diff mbox series

[11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

Message ID 20180423170419.20330-12-hch@lst.de
State Not Applicable
Delegated to: David Miller
Headers show
Series [01/12] iommu-common: move to arch/sparc | expand

Commit Message

Christoph Hellwig April 23, 2018, 5:04 p.m. UTC
This way we have one central definition of it, and user can select it as
needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
indicate the architecture supports swiotlb at all, so that we can still
make the usage optional for a few architectures that want this feature
to be user selectable.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/Kconfig                |  4 +---
 arch/arm64/Kconfig              |  5 ++---
 arch/ia64/Kconfig               |  9 +--------
 arch/mips/Kconfig               |  3 +++
 arch/mips/cavium-octeon/Kconfig |  5 -----
 arch/mips/loongson64/Kconfig    |  8 --------
 arch/powerpc/Kconfig            |  9 ---------
 arch/unicore32/mm/Kconfig       |  5 -----
 arch/x86/Kconfig                | 14 +++-----------
 lib/Kconfig                     | 15 +++++++++++++++
 10 files changed, 25 insertions(+), 52 deletions(-)

Comments

Konrad Rzeszutek Wilk April 23, 2018, 8:11 p.m. UTC | #1
On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> indicate the architecture supports swiotlb at all, so that we can still
> make the usage optional for a few architectures that want this feature
> to be user selectable.

If I follow this select business this will enable it on ARM and x86 by default.

As such:
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Thank you!
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/arm/Kconfig                |  4 +---
>  arch/arm64/Kconfig              |  5 ++---
>  arch/ia64/Kconfig               |  9 +--------
>  arch/mips/Kconfig               |  3 +++
>  arch/mips/cavium-octeon/Kconfig |  5 -----
>  arch/mips/loongson64/Kconfig    |  8 --------
>  arch/powerpc/Kconfig            |  9 ---------
>  arch/unicore32/mm/Kconfig       |  5 -----
>  arch/x86/Kconfig                | 14 +++-----------
>  lib/Kconfig                     | 15 +++++++++++++++
>  10 files changed, 25 insertions(+), 52 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 90b81a3a28a7..f91f69174630 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -106,6 +106,7 @@ config ARM
>  	select REFCOUNT_FULL
>  	select RTC_LIB
>  	select SYS_SUPPORTS_APM_EMULATION
> +	select ARCH_HAS_SWIOTLB
>  	# Above selects are sorted alphabetically; please add new ones
>  	# according to that.  Thanks.
>  	help
> @@ -1773,9 +1774,6 @@ config SECCOMP
>  	  and the task is only allowed to execute a few safe syscalls
>  	  defined by each seccomp mode.
>  
> -config SWIOTLB
> -	bool
> -
>  config PARAVIRT
>  	bool "Enable paravirtualization code"
>  	help
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 4d924eb32e7f..056bc7365adf 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -21,6 +21,7 @@ config ARM64
>  	select ARCH_HAS_SG_CHAIN
>  	select ARCH_HAS_STRICT_KERNEL_RWX
>  	select ARCH_HAS_STRICT_MODULE_RWX
> +	select ARCH_HAS_SWIOTLB
>  	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>  	select ARCH_HAVE_NMI_SAFE_CMPXCHG
>  	select ARCH_INLINE_READ_LOCK if !PREEMPT
> @@ -144,6 +145,7 @@ config ARM64
>  	select POWER_SUPPLY
>  	select REFCOUNT_FULL
>  	select SPARSE_IRQ
> +	select SWIOTLB
>  	select SYSCTL_EXCEPTION_TRACE
>  	select THREAD_INFO_IN_TASK
>  	help
> @@ -239,9 +241,6 @@ config HAVE_GENERIC_GUP
>  config SMP
>  	def_bool y
>  
> -config SWIOTLB
> -	def_bool y
> -
>  config KERNEL_MODE_NEON
>  	def_bool y
>  
> diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
> index 685d557eea48..d396230913e6 100644
> --- a/arch/ia64/Kconfig
> +++ b/arch/ia64/Kconfig
> @@ -56,6 +56,7 @@ config IA64
>  	select HAVE_ARCH_AUDITSYSCALL
>  	select NEED_DMA_MAP_STATE
>  	select NEED_SG_DMA_LENGTH
> +	select ARCH_HAS_SWIOTLB
>  	default y
>  	help
>  	  The Itanium Processor Family is Intel's 64-bit successor to
> @@ -80,9 +81,6 @@ config MMU
>  	bool
>  	default y
>  
> -config SWIOTLB
> -       bool
> -
>  config STACKTRACE_SUPPORT
>  	def_bool y
>  
> @@ -139,7 +137,6 @@ config IA64_GENERIC
>  	bool "generic"
>  	select NUMA
>  	select ACPI_NUMA
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	select PCI_MSI
>  	help
> @@ -160,7 +157,6 @@ config IA64_GENERIC
>  
>  config IA64_DIG
>  	bool "DIG-compliant"
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  
>  config IA64_DIG_VTD
> @@ -176,7 +172,6 @@ config IA64_HP_ZX1
>  
>  config IA64_HP_ZX1_SWIOTLB
>  	bool "HP-zx1/sx1000 with software I/O TLB"
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	help
>  	  Build a kernel that runs on HP zx1 and sx1000 systems even when they
> @@ -200,7 +195,6 @@ config IA64_SGI_UV
>  	bool "SGI-UV"
>  	select NUMA
>  	select ACPI_NUMA
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	help
>  	  Selecting this option will optimize the kernel for use on UV based
> @@ -211,7 +205,6 @@ config IA64_SGI_UV
>  
>  config IA64_HP_SIM
>  	bool "Ski-simulator"
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	depends on !PM
>  
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index e10cc5c7be69..b6b4c1e154f8 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -912,6 +912,8 @@ config CAVIUM_OCTEON_SOC
>  	select MIPS_NR_CPU_NR_MAP_1024
>  	select BUILTIN_DTB
>  	select MTD_COMPLEX_MAPPINGS
> +	select ARCH_HAS_SWIOTLB
> +	select SWIOTLB
>  	select SYS_SUPPORTS_RELOCATABLE
>  	help
>  	  This option supports all of the Octeon reference boards from Cavium
> @@ -1367,6 +1369,7 @@ config CPU_LOONGSON3
>  	select MIPS_PGD_C0_CONTEXT
>  	select MIPS_L1_CACHE_SHIFT_6
>  	select GPIOLIB
> +	select ARCH_HAS_SWIOTLB
>  	help
>  		The Loongson 3 processor implements the MIPS64R2 instruction
>  		set with many extensions.
> diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
> index 5d73041547a7..4984e462be30 100644
> --- a/arch/mips/cavium-octeon/Kconfig
> +++ b/arch/mips/cavium-octeon/Kconfig
> @@ -67,11 +67,6 @@ config CAVIUM_OCTEON_LOCK_L2_MEMCPY
>  	help
>  	  Lock the kernel's implementation of memcpy() into L2.
>  
> -config SWIOTLB
> -	def_bool y
> -	select DMA_DIRECT_OPS
> -	select NEED_SG_DMA_LENGTH
> -
>  config OCTEON_ILM
>  	tristate "Module to measure interrupt latency using Octeon CIU Timer"
>  	help
> diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
> index 641a1477031e..c79e6a565572 100644
> --- a/arch/mips/loongson64/Kconfig
> +++ b/arch/mips/loongson64/Kconfig
> @@ -130,14 +130,6 @@ config LOONGSON_UART_BASE
>  	default y
>  	depends on EARLY_PRINTK || SERIAL_8250
>  
> -config SWIOTLB
> -	bool "Soft IOMMU Support for All-Memory DMA"
> -	default y
> -	depends on CPU_LOONGSON3
> -	select DMA_DIRECT_OPS
> -	select NEED_SG_DMA_LENGTH
> -	select NEED_DMA_MAP_STATE
> -
>  config PHYS48_TO_HT40
>  	bool
>  	default y if CPU_LOONGSON3
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index a4b2ac7c3d2e..1887f8f86a77 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -474,15 +474,6 @@ config MPROFILE_KERNEL
>  	depends on PPC64 && CPU_LITTLE_ENDIAN
>  	def_bool !DISABLE_MPROFILE_KERNEL
>  
> -config SWIOTLB
> -	bool "SWIOTLB support"
> -	default n
> -	---help---
> -	  Support for IO bounce buffering for systems without an IOMMU.
> -	  This allows us to DMA to the full physical address space on
> -	  platforms where the size of a physical address is larger
> -	  than the bus address.  Not all platforms support this.
> -
>  config HOTPLUG_CPU
>  	bool "Support for enabling/disabling CPUs"
>  	depends on SMP && (PPC_PSERIES || \
> diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
> index 1d9fed0ada71..82759b6aba67 100644
> --- a/arch/unicore32/mm/Kconfig
> +++ b/arch/unicore32/mm/Kconfig
> @@ -39,8 +39,3 @@ config CPU_TLB_SINGLE_ENTRY_DISABLE
>  	default y
>  	help
>  	  Say Y here to disable the TLB single entry operations.
> -
> -config SWIOTLB
> -	def_bool y
> -	select DMA_DIRECT_OPS
> -	select NEED_SG_DMA_LENGTH
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 07b031f99eb1..7a5fec800992 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -24,6 +24,7 @@ config X86_64
>  	depends on 64BIT
>  	# Options that are inherently 64-bit kernel only:
>  	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
> +	select ARCH_HAS_SWIOTLB
>  	select ARCH_SUPPORTS_INT128
>  	select ARCH_USE_CMPXCHG_LOCKREF
>  	select HAVE_ARCH_SOFT_DIRTY
> @@ -677,6 +678,7 @@ config STA2X11
>  	bool "STA2X11 Companion Chip Support"
>  	depends on X86_32_NON_STANDARD && PCI
>  	select ARCH_HAS_PHYS_TO_DMA
> +	select ARCH_HAS_SWIOTLB
>  	select X86_DEV_DMA_OPS
>  	select X86_DMA_REMAP
>  	select SWIOTLB
> @@ -916,17 +918,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
>  	  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
> @@ -1448,6 +1439,7 @@ config HIGHMEM
>  config X86_PAE
>  	bool "PAE (Physical Address Extension) Support"
>  	depends on X86_32 && !HIGHMEM4G
> +	select ARCH_HAS_SWIOTLB
>  	select PHYS_ADDR_T_64BIT
>  	select SWIOTLB
>  	---help---
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 1f12faf03819..01a37920949c 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -451,6 +451,21 @@ config DMA_VIRT_OPS
>  	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
>  	default n
>  
> +config ARCH_HAS_SWIOTLB
> +	bool
> +
> +config SWIOTLB
> +	bool "SWIOTLB support"
> +	default ARCH_HAS_SWIOTLB
> +	select DMA_DIRECT_OPS
> +	select NEED_DMA_MAP_STATE
> +	select NEED_SG_DMA_LENGTH
> +	---help---
> +	  Support for IO bounce buffering for systems without an IOMMU.
> +	  This allows us to DMA to the full physical address space on
> +	  platforms where the size of a physical address is larger
> +	  than the bus address.  If unsure, say Y.
> +
>  config CHECK_SIGNATURE
>  	bool
>  
> -- 
> 2.17.0
> 
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Russell King (Oracle) April 23, 2018, 11:52 p.m. UTC | #2
On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> indicate the architecture supports swiotlb at all, so that we can still
> make the usage optional for a few architectures that want this feature
> to be user selectable.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by
default, which probably isn't a good idea - ARM pre-dates the dma_length
parameter in scatterlists, and I don't think all code is guaranteed to
do the right thing if this is enabled.

For example, arch/arm/mach-rpc/dma.c doesn't use the dma_length
member of struct scatterlist.
Christoph Hellwig April 24, 2018, 6:55 a.m. UTC | #3
On Tue, Apr 24, 2018 at 12:52:05AM +0100, Russell King - ARM Linux wrote:
> On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> > This way we have one central definition of it, and user can select it as
> > needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> > indicate the architecture supports swiotlb at all, so that we can still
> > make the usage optional for a few architectures that want this feature
> > to be user selectable.
> > 
> > Signed-off-by: Christoph Hellwig <hch@lst.de>
> 
> Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by
> default, which probably isn't a good idea - ARM pre-dates the dma_length
> parameter in scatterlists, and I don't think all code is guaranteed to
> do the right thing if this is enabled.

We shouldn't end up with NEED_SG_DMA_LENGTH=y on ARM by default.
It is only select by ARM_DMA_USE_IOMMU before the patch, and it will
now also be selected by SWIOTLB, which for arm is never used or seleted
directly by anything but xen-swiotlb.

Then again looking at the series there shouldn't be any need to
even select NEED_SG_DMA_LENGTH for swiotlb, as we'll never merge segments,
so I'll fix that up.
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Russell King (Oracle) April 24, 2018, 7:47 a.m. UTC | #4
On Tue, Apr 24, 2018 at 08:55:49AM +0200, Christoph Hellwig wrote:
> On Tue, Apr 24, 2018 at 12:52:05AM +0100, Russell King - ARM Linux wrote:
> > On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> > > This way we have one central definition of it, and user can select it as
> > > needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> > > indicate the architecture supports swiotlb at all, so that we can still
> > > make the usage optional for a few architectures that want this feature
> > > to be user selectable.
> > > 
> > > Signed-off-by: Christoph Hellwig <hch@lst.de>
> > 
> > Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by
> > default, which probably isn't a good idea - ARM pre-dates the dma_length
> > parameter in scatterlists, and I don't think all code is guaranteed to
> > do the right thing if this is enabled.
> 
> We shouldn't end up with NEED_SG_DMA_LENGTH=y on ARM by default.

Your patch as sent would end up with:

ARM selects ARCH_HAS_SWIOTLB
SWIOTLB is defaulted to ARCH_HAS_SWIOTLB
SWIOTLB selects NEED_SG_DMA_LENGTH

due to:

@@ -106,6 +106,7 @@ config ARM
        select REFCOUNT_FULL
        select RTC_LIB
        select SYS_SUPPORTS_APM_EMULATION
+       select ARCH_HAS_SWIOTLB

and:

+config SWIOTLB
+       bool "SWIOTLB support"
+       default ARCH_HAS_SWIOTLB
+       select NEED_SG_DMA_LENGTH

Therefore, the default state for SWIOTLB and hence NEED_SG_DMA_LENGTH
becomes 'y' on ARM, and any defconfig file that does not mention SWIOTLB
explicitly ends up with both these enabled.

> It is only select by ARM_DMA_USE_IOMMU before the patch, and it will
> now also be selected by SWIOTLB, which for arm is never used or seleted
> directly by anything but xen-swiotlb.

See above.

> Then again looking at the series there shouldn't be any need to
> even select NEED_SG_DMA_LENGTH for swiotlb, as we'll never merge segments,
> so I'll fix that up.

That would help to avoid any regressions along the lines I've spotted
by review.

It does look a bit weird though - patch 10 arranged stuff so that we
didn't end up with SWIOTLB always enabled, but this patch reintroduces
that with the allowance that the user can disable if so desired.
Christoph Hellwig April 24, 2018, 7:56 a.m. UTC | #5
On Tue, Apr 24, 2018 at 08:47:27AM +0100, Russell King - ARM Linux wrote:
> Therefore, the default state for SWIOTLB and hence NEED_SG_DMA_LENGTH
> becomes 'y' on ARM, and any defconfig file that does not mention SWIOTLB
> explicitly ends up with both these enabled.

Indeed, sorry.

> It does look a bit weird though - patch 10 arranged stuff so that we
> didn't end up with SWIOTLB always enabled, but this patch reintroduces
> that with the allowance that the user can disable if so desired.

I am not very happy with that patch, but I have a hard time coming
up with something saner.

Bascially x86_64 and mips/loongson default to SWIOTLB=y but allow to
deselect it, powerpc has it optional without any real dependency
and defaults to n and everyone just selects it otherwise.

I suspect the right thing is to just have it always one for x86_64
and loongson and have a ppc-specific option to enable it on powerpc
so that we can always use select statements.  I'll do that for the
next round.
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diff mbox series

Patch

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 90b81a3a28a7..f91f69174630 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -106,6 +106,7 @@  config ARM
 	select REFCOUNT_FULL
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
+	select ARCH_HAS_SWIOTLB
 	# Above selects are sorted alphabetically; please add new ones
 	# according to that.  Thanks.
 	help
@@ -1773,9 +1774,6 @@  config SECCOMP
 	  and the task is only allowed to execute a few safe syscalls
 	  defined by each seccomp mode.
 
-config SWIOTLB
-	bool
-
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	help
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4d924eb32e7f..056bc7365adf 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -21,6 +21,7 @@  config ARM64
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_STRICT_MODULE_RWX
+	select ARCH_HAS_SWIOTLB
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK if !PREEMPT
@@ -144,6 +145,7 @@  config ARM64
 	select POWER_SUPPLY
 	select REFCOUNT_FULL
 	select SPARSE_IRQ
+	select SWIOTLB
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK
 	help
@@ -239,9 +241,6 @@  config HAVE_GENERIC_GUP
 config SMP
 	def_bool y
 
-config SWIOTLB
-	def_bool y
-
 config KERNEL_MODE_NEON
 	def_bool y
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 685d557eea48..d396230913e6 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -56,6 +56,7 @@  config IA64
 	select HAVE_ARCH_AUDITSYSCALL
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
+	select ARCH_HAS_SWIOTLB
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to
@@ -80,9 +81,6 @@  config MMU
 	bool
 	default y
 
-config SWIOTLB
-       bool
-
 config STACKTRACE_SUPPORT
 	def_bool y
 
@@ -139,7 +137,6 @@  config IA64_GENERIC
 	bool "generic"
 	select NUMA
 	select ACPI_NUMA
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	select PCI_MSI
 	help
@@ -160,7 +157,6 @@  config IA64_GENERIC
 
 config IA64_DIG
 	bool "DIG-compliant"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 
 config IA64_DIG_VTD
@@ -176,7 +172,6 @@  config IA64_HP_ZX1
 
 config IA64_HP_ZX1_SWIOTLB
 	bool "HP-zx1/sx1000 with software I/O TLB"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	help
 	  Build a kernel that runs on HP zx1 and sx1000 systems even when they
@@ -200,7 +195,6 @@  config IA64_SGI_UV
 	bool "SGI-UV"
 	select NUMA
 	select ACPI_NUMA
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	help
 	  Selecting this option will optimize the kernel for use on UV based
@@ -211,7 +205,6 @@  config IA64_SGI_UV
 
 config IA64_HP_SIM
 	bool "Ski-simulator"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	depends on !PM
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e10cc5c7be69..b6b4c1e154f8 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -912,6 +912,8 @@  config CAVIUM_OCTEON_SOC
 	select MIPS_NR_CPU_NR_MAP_1024
 	select BUILTIN_DTB
 	select MTD_COMPLEX_MAPPINGS
+	select ARCH_HAS_SWIOTLB
+	select SWIOTLB
 	select SYS_SUPPORTS_RELOCATABLE
 	help
 	  This option supports all of the Octeon reference boards from Cavium
@@ -1367,6 +1369,7 @@  config CPU_LOONGSON3
 	select MIPS_PGD_C0_CONTEXT
 	select MIPS_L1_CACHE_SHIFT_6
 	select GPIOLIB
+	select ARCH_HAS_SWIOTLB
 	help
 		The Loongson 3 processor implements the MIPS64R2 instruction
 		set with many extensions.
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 5d73041547a7..4984e462be30 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -67,11 +67,6 @@  config CAVIUM_OCTEON_LOCK_L2_MEMCPY
 	help
 	  Lock the kernel's implementation of memcpy() into L2.
 
-config SWIOTLB
-	def_bool y
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
-
 config OCTEON_ILM
 	tristate "Module to measure interrupt latency using Octeon CIU Timer"
 	help
diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
index 641a1477031e..c79e6a565572 100644
--- a/arch/mips/loongson64/Kconfig
+++ b/arch/mips/loongson64/Kconfig
@@ -130,14 +130,6 @@  config LOONGSON_UART_BASE
 	default y
 	depends on EARLY_PRINTK || SERIAL_8250
 
-config SWIOTLB
-	bool "Soft IOMMU Support for All-Memory DMA"
-	default y
-	depends on CPU_LOONGSON3
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
-	select NEED_DMA_MAP_STATE
-
 config PHYS48_TO_HT40
 	bool
 	default y if CPU_LOONGSON3
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a4b2ac7c3d2e..1887f8f86a77 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -474,15 +474,6 @@  config MPROFILE_KERNEL
 	depends on PPC64 && CPU_LITTLE_ENDIAN
 	def_bool !DISABLE_MPROFILE_KERNEL
 
-config SWIOTLB
-	bool "SWIOTLB support"
-	default n
-	---help---
-	  Support for IO bounce buffering for systems without an IOMMU.
-	  This allows us to DMA to the full physical address space on
-	  platforms where the size of a physical address is larger
-	  than the bus address.  Not all platforms support this.
-
 config HOTPLUG_CPU
 	bool "Support for enabling/disabling CPUs"
 	depends on SMP && (PPC_PSERIES || \
diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
index 1d9fed0ada71..82759b6aba67 100644
--- a/arch/unicore32/mm/Kconfig
+++ b/arch/unicore32/mm/Kconfig
@@ -39,8 +39,3 @@  config CPU_TLB_SINGLE_ENTRY_DISABLE
 	default y
 	help
 	  Say Y here to disable the TLB single entry operations.
-
-config SWIOTLB
-	def_bool y
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 07b031f99eb1..7a5fec800992 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -24,6 +24,7 @@  config X86_64
 	depends on 64BIT
 	# Options that are inherently 64-bit kernel only:
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
+	select ARCH_HAS_SWIOTLB
 	select ARCH_SUPPORTS_INT128
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_SOFT_DIRTY
@@ -677,6 +678,7 @@  config STA2X11
 	bool "STA2X11 Companion Chip Support"
 	depends on X86_32_NON_STANDARD && PCI
 	select ARCH_HAS_PHYS_TO_DMA
+	select ARCH_HAS_SWIOTLB
 	select X86_DEV_DMA_OPS
 	select X86_DMA_REMAP
 	select SWIOTLB
@@ -916,17 +918,6 @@  config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 	  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
@@ -1448,6 +1439,7 @@  config HIGHMEM
 config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && !HIGHMEM4G
+	select ARCH_HAS_SWIOTLB
 	select PHYS_ADDR_T_64BIT
 	select SWIOTLB
 	---help---
diff --git a/lib/Kconfig b/lib/Kconfig
index 1f12faf03819..01a37920949c 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -451,6 +451,21 @@  config DMA_VIRT_OPS
 	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
 	default n
 
+config ARCH_HAS_SWIOTLB
+	bool
+
+config SWIOTLB
+	bool "SWIOTLB support"
+	default ARCH_HAS_SWIOTLB
+	select DMA_DIRECT_OPS
+	select NEED_DMA_MAP_STATE
+	select NEED_SG_DMA_LENGTH
+	---help---
+	  Support for IO bounce buffering for systems without an IOMMU.
+	  This allows us to DMA to the full physical address space on
+	  platforms where the size of a physical address is larger
+	  than the bus address.  If unsure, say Y.
+
 config CHECK_SIGNATURE
 	bool