From patchwork Thu Aug 3 13:21:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 9879085 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id D6E89603B4 for ; Thu, 3 Aug 2017 13:22:11 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C785C28807 for ; Thu, 3 Aug 2017 13:22:11 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id BC327288EA; Thu, 3 Aug 2017 13:22:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ABBE728807 for ; Thu, 3 Aug 2017 13:22:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751870AbdHCNWK (ORCPT ); Thu, 3 Aug 2017 09:22:10 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:43232 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751206AbdHCNWI (ORCPT ); Thu, 3 Aug 2017 09:22:08 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id E77E66070B; Thu, 3 Aug 2017 13:22:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1501766527; bh=AJywBC9cCBn1Q+lwyIMPhMbVoZBXEgfUc/NgS6O2//s=; h=From:To:Cc:Subject:Date:From; b=Use8VDwtHcylYMnNp7ebzz1j42GWrVWg4TqckP5Wq0xyVrHq1e2GZaRNv4azZ80ZK stfa2VYT1wLdn0N0Rh/R2UFHHDyyn3f5W/13T+S/EmzbgaYG7lc+ay0J7mxaplfEi6 KxiASoPHBcUfG/1+u8v3dm34WA5ejStGsWO18ZPk= Received: from srichara-linux.qualcomm.com (blr-c-bdr-fw-01_globalnat_allzones-outside.qualcomm.com [103.229.19.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: sricharan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 3069D601A0; Thu, 3 Aug 2017 13:22:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1501766526; bh=AJywBC9cCBn1Q+lwyIMPhMbVoZBXEgfUc/NgS6O2//s=; h=From:To:Cc:Subject:Date:From; b=SpIS2HBrfbkhNgBnwmJuquYwrL3GhDqTPxNZiIPT8t5YS5BITyk/dmwo32QkFyV7P J0gqCJfNxAECYgo42Xn7F0O4ulhqz/JqC3+pd2+A3vPe/9cKw+NUB5uC599oFmOHQi pLjtRYIwWNfwj9g24PPOCxfFRXDbK/Juo7B9JI30= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 3069D601A0 Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=sricharan@codeaurora.org From: Sricharan R To: vinod.koul@intel.com, andy.gross@linaro.org, david.brown@linaro.org, dan.j.williams@intel.com, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Cc: sricharan@codeaurora.org Subject: [PATCH v2] dmaengine: qcom-bam: Process multiple pending descriptors Date: Thu, 3 Aug 2017 18:51:53 +0530 Message-Id: <1501766513-21349-1-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.9.1 Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The bam dmaengine has a circular FIFO to which we add hw descriptors that describes the transaction. The FIFO has space for about 4096 hw descriptors. Currently we add one descriptor and wait for it to complete with interrupt and then add the next pending descriptor. In this way, the FIFO is underutilized since only one descriptor is processed at a time, although there is space in FIFO for the BAM to process more. Instead keep adding descriptors to FIFO till its full, that allows BAM to continue to work on the next descriptor immediately after signalling completion interrupt for the previous descriptor. Also when the client has not set the DMA_PREP_INTERRUPT for a descriptor, then do not configure BAM to trigger a interrupt upon completion of that descriptor. This way we get a interrupt only for the descriptor for which DMA_PREP_INTERRUPT was requested and there signal completion of all the previous completed descriptors. So we still do callbacks for all requested descriptors, but just that the number of interrupts are reduced. CURRENT: ------ ------- --------------- |DES 0| |DESC 1| |DESC 2 + INT | ------ ------- --------------- | | | | | | INTERRUPT: (INT) (INT) (INT) CALLBACK: (CB) (CB) (CB) MTD_SPEEDTEST READ PAGE: 3560 KiB/s MTD_SPEEDTEST WRITE PAGE: 2664 KiB/s IOZONE READ: 2456 KB/s IOZONE WRITE: 1230 KB/s bam dma interrupts (after tests): 96508 CHANGE: ------ ------- ------------- |DES 0| |DESC 1 |DESC 2 + INT | ------ ------- -------------- | | (INT) (CB for 0, 1, 2) MTD_SPEEDTEST READ PAGE: 3860 KiB/s MTD_SPEEDTEST WRITE PAGE: 2837 KiB/s IOZONE READ: 2677 KB/s IOZONE WRITE: 1308 KB/s bam dma interrupts (after tests): 58806 Signed-off-by: Sricharan R Tested-by: Abhishek Sahu --- drivers/dma/qcom/bam_dma.c | 202 +++++++++++++++++++++++++++++---------------- 1 file changed, 129 insertions(+), 73 deletions(-) diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c index 6d89fb6..9e92d7c 100644 --- a/drivers/dma/qcom/bam_dma.c +++ b/drivers/dma/qcom/bam_dma.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include #include @@ -78,6 +79,8 @@ struct bam_async_desc { struct bam_desc_hw *curr_desc; + /* list node for the desc in the bam_chan list of descriptors */ + struct list_head desc_node; enum dma_transfer_direction dir; size_t length; struct bam_desc_hw desc[0]; @@ -356,7 +359,7 @@ struct bam_chan { /* configuration from device tree */ u32 id; - struct bam_async_desc *curr_txd; /* current running dma */ + bool is_busy; /* Set to true if FIFO is full */ /* runtime configuration */ struct dma_slave_config slave; @@ -372,6 +375,8 @@ struct bam_chan { unsigned int initialized; /* is the channel hw initialized? */ unsigned int paused; /* is the channel paused? */ unsigned int reconfigure; /* new slave config? */ + /* list of descriptors currently processed */ + struct list_head desc_list; struct list_head node; }; @@ -539,7 +544,7 @@ static void bam_free_chan(struct dma_chan *chan) vchan_free_chan_resources(to_virt_chan(chan)); - if (bchan->curr_txd) { + if (!list_empty(&bchan->desc_list)) { dev_err(bchan->bdev->dev, "Cannot free busy channel\n"); goto err; } @@ -632,8 +637,6 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan, if (flags & DMA_PREP_INTERRUPT) async_desc->flags |= DESC_FLAG_EOT; - else - async_desc->flags |= DESC_FLAG_INT; async_desc->num_desc = num_alloc; async_desc->curr_desc = async_desc->desc; @@ -684,15 +687,14 @@ static struct dma_async_tx_descriptor *bam_prep_slave_sg(struct dma_chan *chan, static int bam_dma_terminate_all(struct dma_chan *chan) { struct bam_chan *bchan = to_bam_chan(chan); + struct bam_async_desc *async_desc; unsigned long flag; LIST_HEAD(head); /* remove all transactions, including active transaction */ spin_lock_irqsave(&bchan->vc.lock, flag); - if (bchan->curr_txd) { - list_add(&bchan->curr_txd->vd.node, &bchan->vc.desc_issued); - bchan->curr_txd = NULL; - } + list_for_each_entry(async_desc, &bchan->desc_list, desc_node) + list_add(&async_desc->vd.node, &bchan->vc.desc_issued); vchan_get_all_descriptors(&bchan->vc, &head); spin_unlock_irqrestore(&bchan->vc.lock, flag); @@ -763,9 +765,9 @@ static int bam_resume(struct dma_chan *chan) */ static u32 process_channel_irqs(struct bam_device *bdev) { - u32 i, srcs, pipe_stts; + u32 i, srcs, pipe_stts, offset, avail; unsigned long flags; - struct bam_async_desc *async_desc; + struct bam_async_desc *async_desc, *tmp; srcs = readl_relaxed(bam_addr(bdev, 0, BAM_IRQ_SRCS_EE)); @@ -781,31 +783,51 @@ static u32 process_channel_irqs(struct bam_device *bdev) /* clear pipe irq */ pipe_stts = readl_relaxed(bam_addr(bdev, i, BAM_P_IRQ_STTS)); - writel_relaxed(pipe_stts, bam_addr(bdev, i, BAM_P_IRQ_CLR)); spin_lock_irqsave(&bchan->vc.lock, flags); - async_desc = bchan->curr_txd; - - if (async_desc) { - async_desc->num_desc -= async_desc->xfer_len; - async_desc->curr_desc += async_desc->xfer_len; - bchan->curr_txd = NULL; - - /* manage FIFO */ - bchan->head += async_desc->xfer_len; - bchan->head %= MAX_DESCRIPTORS; - - /* - * if complete, process cookie. Otherwise - * push back to front of desc_issued so that - * it gets restarted by the tasklet - */ - if (!async_desc->num_desc) - vchan_cookie_complete(&async_desc->vd); - else - list_add(&async_desc->vd.node, - &bchan->vc.desc_issued); + + offset = readl_relaxed(bam_addr(bdev, i, BAM_P_SW_OFSTS)) & + P_SW_OFSTS_MASK; + offset /= sizeof(struct bam_desc_hw); + + /* Number of bytes available to read */ + avail = CIRC_CNT(offset, bchan->head, MAX_DESCRIPTORS + 1); + + list_for_each_entry_safe(async_desc, tmp, + &bchan->desc_list, desc_node) { + if (async_desc) { + /* Not enough data to read */ + if (avail < async_desc->xfer_len) + break; + + /* manage FIFO */ + bchan->head += async_desc->xfer_len; + bchan->head %= MAX_DESCRIPTORS; + + async_desc->num_desc -= async_desc->xfer_len; + async_desc->curr_desc += async_desc->xfer_len; + avail -= async_desc->xfer_len; + + /* + * if complete, process cookie. Otherwise + * push back to front of desc_issued so that + * it gets restarted by the tasklet + */ + if (!async_desc->num_desc) { + vchan_cookie_complete(&async_desc->vd); + } else { + list_add(&async_desc->vd.node, + &bchan->vc.desc_issued); + } + list_del(&async_desc->desc_node); + + /* + * one desc has completed, so there is space + * in FIFO + */ + bchan->is_busy = false; + } } spin_unlock_irqrestore(&bchan->vc.lock, flags); @@ -867,6 +889,7 @@ static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie, struct dma_tx_state *txstate) { struct bam_chan *bchan = to_bam_chan(chan); + struct bam_async_desc *async_desc; struct virt_dma_desc *vd; int ret; size_t residue = 0; @@ -882,11 +905,17 @@ static enum dma_status bam_tx_status(struct dma_chan *chan, dma_cookie_t cookie, spin_lock_irqsave(&bchan->vc.lock, flags); vd = vchan_find_desc(&bchan->vc, cookie); - if (vd) + if (vd) { residue = container_of(vd, struct bam_async_desc, vd)->length; - else if (bchan->curr_txd && bchan->curr_txd->vd.tx.cookie == cookie) - for (i = 0; i < bchan->curr_txd->num_desc; i++) - residue += bchan->curr_txd->curr_desc[i].size; + } else { + list_for_each_entry(async_desc, &bchan->desc_list, desc_node) { + if (async_desc->vd.tx.cookie != cookie) + continue; + + for (i = 0; i < async_desc->num_desc; i++) + residue += async_desc->curr_desc[i].size; + } + } spin_unlock_irqrestore(&bchan->vc.lock, flags); @@ -927,63 +956,89 @@ static void bam_start_dma(struct bam_chan *bchan) { struct virt_dma_desc *vd = vchan_next_desc(&bchan->vc); struct bam_device *bdev = bchan->bdev; - struct bam_async_desc *async_desc; + struct bam_async_desc *async_desc = NULL; struct bam_desc_hw *desc; struct bam_desc_hw *fifo = PTR_ALIGN(bchan->fifo_virt, sizeof(struct bam_desc_hw)); int ret; + unsigned int avail; + struct dmaengine_desc_callback cb; lockdep_assert_held(&bchan->vc.lock); if (!vd) return; - list_del(&vd->node); - - async_desc = container_of(vd, struct bam_async_desc, vd); - bchan->curr_txd = async_desc; - ret = pm_runtime_get_sync(bdev->dev); if (ret < 0) return; - /* on first use, initialize the channel hardware */ - if (!bchan->initialized) - bam_chan_init_hw(bchan, async_desc->dir); + while (vd && !bchan->is_busy) { + list_del(&vd->node); - /* apply new slave config changes, if necessary */ - if (bchan->reconfigure) - bam_apply_new_config(bchan, async_desc->dir); + async_desc = container_of(vd, struct bam_async_desc, vd); - desc = bchan->curr_txd->curr_desc; + /* on first use, initialize the channel hardware */ + if (!bchan->initialized) + bam_chan_init_hw(bchan, async_desc->dir); - if (async_desc->num_desc > MAX_DESCRIPTORS) - async_desc->xfer_len = MAX_DESCRIPTORS; - else - async_desc->xfer_len = async_desc->num_desc; + /* apply new slave config changes, if necessary */ + if (bchan->reconfigure) + bam_apply_new_config(bchan, async_desc->dir); - /* set any special flags on the last descriptor */ - if (async_desc->num_desc == async_desc->xfer_len) - desc[async_desc->xfer_len - 1].flags |= - cpu_to_le16(async_desc->flags); - else - desc[async_desc->xfer_len - 1].flags |= - cpu_to_le16(DESC_FLAG_INT); + desc = async_desc->curr_desc; + avail = CIRC_SPACE(bchan->tail, bchan->head, + MAX_DESCRIPTORS + 1); + + if (async_desc->num_desc > avail) + async_desc->xfer_len = avail; + else + async_desc->xfer_len = async_desc->num_desc; + + /* set any special flags on the last descriptor */ + if (async_desc->num_desc == async_desc->xfer_len) + desc[async_desc->xfer_len - 1].flags |= + cpu_to_le16(async_desc->flags); + + vd = vchan_next_desc(&bchan->vc); + + /* FIFO is FULL */ + bchan->is_busy = (avail <= async_desc->xfer_len) ? true : false; - if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) { - u32 partial = MAX_DESCRIPTORS - bchan->tail; + dmaengine_desc_get_callback(&async_desc->vd.tx, &cb); - memcpy(&fifo[bchan->tail], desc, - partial * sizeof(struct bam_desc_hw)); - memcpy(fifo, &desc[partial], (async_desc->xfer_len - partial) * + /* + * An interrupt is generated at this desc, if + * - FIFO is FULL. + * - No more descriptors to add. + * - If a callback completion was requested for this DESC, + * In this case, BAM will deliver the completion callback + * for this desc and continue processing the next desc. + */ + if ((bchan->is_busy || !vd || + dmaengine_desc_callback_valid(&cb)) && + !(async_desc->flags & DESC_FLAG_EOT)) + desc[async_desc->xfer_len - 1].flags |= + cpu_to_le16(DESC_FLAG_INT); + + if (bchan->tail + async_desc->xfer_len > MAX_DESCRIPTORS) { + u32 partial = MAX_DESCRIPTORS - bchan->tail; + + memcpy(&fifo[bchan->tail], desc, + partial * sizeof(struct bam_desc_hw)); + memcpy(fifo, &desc[partial], + (async_desc->xfer_len - partial) * sizeof(struct bam_desc_hw)); - } else { - memcpy(&fifo[bchan->tail], desc, - async_desc->xfer_len * sizeof(struct bam_desc_hw)); - } + } else { + memcpy(&fifo[bchan->tail], desc, + async_desc->xfer_len * + sizeof(struct bam_desc_hw)); + } - bchan->tail += async_desc->xfer_len; - bchan->tail %= MAX_DESCRIPTORS; + bchan->tail += async_desc->xfer_len; + bchan->tail %= MAX_DESCRIPTORS; + list_add_tail(&async_desc->desc_node, &bchan->desc_list); + } /* ensure descriptor writes and dma start not reordered */ wmb(); @@ -1012,7 +1067,7 @@ static void dma_tasklet(unsigned long data) bchan = &bdev->channels[i]; spin_lock_irqsave(&bchan->vc.lock, flags); - if (!list_empty(&bchan->vc.desc_issued) && !bchan->curr_txd) + if (!list_empty(&bchan->vc.desc_issued) && !bchan->is_busy) bam_start_dma(bchan); spin_unlock_irqrestore(&bchan->vc.lock, flags); } @@ -1033,7 +1088,7 @@ static void bam_issue_pending(struct dma_chan *chan) spin_lock_irqsave(&bchan->vc.lock, flags); /* if work pending and idle, start a transaction */ - if (vchan_issue_pending(&bchan->vc) && !bchan->curr_txd) + if (vchan_issue_pending(&bchan->vc) && !bchan->is_busy) bam_start_dma(bchan); spin_unlock_irqrestore(&bchan->vc.lock, flags); @@ -1133,6 +1188,7 @@ static void bam_channel_init(struct bam_device *bdev, struct bam_chan *bchan, vchan_init(&bchan->vc, &bdev->common); bchan->vc.desc_free = bam_dma_free_desc; + INIT_LIST_HEAD(&bchan->desc_list); } static const struct of_device_id bam_of_match[] = {