process_cli_delete_link() to process a DELETE_LINK request
as SMC client. When the request is to delete ALL links then terminate
the whole link group. If not, find the link to delete by its link_id,
send the DELETE_LINK response LLC message and then clear the deleted
link. Finally determine and update the link group state.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:07:39 -07:00
Karsten Graul 9ec6bf19ec net/smc: llc_del_link_work and use the LLC flow for delete link
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:07:23 -07:00
Karsten Graul c9a5d24303 net/smc: delete an asymmetric link as SMC server
When a link group moved from asymmetric to symmetric state then the
dangling asymmetric link can be deleted. Add smc_llc_find_asym_link() to
find the respective link and add smc_llc_delete_asym_link() to delete
it.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:07:09 -07:00
Karsten Graul 1551c95b61 net/smc: final part of add link processing as SMC server
This patch finalizes the ADD_LINK processing of new links. Send the
CONFIRM_LINK request to the peer, receive the response and set link
state to ACTIVE.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:07:01 -07:00
Karsten Graul 57b499242c net/smc: rkey processing for a new link as SMC server
Part of SMC server new link establishment is the exchange of rkeys for
used buffers.
Loop over all used RMB buffers and send ADD_LINK_CONTINUE LLC messages
to the peer.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:06:51 -07:00
Karsten Graul 2d2209f201 net/smc: first part of add link processing as SMC server
First set of functions to process an ADD_LINK LLC request as an SMC
server. Find an alternate IB device, determine the new link group type
and get the index for the new link. Then initialize the link and send
the ADD_LINK LLC message to the peer. Save the contents of the response,
ready the link, map all used buffers and register the buffers with the
IB device. If any error occurs, stop the processing and clear the link.
And call smc_llc_srv_add_link() in af_smc.c to start second link
establishment after the initial link of a link group was created.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:06:40 -07:00
Karsten Graul b1570a87f5 net/smc: final part of add link processing as SMC client
This patch finalizes the ADD_LINK processing of new links. Receive the
CONFIRM_LINK request from peer, complete the link initialization,
register all used buffers with the IB device and finally send the
CONFIRM_LINK response, which completes the ADD_LINK processing.
And activate smc_llc_cli_add_link() in af_smc.c.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:06:25 -07:00
Karsten Graul 87f88cda21 net/smc: rkey processing for a new link as SMC client
Part of the SMC client new link establishment process is the exchange of
rkeys for all used buffers.
Add new LLC message type ADD_LINK_CONTINUE which is used to exchange
rkeys of all current RMB buffers. Add functions to iterate over all
used RMB buffers of the link group, and implement the ADD_LINK_CONTINUE
processing.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:06:09 -07:00
Karsten Graul 336ba09f2e net/smc: first part of add link processing as SMC client
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-03 16:05:15 -07:00
David S. Miller 40b94224c3 smc: Remove unused function.
net/smc/smc_llc.c:544:12: warning: ‘smc_llc_alloc_alt_link’ defined but not used [-Wunused-function]
 static int smc_llc_alloc_alt_link(struct smc_link_group *lgr,
            ^~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-02 16:41:06 -07:00
Karsten Graul b45e7f98ab net/smc: llc_add_link_work to handle ADD_LINK LLC requests
Introduce a work that is scheduled when a new ADD_LINK LLC request is
received. The work will call either the SMC client or SMC server
ADD_LINK processing.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:05 -07:00
Karsten Graul 8574cf4055 net/smc: allocate index for a new link
Add smc_llc_alloc_alt_link() to find a free link index for a new link,
depending on the new link group type. And update constants for the
maximum number of links to 3 (2 symmetric and 1 dangling asymmetric link).
These maximum numbers are the same as used by other implementations of the
SMC-R protocol.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:05 -07:00
Karsten Graul 6c868a3edc net/smc: introduce smc_pnet_find_alt_roce()
Introduce a new function in smc_pnet.c that searches for an alternate
IB device, using an existing link group and a primary IB device. The
alternate IB device needs to be active and must have the same PNETID
as the link group.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:05 -07:00
Karsten Graul 33d203302d net/smc: remove DELETE LINK processing from smc_core.c
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 87523930a1 net/smc: take link down instead of terminating the link group
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 541afa10c1 net/smc: add smcr_port_err() and smcr_link_down() processing
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 1f90a05d9f net/smc: add smcr_port_add() and smcr_link_up() processing
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 35dcf7ec02 net/smc: remember PNETID of IB device for later device matching
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul d550066776 net/smc: mutex to protect the lgr against parallel reconfigurations
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul fbed3b37c8 net/smc: extend smc_llc_send_add_link() and smc_llc_send_delete_link()
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul fb33d27727 net/smc: map and register buffers for a new link
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 4a3641c160 net/smc: unmapping of buffers to support multiple links
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 7562a13d5a net/smc: multiple link support for rmb buffer registration
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-01 16:20:04 -07:00
Karsten Graul 41a211d862 net/smc: remove obsolete link state DELETING
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:34 -07:00
Karsten Graul 42d18acce9 net/smc: remove handling of CONFIRM_RKEY_CONTINUE
The new SMC-R multiple link support will support a maximum of 3 links,
and one CONFIRM_RKEY LLC message can transport 3 rkeys of an rmb buffer.
There is no need for the LLC message type CONFIRM_RKEY_CONTINUE which is
needed when more than 3 rkeys per rmb buffer needs to be exchanged.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:34 -07:00
Karsten Graul 218b24fe38 net/smc: adapt SMC remote DELETE_RKEY processing to use the LLC flow
Use the LLC flow framework for the processing of DELETE_RKEY messages
that were received from the peer.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:34 -07:00
Karsten Graul 3bc67e098c net/smc: adapt SMC remote CONFIRM_RKEY processing to use the LLC flow
Use the LLC flow framework for the processing of CONFIRM_RKEY messages
that were received from the peer.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:34 -07:00
Karsten Graul ba21abd22f net/smc: new smc_rtoken_set functions for multiple link support
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:34 -07:00
Karsten Graul 56e8091c7a net/smc: move the TEST_LINK response processing into event handler
Get rid of the extra function and move the two-liner for the TEST_LINK
response processing into the event handler function.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 6d74c3a8a3 net/smc: multiple link support and LLC flow for smc_llc_do_delete_rkey
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: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 3d88a21b0c net/smc: multiple link support and LLC flow for smc_llc_do_confirm_rkey
Adapt smc_llc_do_confirm_rkey() to use the LLC flow and support the
rkeys of multiple links when the CONFIRM_RKEY LLC message is build.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 0fb0b02bd6 net/smc: adapt SMC client code to use the LLC flow
Change the code that processes the SMC client part of connection
establishment to use the LLC flow framework (CONFIRM_LINK request
messages).

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 4667bb4aaa net/smc: adapt SMC server code to use the LLC flow
Change the code that processes the SMC server part of connection
establishment to use the LLC flow framework (CONFIRM_LINK response
messages).

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 92334cfcb3 net/smc: add logic to evaluate CONFIRM_LINK messages to LLC layer
Introduce smc_llc_eval_conf_link() to evaluate the CONFIRM_LINK message
contents. This implements this logic at the LLC layer. The function will
be used by af_smc.c to process the received LLC layer messages.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 81e6e5e70d net/smc: introduce link group type
Add a type field to the link group which reflects the current link group
redundancy state.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul a6688d919b net/smc: enqueue all received LLC messages
Introduce smc_llc_enqueue() to enqueue LLC messages, and adapt
smc_llc_rx_handler() to enqueue all received LLC messages.
smc_llc_enqueue() also makes it possible to enqueue LLC messages from
local code.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 555da9af82 net/smc: add event-based llc_flow framework
The new framework allows to start specific types of LLC control flows,
protects active flows and makes it possible to wait for flows to finish
before starting a new flow.
This mechanism is used for the LLC control layer to model flows like
'add link' or 'delete link' which need to send/receive several LLC
messages and are not allowed to get interrupted by the wrong type of
messages.
'Add link' or 'Delete link' messages arriving in the middle of a flow
are delayed and processed when the current flow finished.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-30 12:44:33 -07:00
Karsten Graul 00a049cfde net/smc: move llc layer related init and clear into smc_llc.c
Introduce smc_llc_lgr_init() and smc_llc_lgr_clear() to implement all
llc layer specific initialization and cleanup in module smc_llc.c.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:33 -07:00
Karsten Graul faca536008 net/smc: use mutex instead of rwlock_t to protect buffers
The locks for sndbufs and rmbs are never used from atomic context. Using
a mutex for these locks will allow to nest locks with other mutexes.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:33 -07:00
Karsten Graul ef79d439cd net/smc: process llc responses in tasklet context
When llc responses are received then possible waiters for this response
are to be notified. This can be done in tasklet context, without to
use a work in the llc work queue. Move all code that handles llc
responses into smc_llc_rx_response().

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:33 -07:00
Karsten Graul 6c8968c421 net/smc: use worker to process incoming llc messages
Incoming llc messages are processed in irq tasklet context, and
a worker is used to send outgoing messages. The worker is needed
because getting a send buffer could result in a wait for a free buffer.

To make sure all incoming llc messages are processed in a serialized way
introduce an event queue and create a new queue entry for each message
which is queued to this event queue. A new worker processes the event
queue entries in order.
And remove the use of a separate worker to send outgoing llc messages
because the messages are processed in worker context already.
With this event queue the serialized llc_wq work queue is obsolete,
remove it.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:32 -07:00
Karsten Graul 2140ac26f8 net/smc: simplify link deactivation
Cancel the testlink worker during link clear processing and remove the
extra function smc_llc_link_inactive().

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:32 -07:00
Karsten Graul 1020e1ef53 net/smc: move testlink work to system work queue
The testlink work waits for a response to the testlink request and
blocks the single threaded llc_wq. This type of work does not have to be
serialized and can be moved to the system work queue.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:32 -07:00
Karsten Graul d854fcbfae net/smc: add new link state and related helpers
Before a link can be reused it must have been cleared. Lowest current
link state is INACTIVE, which does not mean that the link is already
cleared.
Add a new state UNUSED that is set when the link is cleared and can be
reused.
Add helper smc_llc_usable_link() to find an active link in a link group,
and smc_link_usable() to determine if a link is usable.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:32 -07:00
Karsten Graul e07d31dc16 net/smc: multi-link support for smc_rmb_rtoken_handling()
Extend smc_rmb_rtoken_handling() and smc_rtoken_delete() to support
multiple links.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-29 12:26:32 -07:00