From patchwork Wed Apr 12 15:24:42 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Biju Das X-Patchwork-Id: 13209269 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F700C77B78 for ; Wed, 12 Apr 2023 15:25:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230340AbjDLPZB (ORCPT ); Wed, 12 Apr 2023 11:25:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231537AbjDLPY4 (ORCPT ); Wed, 12 Apr 2023 11:24:56 -0400 Received: from relmlie6.idc.renesas.com (relmlor2.renesas.com [210.160.252.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 6D6E619A1; Wed, 12 Apr 2023 08:24:54 -0700 (PDT) X-IronPort-AV: E=Sophos;i="5.98,339,1673881200"; d="scan'208";a="159192070" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 13 Apr 2023 00:24:54 +0900 Received: from localhost.localdomain (unknown [10.226.93.18]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 446A74006A77; Thu, 13 Apr 2023 00:24:51 +0900 (JST) From: Biju Das To: Vinod Koul Cc: Biju Das , Lad Prabhakar , Geert Uytterhoeven , dmaengine@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: [PATCH v3 2/5] dmaengine: sh: rz-dmac: Add device_tx_status() callback Date: Wed, 12 Apr 2023 16:24:42 +0100 Message-Id: <20230412152445.117439-3-biju.das.jz@bp.renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230412152445.117439-1-biju.das.jz@bp.renesas.com> References: <20230412152445.117439-1-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org Add support for device_tx_status() callback as it is needed for RZ/G2L SCIFA driver. Based on a patch in the BSP by Long Luu similar to rcar-dmac Signed-off-by: Biju Das --- v2->v3: * No change. v1->v2: * Replaced the loop for->for_each_sg and dropped sgl and sg_len variables from calculate_total_bytes_in_vd(). * Updated commit description. --- drivers/dma/sh/rz-dmac.c | 169 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 168 insertions(+), 1 deletion(-) diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c index 81e72529f7d3..aaaae1c090ad 100644 --- a/drivers/dma/sh/rz-dmac.c +++ b/drivers/dma/sh/rz-dmac.c @@ -108,10 +108,12 @@ struct rz_dmac { * Registers */ +#define CRTB 0x0020 #define CHSTAT 0x0024 #define CHCTRL 0x0028 #define CHCFG 0x002c #define NXLA 0x0038 +#define CRLA 0x003c #define DCTRL 0x0000 @@ -650,6 +652,171 @@ static void rz_dmac_device_synchronize(struct dma_chan *chan) rz_dmac_set_dmars_register(dmac, channel->index, 0); } +static unsigned int calculate_total_bytes_in_vd(struct rz_dmac_desc *desc) +{ + unsigned int i, size = 0; + struct scatterlist *sg; + + for_each_sg(desc->sg, sg, desc->sgcount, i) + size += sg_dma_len(sg); + + return size; +} + +static unsigned int calculate_residue_bytes_in_vd(struct rz_dmac_chan *channel) +{ + struct rz_lmdesc *lmdesc = channel->lmdesc.head; + struct dma_chan *chan = &channel->vc.chan; + struct rz_dmac *dmac = to_rz_dmac(chan->device); + unsigned int residue = 0, i = 0; + unsigned int crla; + + /* get current lmdesc */ + crla = rz_dmac_ch_readl(channel, CRLA, 1); + while (!(lmdesc->nxla == crla)) { + lmdesc++; + if (lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC)) + lmdesc = channel->lmdesc.base; + i++; + /* Not found current lmdesc */ + if (i > DMAC_NR_LMDESC) + return 0; + } + + /* Point to current processing lmdesc in hardware */ + lmdesc++; + if (lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC)) + lmdesc = channel->lmdesc.base; + + /* Calculate residue from next lmdesc to end of virtual desc*/ + while (lmdesc->chcfg & CHCFG_DEM) { + lmdesc++; + if (lmdesc >= (channel->lmdesc.base + DMAC_NR_LMDESC)) + lmdesc = channel->lmdesc.base; + residue += lmdesc->tb; + } + + dev_dbg(dmac->dev, "%s: Getting residue is %d\n", __func__, residue); + + return residue; +} + +static unsigned int rz_dmac_chan_get_residue(struct rz_dmac_chan *channel, + dma_cookie_t cookie) +{ + struct rz_dmac_desc *current_desc, *desc; + enum dma_status status; + unsigned int residue; + unsigned int crla; + unsigned int crtb; + unsigned int i; + + /* Get current processing virtual descriptor */ + current_desc = list_first_entry(&channel->ld_active, + struct rz_dmac_desc, node); + if (!current_desc) + return 0; + + /* + * If the cookie corresponds to a descriptor that has been completed + * there is no residue. The same check has already been performed by the + * caller but without holding the channel lock, so the descriptor could + * now be complete. + */ + status = dma_cookie_status(&channel->vc.chan, cookie, NULL); + if (status == DMA_COMPLETE) + return 0; + + /* + * If the cookie doesn't correspond to the currently processing virtual + * descriptor then the descriptor hasn't been processed yet, and the + * residue is equal to the full descriptor size. + * Also, a client driver is possible to call this function before + * rz_dmac_irq_handler_thread() runs. In this case, the running + * descriptor will be the next descriptor, and the done list will + * appear. So, if the argument cookie matches the done list's cookie, + * we can assume the residue is zero. + */ + if (cookie != current_desc->vd.tx.cookie) { + list_for_each_entry(desc, &channel->ld_free, node) { + if (cookie == desc->vd.tx.cookie) + return 0; + } + + list_for_each_entry(desc, &channel->ld_queue, node) { + if (cookie == desc->vd.tx.cookie) + return calculate_total_bytes_in_vd(desc); + } + + list_for_each_entry(desc, &channel->ld_active, node) { + if (cookie == desc->vd.tx.cookie) + return calculate_total_bytes_in_vd(desc); + } + + /* + * No descriptor found for the cookie, there's thus no residue. + * This shouldn't happen if the calling driver passes a correct + * cookie value. + */ + WARN(1, "No descriptor for cookie!"); + return 0; + } + + /* + * Correspond to the currently processing virtual descriptor + * + * Make sure the hardware does not move to next lmdesc + * while reading the counter. + * Trying it 3 times should be enough: Initial read, retry, retry + * for the paranoid. + * The current lmdesc running in hardware is channel.lmdesc.head + */ + for (i = 0; i < 3; i++) { + crla = rz_dmac_ch_readl(channel, CRLA, 1); + crtb = rz_dmac_ch_readl(channel, CRTB, 1); + /* Still the same? */ + if (crla == rz_dmac_ch_readl(channel, CRLA, 1)) + break; + } + + WARN_ONCE(i >= 3, "residue might be not continuous!"); + + /* + * Calculate number of byte transferred in processing virtual descriptor + * One virtual descriptor can have many lmdesc + */ + residue = crtb; + residue += calculate_residue_bytes_in_vd(channel); + + return residue; +} + +static enum dma_status rz_dmac_tx_status(struct dma_chan *chan, + dma_cookie_t cookie, + struct dma_tx_state *txstate) +{ + struct rz_dmac_chan *channel = to_rz_dmac_chan(chan); + enum dma_status status; + unsigned int residue; + unsigned long flags; + + status = dma_cookie_status(chan, cookie, txstate); + if (status == DMA_COMPLETE || !txstate) + return status; + + spin_lock_irqsave(&channel->vc.lock, flags); + residue = rz_dmac_chan_get_residue(channel, cookie); + spin_unlock_irqrestore(&channel->vc.lock, flags); + + /* if there's no residue, the cookie is complete */ + if (!residue) + return DMA_COMPLETE; + + dma_set_residue(txstate, residue); + + return status; +} + /* * ----------------------------------------------------------------------------- * IRQ handling @@ -932,7 +1099,7 @@ static int rz_dmac_probe(struct platform_device *pdev) engine->device_alloc_chan_resources = rz_dmac_alloc_chan_resources; engine->device_free_chan_resources = rz_dmac_free_chan_resources; - engine->device_tx_status = dma_cookie_status; + engine->device_tx_status = rz_dmac_tx_status; engine->device_prep_slave_sg = rz_dmac_prep_slave_sg; engine->device_prep_dma_memcpy = rz_dmac_prep_dma_memcpy; engine->device_config = rz_dmac_config;