9 Commits

Author SHA1 Message Date
Gustavo A. R. Silva
65dc2f1a44 chelsio: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 15:26:17 -08:00
Rahul Lakkireddy
c856e2b6fc cxgb4: fix Tx multi channel port rate limit
T6 can support 2 egress traffic management channels per port to
double the total number of traffic classes that can be configured.
In this configuration, if the class belongs to the other channel,
then all the queues must be bound again explicitly to the new class,
for the rate limit parameters on the other channel to take effect.

So, always explicitly bind all queues to the port rate limit traffic
class, regardless of the traffic management channel that it belongs
to. Also, only bind queues to port rate limit traffic class, if all
the queues don't already belong to an existing different traffic
class.

Fixes: 4ec4762d8ec6 ("cxgb4: add TC-MATCHALL classifier egress offload")
Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-19 16:12:02 +01:00
Rahul Lakkireddy
4ec4762d8e cxgb4: add TC-MATCHALL classifier egress offload
Add TC-MATCHALL classifier offload with TC-POLICE action applied for
all outgoing traffic on the underlying interface. Split flow block
offload to support both egress and ingress classification.

For example, to rate limit all outgoing traffic to 1 Gbps:

$ tc qdisc add dev enp2s0f4 clsact
$ tc filter add dev enp2s0f4 egress matchall skip_sw \
	action police rate 1Gbit burst 8Kbit

Note that skip_sw is important. Otherwise, both stack and hardware
will end up doing policing. Policing can't be shared across flow
blocks. Only 1 egress matchall rule can be active at a time on the
underlying interface.

v5:
- No change.

v4:
- Removed check to reject police offload if prio is not 1.
- Moved TC_SETUP_BLOCK code to separate function.

v3:
- Added check to reject police offload if prio is not 1.
- Assign block_shared variable only for TC_SETUP_BLOCK.

v2:
- Added check to reject flow block sharing for policers.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-20 12:05:23 -08:00
Rahul Lakkireddy
0e395b3cb1 cxgb4: add FLOWC based QoS offload
Rework SCHED API to allow offloading TC-MQPRIO QoS configuration.
The existing QUEUE based rate limiting throttles all queues sharing
a traffic class, to the specified max rate limit value. So, if
multiple queues share a traffic class, then all the queues get
the aggregate specified max rate limit.

So, introduce the new FLOWC based rate limiting, where multiple
queues can share a traffic class with each queue getting its own
individual specified max rate limit.

For example, if 2 queues are bound to class 0, which is rate limited
to 1 Gbps, then 2 queues using QUEUE based rate limiting, get the
aggregate output of 1 Gbps only. In FLOWC based rate limiting, each
queue gets its own output of max 1 Gbps each; i.e. 2 queues * 1 Gbps
rate limit = 2 Gbps.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-07 10:41:59 -08:00
Ganesh Goudar
db3408a150 cxgb4: remove the unneeded locks
cxgb_set_tx_maxrate will be called holding rtnl lock,
hence remove all unneeded locks.

Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-10-03 09:34:52 -07:00
Ganesh Goudar
d185efc1da cxgb4: increase max tx rate limit to 100 Gbps
T6 cards can support up to 100 G speeds. So, increase
max programmable tx rate limit to 100 Gbps.

Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-03-09 12:57:35 -05:00
Rahul Lakkireddy
10a2604ea2 cxgb4: add support for tx max rate limiting
Implement set_tx_maxrate NDO to perform per queue tx rate limiting.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-22 18:29:13 -07:00
Rahul Lakkireddy
6cede1f17f cxgb4: add support for per queue tx scheduling
Add support to bind/unbind specified tx queues to/from scheduling
classes.  If a queue is already bound to a scheduling class, it is
unbound first and then bound to a new specified class.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-22 18:29:13 -07:00
Rahul Lakkireddy
b72a32dacd cxgb4: add support for tx traffic scheduling classes
Add support to create tx traffic scheduling classes with specified
scheduling parameters.  Return an existing class if a match is found
with same scheduling parameters.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-08-22 18:29:13 -07:00