linux/net/dcb, branch v5.0

net: dcb: Add priority-to-DSCP map getters

2018-07-27T20:17:50Z

On ingress, a network device such as a switch assigns to packets priority based on various criteria. Common options include interpreting PCP and DSCP fields according to user configuration. When a packet egresses the switch, a reverse process may rewrite PCP and/or DSCP values according to packet priority. The following three functions support a) obtaining a DSCP-to-priority map or vice versa, and b) finding default-priority entries in APP database. The DCB subsystem supports for APP entries a very generous M:N mapping between priorities and protocol identifiers. Understandably, several (say) DSCP values can map to the same priority. But this asymmetry holds the other way around as well--one priority can map to several DSCP values. For this reason, the following functions operate in terms of bitmaps, with ones in positions that match some APP entry. - dcb_ieee_getapp_dscp_prio_mask_map() to compute for a given netdevice a map of DSCP-to-priority-mask, which gives for each DSCP value a bitmap of priorities related to that DSCP value by APP, along the lines of dcb_ieee_getapp_mask(). - dcb_ieee_getapp_prio_dscp_mask_map() similarly to compute for a given netdevice a map from priorities to a bitmap of DSCPs. - dcb_ieee_getapp_default_prio_mask() which finds all default-priority rules for a given port in APP database, and returns a mask of priorities allowed by these default-priority rules. Signed-off-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller

net: dcb: For wild-card lookups, use priority -1, not 0

2018-07-27T20:17:49Z

The function dcb_app_lookup walks the list of specified DCB APP entries, looking for one that matches a given criteria: ifindex, selector, protocol ID and optionally also priority. The "don't care" value for priority is set to 0, because that priority has not been allowed under CEE regime, which predates the IEEE standardization. Under IEEE, 0 is a valid priority number. But because dcb_app_lookup considers zero a wild card, attempts to add an APP entry with priority 0 fail when other entries exist for a given ifindex / selector / PID triplet. Fix by changing the wild-card value to -1. Signed-off-by: Petr Machata Signed-off-by: Ido Schimmel Signed-off-by: David S. Miller

treewide: kmalloc() -> kmalloc_array()

2018-06-12T23:19:22Z

The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook

net/dcb: Add dcbnl buffer attribute

2018-05-24T21:22:59Z

In this patch, we add dcbnl buffer attribute to allow user change the NIC's buffer configuration such as priority to buffer mapping and buffer size of individual buffer. This attribute combined with pfc attribute allows advanced user to fine tune the qos setting for specific priority queue. For example, user can give dedicated buffer for one or more priorities or user can give large buffer to certain priorities. The dcb buffer configuration will be controlled by lldptool. lldptool -T -i eth2 -V BUFFER prio 0,2,5,7,1,2,3,6 maps priorities 0,1,2,3,4,5,6,7 to receive buffer 0,2,5,7,1,2,3,6 lldptool -T -i eth2 -V BUFFER size 87296,87296,0,87296,0,0,0,0 sets receive buffer size for buffer 0,1,2,3,4,5,6,7 respectively After discussion on mailing list with Jakub, Jiri, Ido and John, we agreed to choose dcbnl over devlink interface since this feature is intended to set port attributes which are governed by the netdev instance of that port, where devlink API is more suitable for global ASIC configurations. We present an use case scenario where dcbnl buffer attribute configured by advance user helps reduce the latency of messages of different sizes. Scenarios description: On ConnectX-5, we run latency sensitive traffic with small/medium message sizes ranging from 64B to 256KB and bandwidth sensitive traffic with large messages sizes 512KB and 1MB. We group small, medium, and large message sizes to their own pfc enables priorities as follow. Priorities 1 & 2 (64B, 256B and 1KB) Priorities 3 & 4 (4KB, 8KB, 16KB, 64KB, 128KB and 256KB) Priorities 5 & 6 (512KB and 1MB) By default, ConnectX-5 maps all pfc enabled priorities to a single lossless fixed buffer size of 50% of total available buffer space. The other 50% is assigned to lossy buffer. Using dcbnl buffer attribute, we create three equal size lossless buffers. Each buffer has 25% of total available buffer space. Thus, the lossy buffer size reduces to 25%. Priority to lossless buffer mappings are set as follow. Priorities 1 & 2 on lossless buffer #1 Priorities 3 & 4 on lossless buffer #2 Priorities 5 & 6 on lossless buffer #3 We observe improvements in latency for small and medium message sizes as follows. Please note that the large message sizes bandwidth performance is reduced but the total bandwidth remains the same. 256B message size (42 % latency reduction) 4K message size (21% latency reduction) 64K message size (16% latency reduction) CC: Ido Schimmel CC: Jakub Kicinski CC: Jiri Pirko CC: Or Gerlitz CC: Parav Pandit CC: Aron Silverton Signed-off-by: Huy Nguyen Reviewed-by: Parav Pandit Signed-off-by: Saeed Mahameed

rtnetlink: make rtnl_register accept a flags parameter

2017-08-09T23:57:38Z

This change allows us to later indicate to rtnetlink core that certain doit functions should be called without acquiring rtnl_mutex. This change should have no effect, we simply replace the last (now unused) calcit argument with the new flag. Signed-off-by: Florian Westphal Reviewed-by: Hannes Frederic Sowa Signed-off-by: David S. Miller

dcb: enforce minimum length on IEEE_APPS attribute

2017-05-21T17:42:33Z

Found by reviewing the warning about unused policy table. The code implies that it meant to check for size, but since it unrolled the loop for attribute validation that is never used. Instead do explicit check for attribute. Compile tested only. Needs review by original author. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller

net: rtnetlink: plumb extended ack to doit function

2017-04-17T19:35:38Z

Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse for doit functions that call it directly. This is the first step to using extended error reporting in rtnetlink. >From here individual subsystems can be updated to set netlink_ext_ack as needed. Signed-off-by: David Ahern Signed-off-by: David S. Miller

netlink: pass extended ACK struct to parsing functions

2017-04-13T17:58:22Z

Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

net: dcb: set error code on failures

2016-12-04T04:54:25Z

In function dcbnl_cee_fill(), returns the value of variable err on errors. However, on some error paths (e.g. nla put fails), its value may be 0. It may be better to explicitly set a negative errno to variable err before returning. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=188881 Signed-off-by: Pan Bian Signed-off-by: David S. Miller

net/dcb: make dcbnl.c explicitly non-modular

2015-10-09T14:52:27Z

The Kconfig currently controlling compilation of this code is: net/dcb/Kconfig:config DCB net/dcb/Kconfig: bool "Data Center Bridging support" ...meaning that it currently is not being built as a module by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering remains unchanged with this commit. We can change to one of the other priority initcalls (subsys?) at any later date, if desired. We also delete the MODULE_LICENSE tag etc. since all that information is (or is now) already contained at the top of the file in the comments. Cc: "David S. Miller" Cc: Or Gerlitz Cc: Anish Bhatt Cc: John Fastabend Cc: Shani Michaeli Cc: netdev@vger.kernel.org Signed-off-by: Paul Gortmaker Signed-off-by: David S. Miller