From patchwork Sun Jun 13 15:10:36 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Jonathan Cameron X-Patchwork-Id: 12317739 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D1B29C48BE8 for ; Sun, 13 Jun 2021 15:08:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA2DB611C0 for ; Sun, 13 Jun 2021 15:08:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231782AbhFMPKv (ORCPT ); Sun, 13 Jun 2021 11:10:51 -0400 Received: from mail.kernel.org ([198.145.29.99]:59596 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231841AbhFMPKv (ORCPT ); Sun, 13 Jun 2021 11:10:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 995376128A; Sun, 13 Jun 2021 15:08:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623596929; bh=TftDME3258diEPPsF5wBkvYXL7CwJi11GQ4g7EHXE28=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nTmzIc0vP6dSWnukkuLtzGPlmDxAu5yqzVmnB+D7FyfvRky55GOFQ0eUugOcQTUZH WhDXsJ5kG91GkuWXVfLbm3GcRtosg99Us7oOPLCmIsau15uOkYC8YBIm5YjOm4x5f/ PK+8brVU2SKXeOpq9siGaP/SszPgipkc//6kv+tfcrPpd+7qFxTLvr1kyUXQ5ZXYsN WGQdICoVphs4GPn9T3B/eHUFn/deNMPTER135gt86OTzdt4q+dcmYoRdX7Vnf2ROrr kXncA+aFRnLm1V9bx9RNnM67zaa7qX8re8vjWLZr3t/tQ0qf/cdGzlI0CGrfQPYqNe 67lh+rlt8YELA== From: Jonathan Cameron To: linux-iio@vger.kernel.org, Andy Shevchenko , Nuno Sa Cc: Linus Walleij , Jan Kiszka , Jonathan Cameron Subject: [PATCH v2 1/4] iio: core: Introduce iio_push_to_buffers_with_ts_unaligned() Date: Sun, 13 Jun 2021 16:10:36 +0100 Message-Id: <20210613151039.569883-2-jic23@kernel.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210613151039.569883-1-jic23@kernel.org> References: <20210613151039.569883-1-jic23@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org From: Jonathan Cameron Whilst it is almost always possible to arrange for scan data to be read directly into a buffer that is suitable for passing to iio_push_to_buffers_with_timestamp(), there are a few places where leading data needs to be skipped over. For these cases introduce a function that will allocate an appropriate sized and aligned bounce buffer (if not already allocated) and copy the unaligned data into that before calling iio_push_to_buffers_with_timestamp() on the bounce buffer. We tie the lifespace of this buffer to that of the iio_dev.dev which should ensure no memory leaks occur. Signed-off-by: Jonathan Cameron Reviewed-by: Nuno Sá --- drivers/iio/industrialio-buffer.c | 46 +++++++++++++++++++++++++++++++ include/linux/iio/buffer.h | 4 +++ include/linux/iio/iio-opaque.h | 4 +++ 3 files changed, 54 insertions(+) diff --git a/drivers/iio/industrialio-buffer.c b/drivers/iio/industrialio-buffer.c index fdd623407b96..5241b5a5c6c0 100644 --- a/drivers/iio/industrialio-buffer.c +++ b/drivers/iio/industrialio-buffer.c @@ -1730,6 +1730,52 @@ int iio_push_to_buffers(struct iio_dev *indio_dev, const void *data) } EXPORT_SYMBOL_GPL(iio_push_to_buffers); +/** + * iio_push_to_buffers_with_ts_unaligned() - push to registered buffer, + * no alignment or space requirements. + * @indio_dev: iio_dev structure for device. + * @data: channel data excluding the timestamp. + * @data_sz: size of data. + * @timestamp: timestamp for the sample data. + * + * This special variant of iio_push_to_buffers_with_timestamp() does + * not require space for the timestamp, or 8 byte alignment of data. + * It does however require an allocation on first call and additional + * copies on all calls, so should be avoided if possible. + */ +int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev, + const void *data, + size_t data_sz, + int64_t timestamp) +{ + struct iio_dev_opaque *iio_dev_opaque = to_iio_dev_opaque(indio_dev); + + /* + * Conservative estimate - we can always safely copy the minimum + * of either the data provided or the length of the destination buffer. + * This relaxed limit allows the calling drivers to be lax about + * tracking the size of the data they are pushing, at the cost of + * unnecessary copying of padding. + */ + data_sz = min_t(size_t, indio_dev->scan_bytes, data_sz); + if (iio_dev_opaque->bounce_buffer_size != indio_dev->scan_bytes) { + void *bb; + + bb = devm_krealloc(&indio_dev->dev, + iio_dev_opaque->bounce_buffer, + indio_dev->scan_bytes, GFP_KERNEL); + if (!bb) + return -ENOMEM; + iio_dev_opaque->bounce_buffer = bb; + iio_dev_opaque->bounce_buffer_size = indio_dev->scan_bytes; + } + memcpy(iio_dev_opaque->bounce_buffer, data, data_sz); + return iio_push_to_buffers_with_timestamp(indio_dev, + iio_dev_opaque->bounce_buffer, + timestamp); +} +EXPORT_SYMBOL_GPL(iio_push_to_buffers_with_ts_unaligned); + /** * iio_buffer_release() - Free a buffer's resources * @ref: Pointer to the kref embedded in the iio_buffer struct diff --git a/include/linux/iio/buffer.h b/include/linux/iio/buffer.h index b6928ac5c63d..451379a3984a 100644 --- a/include/linux/iio/buffer.h +++ b/include/linux/iio/buffer.h @@ -38,6 +38,10 @@ static inline int iio_push_to_buffers_with_timestamp(struct iio_dev *indio_dev, return iio_push_to_buffers(indio_dev, data); } +int iio_push_to_buffers_with_ts_unaligned(struct iio_dev *indio_dev, + const void *data, size_t data_sz, + int64_t timestamp); + bool iio_validate_scan_mask_onehot(struct iio_dev *indio_dev, const unsigned long *mask); diff --git a/include/linux/iio/iio-opaque.h b/include/linux/iio/iio-opaque.h index c9504e9da571..2be12b7b5dc5 100644 --- a/include/linux/iio/iio-opaque.h +++ b/include/linux/iio/iio-opaque.h @@ -23,6 +23,8 @@ * @groupcounter: index of next attribute group * @legacy_scan_el_group: attribute group for legacy scan elements attribute group * @legacy_buffer_group: attribute group for legacy buffer attributes group + * @bounce_buffer: for devices that call iio_push_to_buffers_with_timestamp_unaligned() + * @bounce_buffer_size: size of currently allocate bounce buffer * @scan_index_timestamp: cache of the index to the timestamp * @clock_id: timestamping clock posix identifier * @chrdev: associated character device @@ -50,6 +52,8 @@ struct iio_dev_opaque { int groupcounter; struct attribute_group legacy_scan_el_group; struct attribute_group legacy_buffer_group; + void *bounce_buffer; + size_t bounce_buffer_size; unsigned int scan_index_timestamp; clockid_t clock_id;