From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bart Van Assche Subject: [PATCH 1/8] IB/srp: Re-enable FMR for non-page aligned buffers Date: Mon, 10 Aug 2015 17:06:29 -0700 Message-ID: <55C93C85.6090003@sandisk.com> References: <55BBF4B8.2050700@sandisk.com> <20150803152420.GA24193@infradead.org> <55BFB40F.8000500@sandisk.com> <20150804180933.GB5038@obsidianresearch.com> <1438756876.5698.2.camel@haswell.thedillows.org> <20150805195122.GA31595@obsidianresearch.com> <55C2840C.5050301@sandisk.com> <55C2912A.50709@sandisk.com> <20150806001006.GD2483@obsidianresearch.com> <55C2A7FE.7020904@sandisk.com> <20150806043642.GA14153@obsidianresearch.com> <55C93C61.9010508@sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <55C93C61.9010508-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Jason Gunthorpe Cc: "linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-rdma@vger.kernel.org During a discussion in 2011 nobody recalled why FMR was not used for non-page aligned buffers (see also http://thread.gmane.org/gmane.linux.drivers.rdma/7149). Re-enable FMR for such buffers. For the reason why the srp_map_fmr() function needs to be modified, see also patch "IB/srp: rework mapping engine to use multiple FMR entries" (commit ID 8f26c9ff9cd0; January 2011). Signed-off-by: Bart Van Assche --- drivers/infiniband/ulp/srp/ib_srp.c | 14 +++++--------- 1 file changed, 5 insertions(+), 9 deletions(-) diff --git a/drivers/infiniband/ulp/srp/ib_srp.c b/drivers/infiniband/ulp/srp/ib_srp.c index 2968b7b..887e8ca 100644 --- a/drivers/infiniband/ulp/srp/ib_srp.c +++ b/drivers/infiniband/ulp/srp/ib_srp.c @@ -1272,6 +1272,8 @@ static void srp_map_desc(struct srp_map_state *state, dma_addr_t dma_addr, static int srp_map_finish_fmr(struct srp_map_state *state, struct srp_rdma_ch *ch) { + struct srp_target_port *target = ch->target; + struct srp_device *dev = target->srp_host->srp_dev; struct ib_pool_fmr *fmr; u64 io_addr = 0; @@ -1283,7 +1285,8 @@ static int srp_map_finish_fmr(struct srp_map_state *state, *state->next_fmr++ = fmr; state->nmdesc++; - srp_map_desc(state, 0, state->dma_len, fmr->fmr->rkey); + srp_map_desc(state, state->base_dma_addr & ~dev->mr_page_mask, + state->dma_len, fmr->fmr->rkey); return 0; } @@ -1390,14 +1393,7 @@ static int srp_map_sg_entry(struct srp_map_state *state, return 0; } - /* - * Since not all RDMA HW drivers support non-zero page offsets for - * FMR, if we start at an offset into a page, don't merge into the - * current FMR mapping. Finish it out, and use the kernel's MR for - * this sg entry. - */ - if ((!dev->use_fast_reg && dma_addr & ~dev->mr_page_mask) || - dma_len > dev->mr_max_size) { + if (dma_len > dev->mr_max_size) { ret = srp_finish_mapping(state, ch); if (ret) return ret; -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html