This is a note to let you know that I've just added the patch titled
mm/slab: decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
mm-slab-decouple-arch_kmalloc_minalign-from-arch_dma.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 3d2791f7153ab3101661d84e335bd84c95a8b34f
Author: Catalin Marinas <catalin.marinas@xxxxxxx>
Date: Mon Jun 12 16:31:45 2023 +0100
mm/slab: decouple ARCH_KMALLOC_MINALIGN from ARCH_DMA_MINALIGN
[ Upstream commit 4ab5f8ec7d71aea5fe13a48248242130f84ac6bb ]
Patch series "mm, dma, arm64: Reduce ARCH_KMALLOC_MINALIGN to 8", v7.
A series reducing the kmalloc() minimum alignment on arm64 to 8 (from
128).
This patch (of 17):
In preparation for supporting a kmalloc() minimum alignment smaller than
the arch DMA alignment, decouple the two definitions. This requires that
either the kmalloc() caches are aligned to a (run-time) cache-line size or
the DMA API bounces unaligned kmalloc() allocations. Subsequent patches
will implement both options.
After this patch, ARCH_DMA_MINALIGN is expected to be used in static
alignment annotations and defined by an architecture to be the maximum
alignment for all supported configurations/SoCs in a single Image.
Architectures opting in to a smaller ARCH_KMALLOC_MINALIGN will need to
define its value in the arch headers.
Since ARCH_DMA_MINALIGN is now always defined, adjust the #ifdef in
dma_get_cache_alignment() so that there is no change for architectures not
requiring a minimum DMA alignment.
Link: https://lkml.kernel.org/r/20230612153201.554742-1-catalin.marinas@xxxxxxx
Link: https://lkml.kernel.org/r/20230612153201.554742-2-catalin.marinas@xxxxxxx
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Tested-by: Isaac J. Manjarres <isaacmanjarres@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Robin Murphy <robin.murphy@xxxxxxx>
Cc: Alasdair Kergon <agk@xxxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
Cc: Marc Zyngier <maz@xxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxx>
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: Rafael J. Wysocki <rafael@xxxxxxxxxx>
Cc: Saravana Kannan <saravanak@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Jerry Snitselaar <jsnitsel@xxxxxxxxxx>
Cc: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>
Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
Cc: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Stable-dep-of: c83ccdc9586b ("counter: fix privdata alignment")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/linux/cache.h b/include/linux/cache.h
index 5da1bbd96154b..9900d20b76c28 100644
--- a/include/linux/cache.h
+++ b/include/linux/cache.h
@@ -98,4 +98,10 @@ struct cacheline_padding {
#define CACHELINE_PADDING(name)
#endif
+#ifdef ARCH_DMA_MINALIGN
+#define ARCH_HAS_DMA_MINALIGN
+#else
+#define ARCH_DMA_MINALIGN __alignof__(unsigned long long)
+#endif
+
#endif /* __LINUX_CACHE_H */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 0ee20b764000c..a50375331eac0 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -2,6 +2,7 @@
#ifndef _LINUX_DMA_MAPPING_H
#define _LINUX_DMA_MAPPING_H
+#include <linux/cache.h>
#include <linux/sizes.h>
#include <linux/string.h>
#include <linux/device.h>
@@ -545,7 +546,7 @@ static inline int dma_set_min_align_mask(struct device *dev,
static inline int dma_get_cache_alignment(void)
{
-#ifdef ARCH_DMA_MINALIGN
+#ifdef ARCH_HAS_DMA_MINALIGN
return ARCH_DMA_MINALIGN;
#endif
return 1;
diff --git a/include/linux/slab.h b/include/linux/slab.h
index cb4b5deca9a9c..cceb824927760 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -12,6 +12,7 @@
#ifndef _LINUX_SLAB_H
#define _LINUX_SLAB_H
+#include <linux/cache.h>
#include <linux/gfp.h>
#include <linux/overflow.h>
#include <linux/types.h>
@@ -224,12 +225,17 @@ void kmem_dump_obj(void *object);
* alignment larger than the alignment of a 64-bit integer.
* Setting ARCH_DMA_MINALIGN in arch headers allows that.
*/
-#if defined(ARCH_DMA_MINALIGN) && ARCH_DMA_MINALIGN > 8
+#ifdef ARCH_HAS_DMA_MINALIGN
+#if ARCH_DMA_MINALIGN > 8 && !defined(ARCH_KMALLOC_MINALIGN)
#define ARCH_KMALLOC_MINALIGN ARCH_DMA_MINALIGN
-#define KMALLOC_MIN_SIZE ARCH_DMA_MINALIGN
-#define KMALLOC_SHIFT_LOW ilog2(ARCH_DMA_MINALIGN)
-#else
+#endif
+#endif
+
+#ifndef ARCH_KMALLOC_MINALIGN
#define ARCH_KMALLOC_MINALIGN __alignof__(unsigned long long)
+#elif ARCH_KMALLOC_MINALIGN > 8
+#define KMALLOC_MIN_SIZE ARCH_KMALLOC_MINALIGN
+#define KMALLOC_SHIFT_LOW ilog2(KMALLOC_MIN_SIZE)
#endif
/*
