2022-08-16 17:32:11

by Robin Murphy

Subject: [PATCH 1/3] iommu/dma: Clean up Kconfig

Although iommu-dma is a per-architecture chonce, that is currently
implemented in a rather haphazard way. Selecting from the arch Kconfig
was the original logical approach, but is complicated by having to
manage dependencies; conversely, selecting from drivers ends up hiding
the architecture dependency *too* well. Instead, let's just have it
enable itself automatically when IOMMU API support is enabled for the
relevant architectures. It can't get much clearer than that.

Signed-off-by: Robin Murphy <[email protected]>
---
arch/arm64/Kconfig | 1 -
drivers/iommu/Kconfig | 3 +--
drivers/iommu/amd/Kconfig | 1 -
drivers/iommu/intel/Kconfig | 1 -
4 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 571cc234d0b3..59af600445c2 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -209,7 +209,6 @@ config ARM64
select HAVE_KPROBES
select HAVE_KRETPROBES
select HAVE_GENERIC_VDSO
- select IOMMU_DMA if IOMMU_SUPPORT
select IRQ_DOMAIN
select IRQ_FORCED_THREADING
select KASAN_VMALLOC if KASAN
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 5c5cb5bee8b6..1d99c2d984fb 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -137,7 +137,7 @@ config OF_IOMMU

# IOMMU-agnostic DMA-mapping layer
config IOMMU_DMA
- bool
+ def_bool ARM64 || IA64 || X86
select DMA_OPS
select IOMMU_API
select IOMMU_IOVA
@@ -476,7 +476,6 @@ config VIRTIO_IOMMU
depends on VIRTIO
depends on (ARM64 || X86)
select IOMMU_API
- select IOMMU_DMA
select INTERVAL_TREE
select ACPI_VIOT if ACPI
help
diff --git a/drivers/iommu/amd/Kconfig b/drivers/iommu/amd/Kconfig
index a3cbafb603f5..9b5fc3356bf2 100644
--- a/drivers/iommu/amd/Kconfig
+++ b/drivers/iommu/amd/Kconfig
@@ -9,7 +9,6 @@ config AMD_IOMMU
select PCI_PASID
select IOMMU_API
select IOMMU_IOVA
- select IOMMU_DMA
select IOMMU_IO_PGTABLE
depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE
help
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index 39a06d245f12..c48005147ac5 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -19,7 +19,6 @@ config INTEL_IOMMU
select DMAR_TABLE
select SWIOTLB
select IOASID
- select IOMMU_DMA
select PCI_ATS
help
DMA remapping (DMAR) devices support enables independent address
--
2.36.1.dirty

2022-09-02 18:24:31

by Catalin Marinas

Subject: Re: [PATCH 1/3] iommu/dma: Clean up Kconfig

On Tue, Aug 16, 2022 at 06:28:03PM +0100, Robin Murphy wrote:
> Although iommu-dma is a per-architecture chonce, that is currently
> implemented in a rather haphazard way. Selecting from the arch Kconfig
> was the original logical approach, but is complicated by having to
> manage dependencies; conversely, selecting from drivers ends up hiding
> the architecture dependency *too* well. Instead, let's just have it
> enable itself automatically when IOMMU API support is enabled for the
> relevant architectures. It can't get much clearer than that.
>
> Signed-off-by: Robin Murphy <[email protected]>
> ---
> arch/arm64/Kconfig | 1 -

For this change:

Acked-by: Catalin Marinas <[email protected]>

2023-05-05 14:58:04

by Robin Murphy

Subject: Re: [PATCH 1/3] iommu/dma: Clean up Kconfig

On 2023-05-05 15:50, Jason Gunthorpe wrote:
> On Tue, Aug 16, 2022 at 06:28:03PM +0100, Robin Murphy wrote:
>> Although iommu-dma is a per-architecture chonce, that is currently
>> implemented in a rather haphazard way. Selecting from the arch Kconfig
>> was the original logical approach, but is complicated by having to
>> manage dependencies; conversely, selecting from drivers ends up hiding
>> the architecture dependency *too* well. Instead, let's just have it
>> enable itself automatically when IOMMU API support is enabled for the
>> relevant architectures. It can't get much clearer than that.
>>
>> Signed-off-by: Robin Murphy <[email protected]>
>> ---
>> arch/arm64/Kconfig | 1 -
>> drivers/iommu/Kconfig | 3 +--
>> drivers/iommu/amd/Kconfig | 1 -
>> drivers/iommu/intel/Kconfig | 1 -
>> 4 files changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>> index 571cc234d0b3..59af600445c2 100644
>> --- a/arch/arm64/Kconfig
>> +++ b/arch/arm64/Kconfig
>> @@ -209,7 +209,6 @@ config ARM64
>> select HAVE_KPROBES
>> select HAVE_KRETPROBES
>> select HAVE_GENERIC_VDSO
>> - select IOMMU_DMA if IOMMU_SUPPORT
>> select IRQ_DOMAIN
>> select IRQ_FORCED_THREADING
>> select KASAN_VMALLOC if KASAN
>> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
>> index 5c5cb5bee8b6..1d99c2d984fb 100644
>> --- a/drivers/iommu/Kconfig
>> +++ b/drivers/iommu/Kconfig
>> @@ -137,7 +137,7 @@ config OF_IOMMU
>>
>> # IOMMU-agnostic DMA-mapping layer
>> config IOMMU_DMA
>> - bool
>> + def_bool ARM64 || IA64 || X86
>
> Robin, do you remember why you added IA64 here? What is the Itanimum
> IOMMU driver?

config INTEL_IOMMU
bool "Support for Intel IOMMU using DMA Remapping Devices"
depends on PCI_MSI && ACPI && (X86 || IA64)

Yes, really :)

Robin.

2023-05-05 15:01:24

by Jason Gunthorpe

Subject: Re: [PATCH 1/3] iommu/dma: Clean up Kconfig

On Tue, Aug 16, 2022 at 06:28:03PM +0100, Robin Murphy wrote:
> Although iommu-dma is a per-architecture chonce, that is currently
> implemented in a rather haphazard way. Selecting from the arch Kconfig
> was the original logical approach, but is complicated by having to
> manage dependencies; conversely, selecting from drivers ends up hiding
> the architecture dependency *too* well. Instead, let's just have it
> enable itself automatically when IOMMU API support is enabled for the
> relevant architectures. It can't get much clearer than that.
>
> Signed-off-by: Robin Murphy <[email protected]>
> ---
> arch/arm64/Kconfig | 1 -
> drivers/iommu/Kconfig | 3 +--
> drivers/iommu/amd/Kconfig | 1 -
> drivers/iommu/intel/Kconfig | 1 -
> 4 files changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 571cc234d0b3..59af600445c2 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -209,7 +209,6 @@ config ARM64
> select HAVE_KPROBES
> select HAVE_KRETPROBES
> select HAVE_GENERIC_VDSO
> - select IOMMU_DMA if IOMMU_SUPPORT
> select IRQ_DOMAIN
> select IRQ_FORCED_THREADING
> select KASAN_VMALLOC if KASAN
> diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> index 5c5cb5bee8b6..1d99c2d984fb 100644
> --- a/drivers/iommu/Kconfig
> +++ b/drivers/iommu/Kconfig
> @@ -137,7 +137,7 @@ config OF_IOMMU
>
> # IOMMU-agnostic DMA-mapping layer
> config IOMMU_DMA
> - bool
> + def_bool ARM64 || IA64 || X86

Robin, do you remember why you added IA64 here? What is the Itanimum
IOMMU driver?

Thanks,
Jason

2023-05-05 19:39:14

by Jason Gunthorpe

Subject: Re: [PATCH 1/3] iommu/dma: Clean up Kconfig

On Fri, May 05, 2023 at 03:53:54PM +0100, Robin Murphy wrote:
> > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
> > > index 5c5cb5bee8b6..1d99c2d984fb 100644
> > > --- a/drivers/iommu/Kconfig
> > > +++ b/drivers/iommu/Kconfig
> > > @@ -137,7 +137,7 @@ config OF_IOMMU
> > > # IOMMU-agnostic DMA-mapping layer
> > > config IOMMU_DMA
> > > - bool
> > > + def_bool ARM64 || IA64 || X86
> >
> > Robin, do you remember why you added IA64 here? What is the Itanimum
> > IOMMU driver?
>
> config INTEL_IOMMU
> bool "Support for Intel IOMMU using DMA Remapping Devices"
> depends on PCI_MSI && ACPI && (X86 || IA64)
>
> Yes, really :)

Wowo, thanks!

Jason