From patchwork Mon Aug 5 16:14:54 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 2838853 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 094BABF535 for ; Mon, 5 Aug 2013 17:20:30 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 44EC320353 for ; Mon, 5 Aug 2013 17:20:29 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9A1FA20149 for ; Mon, 5 Aug 2013 17:20:27 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1V6NT2-0003c3-Dd; Mon, 05 Aug 2013 16:17:10 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1V6NS4-00009s-Qd; Mon, 05 Aug 2013 16:16:08 +0000 Received: from arroyo.ext.ti.com ([192.94.94.40]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1V6NRl-00005s-82 for linux-arm-kernel@lists.infradead.org; Mon, 05 Aug 2013 16:15:50 +0000 Received: from dlelxv90.itg.ti.com ([172.17.2.17]) by arroyo.ext.ti.com (8.13.7/8.13.7) with ESMTP id r75GFDL7029597; Mon, 5 Aug 2013 11:15:13 -0500 Received: from DLEE70.ent.ti.com (dlee70.ent.ti.com [157.170.170.113]) by dlelxv90.itg.ti.com (8.14.3/8.13.8) with ESMTP id r75GFDaM022315; Mon, 5 Aug 2013 11:15:13 -0500 Received: from dlelxv22.itg.ti.com (172.17.1.197) by DLEE70.ent.ti.com (157.170.170.113) with Microsoft SMTP Server id 14.2.342.3; Mon, 5 Aug 2013 11:15:12 -0500 Received: from joel-laptop.itg.ti.com (h0-56.vpn.ti.com [172.24.0.56]) by dlelxv22.itg.ti.com (8.13.8/8.13.8) with ESMTP id r75GEv1R026253; Mon, 5 Aug 2013 11:15:12 -0500 From: Joel Fernandes To: Tony Lindgren , Sekhar Nori , Santosh Shilimkar , Sricharan R , Rajendra Nayak , Lokesh Vutla , Matt Porter , Grant Likely , Rob Herring , Vinod Koul , Dan Williams , Mark Brown , Benoit Cousson , Russell King , Arnd Bergmann , Olof Johansson , Balaji TK , Gururaja Hebbar , Chris Ball , Jason Kridner Subject: [PATCH v3 09/12] dma: edma: Implement multiple linked sets for continuity Date: Mon, 5 Aug 2013 11:14:54 -0500 Message-ID: <1375719297-12871-10-git-send-email-joelf@ti.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1375719297-12871-1-git-send-email-joelf@ti.com> References: <1375719297-12871-1-git-send-email-joelf@ti.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130805_121549_485598_36DEA6DF X-CRM114-Status: GOOD ( 19.58 ) X-Spam-Score: -5.2 (-----) Cc: Linux DaVinci Kernel List , Joel Fernandes , Linux MMC List , Linux Kernel Mailing List , Linux OMAP List , Linux ARM Kernel List X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,KHOP_BIG_TO_CC, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Here we implement splitting up of the total MAX number of slots available for a channel into 2 cyclically linked sets. Transfer completion Interrupts are enabled on both linked sets and respective handler recycles them on completion to process the next linked set. Both linked sets are cyclically linked to each other to ensure continuity of DMA operations. Interrupt handlers execute asynchronously to the EDMA events and recycles the linked sets at the right time, as a result EDMA is not blocked or dependent on interrupts and DMA continues till the end of the SG-lists without any interruption. Suggested-by: Sekhar Nori Signed-off-by: Joel Fernandes --- drivers/dma/edma.c | 157 +++++++++++++++++++++++++++++++++++++++------------- 1 file changed, 118 insertions(+), 39 deletions(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index df50a04..70923a2 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -48,6 +48,7 @@ /* Max of 16 segments per channel to conserve PaRAM slots */ #define MAX_NR_SG 16 +#define MAX_NR_LS (MAX_NR_SG >> 1) #define EDMA_MAX_SLOTS (MAX_NR_SG+1) #define EDMA_DESCRIPTORS 16 @@ -57,6 +58,7 @@ struct edma_desc { int absync; int pset_nr; int total_processed; + int next_setup_linkset; struct edmacc_param pset[0]; }; @@ -140,7 +142,9 @@ static void edma_execute(struct edma_chan *echan) struct edma_desc *edesc; struct device *dev = echan->vchan.chan.device->dev; - int i, j, total_left, total_process; + int i, total_left, total_link_set; + int ls_cur_off, ls_next_off, slot_off; + struct edmacc_param tmp_param; /* If either we processed all psets or we're still not started */ if (!echan->edesc || @@ -159,48 +163,121 @@ static void edma_execute(struct edma_chan *echan) /* Find out how many left */ total_left = edesc->pset_nr - edesc->total_processed; - total_process = total_left > MAX_NR_SG ? MAX_NR_SG : total_left; - - - /* Write descriptor PaRAM set(s) */ - for (i = 0; i < total_process; i++) { - j = i + edesc->total_processed; - edma_write_slot(echan->slot[i], &edesc->pset[j]); - dev_dbg(echan->vchan.chan.device->dev, - "\n pset[%d]:\n" - " chnum\t%d\n" - " slot\t%d\n" - " opt\t%08x\n" - " src\t%08x\n" - " dst\t%08x\n" - " abcnt\t%08x\n" - " ccnt\t%08x\n" - " bidx\t%08x\n" - " cidx\t%08x\n" - " lkrld\t%08x\n", - j, echan->ch_num, echan->slot[i], - edesc->pset[j].opt, - edesc->pset[j].src, - edesc->pset[j].dst, - edesc->pset[j].a_b_cnt, - edesc->pset[j].ccnt, - edesc->pset[j].src_dst_bidx, - edesc->pset[j].src_dst_cidx, - edesc->pset[j].link_bcntrld); - /* Link to the previous slot if not the last set */ - if (i != (total_process - 1)) + total_link_set = total_left > MAX_NR_LS ? MAX_NR_LS : total_left; + + /* First time, setup 2 cyclically linked sets, each containing half + the slots allocated for this channel */ + if (edesc->total_processed == 0) { + for (i = 0; i < total_link_set; i++) { + edma_write_slot(echan->slot[i+1], &edesc->pset[i]); + + if (i != total_link_set - 1) { + edma_link(echan->slot[i+1], echan->slot[i+2]); + dump_pset(echan, echan->slot[i+1], + edesc->pset, i); + } + } + + edesc->total_processed += total_link_set; + + total_left = edesc->pset_nr - edesc->total_processed; + + total_link_set = total_left > MAX_NR_LS ? + MAX_NR_LS : total_left; + + if (total_link_set) { + /* Don't setup interrupt for first linked set for cases + where total pset_nr is strictly within MAX_NR size */ + if (total_left > total_link_set) + edma_enable_interrupt(echan->slot[i]); + + /* Setup link between linked set 0 to set 1 */ edma_link(echan->slot[i], echan->slot[i+1]); - /* Final pset links to the dummy pset */ - else + + dump_pset(echan, echan->slot[i], edesc->pset, i-1); + + /* Write out linked set 1 */ + for (; i < total_link_set + MAX_NR_LS; i++) { + edma_write_slot(echan->slot[i+1], + &edesc->pset[i]); + + if (i != total_link_set + MAX_NR_LS - 1) { + edma_link(echan->slot[i+1], + echan->slot[i+2]); + dump_pset(echan, echan->slot[i+1], + edesc->pset, i); + } + } + + edesc->total_processed += total_link_set; + total_left = edesc->pset_nr - edesc->total_processed; + + if (total_left) + /* Setup a link from linked set 1 to set 0 */ + edma_link(echan->slot[i], echan->slot[1]); + else + /* Setup a link between linked set 1 to dummy */ + edma_link(echan->slot[i], echan->ecc->dummy_slot); + } else { + /* First linked set was enough, simply link to dummy */ edma_link(echan->slot[i], echan->ecc->dummy_slot); - } + } + + edma_enable_interrupt(echan->slot[i]); + dump_pset(echan, echan->slot[i], edesc->pset, i-1); - edesc->total_processed += total_process; + edesc->next_setup_linkset = 0; - if (edesc->total_processed <= MAX_NR_SG) { + /* Start the ball rolling... */ dev_dbg(dev, "first transfer starting %d\n", echan->ch_num); + + edma_read_slot(echan->slot[1], &tmp_param); + edma_write_slot(echan->slot[0], &tmp_param); edma_start(echan->ch_num); + + return; + } + + /* We got called in the middle of an SG-list transaction as one of the + linked sets completed */ + + /* Setup offsets into echan_slot, +1 is as slot 0 is for chan */ + if (edesc->next_setup_linkset == 1) { + edesc->next_setup_linkset = 0; + ls_cur_off = MAX_NR_LS + 1; + ls_next_off = 1; + } else { + edesc->next_setup_linkset = 1; + ls_cur_off = 1; + ls_next_off = MAX_NR_LS + 1; + } + + for (i = 0; i < total_link_set; i++) { + edma_write_slot(echan->slot[i + ls_cur_off], + &edesc->pset[i + edesc->total_processed]); + + if (i != total_link_set - 1) { + edma_link(echan->slot[i + ls_cur_off], + echan->slot[i + ls_cur_off + 1]); + + dump_pset(echan, echan->slot[i + ls_cur_off], + edesc->pset, i + edesc->total_processed); + } } + + edesc->total_processed += total_link_set; + + slot_off = total_link_set + ls_cur_off - 1; + + if (edesc->total_processed == edesc->pset_nr) + edma_link(echan->slot[slot_off], echan->ecc->dummy_slot); + else + edma_link(echan->slot[slot_off], echan->slot[ls_next_off]); + + edma_enable_interrupt(echan->slot[slot_off]); + + dump_pset(echan, echan->slot[slot_off], + edesc->pset, edesc->total_processed-1); } static int edma_terminate_all(struct edma_chan *echan) @@ -417,15 +494,17 @@ static void edma_callback(unsigned ch_num, u16 ch_status, void *data) spin_lock_irqsave(&echan->vchan.lock, flags); edesc = echan->edesc; + if (edesc) { if (edesc->total_processed == edesc->pset_nr) { - dev_dbg(dev, "transfer complete." \ + dev_dbg(dev, "Transfer complete," " stopping channel %d\n", ch_num); edma_stop(echan->ch_num); vchan_cookie_complete(&edesc->vdesc); } else { - dev_dbg(dev, "Intermediate transfer complete" \ - " on channel %d\n", ch_num); + dev_dbg(dev, "Intermediate transfer " + "complete, setup next linked set on " + "%d\n ", ch_num); } edma_execute(echan);