[PATCH 0/3] iommu/dma: Some housekeeping

[PATCH 0/3] iommu/dma: Some housekeeping

[Robin Murphy]

Hi All,

It's been a while now since iommu-dma grew from a library of DMA ops
helpers for arch code into something more abstracted and closely coupled
to the IOMMU API core, so it seemed about time to do some housekeeping
in the more neglected areas to reflect that.

The header reorganisation does touch a range of areas (a couple of which
seemingly had no reason to be involved anyway), but hopefully these are
all low-impact changes that nobody minds going through the IOMMU tree.

Now for the build-bots to tell me what I've missed...

Thanks,
Robin.


Robin Murphy (3):
  iommu/dma: Clean up Kconfig
  iommu/dma: Move public interfaces to linux/iommu.h
  iommu/dma: Make header private

 arch/arm64/Kconfig                          |  1 -
 arch/arm64/mm/dma-mapping.c                 |  2 +-
 drivers/acpi/viot.c                         |  1 -
 drivers/gpu/drm/exynos/exynos_drm_dma.c     |  1 -
 drivers/iommu/Kconfig                       |  3 +-
 drivers/iommu/amd/Kconfig                   |  1 -
 drivers/iommu/amd/iommu.c                   |  2 +-
 drivers/iommu/apple-dart.c                  |  3 +-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  2 +-
 drivers/iommu/arm/arm-smmu/arm-smmu.c       |  2 +-
 drivers/iommu/dma-iommu.c                   | 18 +++-
 drivers/iommu/dma-iommu.h                   | 38 +++++++++
 drivers/iommu/intel/Kconfig                 |  1 -
 drivers/iommu/intel/iommu.c                 |  2 +-
 drivers/iommu/iommu.c                       |  3 +-
 drivers/iommu/virtio-iommu.c                |  3 +-
 drivers/irqchip/irq-gic-v2m.c               |  2 +-
 drivers/irqchip/irq-gic-v3-its.c            |  2 +-
 drivers/irqchip/irq-gic-v3-mbi.c            |  2 +-
 drivers/irqchip/irq-ls-scfg-msi.c           |  2 +-
 drivers/vfio/vfio_iommu_type1.c             |  1 -
 include/linux/dma-iommu.h                   | 93 ---------------------
 include/linux/iommu.h                       | 36 ++++++++
 23 files changed, 105 insertions(+), 116 deletions(-)
 create mode 100644 drivers/iommu/dma-iommu.h
 delete mode 100644 include/linux/dma-iommu.h

-- 
2.36.1.dirty

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

[Robin Murphy]

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 <robin.murphy@arm.com>
---
 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

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

[Catalin Marinas]

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 <robin.murphy@arm.com>
> ---
>  arch/arm64/Kconfig          | 1 -

For this change:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

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

[Jason Gunthorpe]

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 <robin.murphy@arm.com>
> ---
>  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

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

[Robin Murphy]

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 <robin.murphy@arm.com>
>> ---
>>   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.

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

[Jason Gunthorpe]

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

[PATCH 2/3] iommu/dma: Move public interfaces to linux/iommu.h

[Robin Murphy]

The iommu-dma layer is now mostly encapsulated by iommu_dma_ops, with
only a couple more public interfaces left pertaining to MSI integration.
Since these depend on the main IOMMU API header anyway, move their
declarations there, taking the opportunity to update the half-baked
comments to proper kerneldoc along the way.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---

Note that iommu_setup_dma_ops() should also become internal in a future
phase of the great IOMMU API upheaval - for now as the last bit of true
arch code glue I consider it more "necessarily exposed" than "public".

 arch/arm64/mm/dma-mapping.c       |  2 +-
 drivers/iommu/dma-iommu.c         | 15 ++++++++++--
 drivers/irqchip/irq-gic-v2m.c     |  2 +-
 drivers/irqchip/irq-gic-v3-its.c  |  2 +-
 drivers/irqchip/irq-gic-v3-mbi.c  |  2 +-
 drivers/irqchip/irq-ls-scfg-msi.c |  2 +-
 drivers/vfio/vfio_iommu_type1.c   |  1 -
 include/linux/dma-iommu.h         | 40 -------------------------------
 include/linux/iommu.h             | 36 ++++++++++++++++++++++++++++
 9 files changed, 54 insertions(+), 48 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 599cf81f5685..7d7e9a046305 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -7,7 +7,7 @@
 #include <linux/gfp.h>
 #include <linux/cache.h>
 #include <linux/dma-map-ops.h>
-#include <linux/dma-iommu.h>
+#include <linux/iommu.h>
 #include <xen/xen.h>
 
 #include <asm/cacheflush.h>
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 17dd683b2fce..6809b33ac9df 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1633,6 +1633,13 @@ static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
 	return NULL;
 }
 
+/**
+ * iommu_dma_prepare_msi() - Map the MSI page in the IOMMU domain
+ * @desc: MSI descriptor, will store the MSI page
+ * @msi_addr: MSI target address to be mapped
+ *
+ * Return: 0 on success or negative error code if the mapping failed.
+ */
 int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
 {
 	struct device *dev = msi_desc_to_dev(desc);
@@ -1661,8 +1668,12 @@ int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
 	return 0;
 }
 
-void iommu_dma_compose_msi_msg(struct msi_desc *desc,
-			       struct msi_msg *msg)
+/**
+ * iommu_dma_compose_msi_msg() - Apply translation to an MSI message
+ * @desc: MSI descriptor prepared by iommu_dma_prepare_msi()
+ * @msg: MSI message containing target physical address
+ */
+void iommu_dma_compose_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
 {
 	struct device *dev = msi_desc_to_dev(desc);
 	const struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c
index b249d4df899e..6e1ac330d7a6 100644
--- a/drivers/irqchip/irq-gic-v2m.c
+++ b/drivers/irqchip/irq-gic-v2m.c
@@ -13,7 +13,7 @@
 #define pr_fmt(fmt) "GICv2m: " fmt
 
 #include <linux/acpi.h>
-#include <linux/dma-iommu.h>
+#include <linux/iommu.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 5ff09de6c48f..e7d8d4208ee6 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -11,9 +11,9 @@
 #include <linux/cpu.h>
 #include <linux/crash_dump.h>
 #include <linux/delay.h>
-#include <linux/dma-iommu.h>
 #include <linux/efi.h>
 #include <linux/interrupt.h>
+#include <linux/iommu.h>
 #include <linux/iopoll.h>
 #include <linux/irqdomain.h>
 #include <linux/list.h>
diff --git a/drivers/irqchip/irq-gic-v3-mbi.c b/drivers/irqchip/irq-gic-v3-mbi.c
index a2163d32f17d..e1efdec9e9ac 100644
--- a/drivers/irqchip/irq-gic-v3-mbi.c
+++ b/drivers/irqchip/irq-gic-v3-mbi.c
@@ -6,7 +6,7 @@
 
 #define pr_fmt(fmt) "GICv3: " fmt
 
-#include <linux/dma-iommu.h>
+#include <linux/iommu.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
 #include <linux/kernel.h>
diff --git a/drivers/irqchip/irq-ls-scfg-msi.c b/drivers/irqchip/irq-ls-scfg-msi.c
index b4927e425f7b..527c90e0920e 100644
--- a/drivers/irqchip/irq-ls-scfg-msi.c
+++ b/drivers/irqchip/irq-ls-scfg-msi.c
@@ -11,6 +11,7 @@
 #include <linux/module.h>
 #include <linux/msi.h>
 #include <linux/interrupt.h>
+#include <linux/iommu.h>
 #include <linux/irq.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
@@ -18,7 +19,6 @@
 #include <linux/of_pci.h>
 #include <linux/of_platform.h>
 #include <linux/spinlock.h>
-#include <linux/dma-iommu.h>
 
 #define MSI_IRQS_PER_MSIR	32
 #define MSI_MSIR_OFFSET		4
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index c766aa683110..e65861fdba7b 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -37,7 +37,6 @@
 #include <linux/vfio.h>
 #include <linux/workqueue.h>
 #include <linux/notifier.h>
-#include <linux/dma-iommu.h>
 #include <linux/irqdomain.h>
 #include "vfio.h"
 
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 24607dc3c2ac..e83de4f1f3d6 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -15,27 +15,10 @@
 
 /* Domain management interface for IOMMU drivers */
 int iommu_get_dma_cookie(struct iommu_domain *domain);
-int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
 
-/* Setup call for arch DMA mapping code */
-void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit);
 int iommu_dma_init_fq(struct iommu_domain *domain);
 
-/* The DMA API isn't _quite_ the whole story, though... */
-/*
- * iommu_dma_prepare_msi() - Map the MSI page in the IOMMU device
- *
- * The MSI page will be stored in @desc.
- *
- * Return: 0 on success otherwise an error describing the failure.
- */
-int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr);
-
-/* Update the MSI message if required. */
-void iommu_dma_compose_msi_msg(struct msi_desc *desc,
-			       struct msi_msg *msg);
-
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
 void iommu_dma_free_cpu_cached_iovas(unsigned int cpu,
@@ -46,15 +29,8 @@ extern bool iommu_dma_forcedac;
 #else /* CONFIG_IOMMU_DMA */
 
 struct iommu_domain;
-struct msi_desc;
-struct msi_msg;
 struct device;
 
-static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
-				       u64 dma_limit)
-{
-}
-
 static inline int iommu_dma_init_fq(struct iommu_domain *domain)
 {
 	return -EINVAL;
@@ -65,26 +41,10 @@ static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
 	return -ENODEV;
 }
 
-static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
-{
-	return -ENODEV;
-}
-
 static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
 }
 
-static inline int iommu_dma_prepare_msi(struct msi_desc *desc,
-					phys_addr_t msi_addr)
-{
-	return 0;
-}
-
-static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc,
-					     struct msi_msg *msg)
-{
-}
-
 static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
 }
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 70393fbb57ed..79cb6eb560a8 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1059,4 +1059,40 @@ void iommu_debugfs_setup(void);
 static inline void iommu_debugfs_setup(void) {}
 #endif
 
+#ifdef CONFIG_IOMMU_DMA
+#include <linux/msi.h>
+
+/* Setup call for arch DMA mapping code */
+void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit);
+
+int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
+
+int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr);
+void iommu_dma_compose_msi_msg(struct msi_desc *desc, struct msi_msg *msg);
+
+#else /* CONFIG_IOMMU_DMA */
+
+struct msi_desc;
+struct msi_msg;
+
+static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 dma_limit)
+{
+}
+
+static inline int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
+{
+	return -ENODEV;
+}
+
+static inline int iommu_dma_prepare_msi(struct msi_desc *desc, phys_addr_t msi_addr)
+{
+	return 0;
+}
+
+static inline void iommu_dma_compose_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+}
+
+#endif	/* CONFIG_IOMMU_DMA */
+
 #endif /* __LINUX_IOMMU_H */
-- 
2.36.1.dirty

Re: [PATCH 2/3] iommu/dma: Move public interfaces to linux/iommu.h

[Marc Zyngier]

On Tue, 16 Aug 2022 18:28:04 +0100,
Robin Murphy <robin.murphy@arm.com> wrote:
> 
> The iommu-dma layer is now mostly encapsulated by iommu_dma_ops, with
> only a couple more public interfaces left pertaining to MSI integration.
> Since these depend on the main IOMMU API header anyway, move their
> declarations there, taking the opportunity to update the half-baked
> comments to proper kerneldoc along the way.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> 
> Note that iommu_setup_dma_ops() should also become internal in a future
> phase of the great IOMMU API upheaval - for now as the last bit of true
> arch code glue I consider it more "necessarily exposed" than "public".
> 
>  arch/arm64/mm/dma-mapping.c       |  2 +-
>  drivers/iommu/dma-iommu.c         | 15 ++++++++++--
>  drivers/irqchip/irq-gic-v2m.c     |  2 +-
>  drivers/irqchip/irq-gic-v3-its.c  |  2 +-
>  drivers/irqchip/irq-gic-v3-mbi.c  |  2 +-
>  drivers/irqchip/irq-ls-scfg-msi.c |  2 +-
>  drivers/vfio/vfio_iommu_type1.c   |  1 -
>  include/linux/dma-iommu.h         | 40 -------------------------------
>  include/linux/iommu.h             | 36 ++++++++++++++++++++++++++++
>  9 files changed, 54 insertions(+), 48 deletions(-)

For the irqchip side:

Acked-by: Marc Zyngier <maz@kernel.org>

	M.

-- 
Without deviation from the norm, progress is not possible.

Re: [PATCH 2/3] iommu/dma: Move public interfaces to linux/iommu.h

[Christoph Hellwig]

> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 70393fbb57ed..79cb6eb560a8 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -1059,4 +1059,40 @@ void iommu_debugfs_setup(void);
>  static inline void iommu_debugfs_setup(void) {}
>  #endif
>  
> +#ifdef CONFIG_IOMMU_DMA
> +#include <linux/msi.h>

I don't think msi.h is actually needed here.

Just make the struct msi_desc and struct msi_msg forward declarations
unconditional and we should be fine.

Re: [PATCH 2/3] iommu/dma: Move public interfaces to linux/iommu.h

[Robin Murphy]

On 2022-08-22 12:21, Christoph Hellwig wrote:
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 70393fbb57ed..79cb6eb560a8 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -1059,4 +1059,40 @@ void iommu_debugfs_setup(void);
>>   static inline void iommu_debugfs_setup(void) {}
>>   #endif
>>   
>> +#ifdef CONFIG_IOMMU_DMA
>> +#include <linux/msi.h>
> 
> I don't think msi.h is actually needed here.
> 
> Just make the struct msi_desc and struct msi_msg forward declarations
> unconditional and we should be fine.

dma-iommu.c still needs to pick up msi.h for the actual definitions 
somehow, so it seemed logical to keep things the same shape as before. 
However I don't have a particularly strong preference either way.

Thanks,
Robin.

Re: [PATCH 2/3] iommu/dma: Move public interfaces to linux/iommu.h

[Catalin Marinas]

On Tue, Aug 16, 2022 at 06:28:04PM +0100, Robin Murphy wrote:
> The iommu-dma layer is now mostly encapsulated by iommu_dma_ops, with
> only a couple more public interfaces left pertaining to MSI integration.
> Since these depend on the main IOMMU API header anyway, move their
> declarations there, taking the opportunity to update the half-baked
> comments to proper kerneldoc along the way.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> 
> Note that iommu_setup_dma_ops() should also become internal in a future
> phase of the great IOMMU API upheaval - for now as the last bit of true
> arch code glue I consider it more "necessarily exposed" than "public".
> 
>  arch/arm64/mm/dma-mapping.c       |  2 +-

And here:

Acked-by: Catalin Marinas <catalin.marinas@arm.com>

[PATCH 3/3] iommu/dma: Make header private

[Robin Murphy]

Now that dma-iommu.h only contains internal interfaces, make it
private to the IOMMU subsytem.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/acpi/viot.c                          |  1 -
 drivers/gpu/drm/exynos/exynos_drm_dma.c      |  1 -
 drivers/iommu/amd/iommu.c                    |  2 +-
 drivers/iommu/apple-dart.c                   |  3 ++-
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c  |  2 +-
 drivers/iommu/arm/arm-smmu/arm-smmu.c        |  2 +-
 drivers/iommu/dma-iommu.c                    |  3 ++-
 {include/linux => drivers/iommu}/dma-iommu.h | 17 +----------------
 drivers/iommu/intel/iommu.c                  |  2 +-
 drivers/iommu/iommu.c                        |  3 ++-
 drivers/iommu/virtio-iommu.c                 |  3 ++-
 11 files changed, 13 insertions(+), 26 deletions(-)
 rename {include/linux => drivers/iommu}/dma-iommu.h (67%)

diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
index 6132092dab2a..ed752cbbe636 100644
--- a/drivers/acpi/viot.c
+++ b/drivers/acpi/viot.c
@@ -19,7 +19,6 @@
 #define pr_fmt(fmt) "ACPI: VIOT: " fmt
 
 #include <linux/acpi_viot.h>
-#include <linux/dma-iommu.h>
 #include <linux/fwnode.h>
 #include <linux/iommu.h>
 #include <linux/list.h>
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c
index d819ee69dfb7..7012aa8ed4c6 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dma.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c
@@ -4,7 +4,6 @@
 // Author: Inki Dae <inki.dae@samsung.com>
 // Author: Andrzej Hajda <a.hajda@samsung.com>
 
-#include <linux/dma-iommu.h>
 #include <linux/dma-map-ops.h>
 #include <linux/iommu.h>
 #include <linux/platform_device.h>
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 2df1bfa884e5..b339bf13259d 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -18,7 +18,6 @@
 #include <linux/scatterlist.h>
 #include <linux/dma-map-ops.h>
 #include <linux/dma-direct.h>
-#include <linux/dma-iommu.h>
 #include <linux/iommu-helper.h>
 #include <linux/delay.h>
 #include <linux/amd-iommu.h>
@@ -40,6 +39,7 @@
 #include <asm/dma.h>
 
 #include "amd_iommu.h"
+#include "../dma-iommu.h"
 #include "../irq_remapping.h"
 
 #define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28))
diff --git a/drivers/iommu/apple-dart.c b/drivers/iommu/apple-dart.c
index ed6b5fa538af..716f34a768b1 100644
--- a/drivers/iommu/apple-dart.c
+++ b/drivers/iommu/apple-dart.c
@@ -15,7 +15,6 @@
 #include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/dev_printk.h>
-#include <linux/dma-iommu.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -33,6 +32,8 @@
 #include <linux/swab.h>
 #include <linux/types.h>
 
+#include "dma-iommu.h"
+
 #define DART_MAX_STREAMS 16
 #define DART_MAX_TTBR 4
 #define MAX_DARTS_PER_DEVICE 2
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index c13b46a15dcb..f1785e518a90 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -14,7 +14,6 @@
 #include <linux/bitops.h>
 #include <linux/crash_dump.h>
 #include <linux/delay.h>
-#include <linux/dma-iommu.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
 #include <linux/io-pgtable.h>
@@ -29,6 +28,7 @@
 #include <linux/platform_device.h>
 
 #include "arm-smmu-v3.h"
+#include "../../dma-iommu.h"
 #include "../../iommu-sva-lib.h"
 
 static bool disable_bypass = true;
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 2cece34f4824..c30f82c19240 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -21,7 +21,6 @@
 #include <linux/acpi_iort.h>
 #include <linux/bitfield.h>
 #include <linux/delay.h>
-#include <linux/dma-iommu.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
 #include <linux/interrupt.h>
@@ -40,6 +39,7 @@
 #include <linux/fsl/mc.h>
 
 #include "arm-smmu.h"
+#include "../../dma-iommu.h"
 
 /*
  * Apparently, some Qualcomm arm64 platforms which appear to expose their SMMU
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 6809b33ac9df..9297b741f5e8 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -13,7 +13,6 @@
 #include <linux/crash_dump.h>
 #include <linux/device.h>
 #include <linux/dma-direct.h>
-#include <linux/dma-iommu.h>
 #include <linux/dma-map-ops.h>
 #include <linux/gfp.h>
 #include <linux/huge_mm.h>
@@ -30,6 +29,8 @@
 #include <linux/swiotlb.h>
 #include <linux/vmalloc.h>
 
+#include "dma-iommu.h"
+
 struct iommu_dma_msi_page {
 	struct list_head	list;
 	dma_addr_t		iova;
diff --git a/include/linux/dma-iommu.h b/drivers/iommu/dma-iommu.h
similarity index 67%
rename from include/linux/dma-iommu.h
rename to drivers/iommu/dma-iommu.h
index e83de4f1f3d6..c6d0235feb6e 100644
--- a/include/linux/dma-iommu.h
+++ b/drivers/iommu/dma-iommu.h
@@ -5,15 +5,10 @@
 #ifndef __DMA_IOMMU_H
 #define __DMA_IOMMU_H
 
-#include <linux/errno.h>
-#include <linux/types.h>
+#include <linux/iommu.h>
 
 #ifdef CONFIG_IOMMU_DMA
-#include <linux/dma-mapping.h>
-#include <linux/iommu.h>
-#include <linux/msi.h>
 
-/* Domain management interface for IOMMU drivers */
 int iommu_get_dma_cookie(struct iommu_domain *domain);
 void iommu_put_dma_cookie(struct iommu_domain *domain);
 
@@ -21,16 +16,10 @@ int iommu_dma_init_fq(struct iommu_domain *domain);
 
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
-void iommu_dma_free_cpu_cached_iovas(unsigned int cpu,
-		struct iommu_domain *domain);
-
 extern bool iommu_dma_forcedac;
 
 #else /* CONFIG_IOMMU_DMA */
 
-struct iommu_domain;
-struct device;
-
 static inline int iommu_dma_init_fq(struct iommu_domain *domain)
 {
 	return -EINVAL;
@@ -45,9 +34,5 @@ static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
 {
 }
 
-static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
-{
-}
-
 #endif	/* CONFIG_IOMMU_DMA */
 #endif	/* __DMA_IOMMU_H */
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 9441c070c811..4375d1ee9389 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -15,7 +15,6 @@
 
 #include <linux/crash_dump.h>
 #include <linux/dma-direct.h>
-#include <linux/dma-iommu.h>
 #include <linux/dmi.h>
 #include <linux/intel-svm.h>
 #include <linux/memory.h>
@@ -26,6 +25,7 @@
 #include <linux/tboot.h>
 
 #include "iommu.h"
+#include "../dma-iommu.h"
 #include "../irq_remapping.h"
 #include "../iommu-sva-lib.h"
 #include "pasid.h"
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 07eda7c41aee..862d4e73efd2 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -8,7 +8,6 @@
 
 #include <linux/amba/bus.h>
 #include <linux/device.h>
-#include <linux/dma-iommu.h>
 #include <linux/kernel.h>
 #include <linux/bits.h>
 #include <linux/bug.h>
@@ -30,6 +29,8 @@
 #include <linux/cc_platform.h>
 #include <trace/events/iommu.h>
 
+#include "dma-iommu.h"
+
 static struct kset *iommu_group_kset;
 static DEFINE_IDA(iommu_group_ida);
 
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index bdae3939260a..e355cb5d1e5b 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -8,7 +8,6 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/delay.h>
-#include <linux/dma-iommu.h>
 #include <linux/dma-map-ops.h>
 #include <linux/freezer.h>
 #include <linux/interval_tree.h>
@@ -23,6 +22,8 @@
 
 #include <uapi/linux/virtio_iommu.h>
 
+#include "dma-iommu.h"
+
 #define MSI_IOVA_BASE			0x8000000
 #define MSI_IOVA_LENGTH			0x100000
 
-- 
2.36.1.dirty

Re: [PATCH 0/3] iommu/dma: Some housekeeping

[Joerg Roedel]

On Tue, Aug 16, 2022 at 06:28:02PM +0100, Robin Murphy wrote:
> Robin Murphy (3):
>   iommu/dma: Clean up Kconfig
>   iommu/dma: Move public interfaces to linux/iommu.h
>   iommu/dma: Make header private

Applied, thanks.

>  include/linux/dma-iommu.h                   | 93 ---------------------

Squashed the updated file path in MAINTAINERS into the last patch.