From patchwork Mon Dec 14 15:20:20 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Martin Sperl X-Patchwork-Id: 7845341 Return-Path: X-Original-To: patchwork-linux-spi@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id C7AAFBEEE1 for ; Mon, 14 Dec 2015 15:20:54 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B02EB202EC for ; Mon, 14 Dec 2015 15:20:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A4632203C0 for ; Mon, 14 Dec 2015 15:20:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751568AbbLNPUi (ORCPT ); Mon, 14 Dec 2015 10:20:38 -0500 Received: from 212-186-180-163.dynamic.surfer.at ([212.186.180.163]:39371 "EHLO cgate.sperl.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752240AbbLNPUh (ORCPT ); Mon, 14 Dec 2015 10:20:37 -0500 Received: from raspcm.intern.sperl.org (account martin@sperl.org [10.10.10.41] verified) by sperl.org (CommuniGate Pro SMTP 6.1.2) with ESMTPSA id 6361172; Mon, 14 Dec 2015 15:20:31 +0000 From: kernel@martin.sperl.org To: Mark Brown , Stephen Warren , Lee Jones , Eric Anholt , linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org Cc: Martin Sperl Subject: [PATCH v3 3/8] spi: core: add spi_split_transfers_maxsize Date: Mon, 14 Dec 2015 15:20:20 +0000 Message-Id: <1450106426-2277-4-git-send-email-kernel@martin.sperl.org> X-Mailer: git-send-email 1.7.10.4 In-Reply-To: <1450106426-2277-1-git-send-email-kernel@martin.sperl.org> References: <1450106426-2277-1-git-send-email-kernel@martin.sperl.org> Sender: linux-spi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_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 From: Martin Sperl Add spi_split_transfers_maxsize method that splits spi_transfers transparently into multiple transfers that are below the given max-size. This makes use of the spi_res framework via spi_replace_transfers to allocate/free the extra transfers as well as reverting back the changes applied while processing the spi_message. Signed-off-by: Martin Sperl --- drivers/spi/spi.c | 111 +++++++++++++++++++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 15 +++++++ 2 files changed, 126 insertions(+) Changelog: V2 -> V3: split into distinct patches and rewrite -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index ede3e57..37e6507 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -145,6 +145,8 @@ SPI_STATISTICS_TRANSFER_BYTES_HISTO(14, "16384-32767"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(15, "32768-65535"); SPI_STATISTICS_TRANSFER_BYTES_HISTO(16, "65536+"); +SPI_STATISTICS_SHOW(transfers_split_maxsize, "%lu"); + static struct attribute *spi_dev_attrs[] = { &dev_attr_modalias.attr, NULL, @@ -182,6 +184,7 @@ static struct attribute *spi_device_statistics_attrs[] = { &dev_attr_spi_device_transfer_bytes_histo14.attr, &dev_attr_spi_device_transfer_bytes_histo15.attr, &dev_attr_spi_device_transfer_bytes_histo16.attr, + &dev_attr_spi_device_transfers_split_maxsize.attr, NULL, }; @@ -224,6 +227,7 @@ static struct attribute *spi_master_statistics_attrs[] = { &dev_attr_spi_master_transfer_bytes_histo14.attr, &dev_attr_spi_master_transfer_bytes_histo15.attr, &dev_attr_spi_master_transfer_bytes_histo16.attr, + &dev_attr_spi_master_transfers_split_maxsize.attr, NULL, }; @@ -2235,6 +2239,113 @@ struct spi_replaced_transfers *spi_replace_transfers( } EXPORT_SYMBOL_GPL(spi_replace_transfers); +int __spi_split_transfer_maxsize(struct spi_master *master, + struct spi_message *msg, + struct spi_transfer **xferp, + size_t maxsize, + gfp_t gfp) +{ + struct spi_transfer *xfer = *xferp, *xfers; + struct spi_replaced_transfers *srt; + size_t offset; + size_t count, i; + + /* warn once about this fact that we are splitting a transfer */ + dev_warn_once(&msg->spi->dev, + "spi_transfer of length %i exceed max length of %i - needed to split transfers\n", + xfer->len, maxsize); + + /* calculate how many we have to replace */ + count = DIV_ROUND_UP(xfer->len, maxsize); + + /* create replacement */ + srt = spi_replace_transfers(msg, xfer, 1, count, NULL, 0, gfp); + if (!srt) + return -ENOMEM; + xfers = srt->inserted_transfers; + + /* now handle each of those newly inserted spi_transfers + * note that the replacements spi_transfers all are preset + * to the same values as *xferp, so tx_buf, rx_buf and len + * are all identical (as well as most others) + * so we just have to fix up len and the pointers. + * + * this also includes support for the depreciated + * spi_message.is_dma_mapped interface + */ + + /* the first transfer just needs the length modified, so we + * run it outside the loop + */ + xfers[0].len = min(maxsize, xfer[0].len); + + /* all the others need rx_buf/tx_buf also set */ + for (i = 1, offset = maxsize; i < count; offset += maxsize, i++) { + /* update rx_buf, tx_buf and dma */ + if (xfers[i].rx_buf) + xfers[i].rx_buf += offset; + if (xfers[i].rx_dma) + xfers[i].rx_dma += offset; + if (xfers[i].tx_buf) + xfers[i].tx_buf += offset; + if (xfers[i].tx_dma) + xfers[i].tx_dma += offset; + + /* update length */ + xfers[i].len = min(maxsize, xfers[i].len - offset); + } + + /* we set up xferp to the last entry we have inserted, + * so that we skip those already split transfers + */ + *xferp = &xfers[count - 1]; + + /* increment statistics counters */ + SPI_STATISTICS_INCREMENT_FIELD(&master->statistics, + transfers_split_maxsize); + SPI_STATISTICS_INCREMENT_FIELD(&msg->spi->statistics, + transfers_split_maxsize); + + return 0; +} + +/** + * spi_split_tranfers_maxsize - split spi transfers into multiple transfers + * when an individual transfer exceeds a + * certain size + * @master: the @spi_master for this transfer + * @message: the @spi_message to transform + * @max_size: the maximum when to apply this + * + * Return: status of transformation + */ +int spi_split_transfers_maxsize(struct spi_master *master, + struct spi_message *msg, + size_t maxsize, + gfp_t gfp) +{ + struct spi_transfer *xfer; + int ret; + + /* iterate over the transfer_list, + * but note that xfer is advanced to the last transfer inserted + * to avoid checking sizes again unnecessarily (also xfer does + * potentiall belong to a different list by the time the + * replacement has happened + */ + list_for_each_entry(xfer, &msg->transfers, transfer_list) { + if (xfer->len > maxsize) { + ret = __spi_split_transfer_maxsize( + master, msg, &xfer, maxsize, gfp); + if (ret) + return ret; + } + } + + return 0; +} +EXPORT_SYMBOL_GPL(spi_split_transfers_maxsize); + /*-------------------------------------------------------------------------*/ /* Core methods for SPI master protocol drivers. Some of the diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h index 13831ed..8ced84a 100644 --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -53,6 +53,10 @@ extern struct bus_type spi_bus_type; * * @transfer_bytes_histo: * transfer bytes histogramm + * + * @transfers_split_maxsize: + * number of transfers that have been split because of + * maxsize limit */ struct spi_statistics { spinlock_t lock; /* lock for the whole structure */ @@ -72,6 +76,8 @@ struct spi_statistics { #define SPI_STATISTICS_HISTO_SIZE 17 unsigned long transfer_bytes_histo[SPI_STATISTICS_HISTO_SIZE]; + + unsigned long transfers_split_maxsize; }; void spi_statistics_add_transfer_stats(struct spi_statistics *stats, @@ -920,6 +926,15 @@ extern struct spi_replaced_transfers *spi_replace_transfers( /*---------------------------------------------------------------------------*/ +/* SPI transfer transformation methods */ + +extern int spi_split_transfers_maxsize(struct spi_master *master, + struct spi_message *msg, + size_t maxsize, + gfp_t gfp); + +/*---------------------------------------------------------------------------*/ + /* All these synchronous SPI transfer routines are utilities layered * over the core async transfer primitive. Here, "synchronous" means * they will sleep uninterruptibly until the async transfer completes.