swiotlb: move the SWIOTLB config symbol to lib/Kconfig
This way we have one central definition of it, and user can select it as
needed. The new option is not user visible, which is the behavior
it had in most architectures, with a few notable exceptions:
- On x86_64 and mips/loongson3 it used to be user selectable, but
defaulted to y. It now is unconditional, which seems like the right
thing for 64-bit architectures without guaranteed availablity of
IOMMUs.
- on powerpc the symbol is user selectable and defaults to n, but
many boards select it. This change assumes no working setup
required a manual selection, but if that turned out to be wrong
we'll have to add another select statement or two for the respective
boards.
Signed-off-by: Christoph Hellwig <hch@lst.de>
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 31aad36..f2ee6a8ff 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -29,6 +29,7 @@
select HAVE_ARCH_SOFT_DIRTY
select MODULES_USE_ELF_RELA
select NEED_DMA_MAP_STATE
+ select SWIOTLB
select X86_DEV_DMA_OPS
select ARCH_HAS_SYSCALL_WRAPPER
@@ -919,17 +920,6 @@
Calgary anyway, pass 'iommu=calgary' on the kernel command line.
If unsure, say Y.
-# need this always selected by IOMMU for the VIA workaround
-config SWIOTLB
- def_bool y if X86_64
- select NEED_DMA_MAP_STATE
- ---help---
- Support for software bounce buffers used on x86-64 systems
- which don't have a hardware IOMMU. Using this PCI devices
- which can only access 32-bits of memory can be used on systems
- with more than 3 GB of memory.
- If unsure, say Y.
-
config MAXSMP
bool "Enable Maximum number of SMP Processors and NUMA Nodes"
depends on X86_64 && SMP && DEBUG_KERNEL
