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From:   Alexandru Ardelean <alexandru.ardelean@analog.com>
To:     <linux-kernel@vger.kernel.org>, <linux-iio@vger.kernel.org>
CC:     <lars@metafoo.de>, <Michael.Hennerich@analog.com>,
        <jic23@kernel.org>, <nuno.sa@analog.com>,
        <dragos.bogdan@analog.com>,
        Alexandru Ardelean <alexandru.ardelean@analog.com>
Subject: [PATCH v4 4/6] iio: buffer-dma: reduce the type of block.size to u32
Date:   Wed, 17 Feb 2021 09:36:36 +0200
Message-ID: <20210217073638.21681-5-alexandru.ardelean@analog.com>
In-Reply-To: <20210217073638.21681-1-alexandru.ardelean@analog.com>
References: <20210217073638.21681-1-alexandru.ardelean@analog.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

The type of the 'size' parameter in the block struct is size_t which is
64 bit wide on 64 bit archs.
When the mmap interface gets introduced, we will use a 32 bit field in the
block descriptor for the block size, which will cause some compiler-checks
to fail.

32 bits (4 GB) block sizes should be enough. The idea is to allocate more
blocks if the size of a block grows to 4 GB.

Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
---
 drivers/iio/buffer/industrialio-buffer-dmaengine.c | 6 +++---
 include/linux/iio/buffer-dma.h                     | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/buffer/industrialio-buffer-dmaengine.c b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
index d76179878ff9..19fbe5d9ef5b 100644
--- a/drivers/iio/buffer/industrialio-buffer-dmaengine.c
+++ b/drivers/iio/buffer/industrialio-buffer-dmaengine.c
@@ -35,8 +35,8 @@ struct dmaengine_buffer {
 	struct dma_chan *chan;
 	struct list_head active;
 
-	size_t align;
-	size_t max_size;
+	u32 align;
+	u32 max_size;
 };
 
 static struct dmaengine_buffer *iio_buffer_to_dmaengine_buffer(
@@ -136,7 +136,7 @@ static ssize_t iio_dmaengine_buffer_get_length_align(struct device *dev,
 	struct dmaengine_buffer *dmaengine_buffer =
 		iio_buffer_to_dmaengine_buffer(buffer);
 
-	return sprintf(buf, "%zu\n", dmaengine_buffer->align);
+	return sprintf(buf, "%u\n", dmaengine_buffer->align);
 }
 
 static IIO_DEVICE_ATTR(length_align_bytes, 0444,
diff --git a/include/linux/iio/buffer-dma.h b/include/linux/iio/buffer-dma.h
index 6564bdcdac66..9de27d23e791 100644
--- a/include/linux/iio/buffer-dma.h
+++ b/include/linux/iio/buffer-dma.h
@@ -55,7 +55,7 @@ struct iio_dma_buffer_block {
 	 */
 	void *vaddr;
 	dma_addr_t phys_addr;
-	size_t size;
+	u32 size;
 	struct iio_dma_buffer_queue *queue;
 
 	/* Must not be accessed outside the core. */
-- 
2.17.1