[PATCH v3 0/5] iommu: Remove iommu_fwspec ops

[PATCH v3 0/5] iommu: Remove iommu_fwspec ops

[Robin Murphy]

v2: https://lore.kernel.org/linux-iommu/cover.1718994350.git.robin.murphy@arm.com/

Hi all,

Just a quick update with an extra patch to avoid the mediatek-v1 driver
breaking (and I have now build-tested ARCH=arm to make sure, apologies
for being lazy before...)

Thanks,
Robin.


Robin Murphy (5):
  iommu/mediatek-v1: Clean up redundant fwspec checks
  iommu: Resolve fwspec ops automatically
  ACPI: Retire acpi_iommu_fwspec_ops()
  OF: Simplify of_iommu_configure()
  iommu: Remove iommu_fwspec ops

 drivers/acpi/arm64/iort.c             | 19 +++-------
 drivers/acpi/scan.c                   | 36 +++++--------------
 drivers/acpi/viot.c                   | 11 ++----
 drivers/iommu/arm/arm-smmu/arm-smmu.c |  3 +-
 drivers/iommu/iommu-priv.h            |  7 ++++
 drivers/iommu/iommu.c                 | 20 +++++------
 drivers/iommu/mtk_iommu_v1.c          | 12 ++-----
 drivers/iommu/of_iommu.c              | 50 ++++++++++-----------------
 drivers/iommu/tegra-smmu.c            |  2 +-
 drivers/of/device.c                   | 30 ++++++----------
 include/acpi/acpi_bus.h               |  3 +-
 include/linux/iommu.h                 | 15 ++------
 12 files changed, 67 insertions(+), 141 deletions(-)

-- 
2.39.2.101.g768bb238c484.dirty

[PATCH v3 1/5] iommu/mediatek-v1: Clean up redundant fwspec checks

[Robin Murphy]

The driver explicitly clears any existing fwspec before calling
mtk_iommu_v1_create_mapping(), but even if it didn't, the checks it's
doing there duplicate what iommu_fwspec_init() would do anyway. Clean
them up.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202407020415.KKnhPTUj-lkp@intel.com/
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/mtk_iommu_v1.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index d6e4002200bd..2b64ea46318f 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -401,7 +401,6 @@ static const struct iommu_ops mtk_iommu_v1_ops;
 static int mtk_iommu_v1_create_mapping(struct device *dev,
 				       const struct of_phandle_args *args)
 {
-	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 	struct mtk_iommu_v1_data *data;
 	struct platform_device *m4updev;
 	struct dma_iommu_mapping *mtk_mapping;
@@ -413,14 +412,9 @@ static int mtk_iommu_v1_create_mapping(struct device *dev,
 		return -EINVAL;
 	}
 
-	if (!fwspec) {
-		ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_v1_ops);
-		if (ret)
-			return ret;
-		fwspec = dev_iommu_fwspec_get(dev);
-	} else if (dev_iommu_fwspec_get(dev)->ops != &mtk_iommu_v1_ops) {
-		return -EINVAL;
-	}
+	ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_v1_ops);
+	if (ret)
+		return ret;
 
 	if (!dev_iommu_priv_get(dev)) {
 		/* Get the m4u device */
-- 
2.39.2.101.g768bb238c484.dirty

[PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Robin Murphy]

There's no real need for callers to resolve ops from a fwnode in order
to then pass both to iommu_fwspec_init() - it's simpler and more sensible
for that to resolve the ops itself. This in turn means we can centralise
the notion of checking for a present driver, and enforce that fwspecs
aren't allocated unless and until we know they will be usable.

Also use this opportunity to modernise with some "new" helpers that
arrived shortly after this code was first written; the generic
fwnode_handle_get() clears up that ugly get/put mismatch, while
of_fwnode_handle() can now abstract those open-coded dereferences.

Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
v2: Add of_fwnode_handle() cleanup as well
---
 drivers/acpi/arm64/iort.c             | 19 +++++--------------
 drivers/acpi/scan.c                   |  8 +++-----
 drivers/acpi/viot.c                   | 11 ++---------
 drivers/iommu/arm/arm-smmu/arm-smmu.c |  3 +--
 drivers/iommu/iommu-priv.h            |  2 ++
 drivers/iommu/iommu.c                 |  9 ++++++---
 drivers/iommu/mtk_iommu_v1.c          |  2 +-
 drivers/iommu/of_iommu.c              | 19 ++++++-------------
 drivers/iommu/tegra-smmu.c            |  2 +-
 include/acpi/acpi_bus.h               |  3 +--
 include/linux/iommu.h                 | 13 ++-----------
 11 files changed, 30 insertions(+), 61 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index c0b1c2c19444..1b39e9ae7ac1 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -1221,10 +1221,10 @@ static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
 static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
 			    u32 streamid)
 {
-	const struct iommu_ops *ops;
 	struct fwnode_handle *iort_fwnode;
 
-	if (!node)
+	/* If there's no SMMU driver at all, give up now */
+	if (!node || !iort_iommu_driver_enabled(node->type))
 		return -ENODEV;
 
 	iort_fwnode = iort_get_fwnode(node);
@@ -1232,19 +1232,10 @@ static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
 		return -ENODEV;
 
 	/*
-	 * If the ops look-up fails, this means that either
-	 * the SMMU drivers have not been probed yet or that
-	 * the SMMU drivers are not built in the kernel;
-	 * Depending on whether the SMMU drivers are built-in
-	 * in the kernel or not, defer the IOMMU configuration
-	 * or just abort it.
+	 * If the SMMU drivers are enabled but not loaded/probed
+	 * yet, this will defer.
 	 */
-	ops = iommu_ops_from_fwnode(iort_fwnode);
-	if (!ops)
-		return iort_iommu_driver_enabled(node->type) ?
-		       -EPROBE_DEFER : -ENODEV;
-
-	return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
+	return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode);
 }
 
 struct iort_pci_alias_info {
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 503773707e01..8d5a589db141 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1577,12 +1577,11 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
 
 #ifdef CONFIG_IOMMU_API
 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
-			   struct fwnode_handle *fwnode,
-			   const struct iommu_ops *ops)
+			   struct fwnode_handle *fwnode)
 {
 	int ret;
 
-	ret = iommu_fwspec_init(dev, fwnode, ops);
+	ret = iommu_fwspec_init(dev, fwnode);
 	if (ret)
 		return ret;
 
@@ -1639,8 +1638,7 @@ static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 #else /* !CONFIG_IOMMU_API */
 
 int acpi_iommu_fwspec_init(struct device *dev, u32 id,
-			   struct fwnode_handle *fwnode,
-			   const struct iommu_ops *ops)
+			   struct fwnode_handle *fwnode)
 {
 	return -ENODEV;
 }
diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
index c8025921c129..2aa69a2fba73 100644
--- a/drivers/acpi/viot.c
+++ b/drivers/acpi/viot.c
@@ -307,21 +307,14 @@ void __init acpi_viot_init(void)
 static int viot_dev_iommu_init(struct device *dev, struct viot_iommu *viommu,
 			       u32 epid)
 {
-	const struct iommu_ops *ops;
-
-	if (!viommu)
+	if (!viommu || !IS_ENABLED(CONFIG_VIRTIO_IOMMU))
 		return -ENODEV;
 
 	/* We're not translating ourself */
 	if (device_match_fwnode(dev, viommu->fwnode))
 		return -EINVAL;
 
-	ops = iommu_ops_from_fwnode(viommu->fwnode);
-	if (!ops)
-		return IS_ENABLED(CONFIG_VIRTIO_IOMMU) ?
-			-EPROBE_DEFER : -ENODEV;
-
-	return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode, ops);
+	return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode);
 }
 
 static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index 87c81f75cf84..c200e6d3aed5 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -178,8 +178,7 @@ static int arm_smmu_register_legacy_master(struct device *dev,
 		it.cur_count = 1;
 	}
 
-	err = iommu_fwspec_init(dev, &smmu_dev->of_node->fwnode,
-				&arm_smmu_ops);
+	err = iommu_fwspec_init(dev, NULL);
 	if (err)
 		return err;
 
diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
index 5f731d994803..078cafcf49b4 100644
--- a/drivers/iommu/iommu-priv.h
+++ b/drivers/iommu/iommu-priv.h
@@ -17,6 +17,8 @@ static inline const struct iommu_ops *dev_iommu_ops(struct device *dev)
 	return dev->iommu->iommu_dev->ops;
 }
 
+const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode);
+
 int iommu_group_replace_domain(struct iommu_group *group,
 			       struct iommu_domain *new_domain);
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 9df7cc75c1bc..7618c4285cf9 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -2822,11 +2822,14 @@ const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode
 	return ops;
 }
 
-int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
-		      const struct iommu_ops *ops)
+int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode)
 {
+	const struct iommu_ops *ops = iommu_ops_from_fwnode(iommu_fwnode);
 	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
 
+	if (!ops)
+		return -EPROBE_DEFER;
+
 	if (fwspec)
 		return ops == fwspec->ops ? 0 : -EINVAL;
 
@@ -2838,7 +2841,7 @@ int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
 	if (!fwspec)
 		return -ENOMEM;
 
-	of_node_get(to_of_node(iommu_fwnode));
+	fwnode_handle_get(iommu_fwnode);
 	fwspec->iommu_fwnode = iommu_fwnode;
 	fwspec->ops = ops;
 	dev_iommu_fwspec_set(dev, fwspec);
diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
index 2b64ea46318f..c6ea5b4baff3 100644
--- a/drivers/iommu/mtk_iommu_v1.c
+++ b/drivers/iommu/mtk_iommu_v1.c
@@ -412,7 +412,7 @@ static int mtk_iommu_v1_create_mapping(struct device *dev,
 		return -EINVAL;
 	}
 
-	ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_v1_ops);
+	ret = iommu_fwspec_init(dev, of_fwnode_handle(args->np));
 	if (ret)
 		return ret;
 
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 3afe0b48a48d..08c523ad55ad 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -21,26 +21,19 @@ static int of_iommu_xlate(struct device *dev,
 			  struct of_phandle_args *iommu_spec)
 {
 	const struct iommu_ops *ops;
-	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
 	int ret;
 
-	ops = iommu_ops_from_fwnode(fwnode);
-	if ((ops && !ops->of_xlate) ||
-	    !of_device_is_available(iommu_spec->np))
+	if (!of_device_is_available(iommu_spec->np))
 		return -ENODEV;
 
-	ret = iommu_fwspec_init(dev, fwnode, ops);
+	ret = iommu_fwspec_init(dev, of_fwnode_handle(iommu_spec->np));
+	if (ret == -EPROBE_DEFER)
+		return driver_deferred_probe_check_state(dev);
 	if (ret)
 		return ret;
-	/*
-	 * The otherwise-empty fwspec handily serves to indicate the specific
-	 * IOMMU device we're waiting for, which will be useful if we ever get
-	 * a proper probe-ordering dependency mechanism in future.
-	 */
-	if (!ops)
-		return driver_deferred_probe_check_state(dev);
 
-	if (!try_module_get(ops->owner))
+	ops = dev_iommu_fwspec_get(dev)->ops;
+	if (!ops->of_xlate || !try_module_get(ops->owner))
 		return -ENODEV;
 
 	ret = ops->of_xlate(dev, iommu_spec);
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index f86c7ae91814..4365d9936e68 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -837,7 +837,7 @@ static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
 	const struct iommu_ops *ops = smmu->iommu.ops;
 	int err;
 
-	err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
+	err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
 	if (err < 0) {
 		dev_err(dev, "failed to initialize fwspec: %d\n", err);
 		return err;
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 1a4dfd7a1c4a..9d815837e297 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -736,8 +736,7 @@ struct iommu_ops;
 bool acpi_dma_supported(const 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);
+			   struct fwnode_handle *fwnode);
 int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map);
 int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
 			   const u32 *input_id);
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 17b3f36ad843..81893aad9ee4 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -1005,11 +1005,9 @@ struct iommu_mm_data {
 	struct list_head	sva_handles;
 };
 
-int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
-		      const struct iommu_ops *ops);
+int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode);
 void iommu_fwspec_free(struct device *dev);
 int iommu_fwspec_add_ids(struct device *dev, const u32 *ids, int num_ids);
-const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode);
 
 static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
 {
@@ -1315,8 +1313,7 @@ static inline void iommu_device_unlink(struct device *dev, struct device *link)
 }
 
 static inline int iommu_fwspec_init(struct device *dev,
-				    struct fwnode_handle *iommu_fwnode,
-				    const struct iommu_ops *ops)
+				    struct fwnode_handle *iommu_fwnode)
 {
 	return -ENODEV;
 }
@@ -1331,12 +1328,6 @@ static inline int iommu_fwspec_add_ids(struct device *dev, u32 *ids,
 	return -ENODEV;
 }
 
-static inline
-const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode)
-{
-	return NULL;
-}
-
 static inline int
 iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
 {
-- 
2.39.2.101.g768bb238c484.dirty

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Jon Hunter]

Hi Robin,

On 02/07/2024 12:40, Robin Murphy wrote:
> There's no real need for callers to resolve ops from a fwnode in order
> to then pass both to iommu_fwspec_init() - it's simpler and more sensible
> for that to resolve the ops itself. This in turn means we can centralise
> the notion of checking for a present driver, and enforce that fwspecs
> aren't allocated unless and until we know they will be usable.
> 
> Also use this opportunity to modernise with some "new" helpers that
> arrived shortly after this code was first written; the generic
> fwnode_handle_get() clears up that ugly get/put mismatch, while
> of_fwnode_handle() can now abstract those open-coded dereferences.
> 
> Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
> v2: Add of_fwnode_handle() cleanup as well
> ---
>   drivers/acpi/arm64/iort.c             | 19 +++++--------------
>   drivers/acpi/scan.c                   |  8 +++-----
>   drivers/acpi/viot.c                   | 11 ++---------
>   drivers/iommu/arm/arm-smmu/arm-smmu.c |  3 +--
>   drivers/iommu/iommu-priv.h            |  2 ++
>   drivers/iommu/iommu.c                 |  9 ++++++---
>   drivers/iommu/mtk_iommu_v1.c          |  2 +-
>   drivers/iommu/of_iommu.c              | 19 ++++++-------------
>   drivers/iommu/tegra-smmu.c            |  2 +-
>   include/acpi/acpi_bus.h               |  3 +--
>   include/linux/iommu.h                 | 13 ++-----------
>   11 files changed, 30 insertions(+), 61 deletions(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index c0b1c2c19444..1b39e9ae7ac1 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1221,10 +1221,10 @@ static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
>   static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
>   			    u32 streamid)
>   {
> -	const struct iommu_ops *ops;
>   	struct fwnode_handle *iort_fwnode;
>   
> -	if (!node)
> +	/* If there's no SMMU driver at all, give up now */
> +	if (!node || !iort_iommu_driver_enabled(node->type))
>   		return -ENODEV;
>   
>   	iort_fwnode = iort_get_fwnode(node);
> @@ -1232,19 +1232,10 @@ static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
>   		return -ENODEV;
>   
>   	/*
> -	 * If the ops look-up fails, this means that either
> -	 * the SMMU drivers have not been probed yet or that
> -	 * the SMMU drivers are not built in the kernel;
> -	 * Depending on whether the SMMU drivers are built-in
> -	 * in the kernel or not, defer the IOMMU configuration
> -	 * or just abort it.
> +	 * If the SMMU drivers are enabled but not loaded/probed
> +	 * yet, this will defer.
>   	 */
> -	ops = iommu_ops_from_fwnode(iort_fwnode);
> -	if (!ops)
> -		return iort_iommu_driver_enabled(node->type) ?
> -		       -EPROBE_DEFER : -ENODEV;
> -
> -	return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
> +	return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode);
>   }
>   
>   struct iort_pci_alias_info {
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index 503773707e01..8d5a589db141 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -1577,12 +1577,11 @@ int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map)
>   
>   #ifdef CONFIG_IOMMU_API
>   int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> -			   struct fwnode_handle *fwnode,
> -			   const struct iommu_ops *ops)
> +			   struct fwnode_handle *fwnode)
>   {
>   	int ret;
>   
> -	ret = iommu_fwspec_init(dev, fwnode, ops);
> +	ret = iommu_fwspec_init(dev, fwnode);
>   	if (ret)
>   		return ret;
>   
> @@ -1639,8 +1638,7 @@ static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
>   #else /* !CONFIG_IOMMU_API */
>   
>   int acpi_iommu_fwspec_init(struct device *dev, u32 id,
> -			   struct fwnode_handle *fwnode,
> -			   const struct iommu_ops *ops)
> +			   struct fwnode_handle *fwnode)
>   {
>   	return -ENODEV;
>   }
> diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
> index c8025921c129..2aa69a2fba73 100644
> --- a/drivers/acpi/viot.c
> +++ b/drivers/acpi/viot.c
> @@ -307,21 +307,14 @@ void __init acpi_viot_init(void)
>   static int viot_dev_iommu_init(struct device *dev, struct viot_iommu *viommu,
>   			       u32 epid)
>   {
> -	const struct iommu_ops *ops;
> -
> -	if (!viommu)
> +	if (!viommu || !IS_ENABLED(CONFIG_VIRTIO_IOMMU))
>   		return -ENODEV;
>   
>   	/* We're not translating ourself */
>   	if (device_match_fwnode(dev, viommu->fwnode))
>   		return -EINVAL;
>   
> -	ops = iommu_ops_from_fwnode(viommu->fwnode);
> -	if (!ops)
> -		return IS_ENABLED(CONFIG_VIRTIO_IOMMU) ?
> -			-EPROBE_DEFER : -ENODEV;
> -
> -	return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode, ops);
> +	return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode);
>   }
>   
>   static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, void *data)
> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> index 87c81f75cf84..c200e6d3aed5 100644
> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
> @@ -178,8 +178,7 @@ static int arm_smmu_register_legacy_master(struct device *dev,
>   		it.cur_count = 1;
>   	}
>   
> -	err = iommu_fwspec_init(dev, &smmu_dev->of_node->fwnode,
> -				&arm_smmu_ops);
> +	err = iommu_fwspec_init(dev, NULL);
>   	if (err)
>   		return err;
>   
> diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
> index 5f731d994803..078cafcf49b4 100644
> --- a/drivers/iommu/iommu-priv.h
> +++ b/drivers/iommu/iommu-priv.h
> @@ -17,6 +17,8 @@ static inline const struct iommu_ops *dev_iommu_ops(struct device *dev)
>   	return dev->iommu->iommu_dev->ops;
>   }
>   
> +const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode);
> +
>   int iommu_group_replace_domain(struct iommu_group *group,
>   			       struct iommu_domain *new_domain);
>   
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 9df7cc75c1bc..7618c4285cf9 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -2822,11 +2822,14 @@ const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode
>   	return ops;
>   }
>   
> -int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
> -		      const struct iommu_ops *ops)
> +int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode)
>   {
> +	const struct iommu_ops *ops = iommu_ops_from_fwnode(iommu_fwnode);
>   	struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
>   
> +	if (!ops)
> +		return -EPROBE_DEFER;
> +
>   	if (fwspec)
>   		return ops == fwspec->ops ? 0 : -EINVAL;
>   
> @@ -2838,7 +2841,7 @@ int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
>   	if (!fwspec)
>   		return -ENOMEM;
>   
> -	of_node_get(to_of_node(iommu_fwnode));
> +	fwnode_handle_get(iommu_fwnode);
>   	fwspec->iommu_fwnode = iommu_fwnode;
>   	fwspec->ops = ops;
>   	dev_iommu_fwspec_set(dev, fwspec);
> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
> index 2b64ea46318f..c6ea5b4baff3 100644
> --- a/drivers/iommu/mtk_iommu_v1.c
> +++ b/drivers/iommu/mtk_iommu_v1.c
> @@ -412,7 +412,7 @@ static int mtk_iommu_v1_create_mapping(struct device *dev,
>   		return -EINVAL;
>   	}
>   
> -	ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_v1_ops);
> +	ret = iommu_fwspec_init(dev, of_fwnode_handle(args->np));
>   	if (ret)
>   		return ret;
>   
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> index 3afe0b48a48d..08c523ad55ad 100644
> --- a/drivers/iommu/of_iommu.c
> +++ b/drivers/iommu/of_iommu.c
> @@ -21,26 +21,19 @@ static int of_iommu_xlate(struct device *dev,
>   			  struct of_phandle_args *iommu_spec)
>   {
>   	const struct iommu_ops *ops;
> -	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
>   	int ret;
>   
> -	ops = iommu_ops_from_fwnode(fwnode);
> -	if ((ops && !ops->of_xlate) ||
> -	    !of_device_is_available(iommu_spec->np))
> +	if (!of_device_is_available(iommu_spec->np))
>   		return -ENODEV;
>   
> -	ret = iommu_fwspec_init(dev, fwnode, ops);
> +	ret = iommu_fwspec_init(dev, of_fwnode_handle(iommu_spec->np));
> +	if (ret == -EPROBE_DEFER)
> +		return driver_deferred_probe_check_state(dev);
>   	if (ret)
>   		return ret;
> -	/*
> -	 * The otherwise-empty fwspec handily serves to indicate the specific
> -	 * IOMMU device we're waiting for, which will be useful if we ever get
> -	 * a proper probe-ordering dependency mechanism in future.
> -	 */
> -	if (!ops)
> -		return driver_deferred_probe_check_state(dev);
>   
> -	if (!try_module_get(ops->owner))
> +	ops = dev_iommu_fwspec_get(dev)->ops;
> +	if (!ops->of_xlate || !try_module_get(ops->owner))
>   		return -ENODEV;
>   
>   	ret = ops->of_xlate(dev, iommu_spec);
> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
> index f86c7ae91814..4365d9936e68 100644
> --- a/drivers/iommu/tegra-smmu.c
> +++ b/drivers/iommu/tegra-smmu.c
> @@ -837,7 +837,7 @@ static int tegra_smmu_configure(struct tegra_smmu *smmu, struct device *dev,
>   	const struct iommu_ops *ops = smmu->iommu.ops;
>   	int err;
>   
> -	err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
> +	err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
>   	if (err < 0) {
>   		dev_err(dev, "failed to initialize fwspec: %d\n", err);
>   		return err;
> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
> index 1a4dfd7a1c4a..9d815837e297 100644
> --- a/include/acpi/acpi_bus.h
> +++ b/include/acpi/acpi_bus.h
> @@ -736,8 +736,7 @@ struct iommu_ops;
>   bool acpi_dma_supported(const 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);
> +			   struct fwnode_handle *fwnode);
>   int acpi_dma_get_range(struct device *dev, const struct bus_dma_region **map);
>   int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
>   			   const u32 *input_id);
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 17b3f36ad843..81893aad9ee4 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -1005,11 +1005,9 @@ struct iommu_mm_data {
>   	struct list_head	sva_handles;
>   };
>   
> -int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
> -		      const struct iommu_ops *ops);
> +int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode);
>   void iommu_fwspec_free(struct device *dev);
>   int iommu_fwspec_add_ids(struct device *dev, const u32 *ids, int num_ids);
> -const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode);
>   
>   static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct device *dev)
>   {
> @@ -1315,8 +1313,7 @@ static inline void iommu_device_unlink(struct device *dev, struct device *link)
>   }
>   
>   static inline int iommu_fwspec_init(struct device *dev,
> -				    struct fwnode_handle *iommu_fwnode,
> -				    const struct iommu_ops *ops)
> +				    struct fwnode_handle *iommu_fwnode)
>   {
>   	return -ENODEV;
>   }
> @@ -1331,12 +1328,6 @@ static inline int iommu_fwspec_add_ids(struct device *dev, u32 *ids,
>   	return -ENODEV;
>   }
>   
> -static inline
> -const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode)
> -{
> -	return NULL;
> -}
> -
>   static inline int
>   iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features feat)
>   {


I am seeing some failures on -next with some of our devices. Bisect is 
pointing to this commit. Looks like the host1x device is no longer 
probing successfully. I see the following ...

  tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
  nouveau 57000000.gpu: failed to initialize fwspec: -517

The probe seems to be deferred forever. The above is seen on Tegra210 
but Tegra30 and Tegra194 are also having the same problem. Interestingly 
it is not all devices and so make me wonder if we are missing something 
on these devices? Let me know if you have any thoughts.

Cheers
Jon

-- 
nvpublic

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Robin Murphy]

On 2024-07-12 12:01 pm, Jon Hunter wrote:
> Hi Robin,
> 
> On 02/07/2024 12:40, Robin Murphy wrote:
>> There's no real need for callers to resolve ops from a fwnode in order
>> to then pass both to iommu_fwspec_init() - it's simpler and more sensible
>> for that to resolve the ops itself. This in turn means we can centralise
>> the notion of checking for a present driver, and enforce that fwspecs
>> aren't allocated unless and until we know they will be usable.
>>
>> Also use this opportunity to modernise with some "new" helpers that
>> arrived shortly after this code was first written; the generic
>> fwnode_handle_get() clears up that ugly get/put mismatch, while
>> of_fwnode_handle() can now abstract those open-coded dereferences.
>>
>> Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>> ---
>> v2: Add of_fwnode_handle() cleanup as well
>> ---
>>   drivers/acpi/arm64/iort.c             | 19 +++++--------------
>>   drivers/acpi/scan.c                   |  8 +++-----
>>   drivers/acpi/viot.c                   | 11 ++---------
>>   drivers/iommu/arm/arm-smmu/arm-smmu.c |  3 +--
>>   drivers/iommu/iommu-priv.h            |  2 ++
>>   drivers/iommu/iommu.c                 |  9 ++++++---
>>   drivers/iommu/mtk_iommu_v1.c          |  2 +-
>>   drivers/iommu/of_iommu.c              | 19 ++++++-------------
>>   drivers/iommu/tegra-smmu.c            |  2 +-
>>   include/acpi/acpi_bus.h               |  3 +--
>>   include/linux/iommu.h                 | 13 ++-----------
>>   11 files changed, 30 insertions(+), 61 deletions(-)
>>
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> index c0b1c2c19444..1b39e9ae7ac1 100644
>> --- a/drivers/acpi/arm64/iort.c
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -1221,10 +1221,10 @@ static bool iort_pci_rc_supports_ats(struct 
>> acpi_iort_node *node)
>>   static int iort_iommu_xlate(struct device *dev, struct 
>> acpi_iort_node *node,
>>                   u32 streamid)
>>   {
>> -    const struct iommu_ops *ops;
>>       struct fwnode_handle *iort_fwnode;
>> -    if (!node)
>> +    /* If there's no SMMU driver at all, give up now */
>> +    if (!node || !iort_iommu_driver_enabled(node->type))
>>           return -ENODEV;
>>       iort_fwnode = iort_get_fwnode(node);
>> @@ -1232,19 +1232,10 @@ static int iort_iommu_xlate(struct device 
>> *dev, struct acpi_iort_node *node,
>>           return -ENODEV;
>>       /*
>> -     * If the ops look-up fails, this means that either
>> -     * the SMMU drivers have not been probed yet or that
>> -     * the SMMU drivers are not built in the kernel;
>> -     * Depending on whether the SMMU drivers are built-in
>> -     * in the kernel or not, defer the IOMMU configuration
>> -     * or just abort it.
>> +     * If the SMMU drivers are enabled but not loaded/probed
>> +     * yet, this will defer.
>>        */
>> -    ops = iommu_ops_from_fwnode(iort_fwnode);
>> -    if (!ops)
>> -        return iort_iommu_driver_enabled(node->type) ?
>> -               -EPROBE_DEFER : -ENODEV;
>> -
>> -    return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode, ops);
>> +    return acpi_iommu_fwspec_init(dev, streamid, iort_fwnode);
>>   }
>>   struct iort_pci_alias_info {
>> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
>> index 503773707e01..8d5a589db141 100644
>> --- a/drivers/acpi/scan.c
>> +++ b/drivers/acpi/scan.c
>> @@ -1577,12 +1577,11 @@ int acpi_dma_get_range(struct device *dev, 
>> const struct bus_dma_region **map)
>>   #ifdef CONFIG_IOMMU_API
>>   int acpi_iommu_fwspec_init(struct device *dev, u32 id,
>> -               struct fwnode_handle *fwnode,
>> -               const struct iommu_ops *ops)
>> +               struct fwnode_handle *fwnode)
>>   {
>>       int ret;
>> -    ret = iommu_fwspec_init(dev, fwnode, ops);
>> +    ret = iommu_fwspec_init(dev, fwnode);
>>       if (ret)
>>           return ret;
>> @@ -1639,8 +1638,7 @@ static int acpi_iommu_configure_id(struct device 
>> *dev, const u32 *id_in)
>>   #else /* !CONFIG_IOMMU_API */
>>   int acpi_iommu_fwspec_init(struct device *dev, u32 id,
>> -               struct fwnode_handle *fwnode,
>> -               const struct iommu_ops *ops)
>> +               struct fwnode_handle *fwnode)
>>   {
>>       return -ENODEV;
>>   }
>> diff --git a/drivers/acpi/viot.c b/drivers/acpi/viot.c
>> index c8025921c129..2aa69a2fba73 100644
>> --- a/drivers/acpi/viot.c
>> +++ b/drivers/acpi/viot.c
>> @@ -307,21 +307,14 @@ void __init acpi_viot_init(void)
>>   static int viot_dev_iommu_init(struct device *dev, struct viot_iommu 
>> *viommu,
>>                      u32 epid)
>>   {
>> -    const struct iommu_ops *ops;
>> -
>> -    if (!viommu)
>> +    if (!viommu || !IS_ENABLED(CONFIG_VIRTIO_IOMMU))
>>           return -ENODEV;
>>       /* We're not translating ourself */
>>       if (device_match_fwnode(dev, viommu->fwnode))
>>           return -EINVAL;
>> -    ops = iommu_ops_from_fwnode(viommu->fwnode);
>> -    if (!ops)
>> -        return IS_ENABLED(CONFIG_VIRTIO_IOMMU) ?
>> -            -EPROBE_DEFER : -ENODEV;
>> -
>> -    return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode, ops);
>> +    return acpi_iommu_fwspec_init(dev, epid, viommu->fwnode);
>>   }
>>   static int viot_pci_dev_iommu_init(struct pci_dev *pdev, u16 dev_id, 
>> void *data)
>> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c 
>> b/drivers/iommu/arm/arm-smmu/arm-smmu.c
>> index 87c81f75cf84..c200e6d3aed5 100644
>> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
>> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
>> @@ -178,8 +178,7 @@ static int arm_smmu_register_legacy_master(struct 
>> device *dev,
>>           it.cur_count = 1;
>>       }
>> -    err = iommu_fwspec_init(dev, &smmu_dev->of_node->fwnode,
>> -                &arm_smmu_ops);
>> +    err = iommu_fwspec_init(dev, NULL);
>>       if (err)
>>           return err;
>> diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
>> index 5f731d994803..078cafcf49b4 100644
>> --- a/drivers/iommu/iommu-priv.h
>> +++ b/drivers/iommu/iommu-priv.h
>> @@ -17,6 +17,8 @@ static inline const struct iommu_ops 
>> *dev_iommu_ops(struct device *dev)
>>       return dev->iommu->iommu_dev->ops;
>>   }
>> +const struct iommu_ops *iommu_ops_from_fwnode(const struct 
>> fwnode_handle *fwnode);
>> +
>>   int iommu_group_replace_domain(struct iommu_group *group,
>>                      struct iommu_domain *new_domain);
>> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
>> index 9df7cc75c1bc..7618c4285cf9 100644
>> --- a/drivers/iommu/iommu.c
>> +++ b/drivers/iommu/iommu.c
>> @@ -2822,11 +2822,14 @@ const struct iommu_ops 
>> *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode
>>       return ops;
>>   }
>> -int iommu_fwspec_init(struct device *dev, struct fwnode_handle 
>> *iommu_fwnode,
>> -              const struct iommu_ops *ops)
>> +int iommu_fwspec_init(struct device *dev, struct fwnode_handle 
>> *iommu_fwnode)
>>   {
>> +    const struct iommu_ops *ops = iommu_ops_from_fwnode(iommu_fwnode);
>>       struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev);
>> +    if (!ops)
>> +        return -EPROBE_DEFER;
>> +
>>       if (fwspec)
>>           return ops == fwspec->ops ? 0 : -EINVAL;
>> @@ -2838,7 +2841,7 @@ int iommu_fwspec_init(struct device *dev, struct 
>> fwnode_handle *iommu_fwnode,
>>       if (!fwspec)
>>           return -ENOMEM;
>> -    of_node_get(to_of_node(iommu_fwnode));
>> +    fwnode_handle_get(iommu_fwnode);
>>       fwspec->iommu_fwnode = iommu_fwnode;
>>       fwspec->ops = ops;
>>       dev_iommu_fwspec_set(dev, fwspec);
>> diff --git a/drivers/iommu/mtk_iommu_v1.c b/drivers/iommu/mtk_iommu_v1.c
>> index 2b64ea46318f..c6ea5b4baff3 100644
>> --- a/drivers/iommu/mtk_iommu_v1.c
>> +++ b/drivers/iommu/mtk_iommu_v1.c
>> @@ -412,7 +412,7 @@ static int mtk_iommu_v1_create_mapping(struct 
>> device *dev,
>>           return -EINVAL;
>>       }
>> -    ret = iommu_fwspec_init(dev, &args->np->fwnode, &mtk_iommu_v1_ops);
>> +    ret = iommu_fwspec_init(dev, of_fwnode_handle(args->np));
>>       if (ret)
>>           return ret;
>> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
>> index 3afe0b48a48d..08c523ad55ad 100644
>> --- a/drivers/iommu/of_iommu.c
>> +++ b/drivers/iommu/of_iommu.c
>> @@ -21,26 +21,19 @@ static int of_iommu_xlate(struct device *dev,
>>                 struct of_phandle_args *iommu_spec)
>>   {
>>       const struct iommu_ops *ops;
>> -    struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
>>       int ret;
>> -    ops = iommu_ops_from_fwnode(fwnode);
>> -    if ((ops && !ops->of_xlate) ||
>> -        !of_device_is_available(iommu_spec->np))
>> +    if (!of_device_is_available(iommu_spec->np))
>>           return -ENODEV;
>> -    ret = iommu_fwspec_init(dev, fwnode, ops);
>> +    ret = iommu_fwspec_init(dev, of_fwnode_handle(iommu_spec->np));
>> +    if (ret == -EPROBE_DEFER)
>> +        return driver_deferred_probe_check_state(dev);
>>       if (ret)
>>           return ret;
>> -    /*
>> -     * The otherwise-empty fwspec handily serves to indicate the 
>> specific
>> -     * IOMMU device we're waiting for, which will be useful if we 
>> ever get
>> -     * a proper probe-ordering dependency mechanism in future.
>> -     */
>> -    if (!ops)
>> -        return driver_deferred_probe_check_state(dev);
>> -    if (!try_module_get(ops->owner))
>> +    ops = dev_iommu_fwspec_get(dev)->ops;
>> +    if (!ops->of_xlate || !try_module_get(ops->owner))
>>           return -ENODEV;
>>       ret = ops->of_xlate(dev, iommu_spec);
>> diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
>> index f86c7ae91814..4365d9936e68 100644
>> --- a/drivers/iommu/tegra-smmu.c
>> +++ b/drivers/iommu/tegra-smmu.c
>> @@ -837,7 +837,7 @@ static int tegra_smmu_configure(struct tegra_smmu 
>> *smmu, struct device *dev,
>>       const struct iommu_ops *ops = smmu->iommu.ops;
>>       int err;
>> -    err = iommu_fwspec_init(dev, &dev->of_node->fwnode, ops);
>> +    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
>>       if (err < 0) {
>>           dev_err(dev, "failed to initialize fwspec: %d\n", err);
>>           return err;
>> diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
>> index 1a4dfd7a1c4a..9d815837e297 100644
>> --- a/include/acpi/acpi_bus.h
>> +++ b/include/acpi/acpi_bus.h
>> @@ -736,8 +736,7 @@ struct iommu_ops;
>>   bool acpi_dma_supported(const 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);
>> +               struct fwnode_handle *fwnode);
>>   int acpi_dma_get_range(struct device *dev, const struct 
>> bus_dma_region **map);
>>   int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
>>                  const u32 *input_id);
>> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
>> index 17b3f36ad843..81893aad9ee4 100644
>> --- a/include/linux/iommu.h
>> +++ b/include/linux/iommu.h
>> @@ -1005,11 +1005,9 @@ struct iommu_mm_data {
>>       struct list_head    sva_handles;
>>   };
>> -int iommu_fwspec_init(struct device *dev, struct fwnode_handle 
>> *iommu_fwnode,
>> -              const struct iommu_ops *ops);
>> +int iommu_fwspec_init(struct device *dev, struct fwnode_handle 
>> *iommu_fwnode);
>>   void iommu_fwspec_free(struct device *dev);
>>   int iommu_fwspec_add_ids(struct device *dev, const u32 *ids, int 
>> num_ids);
>> -const struct iommu_ops *iommu_ops_from_fwnode(const struct 
>> fwnode_handle *fwnode);
>>   static inline struct iommu_fwspec *dev_iommu_fwspec_get(struct 
>> device *dev)
>>   {
>> @@ -1315,8 +1313,7 @@ static inline void iommu_device_unlink(struct 
>> device *dev, struct device *link)
>>   }
>>   static inline int iommu_fwspec_init(struct device *dev,
>> -                    struct fwnode_handle *iommu_fwnode,
>> -                    const struct iommu_ops *ops)
>> +                    struct fwnode_handle *iommu_fwnode)
>>   {
>>       return -ENODEV;
>>   }
>> @@ -1331,12 +1328,6 @@ static inline int iommu_fwspec_add_ids(struct 
>> device *dev, u32 *ids,
>>       return -ENODEV;
>>   }
>> -static inline
>> -const struct iommu_ops *iommu_ops_from_fwnode(const struct 
>> fwnode_handle *fwnode)
>> -{
>> -    return NULL;
>> -}
>> -
>>   static inline int
>>   iommu_dev_enable_feature(struct device *dev, enum iommu_dev_features 
>> feat)
>>   {
> 
> 
> I am seeing some failures on -next with some of our devices. Bisect is 
> pointing to this commit. Looks like the host1x device is no longer 
> probing successfully. I see the following ...
> 
>   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
>   nouveau 57000000.gpu: failed to initialize fwspec: -517
> 
> The probe seems to be deferred forever. The above is seen on Tegra210 
> but Tegra30 and Tegra194 are also having the same problem. Interestingly 
> it is not all devices and so make me wonder if we are missing something 
> on these devices? Let me know if you have any thoughts.

Ugh, tegra-smmu has been doing a complete nonsense this whole time - on 
closer inspection, it's passing the fwnode of the *client device* where 
it should be that of the IOMMU device :(

I *think* it should probably just be a case of:

-    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
+    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));

since smmu->dev appears to be the same one initially passed to 
iommu_device_register(), so it at least ought to match and work, but the 
SMMU device vs. MC device thing leaves me mildly wary of how correct it 
might be overall.

(Also now I'm wondering why I didn't just use dev_fwnode() there...)

Thanks,
Robin.

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Jon Hunter]

On 12/07/2024 12:48, Robin Murphy wrote:

...

>> I am seeing some failures on -next with some of our devices. Bisect is 
>> pointing to this commit. Looks like the host1x device is no longer 
>> probing successfully. I see the following ...
>>
>>   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
>>   nouveau 57000000.gpu: failed to initialize fwspec: -517
>>
>> The probe seems to be deferred forever. The above is seen on Tegra210 
>> but Tegra30 and Tegra194 are also having the same problem. 
>> Interestingly it is not all devices and so make me wonder if we are 
>> missing something on these devices? Let me know if you have any thoughts.
> 
> Ugh, tegra-smmu has been doing a complete nonsense this whole time - on 
> closer inspection, it's passing the fwnode of the *client device* where 
> it should be that of the IOMMU device :(
> 
> I *think* it should probably just be a case of:
> 
> -    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
> +    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
> 
> since smmu->dev appears to be the same one initially passed to 
> iommu_device_register(), so it at least ought to match and work, but the 
> SMMU device vs. MC device thing leaves me mildly wary of how correct it 
> might be overall.
> 
> (Also now I'm wondering why I didn't just use dev_fwnode() there...)


Yes making that change in the tegra-smmu driver does fix it.

Thanks!
Jon

-- 
nvpublic

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Will Deacon]

On Fri, Jul 12, 2024 at 04:24:48PM +0100, Jon Hunter wrote:
> 
> On 12/07/2024 12:48, Robin Murphy wrote:
> 
> ...
> 
> > > I am seeing some failures on -next with some of our devices. Bisect
> > > is pointing to this commit. Looks like the host1x device is no
> > > longer probing successfully. I see the following ...
> > > 
> > >   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
> > >   nouveau 57000000.gpu: failed to initialize fwspec: -517
> > > 
> > > The probe seems to be deferred forever. The above is seen on
> > > Tegra210 but Tegra30 and Tegra194 are also having the same problem.
> > > Interestingly it is not all devices and so make me wonder if we are
> > > missing something on these devices? Let me know if you have any
> > > thoughts.
> > 
> > Ugh, tegra-smmu has been doing a complete nonsense this whole time - on
> > closer inspection, it's passing the fwnode of the *client device* where
> > it should be that of the IOMMU device :(
> > 
> > I *think* it should probably just be a case of:
> > 
> > -    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
> > +    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
> > 
> > since smmu->dev appears to be the same one initially passed to
> > iommu_device_register(), so it at least ought to match and work, but the
> > SMMU device vs. MC device thing leaves me mildly wary of how correct it
> > might be overall.
> > 
> > (Also now I'm wondering why I didn't just use dev_fwnode() there...)
> 
> 
> Yes making that change in the tegra-smmu driver does fix it.

Fantastic! I'll pick it up right now.

Cheers,

Will

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Robin Murphy]

On 12/07/2024 4:24 pm, Jon Hunter wrote:
> 
> On 12/07/2024 12:48, Robin Murphy wrote:
> 
> ...
> 
>>> I am seeing some failures on -next with some of our devices. Bisect 
>>> is pointing to this commit. Looks like the host1x device is no longer 
>>> probing successfully. I see the following ...
>>>
>>>   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
>>>   nouveau 57000000.gpu: failed to initialize fwspec: -517
>>>
>>> The probe seems to be deferred forever. The above is seen on Tegra210 
>>> but Tegra30 and Tegra194 are also having the same problem. 
>>> Interestingly it is not all devices and so make me wonder if we are 
>>> missing something on these devices? Let me know if you have any 
>>> thoughts.
>>
>> Ugh, tegra-smmu has been doing a complete nonsense this whole time - 
>> on closer inspection, it's passing the fwnode of the *client device* 
>> where it should be that of the IOMMU device :(
>>
>> I *think* it should probably just be a case of:
>>
>> -    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
>> +    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
>>
>> since smmu->dev appears to be the same one initially passed to 
>> iommu_device_register(), so it at least ought to match and work, but 
>> the SMMU device vs. MC device thing leaves me mildly wary of how 
>> correct it might be overall.
>>
>> (Also now I'm wondering why I didn't just use dev_fwnode() there...)
> 
> 
> Yes making that change in the tegra-smmu driver does fix it.

Ace, thanks for confirming! I was just writing a follow-up to say that 
I've pretty much convinced myself that this (proper diff below) should 
in fact be the right thing to do in general as well :)

Will, Joerg, would you prefer to have a standalone fix patch for the 
nvidia/tegra branch to then re-merge fwspec-ops-removal and fix up the 
conflict, or just a patch on top of fwspec-ops-removal as below?

Thanks,
Robin.

----->8-----
diff --git a/drivers/iommu/tegra-smmu.c b/drivers/iommu/tegra-smmu.c
index 4365d9936e68..7f633bb5efef 100644
--- a/drivers/iommu/tegra-smmu.c
+++ b/drivers/iommu/tegra-smmu.c
@@ -837,7 +837,7 @@ static int tegra_smmu_configure(struct tegra_smmu 
*smmu, struct device *dev,
  	const struct iommu_ops *ops = smmu->iommu.ops;
  	int err;

-	err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
+	err = iommu_fwspec_init(dev, dev_fwnode(smmu->dev));
  	if (err < 0) {
  		dev_err(dev, "failed to initialize fwspec: %d\n", err);
  		return err;

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Will Deacon]

On Fri, Jul 12, 2024 at 04:28:37PM +0100, Robin Murphy wrote:
> On 12/07/2024 4:24 pm, Jon Hunter wrote:
> > 
> > On 12/07/2024 12:48, Robin Murphy wrote:
> > 
> > ...
> > 
> > > > I am seeing some failures on -next with some of our devices.
> > > > Bisect is pointing to this commit. Looks like the host1x device
> > > > is no longer probing successfully. I see the following ...
> > > > 
> > > >   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
> > > >   nouveau 57000000.gpu: failed to initialize fwspec: -517
> > > > 
> > > > The probe seems to be deferred forever. The above is seen on
> > > > Tegra210 but Tegra30 and Tegra194 are also having the same
> > > > problem. Interestingly it is not all devices and so make me
> > > > wonder if we are missing something on these devices? Let me know
> > > > if you have any thoughts.
> > > 
> > > Ugh, tegra-smmu has been doing a complete nonsense this whole time -
> > > on closer inspection, it's passing the fwnode of the *client device*
> > > where it should be that of the IOMMU device :(
> > > 
> > > I *think* it should probably just be a case of:
> > > 
> > > -    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
> > > +    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
> > > 
> > > since smmu->dev appears to be the same one initially passed to
> > > iommu_device_register(), so it at least ought to match and work, but
> > > the SMMU device vs. MC device thing leaves me mildly wary of how
> > > correct it might be overall.
> > > 
> > > (Also now I'm wondering why I didn't just use dev_fwnode() there...)
> > 
> > 
> > Yes making that change in the tegra-smmu driver does fix it.
> 
> Ace, thanks for confirming! I was just writing a follow-up to say that I've
> pretty much convinced myself that this (proper diff below) should in fact be
> the right thing to do in general as well :)
> 
> Will, Joerg, would you prefer to have a standalone fix patch for the
> nvidia/tegra branch to then re-merge fwspec-ops-removal and fix up the
> conflict, or just a patch on top of fwspec-ops-removal as below?

I've just fixed it locally on the tegra branch, so I'll then just
resolve the conflict with fwspec-ops-removal the right way. That way, we
can backport the thing if we need to.

Cheers,

Will

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Robin Murphy]

On 12/07/2024 4:31 pm, Will Deacon wrote:
> On Fri, Jul 12, 2024 at 04:28:37PM +0100, Robin Murphy wrote:
>> On 12/07/2024 4:24 pm, Jon Hunter wrote:
>>>
>>> On 12/07/2024 12:48, Robin Murphy wrote:
>>>
>>> ...
>>>
>>>>> I am seeing some failures on -next with some of our devices.
>>>>> Bisect is pointing to this commit. Looks like the host1x device
>>>>> is no longer probing successfully. I see the following ...
>>>>>
>>>>> ��tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
>>>>> ��nouveau 57000000.gpu: failed to initialize fwspec: -517
>>>>>
>>>>> The probe seems to be deferred forever. The above is seen on
>>>>> Tegra210 but Tegra30 and Tegra194 are also having the same
>>>>> problem. Interestingly it is not all devices and so make me
>>>>> wonder if we are missing something on these devices? Let me know
>>>>> if you have any thoughts.
>>>>
>>>> Ugh, tegra-smmu has been doing a complete nonsense this whole time -
>>>> on closer inspection, it's passing the fwnode of the *client device*
>>>> where it should be that of the IOMMU device :(
>>>>
>>>> I *think* it should probably just be a case of:
>>>>
>>>> -��� err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
>>>> +��� err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
>>>>
>>>> since smmu->dev appears to be the same one initially passed to
>>>> iommu_device_register(), so it at least ought to match and work, but
>>>> the SMMU device vs. MC device thing leaves me mildly wary of how
>>>> correct it might be overall.
>>>>
>>>> (Also now I'm wondering why I didn't just use dev_fwnode() there...)
>>>
>>>
>>> Yes making that change in the tegra-smmu driver does fix it.
>>
>> Ace, thanks for confirming! I was just writing a follow-up to say that I've
>> pretty much convinced myself that this (proper diff below) should in fact be
>> the right thing to do in general as well :)
>>
>> Will, Joerg, would you prefer to have a standalone fix patch for the
>> nvidia/tegra branch to then re-merge fwspec-ops-removal and fix up the
>> conflict, or just a patch on top of fwspec-ops-removal as below?
> 
> I've just fixed it locally on the tegra branch, so I'll then just
> resolve the conflict with fwspec-ops-removal the right way. That way, we
> can backport the thing if we need to.

Cool, thanks for taking care of it!

Robin.

Re: [PATCH v3 2/5] iommu: Resolve fwspec ops automatically

[Will Deacon]

On Fri, Jul 12, 2024 at 12:48:31PM +0100, Robin Murphy wrote:
> On 2024-07-12 12:01 pm, Jon Hunter wrote:
> > I am seeing some failures on -next with some of our devices. Bisect is
> > pointing to this commit. Looks like the host1x device is no longer
> > probing successfully. I see the following ...
> > 
> >   tegra-host1x 50000000.host1x: failed to initialize fwspec: -517
> >   nouveau 57000000.gpu: failed to initialize fwspec: -517
> > 
> > The probe seems to be deferred forever. The above is seen on Tegra210
> > but Tegra30 and Tegra194 are also having the same problem. Interestingly
> > it is not all devices and so make me wonder if we are missing something
> > on these devices? Let me know if you have any thoughts.
> 
> Ugh, tegra-smmu has been doing a complete nonsense this whole time - on
> closer inspection, it's passing the fwnode of the *client device* where it
> should be that of the IOMMU device :(

Ha, so it is!

> I *think* it should probably just be a case of:
> 
> -    err = iommu_fwspec_init(dev, of_fwnode_handle(dev->of_node));
> +    err = iommu_fwspec_init(dev, of_fwnode_handle(smmu->dev->of_node));
> 
> since smmu->dev appears to be the same one initially passed to
> iommu_device_register(), so it at least ought to match and work, but the
> SMMU device vs. MC device thing leaves me mildly wary of how correct it
> might be overall.

Jon -- any chance you could give this fix a go, please? I'm hesitant to
drop the whole branch just for this, but we've basically run out of time
for 6.11 and so knowing we have a working fix would be really helpful.

Cheers,

Will

[PATCH v3 3/5] ACPI: Retire acpi_iommu_fwspec_ops()

[Robin Murphy]

Now that iommu_fwspec_init() can signal for probe deferral directly,
acpi_iommu_fwspec_ops() is unneeded and can be cleaned up.

Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/acpi/scan.c | 28 +++++-----------------------
 1 file changed, 5 insertions(+), 23 deletions(-)

diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 8d5a589db141..2cfbb365c4ab 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1588,26 +1588,14 @@ int acpi_iommu_fwspec_init(struct device *dev, u32 id,
 	return iommu_fwspec_add_ids(dev, &id, 1);
 }
 
-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 int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 {
 	int err;
-	const struct iommu_ops *ops;
 
 	/* Serialise to make dev->iommu stable under our potential fwspec */
 	mutex_lock(&iommu_probe_device_lock);
-	/*
-	 * If we already translated the fwspec there is nothing left to do,
-	 * return the iommu_ops.
-	 */
-	ops = acpi_iommu_fwspec_ops(dev);
-	if (ops) {
+	/* If we already translated the fwspec there is nothing left to do */
+	if (dev_iommu_fwspec_get(dev)) {
 		mutex_unlock(&iommu_probe_device_lock);
 		return 0;
 	}
@@ -1624,15 +1612,7 @@ static int acpi_iommu_configure_id(struct device *dev, const u32 *id_in)
 	if (!err && dev->bus)
 		err = iommu_probe_device(dev);
 
-	if (err == -EPROBE_DEFER)
-		return err;
-	if (err) {
-		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
-		return err;
-	}
-	if (!acpi_iommu_fwspec_ops(dev))
-		return -ENODEV;
-	return 0;
+	return err;
 }
 
 #else /* !CONFIG_IOMMU_API */
@@ -1672,6 +1652,8 @@ int acpi_dma_configure_id(struct device *dev, enum dev_dma_attr attr,
 	ret = acpi_iommu_configure_id(dev, input_id);
 	if (ret == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
+	if (ret)
+		dev_dbg(dev, "Adding to IOMMU failed: %d\n", ret);
 
 	arch_setup_dma_ops(dev, attr == DEV_DMA_COHERENT);
 
-- 
2.39.2.101.g768bb238c484.dirty

[PATCH v3 4/5] OF: Simplify of_iommu_configure()

[Robin Murphy]

We no longer have a notion of partially-initialised fwspecs existing,
and we also no longer need to use an iommu_ops pointer to return status
to of_dma_configure(). Clean up the remains of those, which lends itself
to clarifying the logic around the dma_range_map allocation as well.

Acked-by: Rob Herring (Arm) <robh@kernel.org>
Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/of_iommu.c | 29 ++++++++++-------------------
 drivers/of/device.c      | 30 +++++++++++-------------------
 2 files changed, 21 insertions(+), 38 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 08c523ad55ad..c946521a5906 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -108,7 +108,6 @@ static int of_iommu_configure_device(struct device_node *master_np,
 int of_iommu_configure(struct device *dev, struct device_node *master_np,
 		       const u32 *id)
 {
-	struct iommu_fwspec *fwspec;
 	int err;
 
 	if (!master_np)
@@ -116,14 +115,9 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np,
 
 	/* Serialise to make dev->iommu stable under our potential fwspec */
 	mutex_lock(&iommu_probe_device_lock);
-	fwspec = dev_iommu_fwspec_get(dev);
-	if (fwspec) {
-		if (fwspec->ops) {
-			mutex_unlock(&iommu_probe_device_lock);
-			return 0;
-		}
-		/* In the deferred case, start again from scratch */
-		iommu_fwspec_free(dev);
+	if (dev_iommu_fwspec_get(dev)) {
+		mutex_unlock(&iommu_probe_device_lock);
+		return 0;
 	}
 
 	/*
@@ -143,20 +137,17 @@ int of_iommu_configure(struct device *dev, struct device_node *master_np,
 	} else {
 		err = of_iommu_configure_device(master_np, dev, id);
 	}
+
+	if (err)
+		iommu_fwspec_free(dev);
 	mutex_unlock(&iommu_probe_device_lock);
 
-	if (err == -ENODEV || err == -EPROBE_DEFER)
-		return err;
-	if (err)
-		goto err_log;
+	if (!err && dev->bus)
+		err = iommu_probe_device(dev);
 
-	err = iommu_probe_device(dev);
-	if (err)
-		goto err_log;
-	return 0;
+	if (err && err != -EPROBE_DEFER)
+		dev_dbg(dev, "Adding to IOMMU failed: %d\n", err);
 
-err_log:
-	dev_dbg(dev, "Adding to IOMMU failed: %pe\n", ERR_PTR(err));
 	return err;
 }
 
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 312c63361211..edf3be197265 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -96,8 +96,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 	const struct bus_dma_region *map = NULL;
 	struct device_node *bus_np;
 	u64 mask, end = 0;
-	bool coherent;
-	int iommu_ret;
+	bool coherent, set_map = false;
 	int ret;
 
 	if (np == dev->of_node)
@@ -118,6 +117,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 	} else {
 		/* Determine the overall bounds of all DMA regions */
 		end = dma_range_map_max(map);
+		set_map = true;
 	}
 
 	/*
@@ -144,7 +144,7 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 	dev->coherent_dma_mask &= mask;
 	*dev->dma_mask &= mask;
 	/* ...but only set bus limit and range map if we found valid dma-ranges earlier */
-	if (!ret) {
+	if (set_map) {
 		dev->bus_dma_limit = end;
 		dev->dma_range_map = map;
 	}
@@ -153,29 +153,21 @@ int of_dma_configure_id(struct device *dev, struct device_node *np,
 	dev_dbg(dev, "device is%sdma coherent\n",
 		coherent ? " " : " not ");
 
-	iommu_ret = of_iommu_configure(dev, np, id);
-	if (iommu_ret == -EPROBE_DEFER) {
+	ret = of_iommu_configure(dev, np, id);
+	if (ret == -EPROBE_DEFER) {
 		/* Don't touch range map if it wasn't set from a valid dma-ranges */
-		if (!ret)
+		if (set_map)
 			dev->dma_range_map = NULL;
 		kfree(map);
 		return -EPROBE_DEFER;
-	} else if (iommu_ret == -ENODEV) {
-		dev_dbg(dev, "device is not behind an iommu\n");
-	} else if (iommu_ret) {
-		dev_err(dev, "iommu configuration for device failed with %pe\n",
-			ERR_PTR(iommu_ret));
-
-		/*
-		 * Historically this routine doesn't fail driver probing
-		 * due to errors in of_iommu_configure()
-		 */
-	} else
-		dev_dbg(dev, "device is behind an iommu\n");
+	}
+	/* Take all other IOMMU errors to mean we'll just carry on without it */
+	dev_dbg(dev, "device is%sbehind an iommu\n",
+		!ret ? " " : " not ");
 
 	arch_setup_dma_ops(dev, coherent);
 
-	if (iommu_ret)
+	if (ret)
 		of_dma_set_restricted_buffer(dev, np);
 
 	return 0;
-- 
2.39.2.101.g768bb238c484.dirty

[PATCH v3 5/5] iommu: Remove iommu_fwspec ops

[Robin Murphy]

The ops in iommu_fwspec are only needed for the early configuration and
probe process, and by now are easy enough to derive on-demand in those
couple of places which need them, so remove the redundant stored copy.

Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/iommu-priv.h |  5 +++++
 drivers/iommu/iommu.c      | 11 ++---------
 drivers/iommu/of_iommu.c   |  4 +++-
 include/linux/iommu.h      |  2 --
 4 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
index 078cafcf49b4..a34efed2884b 100644
--- a/drivers/iommu/iommu-priv.h
+++ b/drivers/iommu/iommu-priv.h
@@ -19,6 +19,11 @@ static inline const struct iommu_ops *dev_iommu_ops(struct device *dev)
 
 const struct iommu_ops *iommu_ops_from_fwnode(const struct fwnode_handle *fwnode);
 
+static inline const struct iommu_ops *iommu_fwspec_ops(struct iommu_fwspec *fwspec)
+{
+	return iommu_ops_from_fwnode(fwspec ? fwspec->iommu_fwnode : NULL);
+}
+
 int iommu_group_replace_domain(struct iommu_group *group,
 			       struct iommu_domain *new_domain);
 
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 7618c4285cf9..e15ae1dd494b 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -510,7 +510,6 @@ DEFINE_MUTEX(iommu_probe_device_lock);
 static int __iommu_probe_device(struct device *dev, struct list_head *group_list)
 {
 	const struct iommu_ops *ops;
-	struct iommu_fwspec *fwspec;
 	struct iommu_group *group;
 	struct group_device *gdev;
 	int ret;
@@ -523,12 +522,7 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list
 	 * be present, and that any of their registered instances has suitable
 	 * ops for probing, and thus cheekily co-opt the same mechanism.
 	 */
-	fwspec = dev_iommu_fwspec_get(dev);
-	if (fwspec && fwspec->ops)
-		ops = fwspec->ops;
-	else
-		ops = iommu_ops_from_fwnode(NULL);
-
+	ops = iommu_fwspec_ops(dev_iommu_fwspec_get(dev));
 	if (!ops)
 		return -ENODEV;
 	/*
@@ -2831,7 +2825,7 @@ int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode)
 		return -EPROBE_DEFER;
 
 	if (fwspec)
-		return ops == fwspec->ops ? 0 : -EINVAL;
+		return ops == iommu_fwspec_ops(fwspec) ? 0 : -EINVAL;
 
 	if (!dev_iommu_get(dev))
 		return -ENOMEM;
@@ -2843,7 +2837,6 @@ int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode)
 
 	fwnode_handle_get(iommu_fwnode);
 	fwspec->iommu_fwnode = iommu_fwnode;
-	fwspec->ops = ops;
 	dev_iommu_fwspec_set(dev, fwspec);
 	return 0;
 }
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index c946521a5906..559c5db78edb 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -17,6 +17,8 @@
 #include <linux/slab.h>
 #include <linux/fsl/mc.h>
 
+#include "iommu-priv.h"
+
 static int of_iommu_xlate(struct device *dev,
 			  struct of_phandle_args *iommu_spec)
 {
@@ -32,7 +34,7 @@ static int of_iommu_xlate(struct device *dev,
 	if (ret)
 		return ret;
 
-	ops = dev_iommu_fwspec_get(dev)->ops;
+	ops = iommu_ops_from_fwnode(&iommu_spec->np->fwnode);
 	if (!ops->of_xlate || !try_module_get(ops->owner))
 		return -ENODEV;
 
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 81893aad9ee4..11ae1750cb1d 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -968,7 +968,6 @@ extern struct iommu_group *generic_single_device_group(struct device *dev);
 
 /**
  * struct iommu_fwspec - per-device IOMMU instance data
- * @ops: ops for this device's IOMMU
  * @iommu_fwnode: firmware handle for this device's IOMMU
  * @flags: IOMMU_FWSPEC_* flags
  * @num_ids: number of associated device IDs
@@ -979,7 +978,6 @@ extern struct iommu_group *generic_single_device_group(struct device *dev);
  * consumers.
  */
 struct iommu_fwspec {
-	const struct iommu_ops	*ops;
 	struct fwnode_handle	*iommu_fwnode;
 	u32			flags;
 	unsigned int		num_ids;
-- 
2.39.2.101.g768bb238c484.dirty

Re: [PATCH v3 0/5] iommu: Remove iommu_fwspec ops

[Will Deacon]

On Tue, 02 Jul 2024 12:40:46 +0100, Robin Murphy wrote:
> v2: https://lore.kernel.org/linux-iommu/cover.1718994350.git.robin.murphy@arm.com/
> 
> Hi all,
> 
> Just a quick update with an extra patch to avoid the mediatek-v1 driver
> breaking (and I have now build-tested ARCH=arm to make sure, apologies
> for being lazy before...)
> 
> [...]

Applied to arm64 (fwspec-ops-removal), thanks!

[1/5] iommu/mediatek-v1: Clean up redundant fwspec checks
      https://git.kernel.org/iommu/c/e7acc36f26b0
[2/5] iommu: Resolve fwspec ops automatically
      https://git.kernel.org/iommu/c/3f7c32091628
[3/5] ACPI: Retire acpi_iommu_fwspec_ops()
      https://git.kernel.org/iommu/c/78596b5c321c
[4/5] OF: Simplify of_iommu_configure()
      https://git.kernel.org/iommu/c/5f937bc48a6a
[5/5] iommu: Remove iommu_fwspec ops
      https://git.kernel.org/iommu/c/3e36c15fc1cc

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev