arm64: enable ARCH_WANT_KMALLOC_DMA_BOUNCE for arm64

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>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b1201d2..af42871 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/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

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 66e70ca..3ac2e9d 100644 (file)
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -442,7 +442,12 @@ 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();