iio: imu: adis: ensure proper DMA alignment

commit 8e98b87f515d8c4bae521048a037b2cc431c3fd5 upstream.

Aligning the buffer to the L1 cache is not sufficient in some platforms
as they might have larger cacheline sizes for caches after L1 and thus,
we can't guarantee DMA safety.

That was the whole reason to introduce IIO_DMA_MINALIGN in [1]. Do the same
for the sigma_delta ADCs.

[1]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@kernel.org/

Fixes: ccd2b52f4ac6 ("staging:iio: Add common ADIS library")
Signed-off-by: Nuno Sa <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20240117-adis-improv-v1-1-7f90e9fad200@analog.com
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index dc9ea299e0885cd55018f21b80a35155d0ca1d63..8898966bc0f08c152a8156b85151b223f76e9ffe 100644 (file)
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -11,6 +11,7 @@
 
 #include <linux/spi/spi.h>
 #include <linux/interrupt.h>
+#include <linux/iio/iio.h>
 #include <linux/iio/types.h>
 
 #define ADIS_WRITE_REG(reg) ((0x80 | (reg)))
@@ -131,7 +132,7 @@ struct adis {
        unsigned long           irq_flag;
        void                    *buffer;
 
-       u8                      tx[10] ____cacheline_aligned;
+       u8                      tx[10] __aligned(IIO_DMA_MINALIGN);
        u8                      rx[4];
 };