From patchwork Fri Feb 16 14:10:52 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nuno Sa via B4 Relay X-Patchwork-Id: 13560075 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EF7CB12E1E8 for ; Fri, 16 Feb 2024 14:11:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708092690; cv=none; b=TkSM7ntC2ptyjzvpvvpM8rV0lpS/DEJkkQ6HBx3RBu+U90o8/2Xkto7Q9/kB+EgzYn+1FEjmSEf8eyUKT7cg2r9CRgY1mGmBGBHa71BkQCCKZmuFSbnG6tpqe6/f5kRQCvAr0abgRivHJmTd1OtH8oobdt3jqNkXZR3kmXyShIM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708092690; c=relaxed/simple; bh=K1bI3qSBsID6idTEBGaHrKCumxe2K3HYxfybRHk0M40=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Dbfde9L0rWJLBKma9/lxez19WV5gAJ/BxBfnRjStCKti32Q4iUG/87mkdinfExulluOsszfmR8YfIAtv5dh+OCa3bd98NIVs1Bi3PofvLGbqREgAC8KKeqpmAaGkzkvw4YnQk7+xT+XLKZkK7wgBM3aRIA0xQ1xh5V2Jnz0d2eE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kkX3of4i; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kkX3of4i" Received: by smtp.kernel.org (Postfix) with ESMTPS id 5D9A7C43399; Fri, 16 Feb 2024 14:11:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1708092689; bh=K1bI3qSBsID6idTEBGaHrKCumxe2K3HYxfybRHk0M40=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=kkX3of4i9NyPcU48ivH5plMUxwLJV7FP3BupktQLCSV2JRED3kC1dcwhUbAibkYRo xbtT+pmjjUqqqpPb0M7PMWTiygy0dYLqyXhbDi2+OcdQ4OXoPb2ZSuKLNLIqhJ8rvc VGkATHUXcvdUVqwDf1QCV8KNRwMyQR2uW7gqNm1dyYrgiCrgBKGQxhqg5CEWgpPtDB jo5Q743uxJttlMNtGRXRxmqvcK3Z7PwHroGyxsxsGc3y4wsM7YalNX+lQZ2VRL0C/v 3IrLuweZ9+C/ysZZ43aZnCfcCQOvWU28ITjKn4J4W+ySNMqYuAv/BmfxG/9tLG6Jg7 ppeu6RfeET3cg== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D088C48BF6; Fri, 16 Feb 2024 14:11:29 +0000 (UTC) From: Nuno Sa via B4 Relay Date: Fri, 16 Feb 2024 15:10:52 +0100 Subject: [PATCH RFC 3/8] iio: buffer-dma: Enable buffer write support Precedence: bulk X-Mailing-List: linux-iio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-Id: <20240216-iio-backend-axi-dds-v1-3-22aed9fb07a1@analog.com> References: <20240216-iio-backend-axi-dds-v1-0-22aed9fb07a1@analog.com> In-Reply-To: <20240216-iio-backend-axi-dds-v1-0-22aed9fb07a1@analog.com> To: linux-iio@vger.kernel.org Cc: Jonathan Cameron , Lars-Peter Clausen , Olivier Moysan , Michael Hennerich , Paul Cercueil , Alexandru Ardelean X-Mailer: b4 0.12.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1708092664; l=6566; i=nuno.sa@analog.com; s=20231116; h=from:subject:message-id; bh=L8Ql02GphZ76a78MQMNepoZSe0z1Oo9UelhjeRQ/JC8=; b=wVKa+4l8K+gInZdPI43AQx55LuIW2RzzX2POck+SSNsQFlonW2fbmd1laR6qhF7IuxLzdWfij k/EUH0EKPiFAkHfaWoOp0OnRnYadULH7RQuNz/mH/kcF8hn5Gi8WXBf X-Developer-Key: i=nuno.sa@analog.com; a=ed25519; pk=3NQwYA013OUYZsmDFBf8rmyyr5iQlxV/9H4/Df83o1E= X-Endpoint-Received: by B4 Relay for nuno.sa@analog.com/20231116 with auth_id=100 X-Original-From: Nuno Sa Reply-To: From: Paul Cercueil Adding write support to the buffer-dma code is easy - the write() function basically needs to do the exact same thing as the read() function: dequeue a block, read or write the data, enqueue the block when entirely processed. Therefore, the iio_buffer_dma_read() and the new iio_buffer_dma_write() now both call a function iio_buffer_dma_io(), which will perform this task. Note that we preemptively reset block->bytes_used to the buffer's size in iio_dma_buffer_request_update(), as in the future the iio_dma_buffer_enqueue() function won't reset it. Signed-off-by: Paul Cercueil Reviewed-by: Alexandru Ardelean --- drivers/iio/buffer/industrialio-buffer-dma.c | 89 +++++++++++++++++++++++----- include/linux/iio/buffer-dma.h | 2 + 2 files changed, 75 insertions(+), 16 deletions(-) diff --git a/drivers/iio/buffer/industrialio-buffer-dma.c b/drivers/iio/buffer/industrialio-buffer-dma.c index 404f9867bdc5..29cc3083cb7e 100644 --- a/drivers/iio/buffer/industrialio-buffer-dma.c +++ b/drivers/iio/buffer/industrialio-buffer-dma.c @@ -195,6 +195,18 @@ static void _iio_dma_buffer_block_done(struct iio_dma_buffer_block *block) block->state = IIO_BLOCK_STATE_DONE; } +static void iio_dma_buffer_queue_wake(struct iio_dma_buffer_queue *queue) +{ + __poll_t flags; + + if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) + flags = EPOLLIN | EPOLLRDNORM; + else + flags = EPOLLOUT | EPOLLWRNORM; + + wake_up_interruptible_poll(&queue->buffer.pollq, flags); +} + /** * iio_dma_buffer_block_done() - Indicate that a block has been completed * @block: The completed block @@ -212,7 +224,7 @@ void iio_dma_buffer_block_done(struct iio_dma_buffer_block *block) spin_unlock_irqrestore(&queue->list_lock, flags); iio_buffer_block_put_atomic(block); - wake_up_interruptible_poll(&queue->buffer.pollq, EPOLLIN | EPOLLRDNORM); + iio_dma_buffer_queue_wake(queue); } EXPORT_SYMBOL_GPL(iio_dma_buffer_block_done); @@ -241,7 +253,7 @@ void iio_dma_buffer_block_list_abort(struct iio_dma_buffer_queue *queue, } spin_unlock_irqrestore(&queue->list_lock, flags); - wake_up_interruptible_poll(&queue->buffer.pollq, EPOLLIN | EPOLLRDNORM); + iio_dma_buffer_queue_wake(queue); } EXPORT_SYMBOL_GPL(iio_dma_buffer_block_list_abort); @@ -335,8 +347,24 @@ int iio_dma_buffer_request_update(struct iio_buffer *buffer) queue->fileio.blocks[i] = block; } - block->state = IIO_BLOCK_STATE_QUEUED; - list_add_tail(&block->head, &queue->incoming); + /* + * block->bytes_used may have been modified previously, e.g. by + * iio_dma_buffer_block_list_abort(). Reset it here to the + * block's so that iio_dma_buffer_io() will work. + */ + block->bytes_used = block->size; + + /* + * If it's an input buffer, mark the block as queued, and + * iio_dma_buffer_enable() will submit it. Otherwise mark it as + * done, which means it's ready to be dequeued. + */ + if (queue->buffer.direction == IIO_BUFFER_DIRECTION_IN) { + block->state = IIO_BLOCK_STATE_QUEUED; + list_add_tail(&block->head, &queue->incoming); + } else { + block->state = IIO_BLOCK_STATE_DONE; + } } out_unlock: @@ -488,20 +516,12 @@ static struct iio_dma_buffer_block *iio_dma_buffer_dequeue( return block; } -/** - * iio_dma_buffer_read() - DMA buffer read callback - * @buffer: Buffer to read form - * @n: Number of bytes to read - * @user_buffer: Userspace buffer to copy the data to - * - * Should be used as the read callback for iio_buffer_access_ops - * struct for DMA buffers. - */ -int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, - char __user *user_buffer) +static int iio_dma_buffer_io(struct iio_buffer *buffer, size_t n, + char __user *user_buffer, bool is_from_user) { struct iio_dma_buffer_queue *queue = iio_buffer_to_queue(buffer); struct iio_dma_buffer_block *block; + void *addr; int ret; if (n < buffer->bytes_per_datum) @@ -524,8 +544,13 @@ int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, n = rounddown(n, buffer->bytes_per_datum); if (n > block->bytes_used - queue->fileio.pos) n = block->bytes_used - queue->fileio.pos; + addr = block->vaddr + queue->fileio.pos; - if (copy_to_user(user_buffer, block->vaddr + queue->fileio.pos, n)) { + if (is_from_user) + ret = copy_from_user(addr, user_buffer, n); + else + ret = copy_to_user(user_buffer, addr, n); + if (ret) { ret = -EFAULT; goto out_unlock; } @@ -544,8 +569,40 @@ int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, return ret; } + +/** + * iio_dma_buffer_read() - DMA buffer read callback + * @buffer: Buffer to read form + * @n: Number of bytes to read + * @user_buffer: Userspace buffer to copy the data to + * + * Should be used as the read callback for iio_buffer_access_ops + * struct for DMA buffers. + */ +int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, + char __user *user_buffer) +{ + return iio_dma_buffer_io(buffer, n, user_buffer, false); +} EXPORT_SYMBOL_GPL(iio_dma_buffer_read); +/** + * iio_dma_buffer_write() - DMA buffer write callback + * @buffer: Buffer to read form + * @n: Number of bytes to read + * @user_buffer: Userspace buffer to copy the data from + * + * Should be used as the write callback for iio_buffer_access_ops + * struct for DMA buffers. + */ +int iio_dma_buffer_write(struct iio_buffer *buffer, size_t n, + const char __user *user_buffer) +{ + return iio_dma_buffer_io(buffer, n, + (__force __user char *)user_buffer, true); +} +EXPORT_SYMBOL_GPL(iio_dma_buffer_write); + /** * iio_dma_buffer_usage() - DMA buffer data_available and * space_available callback diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h index 52a838ec0e57..6e27e47077d5 100644 --- a/include/linux/iio/buffer-dma.h +++ b/include/linux/iio/buffer-dma.h @@ -132,6 +132,8 @@ int iio_dma_buffer_disable(struct iio_buffer *buffer, struct iio_dev *indio_dev); int iio_dma_buffer_read(struct iio_buffer *buffer, size_t n, char __user *user_buffer); +int iio_dma_buffer_write(struct iio_buffer *buffer, size_t n, + const char __user *user_buffer); size_t iio_dma_buffer_usage(struct iio_buffer *buffer); int iio_dma_buffer_set_bytes_per_datum(struct iio_buffer *buffer, size_t bpd); int iio_dma_buffer_set_length(struct iio_buffer *buffer, unsigned int length);