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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Cosmin Tanislav <demonsingur@gmail.com>,
        =?UTF-8?q?Nuno=20S=C3=A1?= <nuno.sa@analog.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.18 0589/1095] iio: accel: adxl367: Fix alignment for DMA safety
Date:   Mon, 15 Aug 2022 19:59:48 +0200
Message-Id: <20220815180453.932463861@linuxfoundation.org>
In-Reply-To: <20220815180429.240518113@linuxfoundation.org>
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From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

[ Upstream commit e1f956a804df9074fb5de557563d153ae25252e7 ]

____cacheline_aligned is insufficient guarantee for non-coherent DMA.
Switch to the updated IIO_DMA_MINALIGN definition.

Update comment to reflect that DMA safety may require separate
cachelines.

Fixes: cbab791c5e2a5 ("iio: accel: add ADXL367 driver")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Cosmin Tanislav <demonsingur@gmail.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20220508175712.647246-5-jic23@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/iio/accel/adxl367.c     | 2 +-
 drivers/iio/accel/adxl367_spi.c | 8 +++++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/accel/adxl367.c b/drivers/iio/accel/adxl367.c
index 62960134ea19..d680bec05efc 100644
--- a/drivers/iio/accel/adxl367.c
+++ b/drivers/iio/accel/adxl367.c
@@ -179,7 +179,7 @@ struct adxl367_state {
 	unsigned int	fifo_set_size;
 	unsigned int	fifo_watermark;
 
-	__be16		fifo_buf[ADXL367_FIFO_SIZE] ____cacheline_aligned;
+	__be16		fifo_buf[ADXL367_FIFO_SIZE] __aligned(IIO_DMA_MINALIGN);
 	__be16		sample_buf;
 	u8		act_threshold_buf[2];
 	u8		inact_time_buf[2];
diff --git a/drivers/iio/accel/adxl367_spi.c b/drivers/iio/accel/adxl367_spi.c
index 26dfc821ebbe..118c894015a5 100644
--- a/drivers/iio/accel/adxl367_spi.c
+++ b/drivers/iio/accel/adxl367_spi.c
@@ -9,6 +9,8 @@
 #include <linux/regmap.h>
 #include <linux/spi/spi.h>
 
+#include <linux/iio/iio.h>
+
 #include "adxl367.h"
 
 #define ADXL367_SPI_WRITE_COMMAND	0x0A
@@ -28,10 +30,10 @@ struct adxl367_spi_state {
 	struct spi_transfer	fifo_xfer[2];
 
 	/*
-	 * DMA (thus cache coherency maintenance) requires the
-	 * transfer buffers to live in their own cache lines.
+	 * DMA (thus cache coherency maintenance) may require the
+	 * transfer buffers live in their own cache lines.
 	 */
-	u8			reg_write_tx_buf[1] ____cacheline_aligned;
+	u8			reg_write_tx_buf[1] __aligned(IIO_DMA_MINALIGN);
 	u8			reg_read_tx_buf[2];
 	u8			fifo_tx_buf[1];
 };
-- 
2.35.1