Date: Thu, 25 Aug 2016 05:35:51 +0000 (UTC) From: Sepherosa Ziehau <sephe@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r304790 - in head/sys/dev/hyperv: include vmbus Message-ID: <201608250535.u7P5ZpYq007226@repo.freebsd.org>
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Author: sephe Date: Thu Aug 25 05:35:51 2016 New Revision: 304790 URL: https://svnweb.freebsd.org/changeset/base/304790 Log: hyperv/vmbus: Add function to calculate max # of elements in a bufring. MFC after: 1 week Sponsored by: Microsoft Modified: head/sys/dev/hyperv/include/vmbus.h head/sys/dev/hyperv/vmbus/vmbus_brvar.h head/sys/dev/hyperv/vmbus/vmbus_chan.c Modified: head/sys/dev/hyperv/include/vmbus.h ============================================================================== --- head/sys/dev/hyperv/include/vmbus.h Thu Aug 25 05:28:02 2016 (r304789) +++ head/sys/dev/hyperv/include/vmbus.h Thu Aug 25 05:35:51 2016 (r304790) @@ -161,5 +161,7 @@ uint32_t vmbus_chan_subidx(const struct bool vmbus_chan_is_primary(const struct vmbus_channel *chan); const struct hyperv_guid * vmbus_chan_guid_inst(const struct vmbus_channel *chan); +int vmbus_chan_prplist_nelem(int br_size, int prpcnt_max, + int dlen_max); #endif /* !_VMBUS_H_ */ Modified: head/sys/dev/hyperv/vmbus/vmbus_brvar.h ============================================================================== --- head/sys/dev/hyperv/vmbus/vmbus_brvar.h Thu Aug 25 05:28:02 2016 (r304789) +++ head/sys/dev/hyperv/vmbus/vmbus_brvar.h Thu Aug 25 05:35:51 2016 (r304790) @@ -74,6 +74,7 @@ struct sysctl_oid; static __inline int vmbus_txbr_maxpktsz(const struct vmbus_txbr *tbr) { + /* * - 64 bits for the trailing start index (- sizeof(uint64_t)). * - The rindex and windex can't be same (- 1). See @@ -82,6 +83,17 @@ vmbus_txbr_maxpktsz(const struct vmbus_t return (tbr->txbr_dsize - sizeof(uint64_t) - 1); } +static __inline int +vmbus_br_nelem(int br_size, int elem_size) +{ + + /* Strip bufring header */ + br_size -= sizeof(struct vmbus_bufring); + /* Add per-element trailing index */ + elem_size += sizeof(uint64_t); + return (br_size / elem_size); +} + void vmbus_br_sysctl_create(struct sysctl_ctx_list *ctx, struct sysctl_oid *br_tree, struct vmbus_br *br, const char *name); Modified: head/sys/dev/hyperv/vmbus/vmbus_chan.c ============================================================================== --- head/sys/dev/hyperv/vmbus/vmbus_chan.c Thu Aug 25 05:28:02 2016 (r304789) +++ head/sys/dev/hyperv/vmbus/vmbus_chan.c Thu Aug 25 05:35:51 2016 (r304790) @@ -1411,3 +1411,16 @@ vmbus_chan_guid_inst(const struct vmbus_ { return &chan->ch_guid_inst; } + +int +vmbus_chan_prplist_nelem(int br_size, int prpcnt_max, int dlen_max) +{ + int elem_size; + + elem_size = __offsetof(struct vmbus_chanpkt_prplist, + cp_range[0].gpa_page[prpcnt_max]); + elem_size += dlen_max; + elem_size = VMBUS_CHANPKT_TOTLEN(elem_size); + + return (vmbus_br_nelem(br_size, elem_size)); +}
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