From patchwork Fri Jun 10 18:08:19 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sricharan Ramabadhran X-Patchwork-Id: 9170231 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 515316048C for ; Fri, 10 Jun 2016 18:10:27 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4874F281F9 for ; Fri, 10 Jun 2016 18:10:27 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3CF7B2824F; Fri, 10 Jun 2016 18:10:27 +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=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B566F281F9 for ; Fri, 10 Jun 2016 18:10:25 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1bBQre-0005uP-G0; Fri, 10 Jun 2016 18:09:02 +0000 Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1bBQrV-0005q2-Bj for linux-arm-kernel@lists.infradead.org; Fri, 10 Jun 2016 18:08:54 +0000 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 3133F6145A; Fri, 10 Jun 2016 18:08:37 +0000 (UTC) Received: from blr-ubuntu-32.ap.qualcomm.com (unknown [202.46.23.61]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: sricharan@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id EF792613CE; Fri, 10 Jun 2016 18:08:32 +0000 (UTC) From: Sricharan R To: linux-arm-msm@vger.kernel.org, ntelkar@codeaurora.org, galak@codeaurora.org, linux-kernel@vger.kernel.org, andy.gross@linaro.org, linux-i2c@vger.kernel.org, agross@codeaurora.org, linux-arm-kernel@lists.infradead.org, nkaje@codeaurora.org, absahu@codeaurora.org Subject: [PATCH V4 1/3] i2c: qup: Fix broken dma when CONFIG_DEBUG_SG is enabled Date: Fri, 10 Jun 2016 23:38:19 +0530 Message-Id: <1465582101-19391-2-git-send-email-sricharan@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 In-Reply-To: <1465582101-19391-1-git-send-email-sricharan@codeaurora.org> References: <1465582101-19391-1-git-send-email-sricharan@codeaurora.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160610_110853_448096_0F4E211B X-CRM114-Status: GOOD ( 18.37 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: sricharan@codeaurora.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP With CONFIG_DEBUG_SG is enabled and when dma mode is used, below dump is seen, ------------[ cut here ]------------ kernel BUG at include/linux/scatterlist.h:140! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.4.0-00459-g9f087b9-dirty #7 Hardware name: Qualcomm Technologies, Inc. APQ 8016 SBC (DT) task: ffffffc036868000 ti: ffffffc036870000 task.ti: ffffffc036870000 PC is at qup_sg_set_buf.isra.13+0x138/0x154 LR is at qup_sg_set_buf.isra.13+0x50/0x154 pc : [] lr : [] pstate: 60000145 sp : ffffffc0368735c0 x29: ffffffc0368735c0 x28: ffffffc036873752 x27: ffffffc035233018 x26: ffffffc000c4e000 x25: 0000000000000000 x24: 0000000000000004 x23: 0000000000000000 x22: ffffffc035233668 x21: ffffff80004e3000 x20: ffffffc0352e0018 x19: 0000004000000000 x18: 0000000000000028 x17: 0000000000000004 x16: ffffffc0017a39c8 x15: 0000000000001cdf x14: ffffffc0019929d8 x13: ffffffc0352e0018 x12: 0000000000000000 x11: 0000000000000001 x10: 0000000000000001 x9 : ffffffc0012b2d70 x8 : ffffff80004e3000 x7 : 0000000000000018 x6 : 0000000030000000 x5 : ffffffc00199f018 x4 : ffffffc035233018 x3 : 0000000000000004 x2 : 00000000c0000000 x1 : 0000000000000003 x0 : 0000000000000000 Process swapper/0 (pid: 1, stack limit = 0xffffffc036870020) Stack: (0xffffffc0368735c0 to 0xffffffc036874000) sg_set_bug expects that the buf parameter passed in should be from lowmem and a valid pageframe. This is not true for pages from dma_alloc_coherent which can be carveouts, hence the check fails. Change allocation of sg buffers from dma_coherent memory to kzalloc to fix the issue. Note that now dma_map/unmap is used to make the kzalloc'ed buffers coherent before passing it to the dmaengine. Signed-off-by: Sricharan R Reviewed-by: Andy Gross --- drivers/i2c/busses/i2c-qup.c | 51 +++++++++++++------------------------------- 1 file changed, 15 insertions(+), 36 deletions(-) diff --git a/drivers/i2c/busses/i2c-qup.c b/drivers/i2c/busses/i2c-qup.c index cc6439ab..43adc2d 100644 --- a/drivers/i2c/busses/i2c-qup.c +++ b/drivers/i2c/busses/i2c-qup.c @@ -585,8 +585,8 @@ static void qup_i2c_bam_cb(void *data) } static int qup_sg_set_buf(struct scatterlist *sg, void *buf, - struct qup_i2c_tag *tg, unsigned int buflen, - struct qup_i2c_dev *qup, int map, int dir) + unsigned int buflen, struct qup_i2c_dev *qup, + int dir) { int ret; @@ -595,9 +595,6 @@ static int qup_sg_set_buf(struct scatterlist *sg, void *buf, if (!ret) return -EINVAL; - if (!map) - sg_dma_address(sg) = tg->addr + ((u8 *)buf - tg->start); - return 0; } @@ -670,16 +667,15 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, /* scratch buf to read the start and len tags */ ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], &qup->brx.tag.start[0], - &qup->brx.tag, - 2, qup, 0, 0); + 2, qup, DMA_FROM_DEVICE); if (ret) return ret; ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], &msg->buf[limit * i], - NULL, tlen, qup, - 1, DMA_FROM_DEVICE); + tlen, qup, + DMA_FROM_DEVICE); if (ret) return ret; @@ -688,7 +684,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, } ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], &qup->start_tag.start[off], - &qup->start_tag, len, qup, 0, 0); + len, qup, DMA_TO_DEVICE); if (ret) return ret; @@ -696,8 +692,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, /* scratch buf to read the BAM EOT and FLUSH tags */ ret = qup_sg_set_buf(&qup->brx.sg[rx_buf++], &qup->brx.tag.start[0], - &qup->brx.tag, 2, - qup, 0, 0); + 2, qup, DMA_FROM_DEVICE); if (ret) return ret; } else { @@ -709,17 +704,15 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, len = qup_i2c_set_tags(tags, qup, msg, 1); ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], - tags, - &qup->start_tag, len, - qup, 0, 0); + tags, len, + qup, DMA_TO_DEVICE); if (ret) return ret; tx_len += len; ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], &msg->buf[limit * i], - NULL, tlen, qup, 1, - DMA_TO_DEVICE); + tlen, qup, DMA_TO_DEVICE); if (ret) return ret; i++; @@ -738,8 +731,7 @@ static int qup_i2c_bam_do_xfer(struct qup_i2c_dev *qup, struct i2c_msg *msg, QUP_BAM_FLUSH_STOP; ret = qup_sg_set_buf(&qup->btx.sg[tx_buf++], &qup->btx.tag.start[0], - &qup->btx.tag, len, - qup, 0, 0); + len, qup, DMA_TO_DEVICE); if (ret) return ret; tx_nents += 1; @@ -1407,27 +1399,21 @@ static int qup_i2c_probe(struct platform_device *pdev) /* 2 tag bytes for each block + 5 for start, stop tags */ size = blocks * 2 + 5; - qup->dpool = dma_pool_create("qup_i2c-dma-pool", &pdev->dev, - size, 4, 0); - qup->start_tag.start = dma_pool_alloc(qup->dpool, GFP_KERNEL, - &qup->start_tag.addr); + qup->start_tag.start = devm_kzalloc(&pdev->dev, + size, GFP_KERNEL); if (!qup->start_tag.start) { ret = -ENOMEM; goto fail_dma; } - qup->brx.tag.start = dma_pool_alloc(qup->dpool, - GFP_KERNEL, - &qup->brx.tag.addr); + qup->brx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL); if (!qup->brx.tag.start) { ret = -ENOMEM; goto fail_dma; } - qup->btx.tag.start = dma_pool_alloc(qup->dpool, - GFP_KERNEL, - &qup->btx.tag.addr); + qup->btx.tag.start = devm_kzalloc(&pdev->dev, 2, GFP_KERNEL); if (!qup->btx.tag.start) { ret = -ENOMEM; goto fail_dma; @@ -1566,13 +1552,6 @@ static int qup_i2c_remove(struct platform_device *pdev) struct qup_i2c_dev *qup = platform_get_drvdata(pdev); if (qup->is_dma) { - dma_pool_free(qup->dpool, qup->start_tag.start, - qup->start_tag.addr); - dma_pool_free(qup->dpool, qup->brx.tag.start, - qup->brx.tag.addr); - dma_pool_free(qup->dpool, qup->btx.tag.start, - qup->btx.tag.addr); - dma_pool_destroy(qup->dpool); dma_release_channel(qup->btx.dma); dma_release_channel(qup->brx.dma); }