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From: Jonathan Cameron <jic23@kernel.org>
To: linux-input@vger.kernel.org, Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>,
	Tomohiro Yoshidomi <sylph23k@gmail.com>
Subject: [PATCH 1/9] Input: psxpad - Fix padding for DMA safe buffers.
Date: Sun, 27 Nov 2022 14:41:08 +0000	[thread overview]
Message-ID: <20221127144116.1418083-2-jic23@kernel.org> (raw)
In-Reply-To: <20221127144116.1418083-1-jic23@kernel.org>

From: Jonathan Cameron <Jonathan.Cameron@huawei.com>

On some architectures (e.g. arm64), ____cachline_aligned only aligns
to the cacheline size of the L1 cache size. L1_CACHE_BYTES in
arch64/include/asm/cache.h  Unfortunately DMA safety on these
architectures requires the buffer no share a last level cache cacheline
given by ARCH_DMA_MINALIGN which has a greater granularity.
ARCH_DMA_MINALIGN is not defined for all architectures, but when it is
defined it is used to set the size of ARCH_KMALLOC_MINALIGN
to allow DMA safe buffer allocations.

As such the correct alignment requirement is
__aligned(ARCH_KMALLOC_MINALIGN).
This has recently been fixed in other subsystems such as IIO.

Fixes: 8be193c7b1f4 ("Input: add support for PlayStation 1/2 joypads connected via SPI")
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Tomohiro Yoshidomi <sylph23k@gmail.com>
---
 drivers/input/joystick/psxpad-spi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/input/joystick/psxpad-spi.c b/drivers/input/joystick/psxpad-spi.c
index a32656064f39..8098d205b58d 100644
--- a/drivers/input/joystick/psxpad-spi.c
+++ b/drivers/input/joystick/psxpad-spi.c
@@ -65,8 +65,8 @@ struct psxpad {
 	bool motor2enable;
 	u8 motor1level;
 	u8 motor2level;
-	u8 sendbuf[0x20] ____cacheline_aligned;
-	u8 response[sizeof(PSX_CMD_POLL)] ____cacheline_aligned;
+	u8 sendbuf[0x20] __aligned(ARCH_KMALLOC_MINALIGN);
+	u8 response[sizeof(PSX_CMD_POLL)] __aligned(ARCH_KMALLOC_MINALIGN);
 };
 
 static int psxpad_command(struct psxpad *pad, const u8 sendcmdlen)
-- 
2.38.1


  reply	other threads:[~2022-11-27 14:28 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-27 14:41 [PATCH 0/9] Input: Fix insufficent DMA alignment Jonathan Cameron
2022-11-27 14:41 ` Jonathan Cameron [this message]
2022-11-27 14:41 ` [PATCH 2/9] Input: ad714x - Fix padding for DMA safe buffers Jonathan Cameron
2022-11-28  7:14   ` Hennerich, Michael
2022-11-27 14:41 ` [PATCH 3/9] Input: ad7887 " Jonathan Cameron
2022-11-28  7:14   ` Hennerich, Michael
2022-11-27 14:41 ` [PATCH 4/9] Input: ads7846 " Jonathan Cameron
2022-11-27 14:41 ` [PATCH 5/9] Input: cyttsp " Jonathan Cameron
2022-11-27 14:41 ` [PATCH 6/9] Input: surface3 " Jonathan Cameron
2022-11-27 16:26   ` Jonathan Cameron
2022-11-27 14:41 ` [PATCH 7/9] Input: n64joy - Fix DMA buffer alignment Jonathan Cameron
2022-11-27 16:48   ` Lauri Kasanen
2022-11-27 18:01     ` Jonathan Cameron
2022-11-28  6:49       ` Lauri Kasanen
2022-11-28 18:04     ` Dmitry Torokhov
2022-11-27 14:41 ` [PATCH 8/9] Input: atmel_captouch - Avoid suspect " Jonathan Cameron
2022-11-27 14:41 ` [PATCH 9/9] Input: elants - Fix " Jonathan Cameron
2022-11-28 18:16 ` [PATCH 0/9] Input: Fix insufficent DMA alignment Dmitry Torokhov
2022-11-29  9:18   ` Jonathan Cameron
2022-11-30  1:23     ` Dmitry Torokhov

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