From patchwork Mon Apr 3 15:49:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paul Cercueil X-Patchwork-Id: 13198383 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 742CCC761A6 for ; Mon, 3 Apr 2023 15:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232953AbjDCP4s (ORCPT ); Mon, 3 Apr 2023 11:56:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233028AbjDCP4h (ORCPT ); Mon, 3 Apr 2023 11:56:37 -0400 Received: from aposti.net (aposti.net [89.234.176.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E7A9180; Mon, 3 Apr 2023 08:56:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=crapouillou.net; s=mail; t=1680537005; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=wA4riywwKKpvJAgChQaqtpae762HoiQ3X43R1omKQq4=; b=w2Vbrqzju+FpRpVjzxZ2RLYiP3a1YX0fUt98d/TwX/8ordZETUPCJEcVcrO40kky/ffb9S crFaELFhXS+K44RKouzy6bUJopS6o5LK2G4sSwcSpNycj2XHVf7p/0YKpt+mQ99jEQKCwj YMLN5v0VHzBRjP/xQ0K8kCdC+HOP350= From: Paul Cercueil To: Jonathan Cameron , Lars-Peter Clausen , Vinod Koul , Michael Hennerich , =?utf-8?q?Nuno_S=C3=A1?= , Sumit Semwal , =?utf-8?q?Christian_K=C3=B6nig?= Cc: linux-kernel@vger.kernel.org, dmaengine@vger.kernel.org, linux-iio@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, Paul Cercueil Subject: [PATCH v3 10/11] iio: buffer-dmaengine: Support new DMABUF based userspace API Date: Mon, 3 Apr 2023 17:49:54 +0200 Message-Id: <20230403154955.216148-1-paul@crapouillou.net> In-Reply-To: <20230403154800.215924-1-paul@crapouillou.net> References: <20230403154800.215924-1-paul@crapouillou.net> MIME-Version: 1.0 X-Spam: Yes Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Use the functions provided by the buffer-dma core to implement the DMABUF userspace API in the buffer-dmaengine IIO buffer implementation. Since we want to be able to transfer an arbitrary number of bytes and not necesarily the full DMABUF, the associated scatterlist is converted to an array of DMA addresses + lengths, which is then passed to dmaengine_prep_slave_dma_array(). Signed-off-by: Paul Cercueil --- v3: Use the new dmaengine_prep_slave_dma_array(), and adapt the code to work with the new functions introduced in industrialio-buffer-dma.c. --- .../buffer/industrialio-buffer-dmaengine.c | 69 ++++++++++++++++--- include/linux/iio/buffer-dma.h | 2 + 2 files changed, 60 insertions(+), 11 deletions(-) diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c index 866c8b84bb24..faed9c2b089c 100644 --- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c +++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c @@ -65,25 +65,68 @@ static int iio_dmaengine_buffer_submit_block(struct iio_dma_buffer_queue *queue, iio_buffer_to_dmaengine_buffer(&queue->buffer); struct dma_async_tx_descriptor *desc; enum dma_transfer_direction dma_dir; + unsigned int i, nents, *lenghts; + struct scatterlist *sgl; + unsigned long flags; + dma_addr_t *addrs; size_t max_size; dma_cookie_t cookie; + size_t len_total; - max_size = min(block->size, dmaengine_buffer->max_size); - max_size = round_down(max_size, dmaengine_buffer->align); + if (!block->bytes_used) + return -EINVAL; - if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) { - block->bytes_used = max_size; + if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) dma_dir = DMA_DEV_TO_MEM; - } else { + else dma_dir = DMA_MEM_TO_DEV; - } - if (!block->bytes_used || block->bytes_used > max_size) - return -EINVAL; + if (block->sg_table) { + sgl = block->sg_table->sgl; + nents = sg_nents_for_len(sgl, block->bytes_used); + + addrs = kmalloc_array(nents, sizeof(*addrs), GFP_KERNEL); + if (!addrs) + return -ENOMEM; + + lenghts = kmalloc_array(nents, sizeof(*lenghts), GFP_KERNEL); + if (!lenghts) { + kfree(addrs); + return -ENOMEM; + } + + len_total = block->bytes_used; - desc = dmaengine_prep_slave_single(dmaengine_buffer->chan, - block->phys_addr, block->bytes_used, dma_dir, - DMA_PREP_INTERRUPT); + for (i = 0; i < nents; i++) { + addrs[i] = sg_dma_address(sgl); + lenghts[i] = min(sg_dma_len(sgl), len_total); + len_total -= lenghts[i]; + + sgl = sg_next(sgl); + } + + flags = block->cyclic ? DMA_PREP_REPEAT : DMA_PREP_INTERRUPT; + + desc = dmaengine_prep_slave_dma_array(dmaengine_buffer->chan, + addrs, lenghts, nents, + dma_dir, flags); + kfree(addrs); + kfree(lenghts); + } else { + max_size = min(block->size, dmaengine_buffer->max_size); + max_size = round_down(max_size, dmaengine_buffer->align); + + if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) + block->bytes_used = max_size; + + if (block->bytes_used > max_size) + return -EINVAL; + + desc = dmaengine_prep_slave_single(dmaengine_buffer->chan, + block->phys_addr, + block->bytes_used, dma_dir, + DMA_PREP_INTERRUPT); + } if (!desc) return -ENOMEM; @@ -133,6 +176,10 @@ static const struct iio_buffer_access_funcs iio_dmaengine_buffer_ops = { .space_available = iio_dma_buffer_space_available, .release = iio_dmaengine_buffer_release, + .enqueue_dmabuf = iio_dma_buffer_enqueue_dmabuf, + .attach_dmabuf = iio_dma_buffer_attach_dmabuf, + .detach_dmabuf = iio_dma_buffer_detach_dmabuf, + .modes = INDIO_BUFFER_HARDWARE, .flags = INDIO_BUFFER_FLAG_FIXED_WATERMARK, }; diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h index e5e5817e99db..48f7ffaf0867 100644 --- a/include/linux/iio/buffer-dma.h +++ b/include/linux/iio/buffer-dma.h @@ -43,6 +43,7 @@ enum iio_block_state { * @queue: Parent DMA buffer queue * @kref: kref used to manage the lifetime of block * @state: Current state of the block + * @cyclic: True if this is a cyclic buffer * @fileio: True if this buffer is used for fileio mode */ struct iio_dma_buffer_block { @@ -67,6 +68,7 @@ struct iio_dma_buffer_block { */ enum iio_block_state state; + bool cyclic; bool fileio; struct dma_buf_attachment *attach;