From: David S. Miller Date: Wed, 28 Sep 2016 08:48:20 +0000 (-0400) Subject: Merge branch 'fib-offload-notifications' X-Git-Tag: v4.9-rc1~127^2~43 X-Git-Url: http://git.cascardo.info/?p=cascardo%2Flinux.git;a=commitdiff_plain;h=9c5982fe260a28e84d167e894123dc342e76c39f Merge branch 'fib-offload-notifications' Jiri Pirko says: ==================== fib offload: switch to notifier The goal of this patchset is to allow driver to propagate all prefixes configured in kernel down HW. This is necessary for routing to work as expected. If we don't do that HW might forward prefixes known to kernel incorrectly. Take an example when default route is set in switch HW and there is an IP address set on a management (non-switch) port. Currently, only FIB entries related to the switch port netdev are offloaded using switchdev ops. This model is not extendable so the first patch introduces a replacement: notifier to propagate FIB entry additions and removals to whoever is interested. The second patch introduces couple of helpers to deal with RTNH_F_OFFLOAD flags. Currently it is set in switchdev core. There the assumption is that only one offload device exists. But for FIB notifier, we assume multiple offload devices. So the patch introduces a per FIB entry reference counter and helpers use it in order to achieve this: 0 means RTNH_F_OFFLOAD is not set, no device offloads this entry n means RTNH_F_OFFLOAD is set and the entry is offloaded by n devices Patches 3 and 4 convert mlxsw and rocker to adopt this new way, registering one notifier block for each asic instance. Both of these patches also implement internal "abort" mechanism. Using switchdev ops, "abort" is called by switchdev core whenever there is an error during FIB entry add offload. This leads to removal of all offloaded entries on system by fib_trie code. Now the new notifier assumes the driver takes care of the abort action. Here's why: 1) The fact that one HW cannot offload an entry does not mean that the others can't do it. So let only one entity to abort and leave the rest to work happily. 2) The driver knows what to in order to properly abort. For example, currently abort is broken for mlxsw, as for Spectrum there is a need to set 0.0.0.0/0 trap in RALUE register. The fifth patch removes the old, no longer used FIB offload infrastructure. The last patch reflects the changes into switchdev documentation file. --- v2->v3: -patch 3/6 -fixed offload inc/dec to be done in fib4_entry_init/fini and only in case !trap as suggested by Ido v1->v2: -patch 3/6: -fixed lpm tree setup and binding for abort and pointed out by Ido -do nexthop checks as suggested by Ido -fix use after free during abort -patch 6/6: -fixed texts as suggested by Ido ==================== Signed-off-by: David S. Miller --- 9c5982fe260a28e84d167e894123dc342e76c39f