From patchwork Fri Apr 21 17:28:58 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 9693353 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 EC72E6038E for ; Fri, 21 Apr 2017 18:20:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E12272865B for ; Fri, 21 Apr 2017 18:20:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D5B2828609; Fri, 21 Apr 2017 18:20:02 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable 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 DBBF928636 for ; Fri, 21 Apr 2017 18:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1041637AbdDUSNG (ORCPT ); Fri, 21 Apr 2017 14:13:06 -0400 Received: from mezzanine.sirena.org.uk ([106.187.55.193]:57656 "EHLO mezzanine.sirena.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1423102AbdDUR65 (ORCPT ); Fri, 21 Apr 2017 13:58:57 -0400 Received: from [2001:470:1f1d:6b5::3] (helo=debutante) by mezzanine.sirena.org.uk with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1d1cMf-0003JP-Ke; Fri, 21 Apr 2017 17:29:03 +0000 Received: from broonie by debutante with local (Exim 4.89) (envelope-from ) id 1d1cMc-00029N-V7; Fri, 21 Apr 2017 18:28:58 +0100 From: Mark Brown To: Vignesh R Cc: Mark Brown , Mark Brown , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, linux-spi@vger.kernel.org In-Reply-To: <20170411115225.31709-3-vigneshr@ti.com> Message-Id: Date: Fri, 21 Apr 2017 18:28:58 +0100 X-SA-Exim-Connect-IP: 2001:470:1f1d:6b5::3 X-SA-Exim-Mail-From: broonie@sirena.org.uk Subject: Applied "spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble" to the spi tree X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:24:06 +0000) X-SA-Exim-Scanned: No (on mezzanine.sirena.org.uk); Unknown failure Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The patch spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble has been applied to the spi tree at git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted. You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed. If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced. Please add any relevant lists and maintainers to the CCs when replying to this mail. Thanks, Mark From c687c46e9e4527c4b4d82bc3cca58c1b08bcfb83 Mon Sep 17 00:00:00 2001 From: Vignesh R Date: Tue, 11 Apr 2017 17:22:25 +0530 Subject: [PATCH] spi: spi-ti-qspi: Use bounce buffer if read buffer is not DMA'ble Flash filesystems like JFFS2, UBIFS and MTD block layer can provide vmalloc'd or kmap'd buffers that cannot be mapped using dma_map_sg() and can potentially be in memory region above 32bit addressable region(ie buffers belonging to memory region backed by LPAE) of DMA, implement spi_flash_can_dma() interface to inform SPI core not to map such buffers. When buffers are not mapped for DMA, then use a pre allocated bounce buffer(64K = typical flash erase sector size) to read from flash and then do a copy to actual destination buffer. This is approach is much faster than using memcpy using CPU and also reduces CPU load. With this patch, UBIFS read speed is ~18MB/s and CPU utilization <20% on DRA74 Rev H EVM. Performance degradation is negligible when compared with non bounce buffer case while using UBIFS. Signed-off-by: Vignesh R Signed-off-by: Mark Brown --- drivers/spi/spi-ti-qspi.c | 66 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 59 insertions(+), 7 deletions(-) diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c index 804914ebfd9d..23a06148b8ae 100644 --- a/drivers/spi/spi-ti-qspi.c +++ b/drivers/spi/spi-ti-qspi.c @@ -33,6 +33,7 @@ #include #include #include +#include #include @@ -57,6 +58,8 @@ struct ti_qspi { struct ti_qspi_regs ctx_reg; dma_addr_t mmap_phys_base; + dma_addr_t rx_bb_dma_addr; + void *rx_bb_addr; struct dma_chan *rx_chan; u32 spi_max_frequency; @@ -126,6 +129,8 @@ struct ti_qspi { #define QSPI_SETUP_ADDR_SHIFT 8 #define QSPI_SETUP_DUMMY_SHIFT 10 +#define QSPI_DMA_BUFFER_SIZE SZ_64K + static inline unsigned long ti_qspi_read(struct ti_qspi *qspi, unsigned long reg) { @@ -429,6 +434,35 @@ static int ti_qspi_dma_xfer(struct ti_qspi *qspi, dma_addr_t dma_dst, return 0; } +static int ti_qspi_dma_bounce_buffer(struct ti_qspi *qspi, + struct spi_flash_read_message *msg) +{ + size_t readsize = msg->len; + void *to = msg->buf; + dma_addr_t dma_src = qspi->mmap_phys_base + msg->from; + int ret = 0; + + /* + * Use bounce buffer as FS like jffs2, ubifs may pass + * buffers that does not belong to kernel lowmem region. + */ + while (readsize != 0) { + size_t xfer_len = min_t(size_t, QSPI_DMA_BUFFER_SIZE, + readsize); + + ret = ti_qspi_dma_xfer(qspi, qspi->rx_bb_dma_addr, + dma_src, xfer_len); + if (ret != 0) + return ret; + memcpy(to, qspi->rx_bb_addr, xfer_len); + readsize -= xfer_len; + dma_src += xfer_len; + to += xfer_len; + } + + return ret; +} + static int ti_qspi_dma_xfer_sg(struct ti_qspi *qspi, struct sg_table rx_sg, loff_t from) { @@ -496,6 +530,12 @@ static void ti_qspi_setup_mmap_read(struct spi_device *spi, QSPI_SPI_SETUP_REG(spi->chip_select)); } +static bool ti_qspi_spi_flash_can_dma(struct spi_device *spi, + struct spi_flash_read_message *msg) +{ + return virt_addr_valid(msg->buf); +} + static int ti_qspi_spi_flash_read(struct spi_device *spi, struct spi_flash_read_message *msg) { @@ -509,15 +549,12 @@ static int ti_qspi_spi_flash_read(struct spi_device *spi, ti_qspi_setup_mmap_read(spi, msg); if (qspi->rx_chan) { - if (msg->cur_msg_mapped) { + if (msg->cur_msg_mapped) ret = ti_qspi_dma_xfer_sg(qspi, msg->rx_sg, msg->from); - if (ret) - goto err_unlock; - } else { - dev_err(qspi->dev, "Invalid address for DMA\n"); - ret = -EIO; + else + ret = ti_qspi_dma_bounce_buffer(qspi, msg); + if (ret) goto err_unlock; - } } else { memcpy_fromio(msg->buf, qspi->mmap_base + msg->from, msg->len); } @@ -718,6 +755,17 @@ static int ti_qspi_probe(struct platform_device *pdev) ret = 0; goto no_dma; } + qspi->rx_bb_addr = dma_alloc_coherent(qspi->dev, + QSPI_DMA_BUFFER_SIZE, + &qspi->rx_bb_dma_addr, + GFP_KERNEL | GFP_DMA); + if (!qspi->rx_bb_addr) { + dev_err(qspi->dev, + "dma_alloc_coherent failed, using PIO mode\n"); + dma_release_channel(qspi->rx_chan); + goto no_dma; + } + master->spi_flash_can_dma = ti_qspi_spi_flash_can_dma; master->dma_rx = qspi->rx_chan; init_completion(&qspi->transfer_complete); if (res_mmap) @@ -757,6 +805,10 @@ static int ti_qspi_remove(struct platform_device *pdev) pm_runtime_put_sync(&pdev->dev); pm_runtime_disable(&pdev->dev); + if (qspi->rx_bb_addr) + dma_free_coherent(qspi->dev, QSPI_DMA_BUFFER_SIZE, + qspi->rx_bb_addr, + qspi->rx_bb_dma_addr); if (qspi->rx_chan) dma_release_channel(qspi->rx_chan);