+ arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64.patch added to mm-unstable branch

+ arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: arm64: enable ARCH_WANT_KMALLOC_DMA_BOUNCE for arm64
has been added to the -mm mm-unstable branch.  Its filename is
     arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Catalin Marinas <catalin.marinas@arm.com>
Subject: arm64: enable ARCH_WANT_KMALLOC_DMA_BOUNCE for arm64
Date: Mon, 12 Jun 2023 16:32:01 +0100

With the DMA bouncing of unaligned kmalloc() buffers now in place, enable
it for arm64 to allow the kmalloc-{8,16,32,48,96} caches.  In addition,
always create the swiotlb buffer even when the end of RAM is within the
32-bit physical address range (the swiotlb buffer can still be disabled on
the kernel command line).

Link: https://lkml.kernel.org/r/20230612153201.554742-18-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Isaac J. Manjarres <isaacmanjarres@google.com>
Cc: Will Deacon <will@kernel.org>
Cc: Alasdair Kergon <agk@redhat.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Jerry Snitselaar <jsnitsel@redhat.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Lars-Peter Clausen <lars@metafoo.de>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Mike Snitzer <snitzer@kernel.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Saravana Kannan <saravanak@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/arm64/Kconfig   |    1 +
 arch/arm64/mm/init.c |    7 ++++++-
 2 files changed, 7 insertions(+), 1 deletion(-)

--- a/arch/arm64/Kconfig~arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64
+++ a/arch/arm64/Kconfig
@@ -120,6 +120,7 @@ config ARM64
 	select CRC32
 	select DCACHE_WORD_ACCESS
 	select DYNAMIC_FTRACE if FUNCTION_TRACER
+	select DMA_BOUNCE_UNALIGNED_KMALLOC
 	select DMA_DIRECT_REMAP
 	select EDAC_SUPPORT
 	select FRAME_POINTER
--- a/arch/arm64/mm/init.c~arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64
+++ a/arch/arm64/mm/init.c
@@ -440,7 +440,12 @@ void __init bootmem_init(void)
  */
 void __init mem_init(void)
 {
-	swiotlb_init(max_pfn > PFN_DOWN(arm64_dma_phys_limit), SWIOTLB_VERBOSE);
+	bool swiotlb = max_pfn > PFN_DOWN(arm64_dma_phys_limit);
+
+	if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC))
+		swiotlb = true;
+
+	swiotlb_init(swiotlb, SWIOTLB_VERBOSE);
 
 	/* this will put all unused low memory onto the freelists */
 	memblock_free_all();
_

Patches currently in -mm which might be from catalin.marinas@arm.com are

mm-slab-decouple-arch_kmalloc_minalign-from-arch_dma_minalign.patch
dma-allow-dma_get_cache_alignment-to-be-overridden-by-the-arch-code.patch
mm-slab-simplify-create_kmalloc_cache-args-and-make-it-static.patch
mm-slab-limit-kmalloc-minimum-alignment-to-dma_get_cache_alignment.patch
drivers-base-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
drivers-gpu-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
drivers-usb-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
drivers-spi-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
dm-crypt-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
iio-core-use-arch_dma_minalign-instead-of-arch_kmalloc_minalign.patch
arm64-allow-kmalloc-caches-aligned-to-the-smaller-cache_line_size.patch
dma-mapping-force-bouncing-if-the-kmalloc-size-is-not-cache-line-aligned.patch
iommu-dma-force-bouncing-if-the-size-is-not-cacheline-aligned.patch
mm-slab-reduce-the-kmalloc-minimum-alignment-if-dma-bouncing-possible.patch
arm64-enable-arch_want_kmalloc_dma_bounce-for-arm64.patch