[PATCH v3 13/13] dma: arm64: Add CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC and enable it for arm64

[Catalin Marinas <catalin.marinas@arm.com>]

With all the infrastructure in place for bouncing small kmalloc()
buffers, add the corresponding Kconfig entry and select it for arm64.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Robin Murphy <robin.murphy@arm.com>
---
 arch/arm64/Kconfig | 1 +
 kernel/dma/Kconfig | 8 ++++++++
 2 files changed, 9 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3991cb7b8a33..f889cf16e6ab 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -100,6 +100,7 @@ config ARM64
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_HUGE_PMD_SHARE if ARM64_4K_PAGES || (ARM64_16K_PAGES && !ARM64_VA_BITS_36)
 	select ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
+	select ARCH_WANT_KMALLOC_DMA_BOUNCE
 	select ARCH_WANT_LD_ORPHAN_WARN
 	select ARCH_WANTS_NO_INSTR
 	select ARCH_WANTS_THP_SWAP if ARM64_4K_PAGES
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index d6fab8e3cbae..b56e76371023 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -86,6 +86,14 @@ config SWIOTLB
 	bool
 	select NEED_DMA_MAP_STATE
 
+config ARCH_WANT_KMALLOC_DMA_BOUNCE
+	bool
+
+config DMA_BOUNCE_UNALIGNED_KMALLOC
+	def_bool y
+	depends on ARCH_WANT_KMALLOC_DMA_BOUNCE
+	depends on SWIOTLB && !SLOB
+
 config DMA_RESTRICTED_POOL
 	bool "DMA Restricted Pool"
 	depends on OF && OF_RESERVED_MEM && SWIOTLB