[v4,2/6] ACPI: Move IOMMU setup code out of IORT

Message ID 20210610075130.67517-3-jean-philippe@linaro.org
State Superseded
Headers show
Series
  • Add support for ACPI VIOT
Related show

Commit Message

Jean-Philippe Brucker June 10, 2021, 7:51 a.m.
Extract the code that sets up the IOMMU infrastructure from IORT, since
it can be reused by VIOT. Move it one level up into a new
acpi_iommu_configure_id() function, which calls the IORT parsing
function which in turn calls the acpi_iommu_fwspec_init() helper.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

---
 include/acpi/acpi_bus.h   |  3 ++
 include/linux/acpi_iort.h |  8 ++---
 drivers/acpi/arm64/iort.c | 75 +++++----------------------------------
 drivers/acpi/scan.c       | 73 ++++++++++++++++++++++++++++++++++++-
 4 files changed, 87 insertions(+), 72 deletions(-)

-- 
2.31.1

Comments

Eric Auger June 16, 2021, 9:35 a.m. | #1
Hi jean,
On 6/10/21 9:51 AM, Jean-Philippe Brucker wrote:
> Extract the code that sets up the IOMMU infrastructure from IORT, since

> it can be reused by VIOT. Move it one level up into a new

> acpi_iommu_configure_id() function, which calls the IORT parsing

> function which in turn calls the acpi_iommu_fwspec_init() helper.

>

> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

> ---

>  include/acpi/acpi_bus.h   |  3 ++

>  include/linux/acpi_iort.h |  8 ++---

>  drivers/acpi/arm64/iort.c | 75 +++++----------------------------------

>  drivers/acpi/scan.c       | 73 ++++++++++++++++++++++++++++++++++++-

>  4 files changed, 87 insertions(+), 72 deletions(-)

>

> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h

> index 3a82faac5767..41f092a269f6 100644

> --- a/include/acpi/acpi_bus.h

> +++ b/include/acpi/acpi_bus.h

> @@ -588,6 +588,9 @@ struct acpi_pci_root {

>  

>  bool acpi_dma_supported(struct acpi_device *adev);

>  enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);

> +int acpi_iommu_fwspec_init(struct device *dev, u32 id,

> +			   struct fwnode_handle *fwnode,

> +			   const struct iommu_ops *ops);

>  int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,

>  		       u64 *size);

>  int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,

> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h

> index f7f054833afd..f1f0842a2cb2 100644

> --- a/include/linux/acpi_iort.h

> +++ b/include/linux/acpi_iort.h

> @@ -35,8 +35,7 @@ void acpi_configure_pmsi_domain(struct device *dev);

>  int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);

>  /* IOMMU interface */

>  int iort_dma_get_ranges(struct device *dev, u64 *size);

> -const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

> -						const u32 *id_in);

> +int iort_iommu_configure_id(struct device *dev, const u32 *id_in);

>  int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);

>  phys_addr_t acpi_iort_dma_get_max_cpu_address(void);

>  #else

> @@ -50,9 +49,8 @@ static inline void acpi_configure_pmsi_domain(struct device *dev) { }

>  /* IOMMU interface */

>  static inline int iort_dma_get_ranges(struct device *dev, u64 *size)

>  { return -ENODEV; }

> -static inline const struct iommu_ops *iort_iommu_configure_id(

> -				      struct device *dev, const u32 *id_in)

> -{ return NULL; }

> +static inline int iort_iommu_configure_id(struct device *dev, const u32 *id_in)

> +{ return -ENODEV; }

>  static inline

>  int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)

>  { return 0; }

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c

> index a940be1cf2af..b5b021e064b6 100644

> --- a/drivers/acpi/arm64/iort.c

> +++ b/drivers/acpi/arm64/iort.c

> @@ -806,23 +806,6 @@ static struct acpi_iort_node *iort_get_msi_resv_iommu(struct device *dev)

>  	return NULL;

>  }

>  

> -static inline const struct iommu_ops *iort_fwspec_iommu_ops(struct device *dev)

> -{

> -	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

> -

> -	return (fwspec && fwspec->ops) ? fwspec->ops : NULL;

> -}

> -

> -static inline int iort_add_device_replay(struct device *dev)

> -{

> -	int err = 0;

> -

> -	if (dev->bus && !device_iommu_mapped(dev))

> -		err = iommu_probe_device(dev);

> -

> -	return err;

> -}

> -

>  /**

>   * iort_iommu_msi_get_resv_regions - Reserved region driver helper

>   * @dev: Device from iommu_get_resv_regions()

> @@ -900,18 +883,6 @@ static inline bool iort_iommu_driver_enabled(u8 type)

>  	}

>  }

>  

> -static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,

> -			       struct fwnode_handle *fwnode,

> -			       const struct iommu_ops *ops)

> -{

> -	int ret = iommu_fwspec_init(dev, fwnode, ops);

> -

> -	if (!ret)

> -		ret = iommu_fwspec_add_ids(dev, &streamid, 1);

> -

> -	return ret;

> -}

> -

>  static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)

>  {

>  	struct acpi_iort_root_complex *pci_rc;

> @@ -946,7 +917,7 @@ static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,

>  		return iort_iommu_driver_enabled(node->type) ?

>  		       -EPROBE_DEFER : -ENODEV;

>  

> -	return arm_smmu_iort_xlate(dev, streamid, iort_fwnode, ops);

> +	return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);

>  }

>  

>  struct iort_pci_alias_info {

> @@ -1020,24 +991,14 @@ static int iort_nc_iommu_map_id(struct device *dev,

>   * @dev: device to configure

>   * @id_in: optional input id const value pointer

>   *

> - * Returns: iommu_ops pointer on configuration success

> - *          NULL on configuration failure

> + * Returns: 0 on success, <0 on failure

>   */

> -const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

> -						const u32 *id_in)

> +int iort_iommu_configure_id(struct device *dev, const u32 *id_in)

>  {

>  	struct acpi_iort_node *node;

> -	const struct iommu_ops *ops;

> +	const struct iommu_ops *ops = NULL;

>  	int err = -ENODEV;

>  

> -	/*

> -	 * If we already translated the fwspec there

> -	 * is nothing left to do, return the iommu_ops.

> -	 */

> -	ops = iort_fwspec_iommu_ops(dev);

> -	if (ops)

> -		return ops;

> -

>  	if (dev_is_pci(dev)) {

>  		struct iommu_fwspec *fwspec;

>  		struct pci_bus *bus = to_pci_dev(dev)->bus;

> @@ -1046,7 +1007,7 @@ const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

>  		node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,

>  				      iort_match_node_callback, &bus->dev);

>  		if (!node)

> -			return NULL;

> +			return -ENODEV;

>  

>  		info.node = node;

>  		err = pci_for_each_dma_alias(to_pci_dev(dev),

> @@ -1059,7 +1020,7 @@ const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

>  		node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,

>  				      iort_match_node_callback, dev);

>  		if (!node)

> -			return NULL;

> +			return -ENODEV;

>  

>  		err = id_in ? iort_nc_iommu_map_id(dev, node, id_in) :

>  			      iort_nc_iommu_map(dev, node);

> @@ -1068,32 +1029,14 @@ const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

>  			iort_named_component_init(dev, node);

>  	}

>  

> -	/*

> -	 * If we have reason to believe the IOMMU driver missed the initial

> -	 * add_device callback for dev, replay it to get things in order.

> -	 */

> -	if (!err) {

> -		ops = iort_fwspec_iommu_ops(dev);

> -		err = iort_add_device_replay(dev);

> -	}

> -

> -	/* Ignore all other errors apart from EPROBE_DEFER */

> -	if (err == -EPROBE_DEFER) {

> -		ops = ERR_PTR(err);

> -	} else if (err) {

> -		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);

> -		ops = NULL;

> -	}

> -

> -	return ops;

> +	return err;

>  }

>  

>  #else

>  int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)

>  { return 0; }

> -const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

> -						const u32 *input_id)

> -{ return NULL; }

> +int iort_iommu_configure_id(struct device *dev, const u32 *input_id)

> +{ return -ENODEV; }

>  #endif

>  

>  static int nc_dma_get_range(struct device *dev, u64 *size)

> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c

> index ea613df8f913..0c53c8533300 100644

> --- a/drivers/acpi/scan.c

> +++ b/drivers/acpi/scan.c

> @@ -9,6 +9,7 @@

>  #include <linux/kernel.h>

>  #include <linux/acpi.h>

>  #include <linux/acpi_iort.h>

> +#include <linux/iommu.h>

>  #include <linux/signal.h>

>  #include <linux/kthread.h>

>  #include <linux/dmi.h>

> @@ -1520,6 +1521,76 @@ int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,

>  	return ret >= 0 ? 0 : ret;

>  }

>  

> +#ifdef CONFIG_IOMMU_API

> +int acpi_iommu_fwspec_init(struct device *dev, u32 id,

> +			   struct fwnode_handle *fwnode,

> +			   const struct iommu_ops *ops)

> +{

> +	int ret = iommu_fwspec_init(dev, fwnode, ops);

> +

> +	if (!ret)

> +		ret = iommu_fwspec_add_ids(dev, &id, 1);

> +

> +	return ret;

> +}

> +

> +static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)

> +{

> +	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);

> +

> +	return fwspec ? fwspec->ops : NULL;

> +}

> +

> +static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,

> +						       const u32 *id_in)

> +{

> +	int err;

> +	const struct iommu_ops *ops;

> +

> +	/*

> +	 * If we already translated the fwspec there is nothing left to do,

> +	 * return the iommu_ops.

> +	 */

> +	ops = acpi_iommu_fwspec_ops(dev);

> +	if (ops)

> +		return ops;

> +

> +	err = iort_iommu_configure_id(dev, id_in);

> +

> +	/*

> +	 * If we have reason to believe the IOMMU driver missed the initial

> +	 * add_device callback for dev, replay it to get things in order.

> +	 */

> +	if (!err && dev->bus && !device_iommu_mapped(dev))

> +		err = iommu_probe_device(dev);

Previously we had:
    if (!err) {
        ops = iort_fwspec_iommu_ops(dev);
        err = iort_add_device_replay(dev);
    }

Please can you explain the transform? I see the

acpi_iommu_fwspec_ops call below but is it not straightforward to me.
Also the comment mentions replay. Unsure if it is still OK.

> +

> +	/* Ignore all other errors apart from EPROBE_DEFER */

> +	if (err == -EPROBE_DEFER) {

> +		return ERR_PTR(err);

> +	} else if (err) {

> +		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);

> +		return NULL;

> +	}

> +	return acpi_iommu_fwspec_ops(dev);

> +}

> +

> +#else /* !CONFIG_IOMMU_API */

> +

> +int acpi_iommu_fwspec_init(struct device *dev, u32 id,

> +			   struct fwnode_handle *fwnode,

> +			   const struct iommu_ops *ops)

> +{

> +	return -ENODEV;

> +}

> +

> +static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,

> +						       const u32 *id_in)

> +{

> +	return NULL;

> +}

> +

> +#endif /* !CONFIG_IOMMU_API */

> +

>  /**

>   * acpi_dma_configure_id - Set-up DMA configuration for the device.

>   * @dev: The pointer to the device

> @@ -1539,7 +1610,7 @@ int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,

>  

>  	acpi_arch_dma_setup(dev, &dma_addr, &size);

>  

> -	iommu = iort_iommu_configure_id(dev, input_id);

> +	iommu = acpi_iommu_configure_id(dev, input_id);

>  	if (PTR_ERR(iommu) == -EPROBE_DEFER)

>  		return -EPROBE_DEFER;

>  

Thanks

Eric
Jean-Philippe Brucker June 18, 2021, 7:41 a.m. | #2
Hi Eric,

On Wed, Jun 16, 2021 at 11:35:13AM +0200, Eric Auger wrote:
> > -const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

> > -						const u32 *id_in)

> > +int iort_iommu_configure_id(struct device *dev, const u32 *id_in)

> >  {

> >  	struct acpi_iort_node *node;

> > -	const struct iommu_ops *ops;

> > +	const struct iommu_ops *ops = NULL;


Oops, I need to remove this (and add -Werror to my tests.)


> > +static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,

> > +						       const u32 *id_in)

> > +{

> > +	int err;

> > +	const struct iommu_ops *ops;

> > +

> > +	/*

> > +	 * If we already translated the fwspec there is nothing left to do,

> > +	 * return the iommu_ops.

> > +	 */

> > +	ops = acpi_iommu_fwspec_ops(dev);

> > +	if (ops)

> > +		return ops;

> > +

> > +	err = iort_iommu_configure_id(dev, id_in);

> > +

> > +	/*

> > +	 * If we have reason to believe the IOMMU driver missed the initial

> > +	 * add_device callback for dev, replay it to get things in order.

> > +	 */

> > +	if (!err && dev->bus && !device_iommu_mapped(dev))

> > +		err = iommu_probe_device(dev);

> Previously we had:

>     if (!err) {

>         ops = iort_fwspec_iommu_ops(dev);

>         err = iort_add_device_replay(dev);

>     }

> 

> Please can you explain the transform? I see the

> 

> acpi_iommu_fwspec_ops call below but is it not straightforward to me.


I figured that iort_add_device_replay() is only used once and is
sufficiently simple to be inlined manually (saving 10 lines). Then I
replaced the ops assignment with returns, which saves another line and may
be slightly clearer?  I guess it's mostly a matter of taste, the behavior
should be exactly the same.

> Also the comment mentions replay. Unsure if it is still OK.


The "replay" part is, but "add_device" isn't accurate because it has since
been replaced by probe_device. I'll refresh the comment.

Thanks,
Jean
Robin Murphy June 18, 2021, 9:16 a.m. | #3
On 2021-06-18 08:41, Jean-Philippe Brucker wrote:
> Hi Eric,

> 

> On Wed, Jun 16, 2021 at 11:35:13AM +0200, Eric Auger wrote:

>>> -const struct iommu_ops *iort_iommu_configure_id(struct device *dev,

>>> -						const u32 *id_in)

>>> +int iort_iommu_configure_id(struct device *dev, const u32 *id_in)

>>>   {

>>>   	struct acpi_iort_node *node;

>>> -	const struct iommu_ops *ops;

>>> +	const struct iommu_ops *ops = NULL;

> 

> Oops, I need to remove this (and add -Werror to my tests.)

> 

> 

>>> +static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,

>>> +						       const u32 *id_in)

>>> +{

>>> +	int err;

>>> +	const struct iommu_ops *ops;

>>> +

>>> +	/*

>>> +	 * If we already translated the fwspec there is nothing left to do,

>>> +	 * return the iommu_ops.

>>> +	 */

>>> +	ops = acpi_iommu_fwspec_ops(dev);

>>> +	if (ops)

>>> +		return ops;

>>> +

>>> +	err = iort_iommu_configure_id(dev, id_in);

>>> +

>>> +	/*

>>> +	 * If we have reason to believe the IOMMU driver missed the initial

>>> +	 * add_device callback for dev, replay it to get things in order.

>>> +	 */

>>> +	if (!err && dev->bus && !device_iommu_mapped(dev))

>>> +		err = iommu_probe_device(dev);

>> Previously we had:

>>      if (!err) {

>>          ops = iort_fwspec_iommu_ops(dev);

>>          err = iort_add_device_replay(dev);

>>      }

>>

>> Please can you explain the transform? I see the

>>

>> acpi_iommu_fwspec_ops call below but is it not straightforward to me.

> 

> I figured that iort_add_device_replay() is only used once and is

> sufficiently simple to be inlined manually (saving 10 lines). Then I

> replaced the ops assignment with returns, which saves another line and may

> be slightly clearer?  I guess it's mostly a matter of taste, the behavior

> should be exactly the same.


Right, IIRC the multiple assignments to ops were more of a haphazard 
evolution inherited from the DT version, and looking at it now I think 
the multiple-return is indeed a bit nicer.

Similarly, it looks like the factoring out of iort_add_device_replay() 
was originally an attempt to encapsulate the IOMMU_API dependency, but 
things have moved around a lot since then, so that seems like a sensible 
simplification to make too.

Robin.

> 

>> Also the comment mentions replay. Unsure if it is still OK.

> 

> The "replay" part is, but "add_device" isn't accurate because it has since

> been replaced by probe_device. I'll refresh the comment.

> 

> Thanks,

> Jean

> _______________________________________________

> iommu mailing list

> iommu@lists.linux-foundation.org

> https://lists.linuxfoundation.org/mailman/listinfo/iommu

>

Patch

diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 3a82faac5767..41f092a269f6 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -588,6 +588,9 @@  struct acpi_pci_root {
 
 bool acpi_dma_supported(struct acpi_device *adev);
 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
+int acpi_iommu_fwspec_init(struct device *dev, u32 id,
+			   struct fwnode_handle *fwnode,
+			   const struct iommu_ops *ops);
 int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
 		       u64 *size);
 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index f7f054833afd..f1f0842a2cb2 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -35,8 +35,7 @@  void acpi_configure_pmsi_domain(struct device *dev);
 int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
 /* IOMMU interface */
 int iort_dma_get_ranges(struct device *dev, u64 *size);
-const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
-						const u32 *id_in);
+int iort_iommu_configure_id(struct device *dev, const u32 *id_in);
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
 phys_addr_t acpi_iort_dma_get_max_cpu_address(void);
 #else
@@ -50,9 +49,8 @@  static inline void acpi_configure_pmsi_domain(struct device *dev) { }
 /* IOMMU interface */
 static inline int iort_dma_get_ranges(struct device *dev, u64 *size)
 { return -ENODEV; }
-static inline const struct iommu_ops *iort_iommu_configure_id(
-				      struct device *dev, const u32 *id_in)
-{ return NULL; }
+static inline int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
+{ return -ENODEV; }
 static inline
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index a940be1cf2af..b5b021e064b6 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -806,23 +806,6 @@  static struct acpi_iort_node *iort_get_msi_resv_iommu(struct device *dev)
 	return NULL;
 }
 
-static inline const struct iommu_ops *iort_fwspec_iommu_ops(struct device *dev)
-{
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
-
-	return (fwspec && fwspec->ops) ? fwspec->ops : NULL;
-}
-
-static inline int iort_add_device_replay(struct device *dev)
-{
-	int err = 0;
-
-	if (dev->bus && !device_iommu_mapped(dev))
-		err = iommu_probe_device(dev);
-
-	return err;
-}
-
 /**
  * iort_iommu_msi_get_resv_regions - Reserved region driver helper
  * @dev: Device from iommu_get_resv_regions()
@@ -900,18 +883,6 @@  static inline bool iort_iommu_driver_enabled(u8 type)
 	}
 }
 
-static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
-			       struct fwnode_handle *fwnode,
-			       const struct iommu_ops *ops)
-{
-	int ret = iommu_fwspec_init(dev, fwnode, ops);
-
-	if (!ret)
-		ret = iommu_fwspec_add_ids(dev, &streamid, 1);
-
-	return ret;
-}
-
 static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
 {
 	struct acpi_iort_root_complex *pci_rc;
@@ -946,7 +917,7 @@  static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
 		return iort_iommu_driver_enabled(node->type) ?
 		       -EPROBE_DEFER : -ENODEV;
 
-	return arm_smmu_iort_xlate(dev, streamid, iort_fwnode, ops);
+	return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
 }
 
 struct iort_pci_alias_info {
@@ -1020,24 +991,14 @@  static int iort_nc_iommu_map_id(struct device *dev,
  * @dev: device to configure
  * @id_in: optional input id const value pointer
  *
- * Returns: iommu_ops pointer on configuration success
- *          NULL on configuration failure
+ * Returns: 0 on success, <0 on failure
  */
-const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
-						const u32 *id_in)
+int iort_iommu_configure_id(struct device *dev, const u32 *id_in)
 {
 	struct acpi_iort_node *node;
-	const struct iommu_ops *ops;
+	const struct iommu_ops *ops = NULL;
 	int err = -ENODEV;
 
-	/*
-	 * If we already translated the fwspec there
-	 * is nothing left to do, return the iommu_ops.
-	 */
-	ops = iort_fwspec_iommu_ops(dev);
-	if (ops)
-		return ops;
-
 	if (dev_is_pci(dev)) {
 		struct iommu_fwspec *fwspec;
 		struct pci_bus *bus = to_pci_dev(dev)->bus;
@@ -1046,7 +1007,7 @@  const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
 		node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
 				      iort_match_node_callback, &bus->dev);
 		if (!node)
-			return NULL;
+			return -ENODEV;
 
 		info.node = node;
 		err = pci_for_each_dma_alias(to_pci_dev(dev),
@@ -1059,7 +1020,7 @@  const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
 		node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
 				      iort_match_node_callback, dev);
 		if (!node)
-			return NULL;
+			return -ENODEV;
 
 		err = id_in ? iort_nc_iommu_map_id(dev, node, id_in) :
 			      iort_nc_iommu_map(dev, node);
@@ -1068,32 +1029,14 @@  const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
 			iort_named_component_init(dev, node);
 	}
 
-	/*
-	 * If we have reason to believe the IOMMU driver missed the initial
-	 * add_device callback for dev, replay it to get things in order.
-	 */
-	if (!err) {
-		ops = iort_fwspec_iommu_ops(dev);
-		err = iort_add_device_replay(dev);
-	}
-
-	/* Ignore all other errors apart from EPROBE_DEFER */
-	if (err == -EPROBE_DEFER) {
-		ops = ERR_PTR(err);
-	} else if (err) {
-		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
-		ops = NULL;
-	}
-
-	return ops;
+	return err;
 }
 
 #else
 int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 { return 0; }
-const struct iommu_ops *iort_iommu_configure_id(struct device *dev,
-						const u32 *input_id)
-{ return NULL; }
+int iort_iommu_configure_id(struct device *dev, const u32 *input_id)
+{ return -ENODEV; }
 #endif
 
 static int nc_dma_get_range(struct device *dev, u64 *size)
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index ea613df8f913..0c53c8533300 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -9,6 +9,7 @@ 
 #include <linux/kernel.h>
 #include <linux/acpi.h>
 #include <linux/acpi_iort.h>
+#include <linux/iommu.h>
 #include <linux/signal.h>
 #include <linux/kthread.h>
 #include <linux/dmi.h>
@@ -1520,6 +1521,76 @@  int acpi_dma_get_range(struct device *dev, u64 *dma_addr, u64 *offset,
 	return ret >= 0 ? 0 : ret;
 }
 
+#ifdef CONFIG_IOMMU_API
+int acpi_iommu_fwspec_init(struct device *dev, u32 id,
+			   struct fwnode_handle *fwnode,
+			   const struct iommu_ops *ops)
+{
+	int ret = iommu_fwspec_init(dev, fwnode, ops);
+
+	if (!ret)
+		ret = iommu_fwspec_add_ids(dev, &id, 1);
+
+	return ret;
+}
+
+static inline const struct iommu_ops *acpi_iommu_fwspec_ops(struct device *dev)
+{
+	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
+
+	return fwspec ? fwspec->ops : NULL;
+}
+
+static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
+						       const u32 *id_in)
+{
+	int err;
+	const struct iommu_ops *ops;
+
+	/*
+	 * If we already translated the fwspec there is nothing left to do,
+	 * return the iommu_ops.
+	 */
+	ops = acpi_iommu_fwspec_ops(dev);
+	if (ops)
+		return ops;
+
+	err = iort_iommu_configure_id(dev, id_in);
+
+	/*
+	 * If we have reason to believe the IOMMU driver missed the initial
+	 * add_device callback for dev, replay it to get things in order.
+	 */
+	if (!err && dev->bus && !device_iommu_mapped(dev))
+		err = iommu_probe_device(dev);
+
+	/* Ignore all other errors apart from EPROBE_DEFER */
+	if (err == -EPROBE_DEFER) {
+		return ERR_PTR(err);
+	} else if (err) {
+		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
+		return NULL;
+	}
+	return acpi_iommu_fwspec_ops(dev);
+}
+
+#else /* !CONFIG_IOMMU_API */
+
+int acpi_iommu_fwspec_init(struct device *dev, u32 id,
+			   struct fwnode_handle *fwnode,
+			   const struct iommu_ops *ops)
+{
+	return -ENODEV;
+}
+
+static const struct iommu_ops *acpi_iommu_configure_id(struct device *dev,
+						       const u32 *id_in)
+{
+	return NULL;
+}
+
+#endif /* !CONFIG_IOMMU_API */
+
 /**
  * acpi_dma_configure_id - Set-up DMA configuration for the device.
  * @dev: The pointer to the device
@@ -1539,7 +1610,7 @@  int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
 
 	acpi_arch_dma_setup(dev, &dma_addr, &size);
 
-	iommu = iort_iommu_configure_id(dev, input_id);
+	iommu = acpi_iommu_configure_id(dev, input_id);
 	if (PTR_ERR(iommu) == -EPROBE_DEFER)
 		return -EPROBE_DEFER;