arc: use the generic remapping allocator for coherent DMA allocations

Replace the code that sets up uncached PTEs with the generic vmap based
remapping code.  It also provides an atomic pool for allocations from
non-blocking context, which we not properly supported by the existing
arc code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Evgeniy Paltsev <paltsev@synopsys.com>
Tested-by: Evgeniy Paltsev <paltsev@synopsys.com>
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 23e063d..cdad7d3 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -10,6 +10,7 @@
 	def_bool y
 	select ARC_TIMERS
 	select ARCH_HAS_DMA_COHERENT_TO_PFN
+	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_PTE_SPECIAL
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
@@ -19,6 +20,7 @@
 	select BUILDTIME_EXTABLE_SORT
 	select CLONE_BACKWARDS
 	select COMMON_CLK
+	select DMA_DIRECT_REMAP
 	select GENERIC_ATOMIC64 if !ISA_ARCV2 || !(ARC_HAS_LL64 && ARC_HAS_LLSC)
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_FIND_FIRST_BIT