dma-mapping: remove CONFIG_DMA_REMAP

CONFIG_DMA_REMAP is used to build a few helpers around the core
vmalloc code, and to use them in case there is a highmem page in
dma-direct, and to make dma coherent allocations be able to use
non-contiguous pages allocations for DMA allocations in the dma-iommu
layer.

Right now it needs to be explicitly selected by architectures, and
is only done so by architectures that require remapping to deal
with devices that are not DMA coherent.  Make it unconditional for
builds with CONFIG_MMU as it is very little extra code, but makes
it much more likely that large DMA allocations succeed on x86.

This fixes hot plugging a NVMe thunderbolt SSD for me, which tries
to allocate a 1MB buffer that is otherwise hard to obtain due to
memory fragmentation on a heavily used laptop.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index 8ac599aa6d99..76438ee313d1 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -17,7 +17,7 @@ config XTENSA
 	select BUILDTIME_TABLE_SORT
 	select CLONE_BACKWARDS
 	select COMMON_CLK
-	select DMA_REMAP if MMU
+	select DMA_NONCOHERENT_MMAP if MMU
 	select GENERIC_ATOMIC64
 	select GENERIC_IRQ_SHOW
 	select GENERIC_PCI_IOMAP