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authorNuno Sa <nuno.sa@analog.com>2024-02-09 16:50:34 +0100
committerWilliam Breathitt Gray <wbg@ishicorp.com>2024-02-16 18:51:00 -0500
commitc83ccdc9586b3e9882da9e27507c046751999d59 (patch)
treeb55ded02769aef6d1bfee67c39e24f863293ae32 /drivers/counter
parent6613476e225e090cc9aad49be7fa504e290dd33d (diff)
counter: fix privdata alignment
Aligning to the L1 cache does not guarantee the same alignment as kmallocing an object [1]. Furthermore, in some platforms, that alignment is not sufficient for DMA safety (in case someone wants to have a DMA safe buffer in privdata) [2]. Sometime ago, we had the same fixes in IIO. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/base/devres.c#n35 [2]: https://lore.kernel.org/linux-iio/20220508175712.647246-2-jic23@kernel.org/ Fixes: c18e2760308e ("counter: Provide alternative counter registration functions") Signed-off-by: Nuno Sa <nuno.sa@analog.com> Link: https://lore.kernel.org/r/20240209-counter-align-fix-v2-1-5777ea0a2722@analog.com Signed-off-by: William Breathitt Gray <william.gray@linaro.org>
Diffstat (limited to 'drivers/counter')
-rw-r--r--drivers/counter/counter-core.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/counter/counter-core.c b/drivers/counter/counter-core.c
index 09c77afb33ca..3f24481fc04a 100644
--- a/drivers/counter/counter-core.c
+++ b/drivers/counter/counter-core.c
@@ -31,10 +31,11 @@ struct counter_device_allochelper {
struct counter_device counter;
/*
- * This is cache line aligned to ensure private data behaves like if it
- * were kmalloced separately.
+ * This ensures private data behaves like if it were kmalloced
+ * separately. Also ensures the minimum alignment for safe DMA
+ * operations (which may or may not mean cache alignment).
*/
- unsigned long privdata[] ____cacheline_aligned;
+ unsigned long privdata[] __aligned(ARCH_DMA_MINALIGN);
};
static void counter_device_release(struct device *dev)