[PATCH v4 4/6] iio: buffer-dma: reduce the type of block.size to u32

From: Alexandru Ardelean
Date: Wed Feb 17 2021 - 02:39:13 EST


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@xxxxxxxxxx>
---
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