[PATCH v10 0/3] of: parsing of multi #{iommu,msi}-cells in maps

[PATCH v10 0/3] of: parsing of multi #{iommu,msi}-cells in maps

[Vijayanand Jitta]

So far our parsing of {iommu,msi}-map properites has always blindly
assumed that the output specifiers will always have exactly 1 cell.
This typically does happen to be the case, but is not actually enforced
(and the PCI msi-map binding even explicitly states support for 0 or 1
cells) - as a result we've now ended up with dodgy DTs out in the field
which depend on this behaviour to map a 1-cell specifier for a 2-cell
provider, despite that being bogus per the bindings themselves.

Since there is some potential use[1] in being able to map at least
single input IDs to multi-cell output specifiers (and properly support
0-cell outputs as well), add support for properly parsing and using the
target nodes' #cells values, albeit with the unfortunate complication of
still having to work around expectations of the old behaviour too.
							-- Robin.

Unlike single #{}-cell, it is complex to establish a linear relation
between input 'id' and output specifier for multi-cell properties, thus
it is always expected that len never going to be > 1. 

These changes have been tested on QEMU for the arm64 architecture.

[1] https://lore.kernel.org/all/20250627-video_cb-v3-0-51e18c0ffbce@quicinc.com/

V10:
  - Move of_map_iommu_id()/of_map_msi_id() from include/linux/of.h to
    drivers/of/base.c as out-of-line helpers per feedback from Marc Zyngier
    and Rob Herring.
  - Add kernel-doc to document both helpers for discoverability and
    usage clarity.
  - Fix of_map_msi_id() wrapper and all its callers (cdx_msi.c,
    irq-gic-its-msi-parent.c, drivers/of/irq.c) to correctly use the new
    struct of_phandle_args-based API with proper of_node_put() handling
    as per feeback from Dmitry.
  Link to v9:
  https://lore.kernel.org/r/20260301-parse_iommu_cells-v9-0-4d1bceecc5e1@oss.qualcomm.com

V9:
  - Updated TO/CC list based on feedback to include all relevant
    maintainers.
  - No functional changes to the patches themselves.

  Link to V8:
  https://lore.kernel.org/all/20260226074245.3098486-1-vijayanand.jitta@oss.qualcomm.com/

V8:
  - Removed mentions of of_map_args from commit message to match code.

  Link to V7:
  https://lore.kernel.org/all/20260210101157.2145113-1-vijayanand.jitta@oss.qualcomm.com/

V7:
  - Removed of_map_id_args structure and replaced it with
    of_phandle_args as suggested by Dmitry.

  Link to V6:
  https://lore.kernel.org/all/20260121055400.937856-1-vijayanand.jitta@oss.qualcomm.com/

V6:
  - Fixed build error reported by kernel test bot.

  Link to V5:
  https://lore.kernel.org/all/20260118181125.1436036-1-vijayanand.jitta@oss.qualcomm.com/

V5:
  - Fixed Build Warnings.
  - Raised PR for iommu-map dtschema: https://github.com/devicetree-org/dt-schema/pull/184

  Link to V4:
  https://lore.kernel.org/all/20251231114257.2382820-1-vijayanand.jitta@oss.qualcomm.com/

V4:
  - Added Reviewed-by tag.
  - Resolved warnings reported by kernel test bot, minor code
    reorganization.

  Link to V3:
  https://lore.kernel.org/all/20251221213602.2413124-1-vijayanand.jitta@oss.qualcomm.com/

V3:
  - Added Reviewed-by tag.
  - Updated of_map_id_args struct as a wrapper to of_phandle_args and
    added comment description as suggested by Rob Herring.

  Link to V2:
  https://lore.kernel.org/all/20251204095530.8627-1-vijayanand.jitta@oss.qualcomm.com/

V2:
  - Incorporated the patches from Robin that does the clean implementation.
  - Dropped the patches the were adding multi-map support from this series
    as suggested.

V1:
 https://lore.kernel.org/all/cover.1762235099.git.charan.kalla@oss.qualcomm.com/

RFC:
 https://lore.kernel.org/all/20250928171718.436440-1-charan.kalla@oss.qualcomm.com/#r

Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
---

---
Charan Teja Kalla (1):
      of: factor arguments passed to of_map_id() into a struct

Robin Murphy (2):
      of: Add convenience wrappers for of_map_id()
      of: Respect #{iommu,msi}-cells in maps

 drivers/cdx/cdx_msi.c                    |   6 +-
 drivers/iommu/of_iommu.c                 |   6 +-
 drivers/irqchip/irq-gic-its-msi-parent.c |  11 +-
 drivers/of/base.c                        | 202 ++++++++++++++++++++++++-------
 drivers/of/irq.c                         |   9 +-
 drivers/pci/controller/dwc/pci-imx6.c    |  18 ++-
 drivers/pci/controller/pcie-apple.c      |   6 +-
 drivers/xen/grant-dma-ops.c              |   5 +-
 include/linux/of.h                       |  28 ++++-
 9 files changed, 222 insertions(+), 69 deletions(-)
---
base-commit: 3fa5e5702a82d259897bd7e209469bc06368bf31
change-id: 20260301-parse_iommu_cells-1c33768aebba

Best regards,
-- 
Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>

[PATCH v10 1/3] of: Add convenience wrappers for of_map_id()

[Vijayanand Jitta]

From: Robin Murphy <robin.murphy@arm.com>

Since we now have quite a few users parsing "iommu-map" and "msi-map"
properties, give them some wrappers to conveniently encapsulate the
appropriate sets of property names. This will also make it easier to
then change of_map_id() to correctly account for specifier cells.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
---
 drivers/cdx/cdx_msi.c                    |  3 +--
 drivers/iommu/of_iommu.c                 |  4 +---
 drivers/irqchip/irq-gic-its-msi-parent.c |  2 +-
 drivers/of/base.c                        | 36 ++++++++++++++++++++++++++++++++
 drivers/of/irq.c                         |  3 +--
 drivers/pci/controller/dwc/pci-imx6.c    |  6 ++----
 drivers/pci/controller/pcie-apple.c      |  3 +--
 drivers/xen/grant-dma-ops.c              |  3 +--
 include/linux/of.h                       | 18 ++++++++++++++++
 9 files changed, 62 insertions(+), 16 deletions(-)

diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
index 91b95422b263..63b3544ec997 100644
--- a/drivers/cdx/cdx_msi.c
+++ b/drivers/cdx/cdx_msi.c
@@ -128,8 +128,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
 	int ret;
 
 	/* Retrieve device ID from requestor ID using parent device */
-	ret = of_map_id(parent->of_node, cdx_dev->msi_dev_id, "msi-map", "msi-map-mask",
-			NULL, &dev_id);
+	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, NULL, &dev_id);
 	if (ret) {
 		dev_err(dev, "of_map_id failed for MSI: %d\n", ret);
 		return ret;
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 6b989a62def2..a511ecf21fcd 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -48,9 +48,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
 	struct of_phandle_args iommu_spec = { .args_count = 1 };
 	int err;
 
-	err = of_map_id(master_np, *id, "iommu-map",
-			 "iommu-map-mask", &iommu_spec.np,
-			 iommu_spec.args);
+	err = of_map_iommu_id(master_np, *id, &iommu_spec.np, iommu_spec.args);
 	if (err)
 		return err;
 
diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
index d36b278ae66c..b63343a227a9 100644
--- a/drivers/irqchip/irq-gic-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-its-msi-parent.c
@@ -180,7 +180,7 @@ static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u
 
 	struct device_node *msi_ctrl __free(device_node) = NULL;
 
-	return of_map_id(dev->of_node, dev->id, "msi-map", "msi-map-mask", &msi_ctrl, dev_id);
+	return of_map_msi_id(dev->of_node, dev->id, &msi_ctrl, dev_id);
 }
 
 static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 57420806c1a2..959305a84748 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2201,3 +2201,39 @@ int of_map_id(const struct device_node *np, u32 id,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_map_id);
+
+/**
+ * of_map_iommu_id - Translate an ID using "iommu-map" bindings.
+ * @np: root complex device node.
+ * @id: device ID to map.
+ * @target: optional pointer to a target device node.
+ * @id_out: optional pointer to receive the translated ID.
+ *
+ * Convenience wrapper around of_map_id() using "iommu-map" and "iommu-map-mask".
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_iommu_id(const struct device_node *np, u32 id,
+		    struct device_node **target, u32 *id_out)
+{
+	return of_map_id(np, id, "iommu-map", "iommu-map-mask", target, id_out);
+}
+EXPORT_SYMBOL_GPL(of_map_iommu_id);
+
+/**
+ * of_map_msi_id - Translate an ID using "msi-map" bindings.
+ * @np: root complex device node.
+ * @id: device ID to map.
+ * @target: optional pointer to a target device node.
+ * @id_out: optional pointer to receive the translated ID.
+ *
+ * Convenience wrapper around of_map_id() using "msi-map" and "msi-map-mask".
+ *
+ * Return: 0 on success or a standard error code on failure.
+ */
+int of_map_msi_id(const struct device_node *np, u32 id,
+		  struct device_node **target, u32 *id_out)
+{
+	return of_map_id(np, id, "msi-map", "msi-map-mask", target, id_out);
+}
+EXPORT_SYMBOL_GPL(of_map_msi_id);
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 6367c67732d2..e37c1b3f8736 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -817,8 +817,7 @@ u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
 	 * "msi-map" or an "msi-parent" property.
 	 */
 	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
-		if (!of_map_id(parent_dev->of_node, id_in, "msi-map",
-				"msi-map-mask", msi_np, &id_out))
+		if (!of_map_msi_id(parent_dev->of_node, id_in, msi_np, &id_out))
 			break;
 		if (!of_check_msi_parent(parent_dev->of_node, msi_np))
 			break;
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index a5b8d0b71677..bff8289f804a 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1144,8 +1144,7 @@ static int imx_pcie_add_lut_by_rid(struct imx_pcie *imx_pcie, u32 rid)
 	u32 sid = 0;
 
 	target = NULL;
-	err_i = of_map_id(dev->of_node, rid, "iommu-map", "iommu-map-mask",
-			  &target, &sid_i);
+	err_i = of_map_iommu_id(dev->of_node, rid, &target, &sid_i);
 	if (target) {
 		of_node_put(target);
 	} else {
@@ -1158,8 +1157,7 @@ static int imx_pcie_add_lut_by_rid(struct imx_pcie *imx_pcie, u32 rid)
 	}
 
 	target = NULL;
-	err_m = of_map_id(dev->of_node, rid, "msi-map", "msi-map-mask",
-			  &target, &sid_m);
+	err_m = of_map_msi_id(dev->of_node, rid, &target, &sid_m);
 
 	/*
 	 *   err_m      target
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index 2d92fc79f6dd..a0937b7b3c4d 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -764,8 +764,7 @@ static int apple_pcie_enable_device(struct pci_host_bridge *bridge, struct pci_d
 	dev_dbg(&pdev->dev, "added to bus %s, index %d\n",
 		pci_name(pdev->bus->self), port->idx);
 
-	err = of_map_id(port->pcie->dev->of_node, rid, "iommu-map",
-			"iommu-map-mask", NULL, &sid);
+	err = of_map_iommu_id(port->pcie->dev->of_node, rid, NULL, &sid);
 	if (err)
 		return err;
 
diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
index c2603e700178..1b7696b2d762 100644
--- a/drivers/xen/grant-dma-ops.c
+++ b/drivers/xen/grant-dma-ops.c
@@ -325,8 +325,7 @@ static int xen_dt_grant_init_backend_domid(struct device *dev,
 		struct pci_dev *pdev = to_pci_dev(dev);
 		u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
 
-		if (of_map_id(np, rid, "iommu-map", "iommu-map-mask", &iommu_spec.np,
-				iommu_spec.args)) {
+		if (of_map_iommu_id(np, rid, &iommu_spec.np, iommu_spec.args)) {
 			dev_dbg(dev, "Cannot translate ID\n");
 			return -ESRCH;
 		}
diff --git a/include/linux/of.h b/include/linux/of.h
index be6ec4916adf..fe841f3cc747 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -465,6 +465,12 @@ int of_map_id(const struct device_node *np, u32 id,
 	       const char *map_name, const char *map_mask_name,
 	       struct device_node **target, u32 *id_out);
 
+int of_map_iommu_id(const struct device_node *np, u32 id,
+		    struct device_node **target, u32 *id_out);
+
+int of_map_msi_id(const struct device_node *np, u32 id,
+		  struct device_node **target, u32 *id_out);
+
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
 struct kimage;
@@ -934,6 +940,18 @@ static inline int of_map_id(const struct device_node *np, u32 id,
 	return -EINVAL;
 }
 
+static inline int of_map_iommu_id(const struct device_node *np, u32 id,
+				  struct device_node **target, u32 *id_out)
+{
+	return -EINVAL;
+}
+
+static inline int of_map_msi_id(const struct device_node *np, u32 id,
+				struct device_node **target, u32 *id_out)
+{
+	return -EINVAL;
+}
+
 static inline phys_addr_t of_dma_get_max_cpu_address(struct device_node *np)
 {
 	return PHYS_ADDR_MAX;

-- 
2.34.1

Re: [PATCH v10 1/3] of: Add convenience wrappers for of_map_id()

[Dmitry Baryshkov]

On Mon, Mar 09, 2026 at 01:03:37AM +0530, Vijayanand Jitta wrote:
> From: Robin Murphy <robin.murphy@arm.com>
> 
> Since we now have quite a few users parsing "iommu-map" and "msi-map"
> properties, give them some wrappers to conveniently encapsulate the
> appropriate sets of property names. This will also make it easier to
> then change of_map_id() to correctly account for specifier cells.
> 
> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
> ---
>  drivers/cdx/cdx_msi.c                    |  3 +--
>  drivers/iommu/of_iommu.c                 |  4 +---
>  drivers/irqchip/irq-gic-its-msi-parent.c |  2 +-
>  drivers/of/base.c                        | 36 ++++++++++++++++++++++++++++++++
>  drivers/of/irq.c                         |  3 +--
>  drivers/pci/controller/dwc/pci-imx6.c    |  6 ++----
>  drivers/pci/controller/pcie-apple.c      |  3 +--
>  drivers/xen/grant-dma-ops.c              |  3 +--
>  include/linux/of.h                       | 18 ++++++++++++++++
>  9 files changed, 62 insertions(+), 16 deletions(-)
> 
> +
> +/**
> + * of_map_msi_id - Translate an ID using "msi-map" bindings.

Which ID are we talking about wrt. MSI interrupts?

> + * @np: root complex device node.
> + * @id: device ID to map.
> + * @target: optional pointer to a target device node.
> + * @id_out: optional pointer to receive the translated ID.
> + *
> + * Convenience wrapper around of_map_id() using "msi-map" and "msi-map-mask".
> + *
> + * Return: 0 on success or a standard error code on failure.
> + */
> +int of_map_msi_id(const struct device_node *np, u32 id,
> +		  struct device_node **target, u32 *id_out)
> +{
> +	return of_map_id(np, id, "msi-map", "msi-map-mask", target, id_out);
> +}
> +EXPORT_SYMBOL_GPL(of_map_msi_id);

-- 
With best wishes
Dmitry

Re: [PATCH v10 1/3] of: Add convenience wrappers for of_map_id()

[Vijayanand Jitta]

On 3/10/2026 2:46 AM, Dmitry Baryshkov wrote:
> On Mon, Mar 09, 2026 at 01:03:37AM +0530, Vijayanand Jitta wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>>
>> Since we now have quite a few users parsing "iommu-map" and "msi-map"
>> properties, give them some wrappers to conveniently encapsulate the
>> appropriate sets of property names. This will also make it easier to
>> then change of_map_id() to correctly account for specifier cells.
>>
>> Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
>> Reviewed-by: Frank Li <Frank.Li@nxp.com>
>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
>> ---
>>  drivers/cdx/cdx_msi.c                    |  3 +--
>>  drivers/iommu/of_iommu.c                 |  4 +---
>>  drivers/irqchip/irq-gic-its-msi-parent.c |  2 +-
>>  drivers/of/base.c                        | 36 ++++++++++++++++++++++++++++++++
>>  drivers/of/irq.c                         |  3 +--
>>  drivers/pci/controller/dwc/pci-imx6.c    |  6 ++----
>>  drivers/pci/controller/pcie-apple.c      |  3 +--
>>  drivers/xen/grant-dma-ops.c              |  3 +--
>>  include/linux/of.h                       | 18 ++++++++++++++++
>>  9 files changed, 62 insertions(+), 16 deletions(-)
>>
>> +
>> +/**
>> + * of_map_msi_id - Translate an ID using "msi-map" bindings.
> 
> Which ID are we talking about wrt. MSI interrupts?
> 

id refers to the device’s requester ID (RID/BDF or platform stream ID),
not an MSI interrupt number; it is the key used in msi-map to obtain
the translated MSI device ID (id_out).

I'll update the kernel doc as below to clarify.


* @id: Requester ID of the device (e.g. PCI RID/BDF or a platform
*      stream/device ID) used as the lookup key in the msi-map table.

Thanks,
Vijay

>> + * @np: root complex device node.
>> + * @id: device ID to map.
>> + * @target: optional pointer to a target device node.
>> + * @id_out: optional pointer to receive the translated ID.
>> + *
>> + * Convenience wrapper around of_map_id() using "msi-map" and "msi-map-mask".
>> + *
>> + * Return: 0 on success or a standard error code on failure.
>> + */
>> +int of_map_msi_id(const struct device_node *np, u32 id,
>> +		  struct device_node **target, u32 *id_out)
>> +{
>> +	return of_map_id(np, id, "msi-map", "msi-map-mask", target, id_out);
>> +}
>> +EXPORT_SYMBOL_GPL(of_map_msi_id);
> 

[PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Vijayanand Jitta]

From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>

Change of_map_id() to take a pointer to struct of_phandle_args
instead of passing target device node and translated IDs separately.
Update all callers accordingly.

Subsequent patch will make use of the args_count field in
struct of_phandle_args.

Suggested-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
---
 drivers/cdx/cdx_msi.c                    |  5 ++-
 drivers/iommu/of_iommu.c                 |  2 +-
 drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
 drivers/of/base.c                        | 63 ++++++++++++++++----------------
 drivers/of/irq.c                         |  8 +++-
 drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
 drivers/pci/controller/pcie-apple.c      |  5 ++-
 drivers/xen/grant-dma-ops.c              |  4 +-
 include/linux/of.h                       | 12 +++---
 9 files changed, 76 insertions(+), 50 deletions(-)

diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
index 63b3544ec997..03232b5ffbca 100644
--- a/drivers/cdx/cdx_msi.c
+++ b/drivers/cdx/cdx_msi.c
@@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
 			   struct device *dev,
 			   int nvec, msi_alloc_info_t *info)
 {
+	struct of_phandle_args msi_spec = { .np = NULL };
 	struct cdx_device *cdx_dev = to_cdx_device(dev);
 	struct device *parent = cdx_dev->cdx->dev;
 	struct msi_domain_info *msi_info;
@@ -128,11 +129,13 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
 	int ret;
 
 	/* Retrieve device ID from requestor ID using parent device */
-	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, NULL, &dev_id);
+	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, &msi_spec);
 	if (ret) {
 		dev_err(dev, "of_map_id failed for MSI: %d\n", ret);
 		return ret;
 	}
+	of_node_put(msi_spec.np);
+	dev_id = msi_spec.args[0];
 
 #ifdef GENERIC_MSI_DOMAIN_OPS
 	/* Set the device Id to be passed to the GIC-ITS */
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index a511ecf21fcd..d255d0f58e8c 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -48,7 +48,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
 	struct of_phandle_args iommu_spec = { .args_count = 1 };
 	int err;
 
-	err = of_map_iommu_id(master_np, *id, &iommu_spec.np, iommu_spec.args);
+	err = of_map_iommu_id(master_np, *id, &iommu_spec);
 	if (err)
 		return err;
 
diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
index b63343a227a9..729fa2f9f758 100644
--- a/drivers/irqchip/irq-gic-its-msi-parent.c
+++ b/drivers/irqchip/irq-gic-its-msi-parent.c
@@ -152,6 +152,8 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
 static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u32 *dev_id,
 				phys_addr_t *pa)
 {
+	struct device_node *msi_ctrl __free(device_node) = NULL;
+	struct of_phandle_args msi_spec = { .np = NULL };
 	struct of_phandle_iterator it;
 	int ret;
 
@@ -178,9 +180,12 @@ static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u
 		}
 	}
 
-	struct device_node *msi_ctrl __free(device_node) = NULL;
-
-	return of_map_msi_id(dev->of_node, dev->id, &msi_ctrl, dev_id);
+	ret = of_map_msi_id(dev->of_node, dev->id, &msi_spec);
+	if (!ret) {
+		msi_ctrl = msi_spec.np;
+		*dev_id = msi_spec.args[0];
+	}
+	return ret;
 }
 
 static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 959305a84748..b6e07c5fe715 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2102,36 +2102,37 @@ int of_find_last_cache_level(unsigned int cpu)
  * @id: device ID to map.
  * @map_name: property name of the map to use.
  * @map_mask_name: optional property name of the mask to use.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @arg: pointer to a &struct of_phandle_args. On input, @arg->np may be
+ *	set to a target device node to match, or NULL to match any. On
+ *	success, @arg->np will be set to the matched target node (with a
+ *	reference held) and @arg->args[0] will contain the translated ID.
  *
  * Given a device ID, look up the appropriate implementation-defined
  * platform ID and/or the target device which receives transactions on that
- * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
- * @id_out may be NULL if only the other is required. If @target points to
- * a non-NULL device node pointer, only entries targeting that node will be
- * matched; if it points to a NULL value, it will receive the device node of
- * the first matching target phandle, with a reference held.
+ * ID, as per the "iommu-map" and "msi-map" bindings. If @arg->np points to
+ * a non-NULL device node, only entries targeting that node will be matched;
+ * if it is NULL, it will receive the device node of the first matching
+ * target phandle, with a reference held.
  *
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_id(const struct device_node *np, u32 id,
 	       const char *map_name, const char *map_mask_name,
-	       struct device_node **target, u32 *id_out)
+	       struct of_phandle_args *arg)
 {
 	u32 map_mask, masked_id;
 	int map_len;
 	const __be32 *map = NULL;
 
-	if (!np || !map_name || (!target && !id_out))
+	if (!np || !map_name || !arg)
 		return -EINVAL;
 
 	map = of_get_property(np, map_name, &map_len);
 	if (!map) {
-		if (target)
+		if (arg->np)
 			return -ENODEV;
 		/* Otherwise, no map implies no translation */
-		*id_out = id;
+		arg->args[0] = id;
 		return 0;
 	}
 
@@ -2173,18 +2174,15 @@ int of_map_id(const struct device_node *np, u32 id,
 		if (!phandle_node)
 			return -ENODEV;
 
-		if (target) {
-			if (*target)
-				of_node_put(phandle_node);
-			else
-				*target = phandle_node;
+		if (arg->np)
+			of_node_put(phandle_node);
+		else
+			arg->np = phandle_node;
 
-			if (*target != phandle_node)
-				continue;
-		}
+		if (arg->np != phandle_node)
+			continue;
 
-		if (id_out)
-			*id_out = masked_id - id_base + out_base;
+		arg->args[0] = masked_id - id_base + out_base;
 
 		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
 			np, map_name, map_mask, id_base, out_base,
@@ -2193,11 +2191,10 @@ int of_map_id(const struct device_node *np, u32 id,
 	}
 
 	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
-		id, target && *target ? *target : NULL);
+		id, arg->np);
 
 	/* Bypasses translation */
-	if (id_out)
-		*id_out = id;
+	arg->args[0] = id;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(of_map_id);
@@ -2206,17 +2203,18 @@ EXPORT_SYMBOL_GPL(of_map_id);
  * of_map_iommu_id - Translate an ID using "iommu-map" bindings.
  * @np: root complex device node.
  * @id: device ID to map.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->np holds a reference to the target node that the caller must
+ *	release with of_node_put().
  *
  * Convenience wrapper around of_map_id() using "iommu-map" and "iommu-map-mask".
  *
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_iommu_id(const struct device_node *np, u32 id,
-		    struct device_node **target, u32 *id_out)
+		    struct of_phandle_args *arg)
 {
-	return of_map_id(np, id, "iommu-map", "iommu-map-mask", target, id_out);
+	return of_map_id(np, id, "iommu-map", "iommu-map-mask", arg);
 }
 EXPORT_SYMBOL_GPL(of_map_iommu_id);
 
@@ -2224,16 +2222,17 @@ EXPORT_SYMBOL_GPL(of_map_iommu_id);
  * of_map_msi_id - Translate an ID using "msi-map" bindings.
  * @np: root complex device node.
  * @id: device ID to map.
- * @target: optional pointer to a target device node.
- * @id_out: optional pointer to receive the translated ID.
+ * @arg: pointer to a &struct of_phandle_args for the result. On success,
+ *	@arg->np holds a reference to the target node that the caller must
+ *	release with of_node_put().
  *
  * Convenience wrapper around of_map_id() using "msi-map" and "msi-map-mask".
  *
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_msi_id(const struct device_node *np, u32 id,
-		  struct device_node **target, u32 *id_out)
+		  struct of_phandle_args *arg)
 {
-	return of_map_id(np, id, "msi-map", "msi-map-mask", target, id_out);
+	return of_map_id(np, id, "msi-map", "msi-map-mask", arg);
 }
 EXPORT_SYMBOL_GPL(of_map_msi_id);
diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index e37c1b3f8736..18248c3d76ae 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -817,8 +817,14 @@ u32 of_msi_xlate(struct device *dev, struct device_node **msi_np, u32 id_in)
 	 * "msi-map" or an "msi-parent" property.
 	 */
 	for (parent_dev = dev; parent_dev; parent_dev = parent_dev->parent) {
-		if (!of_map_msi_id(parent_dev->of_node, id_in, msi_np, &id_out))
+		struct of_phandle_args msi_spec = { .np = *msi_np };
+
+		if (!of_map_msi_id(parent_dev->of_node, id_in, &msi_spec)) {
+			id_out = msi_spec.args[0];
+			if (!*msi_np && msi_spec.np)
+				*msi_np = msi_spec.np;
 			break;
+		}
 		if (!of_check_msi_parent(parent_dev->of_node, msi_np))
 			break;
 	}
diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
index bff8289f804a..5f8a11774eb5 100644
--- a/drivers/pci/controller/dwc/pci-imx6.c
+++ b/drivers/pci/controller/dwc/pci-imx6.c
@@ -1137,6 +1137,8 @@ static void imx_pcie_remove_lut(struct imx_pcie *imx_pcie, u16 rid)
 
 static int imx_pcie_add_lut_by_rid(struct imx_pcie *imx_pcie, u32 rid)
 {
+	struct of_phandle_args iommu_spec = { .np = NULL };
+	struct of_phandle_args msi_spec = { .np = NULL };
 	struct device *dev = imx_pcie->pci->dev;
 	struct device_node *target;
 	u32 sid_i, sid_m;
@@ -1144,7 +1146,12 @@ static int imx_pcie_add_lut_by_rid(struct imx_pcie *imx_pcie, u32 rid)
 	u32 sid = 0;
 
 	target = NULL;
-	err_i = of_map_iommu_id(dev->of_node, rid, &target, &sid_i);
+	err_i = of_map_iommu_id(dev->of_node, rid, &iommu_spec);
+	if (!err_i) {
+		target = iommu_spec.np;
+		sid_i = iommu_spec.args[0];
+	}
+
 	if (target) {
 		of_node_put(target);
 	} else {
@@ -1156,8 +1163,11 @@ static int imx_pcie_add_lut_by_rid(struct imx_pcie *imx_pcie, u32 rid)
 		err_i = -EINVAL;
 	}
 
-	target = NULL;
-	err_m = of_map_msi_id(dev->of_node, rid, &target, &sid_m);
+	err_m = of_map_msi_id(dev->of_node, rid, &msi_spec);
+	if (!err_m) {
+		target = msi_spec.np;
+		sid_m = msi_spec.args[0];
+	}
 
 	/*
 	 *   err_m      target
diff --git a/drivers/pci/controller/pcie-apple.c b/drivers/pci/controller/pcie-apple.c
index a0937b7b3c4d..2e86f8fd300b 100644
--- a/drivers/pci/controller/pcie-apple.c
+++ b/drivers/pci/controller/pcie-apple.c
@@ -755,6 +755,7 @@ static int apple_pcie_enable_device(struct pci_host_bridge *bridge, struct pci_d
 {
 	u32 sid, rid = pci_dev_id(pdev);
 	struct apple_pcie_port *port;
+	struct of_phandle_args iommu_spec = { .np = NULL };
 	int idx, err;
 
 	port = apple_pcie_get_port(pdev);
@@ -764,10 +765,12 @@ static int apple_pcie_enable_device(struct pci_host_bridge *bridge, struct pci_d
 	dev_dbg(&pdev->dev, "added to bus %s, index %d\n",
 		pci_name(pdev->bus->self), port->idx);
 
-	err = of_map_iommu_id(port->pcie->dev->of_node, rid, NULL, &sid);
+	err = of_map_iommu_id(port->pcie->dev->of_node, rid, &iommu_spec);
 	if (err)
 		return err;
 
+	of_node_put(iommu_spec.np);
+	sid = iommu_spec.args[0];
 	mutex_lock(&port->pcie->lock);
 
 	idx = bitmap_find_free_region(port->sid_map, port->sid_map_sz, 0);
diff --git a/drivers/xen/grant-dma-ops.c b/drivers/xen/grant-dma-ops.c
index 1b7696b2d762..36547d7cf1d6 100644
--- a/drivers/xen/grant-dma-ops.c
+++ b/drivers/xen/grant-dma-ops.c
@@ -319,13 +319,13 @@ static int xen_dt_grant_init_backend_domid(struct device *dev,
 					   struct device_node *np,
 					   domid_t *backend_domid)
 {
-	struct of_phandle_args iommu_spec = { .args_count = 1 };
+	struct of_phandle_args iommu_spec = { .np = NULL };
 
 	if (dev_is_pci(dev)) {
 		struct pci_dev *pdev = to_pci_dev(dev);
 		u32 rid = PCI_DEVID(pdev->bus->number, pdev->devfn);
 
-		if (of_map_iommu_id(np, rid, &iommu_spec.np, iommu_spec.args)) {
+		if (of_map_iommu_id(np, rid, &iommu_spec)) {
 			dev_dbg(dev, "Cannot translate ID\n");
 			return -ESRCH;
 		}
diff --git a/include/linux/of.h b/include/linux/of.h
index fe841f3cc747..f50d7a3a3b28 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -463,13 +463,13 @@ bool of_console_check(const struct device_node *dn, char *name, int index);
 
 int of_map_id(const struct device_node *np, u32 id,
 	       const char *map_name, const char *map_mask_name,
-	       struct device_node **target, u32 *id_out);
+	       struct of_phandle_args *arg);
 
 int of_map_iommu_id(const struct device_node *np, u32 id,
-		    struct device_node **target, u32 *id_out);
+		    struct of_phandle_args *arg);
 
 int of_map_msi_id(const struct device_node *np, u32 id,
-		  struct device_node **target, u32 *id_out);
+		  struct of_phandle_args *arg);
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
@@ -935,19 +935,19 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag
 
 static inline int of_map_id(const struct device_node *np, u32 id,
 			     const char *map_name, const char *map_mask_name,
-			     struct device_node **target, u32 *id_out)
+			     struct of_phandle_args *arg)
 {
 	return -EINVAL;
 }
 
 static inline int of_map_iommu_id(const struct device_node *np, u32 id,
-				  struct device_node **target, u32 *id_out)
+				  struct of_phandle_args *arg)
 {
 	return -EINVAL;
 }
 
 static inline int of_map_msi_id(const struct device_node *np, u32 id,
-				struct device_node **target, u32 *id_out)
+				struct of_phandle_args *arg)
 {
 	return -EINVAL;
 }

-- 
2.34.1

Re: [PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Dmitry Baryshkov]

On Mon, Mar 09, 2026 at 01:03:38AM +0530, Vijayanand Jitta wrote:
> From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
> 
> Change of_map_id() to take a pointer to struct of_phandle_args
> instead of passing target device node and translated IDs separately.
> Update all callers accordingly.
> 
> Subsequent patch will make use of the args_count field in
> struct of_phandle_args.
> 
> Suggested-by: Rob Herring (Arm) <robh@kernel.org>
> Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
> ---
>  drivers/cdx/cdx_msi.c                    |  5 ++-
>  drivers/iommu/of_iommu.c                 |  2 +-
>  drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
>  drivers/of/base.c                        | 63 ++++++++++++++++----------------
>  drivers/of/irq.c                         |  8 +++-
>  drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
>  drivers/pci/controller/pcie-apple.c      |  5 ++-
>  drivers/xen/grant-dma-ops.c              |  4 +-
>  include/linux/of.h                       | 12 +++---
>  9 files changed, 76 insertions(+), 50 deletions(-)
> 
> diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
> index 63b3544ec997..03232b5ffbca 100644
> --- a/drivers/cdx/cdx_msi.c
> +++ b/drivers/cdx/cdx_msi.c
> @@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
>  			   struct device *dev,
>  			   int nvec, msi_alloc_info_t *info)
>  {
> +	struct of_phandle_args msi_spec = { .np = NULL };

Why do you need to set it? Parse functions ignore passed args, don't
they?

>  	struct cdx_device *cdx_dev = to_cdx_device(dev);
>  	struct device *parent = cdx_dev->cdx->dev;
>  	struct msi_domain_info *msi_info;
> @@ -128,11 +129,13 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
>  	int ret;
>  
>  	/* Retrieve device ID from requestor ID using parent device */
> -	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, NULL, &dev_id);
> +	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, &msi_spec);
>  	if (ret) {
>  		dev_err(dev, "of_map_id failed for MSI: %d\n", ret);
>  		return ret;
>  	}
> +	of_node_put(msi_spec.np);
> +	dev_id = msi_spec.args[0];
>  
>  #ifdef GENERIC_MSI_DOMAIN_OPS
>  	/* Set the device Id to be passed to the GIC-ITS */
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> index a511ecf21fcd..d255d0f58e8c 100644
> --- a/drivers/iommu/of_iommu.c
> +++ b/drivers/iommu/of_iommu.c
> @@ -48,7 +48,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
>  	struct of_phandle_args iommu_spec = { .args_count = 1 };

.args_count = 1 should be set by of_map_iommu_id now (and dropped here).

>  	int err;
>  
> -	err = of_map_iommu_id(master_np, *id, &iommu_spec.np, iommu_spec.args);
> +	err = of_map_iommu_id(master_np, *id, &iommu_spec);
>  	if (err)
>  		return err;
>  
> diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
> index b63343a227a9..729fa2f9f758 100644
> --- a/drivers/irqchip/irq-gic-its-msi-parent.c
> +++ b/drivers/irqchip/irq-gic-its-msi-parent.c
> @@ -152,6 +152,8 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
>  static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u32 *dev_id,
>  				phys_addr_t *pa)
>  {
> +	struct device_node *msi_ctrl __free(device_node) = NULL;
> +	struct of_phandle_args msi_spec = { .np = NULL };
>  	struct of_phandle_iterator it;
>  	int ret;
>  
> @@ -178,9 +180,12 @@ static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u
>  		}
>  	}
>  
> -	struct device_node *msi_ctrl __free(device_node) = NULL;
> -
> -	return of_map_msi_id(dev->of_node, dev->id, &msi_ctrl, dev_id);
> +	ret = of_map_msi_id(dev->of_node, dev->id, &msi_spec);
> +	if (!ret) {
> +		msi_ctrl = msi_spec.np;
> +		*dev_id = msi_spec.args[0];
> +	}
> +	return ret;
>  }
>  
>  static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 959305a84748..b6e07c5fe715 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -2102,36 +2102,37 @@ int of_find_last_cache_level(unsigned int cpu)
>   * @id: device ID to map.
>   * @map_name: property name of the map to use.
>   * @map_mask_name: optional property name of the mask to use.
> - * @target: optional pointer to a target device node.
> - * @id_out: optional pointer to receive the translated ID.
> + * @arg: pointer to a &struct of_phandle_args. On input, @arg->np may be
> + *	set to a target device node to match, or NULL to match any. On
> + *	success, @arg->np will be set to the matched target node (with a
> + *	reference held) and @arg->args[0] will contain the translated ID.

Is this part being actually used (and useful)?

>   *
>   * Given a device ID, look up the appropriate implementation-defined
>   * platform ID and/or the target device which receives transactions on that
> - * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
> - * @id_out may be NULL if only the other is required. If @target points to
> - * a non-NULL device node pointer, only entries targeting that node will be
> - * matched; if it points to a NULL value, it will receive the device node of
> - * the first matching target phandle, with a reference held.
> + * ID, as per the "iommu-map" and "msi-map" bindings. If @arg->np points to
> + * a non-NULL device node, only entries targeting that node will be matched;
> + * if it is NULL, it will receive the device node of the first matching
> + * target phandle, with a reference held.
>   *
>   * Return: 0 on success or a standard error code on failure.
>   */
>  int of_map_id(const struct device_node *np, u32 id,
>  	       const char *map_name, const char *map_mask_name,
> -	       struct device_node **target, u32 *id_out)
> +	       struct of_phandle_args *arg)
>  {
>  	u32 map_mask, masked_id;
>  	int map_len;
>  	const __be32 *map = NULL;
>  
> -	if (!np || !map_name || (!target && !id_out))
> +	if (!np || !map_name || !arg)
>  		return -EINVAL;
>  
>  	map = of_get_property(np, map_name, &map_len);
>  	if (!map) {
> -		if (target)
> +		if (arg->np)
>  			return -ENODEV;
>  		/* Otherwise, no map implies no translation */
> -		*id_out = id;
> +		arg->args[0] = id;
>  		return 0;
>  	}
>  
> @@ -2173,18 +2174,15 @@ int of_map_id(const struct device_node *np, u32 id,
>  		if (!phandle_node)
>  			return -ENODEV;
>  
> -		if (target) {
> -			if (*target)
> -				of_node_put(phandle_node);
> -			else
> -				*target = phandle_node;
> +		if (arg->np)
> +			of_node_put(phandle_node);
> +		else
> +			arg->np = phandle_node;
>  
> -			if (*target != phandle_node)
> -				continue;
> -		}
> +		if (arg->np != phandle_node)
> +			continue;
>  
> -		if (id_out)
> -			*id_out = masked_id - id_base + out_base;
> +		arg->args[0] = masked_id - id_base + out_base;
>  
>  		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
>  			np, map_name, map_mask, id_base, out_base,

-- 
With best wishes
Dmitry

Re: [PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Vijayanand Jitta]

On 3/10/2026 2:53 AM, Dmitry Baryshkov wrote:
> On Mon, Mar 09, 2026 at 01:03:38AM +0530, Vijayanand Jitta wrote:
>> From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
>>
>> Change of_map_id() to take a pointer to struct of_phandle_args
>> instead of passing target device node and translated IDs separately.
>> Update all callers accordingly.
>>
>> Subsequent patch will make use of the args_count field in
>> struct of_phandle_args.
>>
>> Suggested-by: Rob Herring (Arm) <robh@kernel.org>
>> Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
>> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
>> ---
>>  drivers/cdx/cdx_msi.c                    |  5 ++-
>>  drivers/iommu/of_iommu.c                 |  2 +-
>>  drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
>>  drivers/of/base.c                        | 63 ++++++++++++++++----------------
>>  drivers/of/irq.c                         |  8 +++-
>>  drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
>>  drivers/pci/controller/pcie-apple.c      |  5 ++-
>>  drivers/xen/grant-dma-ops.c              |  4 +-
>>  include/linux/of.h                       | 12 +++---
>>  9 files changed, 76 insertions(+), 50 deletions(-)
>>
>> diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
>> index 63b3544ec997..03232b5ffbca 100644
>> --- a/drivers/cdx/cdx_msi.c
>> +++ b/drivers/cdx/cdx_msi.c
>> @@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
>>  			   struct device *dev,
>>  			   int nvec, msi_alloc_info_t *info)
>>  {
>> +	struct of_phandle_args msi_spec = { .np = NULL };
> 
> Why do you need to set it? Parse functions ignore passed args, don't
> they?
> 

The parse function does check arg->np on input — if it is non-NULL,
it is used to match only entries targeting that specific node.

Also, there is this existing path in drivers/pci/msi/irqdomain.c which
pre-sets the node and passes it as input to of_msi_xlate(), so the node
pointer is not ignored by the parse code:

u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
{
        struct device_node *of_node;
        u32 rid = pci_dev_id(pdev);

        pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);

        of_node = irq_domain_get_of_node(domain);
        rid = of_node ? of_msi_xlate(&pdev->dev, &of_node, rid) :
                        iort_msi_map_id(&pdev->dev, rid);

        return rid;
}

>>  	struct cdx_device *cdx_dev = to_cdx_device(dev);
>>  	struct device *parent = cdx_dev->cdx->dev;
>>  	struct msi_domain_info *msi_info;
>> @@ -128,11 +129,13 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
>>  	int ret;
>>  
>>  	/* Retrieve device ID from requestor ID using parent device */
>> -	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, NULL, &dev_id);
>> +	ret = of_map_msi_id(parent->of_node, cdx_dev->msi_dev_id, &msi_spec);
>>  	if (ret) {
>>  		dev_err(dev, "of_map_id failed for MSI: %d\n", ret);
>>  		return ret;
>>  	}
>> +	of_node_put(msi_spec.np);
>> +	dev_id = msi_spec.args[0];
>>  
>>  #ifdef GENERIC_MSI_DOMAIN_OPS
>>  	/* Set the device Id to be passed to the GIC-ITS */
>> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
>> index a511ecf21fcd..d255d0f58e8c 100644
>> --- a/drivers/iommu/of_iommu.c
>> +++ b/drivers/iommu/of_iommu.c
>> @@ -48,7 +48,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
>>  	struct of_phandle_args iommu_spec = { .args_count = 1 };
> 
> .args_count = 1 should be set by of_map_iommu_id now (and dropped here).
> 

Sure, will move it.

>>  	int err;
>>  
>> -	err = of_map_iommu_id(master_np, *id, &iommu_spec.np, iommu_spec.args);
>> +	err = of_map_iommu_id(master_np, *id, &iommu_spec);
>>  	if (err)
>>  		return err;
>>  
>> diff --git a/drivers/irqchip/irq-gic-its-msi-parent.c b/drivers/irqchip/irq-gic-its-msi-parent.c
>> index b63343a227a9..729fa2f9f758 100644
>> --- a/drivers/irqchip/irq-gic-its-msi-parent.c
>> +++ b/drivers/irqchip/irq-gic-its-msi-parent.c
>> @@ -152,6 +152,8 @@ static int its_v5_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
>>  static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u32 *dev_id,
>>  				phys_addr_t *pa)
>>  {
>> +	struct device_node *msi_ctrl __free(device_node) = NULL;
>> +	struct of_phandle_args msi_spec = { .np = NULL };
>>  	struct of_phandle_iterator it;
>>  	int ret;
>>  
>> @@ -178,9 +180,12 @@ static int of_pmsi_get_msi_info(struct irq_domain *domain, struct device *dev, u
>>  		}
>>  	}
>>  
>> -	struct device_node *msi_ctrl __free(device_node) = NULL;
>> -
>> -	return of_map_msi_id(dev->of_node, dev->id, &msi_ctrl, dev_id);
>> +	ret = of_map_msi_id(dev->of_node, dev->id, &msi_spec);
>> +	if (!ret) {
>> +		msi_ctrl = msi_spec.np;
>> +		*dev_id = msi_spec.args[0];
>> +	}
>> +	return ret;
>>  }
>>  
>>  static int its_pmsi_prepare(struct irq_domain *domain, struct device *dev,
>> diff --git a/drivers/of/base.c b/drivers/of/base.c
>> index 959305a84748..b6e07c5fe715 100644
>> --- a/drivers/of/base.c
>> +++ b/drivers/of/base.c
>> @@ -2102,36 +2102,37 @@ int of_find_last_cache_level(unsigned int cpu)
>>   * @id: device ID to map.
>>   * @map_name: property name of the map to use.
>>   * @map_mask_name: optional property name of the mask to use.
>> - * @target: optional pointer to a target device node.
>> - * @id_out: optional pointer to receive the translated ID.
>> + * @arg: pointer to a &struct of_phandle_args. On input, @arg->np may be
>> + *	set to a target device node to match, or NULL to match any. On
>> + *	success, @arg->np will be set to the matched target node (with a
>> + *	reference held) and @arg->args[0] will contain the translated ID.
> 
> Is this part being actually used (and useful)?
> 

Please refer the above comment. I see there is existing path in
drivers/pci/msi/irqdomain.c which sets np.

Thanks,
Vijay

>>   *
>>   * Given a device ID, look up the appropriate implementation-defined
>>   * platform ID and/or the target device which receives transactions on that
>> - * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
>> - * @id_out may be NULL if only the other is required. If @target points to
>> - * a non-NULL device node pointer, only entries targeting that node will be
>> - * matched; if it points to a NULL value, it will receive the device node of
>> - * the first matching target phandle, with a reference held.
>> + * ID, as per the "iommu-map" and "msi-map" bindings. If @arg->np points to
>> + * a non-NULL device node, only entries targeting that node will be matched;
>> + * if it is NULL, it will receive the device node of the first matching
>> + * target phandle, with a reference held.
>>   *
>>   * Return: 0 on success or a standard error code on failure.
>>   */
>>  int of_map_id(const struct device_node *np, u32 id,
>>  	       const char *map_name, const char *map_mask_name,
>> -	       struct device_node **target, u32 *id_out)
>> +	       struct of_phandle_args *arg)
>>  {
>>  	u32 map_mask, masked_id;
>>  	int map_len;
>>  	const __be32 *map = NULL;
>>  
>> -	if (!np || !map_name || (!target && !id_out))
>> +	if (!np || !map_name || !arg)
>>  		return -EINVAL;
>>  
>>  	map = of_get_property(np, map_name, &map_len);
>>  	if (!map) {
>> -		if (target)
>> +		if (arg->np)
>>  			return -ENODEV;
>>  		/* Otherwise, no map implies no translation */
>> -		*id_out = id;
>> +		arg->args[0] = id;
>>  		return 0;
>>  	}
>>  
>> @@ -2173,18 +2174,15 @@ int of_map_id(const struct device_node *np, u32 id,
>>  		if (!phandle_node)
>>  			return -ENODEV;
>>  
>> -		if (target) {
>> -			if (*target)
>> -				of_node_put(phandle_node);
>> -			else
>> -				*target = phandle_node;
>> +		if (arg->np)
>> +			of_node_put(phandle_node);
>> +		else
>> +			arg->np = phandle_node;
>>  
>> -			if (*target != phandle_node)
>> -				continue;
>> -		}
>> +		if (arg->np != phandle_node)
>> +			continue;
>>  
>> -		if (id_out)
>> -			*id_out = masked_id - id_base + out_base;
>> +		arg->args[0] = masked_id - id_base + out_base;
>>  
>>  		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
>>  			np, map_name, map_mask, id_base, out_base,
> 

Re: [PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Dmitry Baryshkov]

On Thu, Mar 12, 2026 at 05:12:51PM +0530, Vijayanand Jitta wrote:
> 
> 
> On 3/10/2026 2:53 AM, Dmitry Baryshkov wrote:
> > On Mon, Mar 09, 2026 at 01:03:38AM +0530, Vijayanand Jitta wrote:
> >> From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
> >>
> >> Change of_map_id() to take a pointer to struct of_phandle_args
> >> instead of passing target device node and translated IDs separately.
> >> Update all callers accordingly.
> >>
> >> Subsequent patch will make use of the args_count field in
> >> struct of_phandle_args.
> >>
> >> Suggested-by: Rob Herring (Arm) <robh@kernel.org>
> >> Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
> >> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
> >> ---
> >>  drivers/cdx/cdx_msi.c                    |  5 ++-
> >>  drivers/iommu/of_iommu.c                 |  2 +-
> >>  drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
> >>  drivers/of/base.c                        | 63 ++++++++++++++++----------------
> >>  drivers/of/irq.c                         |  8 +++-
> >>  drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
> >>  drivers/pci/controller/pcie-apple.c      |  5 ++-
> >>  drivers/xen/grant-dma-ops.c              |  4 +-
> >>  include/linux/of.h                       | 12 +++---
> >>  9 files changed, 76 insertions(+), 50 deletions(-)
> >>
> >> diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
> >> index 63b3544ec997..03232b5ffbca 100644
> >> --- a/drivers/cdx/cdx_msi.c
> >> +++ b/drivers/cdx/cdx_msi.c
> >> @@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
> >>  			   struct device *dev,
> >>  			   int nvec, msi_alloc_info_t *info)
> >>  {
> >> +	struct of_phandle_args msi_spec = { .np = NULL };
> > 
> > Why do you need to set it? Parse functions ignore passed args, don't
> > they?
> > 
> 
> The parse function does check arg->np on input — if it is non-NULL,
> it is used to match only entries targeting that specific node.
> 
> Also, there is this existing path in drivers/pci/msi/irqdomain.c which
> pre-sets the node and passes it as input to of_msi_xlate(), so the node
> pointer is not ignored by the parse code:

Is it only being used for MSIs? If so, can we make that explicit in the
API by having the 'filter' device_node pointer?

> 
> u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
> {
>         struct device_node *of_node;
>         u32 rid = pci_dev_id(pdev);
> 
>         pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
> 
>         of_node = irq_domain_get_of_node(domain);
>         rid = of_node ? of_msi_xlate(&pdev->dev, &of_node, rid) :
>                         iort_msi_map_id(&pdev->dev, rid);
> 
>         return rid;
> }
> 

-- 
With best wishes
Dmitry

Re: [PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Vijayanand Jitta]

On 3/12/2026 7:48 PM, Dmitry Baryshkov wrote:
> On Thu, Mar 12, 2026 at 05:12:51PM +0530, Vijayanand Jitta wrote:
>>
>>
>> On 3/10/2026 2:53 AM, Dmitry Baryshkov wrote:
>>> On Mon, Mar 09, 2026 at 01:03:38AM +0530, Vijayanand Jitta wrote:
>>>> From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
>>>>
>>>> Change of_map_id() to take a pointer to struct of_phandle_args
>>>> instead of passing target device node and translated IDs separately.
>>>> Update all callers accordingly.
>>>>
>>>> Subsequent patch will make use of the args_count field in
>>>> struct of_phandle_args.
>>>>
>>>> Suggested-by: Rob Herring (Arm) <robh@kernel.org>
>>>> Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
>>>> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
>>>> ---
>>>>  drivers/cdx/cdx_msi.c                    |  5 ++-
>>>>  drivers/iommu/of_iommu.c                 |  2 +-
>>>>  drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
>>>>  drivers/of/base.c                        | 63 ++++++++++++++++----------------
>>>>  drivers/of/irq.c                         |  8 +++-
>>>>  drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
>>>>  drivers/pci/controller/pcie-apple.c      |  5 ++-
>>>>  drivers/xen/grant-dma-ops.c              |  4 +-
>>>>  include/linux/of.h                       | 12 +++---
>>>>  9 files changed, 76 insertions(+), 50 deletions(-)
>>>>
>>>> diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
>>>> index 63b3544ec997..03232b5ffbca 100644
>>>> --- a/drivers/cdx/cdx_msi.c
>>>> +++ b/drivers/cdx/cdx_msi.c
>>>> @@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
>>>>  			   struct device *dev,
>>>>  			   int nvec, msi_alloc_info_t *info)
>>>>  {
>>>> +	struct of_phandle_args msi_spec = { .np = NULL };
>>>
>>> Why do you need to set it? Parse functions ignore passed args, don't
>>> they?
>>>
>>
>> The parse function does check arg->np on input — if it is non-NULL,
>> it is used to match only entries targeting that specific node.
>>
>> Also, there is this existing path in drivers/pci/msi/irqdomain.c which
>> pre-sets the node and passes it as input to of_msi_xlate(), so the node
>> pointer is not ignored by the parse code:
> 
> Is it only being used for MSIs? If so, can we make that explicit in the
> API by having the 'filter' device_node pointer?
> 

Yes, I see this is used only in the MSI path via of_msi_xlate(). 

By filter do you mean the below changes ? here of_map_id() and of_map_msi_id() would accept the filter
as a separate parameter so that arg becomes a pure output:


int of_map_id(const struct device_node *np, u32 id, const char *map_name,
              const char *cells_name, const char *map_mask_name,
              const struct device_node *filter_np, struct of_phandle_args *arg);

int of_map_msi_id(const struct device_node *np, u32 id,
                  const struct device_node *filter_np, struct of_phandle_args *arg);

of_msi_xlate() would then pass *msi_np as filter_np down to of_map_msi_id
and IOMMU callers would pass NULL to of_map_id. 

Does this look fine ? I can include this in v11.

Thanks,
Vijay

>>
>> u32 pci_msi_domain_get_msi_rid(struct irq_domain *domain, struct pci_dev *pdev)
>> {
>>         struct device_node *of_node;
>>         u32 rid = pci_dev_id(pdev);
>>
>>         pci_for_each_dma_alias(pdev, get_msi_id_cb, &rid);
>>
>>         of_node = irq_domain_get_of_node(domain);
>>         rid = of_node ? of_msi_xlate(&pdev->dev, &of_node, rid) :
>>                         iort_msi_map_id(&pdev->dev, rid);
>>
>>         return rid;
>> }
>>
> 

Re: [PATCH v10 2/3] of: factor arguments passed to of_map_id() into a struct

[Dmitry Baryshkov]

On Mon, Mar 16, 2026 at 10:37:25PM +0530, Vijayanand Jitta wrote:
> 
> 
> On 3/12/2026 7:48 PM, Dmitry Baryshkov wrote:
> > On Thu, Mar 12, 2026 at 05:12:51PM +0530, Vijayanand Jitta wrote:
> >>
> >>
> >> On 3/10/2026 2:53 AM, Dmitry Baryshkov wrote:
> >>> On Mon, Mar 09, 2026 at 01:03:38AM +0530, Vijayanand Jitta wrote:
> >>>> From: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
> >>>>
> >>>> Change of_map_id() to take a pointer to struct of_phandle_args
> >>>> instead of passing target device node and translated IDs separately.
> >>>> Update all callers accordingly.
> >>>>
> >>>> Subsequent patch will make use of the args_count field in
> >>>> struct of_phandle_args.
> >>>>
> >>>> Suggested-by: Rob Herring (Arm) <robh@kernel.org>
> >>>> Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
> >>>> Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
> >>>> ---
> >>>>  drivers/cdx/cdx_msi.c                    |  5 ++-
> >>>>  drivers/iommu/of_iommu.c                 |  2 +-
> >>>>  drivers/irqchip/irq-gic-its-msi-parent.c | 11 ++++--
> >>>>  drivers/of/base.c                        | 63 ++++++++++++++++----------------
> >>>>  drivers/of/irq.c                         |  8 +++-
> >>>>  drivers/pci/controller/dwc/pci-imx6.c    | 16 ++++++--
> >>>>  drivers/pci/controller/pcie-apple.c      |  5 ++-
> >>>>  drivers/xen/grant-dma-ops.c              |  4 +-
> >>>>  include/linux/of.h                       | 12 +++---
> >>>>  9 files changed, 76 insertions(+), 50 deletions(-)
> >>>>
> >>>> diff --git a/drivers/cdx/cdx_msi.c b/drivers/cdx/cdx_msi.c
> >>>> index 63b3544ec997..03232b5ffbca 100644
> >>>> --- a/drivers/cdx/cdx_msi.c
> >>>> +++ b/drivers/cdx/cdx_msi.c
> >>>> @@ -121,6 +121,7 @@ static int cdx_msi_prepare(struct irq_domain *msi_domain,
> >>>>  			   struct device *dev,
> >>>>  			   int nvec, msi_alloc_info_t *info)
> >>>>  {
> >>>> +	struct of_phandle_args msi_spec = { .np = NULL };
> >>>
> >>> Why do you need to set it? Parse functions ignore passed args, don't
> >>> they?
> >>>
> >>
> >> The parse function does check arg->np on input — if it is non-NULL,
> >> it is used to match only entries targeting that specific node.
> >>
> >> Also, there is this existing path in drivers/pci/msi/irqdomain.c which
> >> pre-sets the node and passes it as input to of_msi_xlate(), so the node
> >> pointer is not ignored by the parse code:
> > 
> > Is it only being used for MSIs? If so, can we make that explicit in the
> > API by having the 'filter' device_node pointer?
> > 
> 
> Yes, I see this is used only in the MSI path via of_msi_xlate(). 
> 
> By filter do you mean the below changes ? here of_map_id() and of_map_msi_id() would accept the filter
> as a separate parameter so that arg becomes a pure output:
> 
> 
> int of_map_id(const struct device_node *np, u32 id, const char *map_name,
>               const char *cells_name, const char *map_mask_name,
>               const struct device_node *filter_np, struct of_phandle_args *arg);
> 
> int of_map_msi_id(const struct device_node *np, u32 id,
>                   const struct device_node *filter_np, struct of_phandle_args *arg);
> 
> of_msi_xlate() would then pass *msi_np as filter_np down to of_map_msi_id
> and IOMMU callers would pass NULL to of_map_id. 
> 
> Does this look fine ? I can include this in v11.

As this changes the params, you will also need to change the semantics,
removing the of_node_put() from the function and making the caller
release the reference (as it should be).

-- 
With best wishes
Dmitry

[PATCH v10 3/3] of: Respect #{iommu,msi}-cells in maps

[Vijayanand Jitta]

From: Robin Murphy <robin.murphy@arm.com>

So far our parsing of {iommu,msi}-map properites has always blindly
assumed that the output specifiers will always have exactly 1 cell.
This typically does happen to be the case, but is not actually enforced
(and the PCI msi-map binding even explicitly states support for 0 or 1
cells) - as a result we've now ended up with dodgy DTs out in the field
which depend on this behaviour to map a 1-cell specifier for a 2-cell
provider, despite that being bogus per the bindings themselves.

Since there is some potential use in being able to map at least single
input IDs to multi-cell output specifiers (and properly support 0-cell
outputs as well), add support for properly parsing and using the target
nodes' #cells values, albeit with the unfortunate complication of still
having to work around expectations of the old behaviour too.

Since there are multi-cell output specifiers, the callers of of_map_id()
may need to get the exact cell output value for further processing.
Added support for that part --charan

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
Signed-off-by: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
---
 drivers/iommu/of_iommu.c |   2 +-
 drivers/of/base.c        | 129 ++++++++++++++++++++++++++++++++++++++---------
 include/linux/of.h       |   6 ++-
 3 files changed, 109 insertions(+), 28 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index d255d0f58e8c..a18bb60f6f3d 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -45,7 +45,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
 				     struct device *dev,
 				     const u32 *id)
 {
-	struct of_phandle_args iommu_spec = { .args_count = 1 };
+	struct of_phandle_args iommu_spec = {};
 	int err;
 
 	err = of_map_iommu_id(master_np, *id, &iommu_spec);
diff --git a/drivers/of/base.c b/drivers/of/base.c
index b6e07c5fe715..9c44eb6d445d 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2096,16 +2096,46 @@ int of_find_last_cache_level(unsigned int cpu)
 	return cache_level;
 }
 
+/*
+ * Some DTs have an iommu-map targeting a 2-cell IOMMU node while
+ * specifying only 1 cell. Fortunately they all consist of value '1'
+ * as the 2nd cell entry with the same target, so check for that pattern.
+ *
+ * Example:
+ *	IOMMU node:
+ *		#iommu-cells = <2>;
+ *
+ *	Device node:
+ *		iommu-map = <0x0000 &smmu 0x0000 0x1>,
+ *			    <0x0100 &smmu 0x0100 0x1>;
+ */
+static bool of_check_bad_map(const __be32 *map, int len)
+{
+	__be32 phandle = map[1];
+
+	if (len % 4)
+		return false;
+	for (int i = 0; i < len; i += 4) {
+		if (map[i + 1] != phandle || map[i + 3] != cpu_to_be32(1))
+			return false;
+	}
+	return true;
+}
+
 /**
  * of_map_id - Translate an ID through a downstream mapping.
  * @np: root complex device node.
  * @id: device ID to map.
  * @map_name: property name of the map to use.
+ * @cells_name: property name of target specifier cells.
  * @map_mask_name: optional property name of the mask to use.
  * @arg: pointer to a &struct of_phandle_args. On input, @arg->np may be
  *	set to a target device node to match, or NULL to match any. On
  *	success, @arg->np will be set to the matched target node (with a
- *	reference held) and @arg->args[0] will contain the translated ID.
+ *	reference held), @arg->args_count will be set to the number of
+ *	output specifier cells as defined by @cells_name in the target node,
+ *	and @arg->args[0..args_count-1] will contain the translated output
+ *	specifier values.
  *
  * Given a device ID, look up the appropriate implementation-defined
  * platform ID and/or the target device which receives transactions on that
@@ -2117,17 +2147,19 @@ int of_find_last_cache_level(unsigned int cpu)
  * Return: 0 on success or a standard error code on failure.
  */
 int of_map_id(const struct device_node *np, u32 id,
-	       const char *map_name, const char *map_mask_name,
+	       const char *map_name, const char *cells_name,
+	       const char *map_mask_name,
 	       struct of_phandle_args *arg)
 {
 	u32 map_mask, masked_id;
-	int map_len;
+	int map_bytes, map_len, offset = 0;
+	bool bad_map = false;
 	const __be32 *map = NULL;
 
 	if (!np || !map_name || !arg)
 		return -EINVAL;
 
-	map = of_get_property(np, map_name, &map_len);
+	map = of_get_property(np, map_name, &map_bytes);
 	if (!map) {
 		if (arg->np)
 			return -ENODEV;
@@ -2136,11 +2168,9 @@ int of_map_id(const struct device_node *np, u32 id,
 		return 0;
 	}
 
-	if (!map_len || map_len % (4 * sizeof(*map))) {
-		pr_err("%pOF: Error: Bad %s length: %d\n", np,
-			map_name, map_len);
-		return -EINVAL;
-	}
+	if (map_bytes % sizeof(*map))
+		goto err_map_len;
+	map_len = map_bytes / sizeof(*map);
 
 	/* The default is to select all bits. */
 	map_mask = 0xffffffff;
@@ -2153,27 +2183,69 @@ int of_map_id(const struct device_node *np, u32 id,
 		of_property_read_u32(np, map_mask_name, &map_mask);
 
 	masked_id = map_mask & id;
-	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
+
+	while (offset < map_len) {
 		struct device_node *phandle_node;
-		u32 id_base = be32_to_cpup(map + 0);
-		u32 phandle = be32_to_cpup(map + 1);
-		u32 out_base = be32_to_cpup(map + 2);
-		u32 id_len = be32_to_cpup(map + 3);
+		u32 id_base, phandle, id_len, id_off, cells = 0;
+		const __be32 *out_base;
+
+		if (map_len - offset < 2)
+			goto err_map_len;
+
+		id_base = be32_to_cpup(map + offset);
 
 		if (id_base & ~map_mask) {
-			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
-				np, map_name, map_name,
-				map_mask, id_base);
+			pr_err("%pOF: Invalid %s translation - %s (0x%x) ignores id-base (0x%x)\n",
+			       np, map_name, map_mask_name, map_mask, id_base);
 			return -EFAULT;
 		}
 
-		if (masked_id < id_base || masked_id >= id_base + id_len)
-			continue;
-
+		phandle = be32_to_cpup(map + offset + 1);
 		phandle_node = of_find_node_by_phandle(phandle);
 		if (!phandle_node)
 			return -ENODEV;
 
+		if (!bad_map && of_property_read_u32(phandle_node, cells_name, &cells)) {
+			pr_err("%pOF: missing %s property\n", phandle_node, cells_name);
+			of_node_put(phandle_node);
+			return -EINVAL;
+		}
+
+		if (map_len - offset < 3 + cells) {
+			of_node_put(phandle_node);
+			goto err_map_len;
+		}
+
+		if (offset == 0 && cells == 2) {
+			bad_map = of_check_bad_map(map, map_len);
+			if (bad_map) {
+				pr_warn_once("%pOF: %s mismatches target %s, assuming extra cell of 0\n",
+					     np, map_name, cells_name);
+				cells = 1;
+			}
+		}
+
+		out_base = map + offset + 2;
+		offset += 3 + cells;
+
+		id_len = be32_to_cpup(map + offset - 1);
+		if (id_len > 1 && cells > 1) {
+			/*
+			 * With 1 output cell we reasonably assume its value
+			 * has a linear relationship to the input; with more,
+			 * we'd need help from the provider to know what to do.
+			 */
+			pr_err("%pOF: Unsupported %s - cannot handle %d-ID range with %d-cell output specifier\n",
+			       np, map_name, id_len, cells);
+			of_node_put(phandle_node);
+			return -EINVAL;
+		}
+		id_off = masked_id - id_base;
+		if (masked_id < id_base || id_off >= id_len) {
+			of_node_put(phandle_node);
+			continue;
+		}
+
 		if (arg->np)
 			of_node_put(phandle_node);
 		else
@@ -2182,11 +2254,14 @@ int of_map_id(const struct device_node *np, u32 id,
 		if (arg->np != phandle_node)
 			continue;
 
-		arg->args[0] = masked_id - id_base + out_base;
+		for (int i = 0; i < cells; i++)
+			arg->args[i] = (id_off + be32_to_cpu(out_base[i]));
+
+		arg->args_count = cells;
 
 		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
-			np, map_name, map_mask, id_base, out_base,
-			id_len, id, masked_id - id_base + out_base);
+			np, map_name, map_mask, id_base, be32_to_cpup(out_base),
+			id_len, id, id_off + be32_to_cpup(out_base));
 		return 0;
 	}
 
@@ -2196,6 +2271,10 @@ int of_map_id(const struct device_node *np, u32 id,
 	/* Bypasses translation */
 	arg->args[0] = id;
 	return 0;
+
+err_map_len:
+	pr_err("%pOF: Error: Bad %s length: %d\n", np, map_name, map_bytes);
+	return -EINVAL;
 }
 EXPORT_SYMBOL_GPL(of_map_id);
 
@@ -2214,7 +2293,7 @@ EXPORT_SYMBOL_GPL(of_map_id);
 int of_map_iommu_id(const struct device_node *np, u32 id,
 		    struct of_phandle_args *arg)
 {
-	return of_map_id(np, id, "iommu-map", "iommu-map-mask", arg);
+	return of_map_id(np, id, "iommu-map", "#iommu-cells", "iommu-map-mask", arg);
 }
 EXPORT_SYMBOL_GPL(of_map_iommu_id);
 
@@ -2233,6 +2312,6 @@ EXPORT_SYMBOL_GPL(of_map_iommu_id);
 int of_map_msi_id(const struct device_node *np, u32 id,
 		  struct of_phandle_args *arg)
 {
-	return of_map_id(np, id, "msi-map", "msi-map-mask", arg);
+	return of_map_id(np, id, "msi-map", "#msi-cells", "msi-map-mask", arg);
 }
 EXPORT_SYMBOL_GPL(of_map_msi_id);
diff --git a/include/linux/of.h b/include/linux/of.h
index f50d7a3a3b28..953f2dbe0e86 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -462,7 +462,8 @@ const char *of_prop_next_string(const struct property *prop, const char *cur);
 bool of_console_check(const struct device_node *dn, char *name, int index);
 
 int of_map_id(const struct device_node *np, u32 id,
-	       const char *map_name, const char *map_mask_name,
+	       const char *map_name, const char *cells_name,
+	       const char *map_mask_name,
 	       struct of_phandle_args *arg);
 
 int of_map_iommu_id(const struct device_node *np, u32 id,
@@ -934,7 +935,8 @@ static inline void of_property_clear_flag(struct property *p, unsigned long flag
 }
 
 static inline int of_map_id(const struct device_node *np, u32 id,
-			     const char *map_name, const char *map_mask_name,
+			     const char *map_name, const char *cells_name,
+			     const char *map_mask_name,
 			     struct of_phandle_args *arg)
 {
 	return -EINVAL;

-- 
2.34.1

Re: [PATCH v10 3/3] of: Respect #{iommu,msi}-cells in maps

[Bjorn Helgaas]

On Mon, Mar 09, 2026 at 01:03:39AM +0530, Vijayanand Jitta wrote:
> From: Robin Murphy <robin.murphy@arm.com>
> 
> So far our parsing of {iommu,msi}-map properites has always blindly

s/properites/properties/

Re: [PATCH v10 3/3] of: Respect #{iommu,msi}-cells in maps

[Vijayanand Jitta]

On 3/10/2026 2:38 AM, Bjorn Helgaas wrote:
> On Mon, Mar 09, 2026 at 01:03:39AM +0530, Vijayanand Jitta wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>>
>> So far our parsing of {iommu,msi}-map properites has always blindly
> 
> s/properites/properties/

sure , will update.

Thanks,
Vijay

Re: [PATCH v10 0/3] of: parsing of multi #{iommu,msi}-cells in maps

[Bjorn Helgaas]

On Mon, Mar 09, 2026 at 01:03:36AM +0530, Vijayanand Jitta wrote:
> ...

> Charan Teja Kalla (1):
>       of: factor arguments passed to of_map_id() into a struct

Please make this subject line match the capitalization of those below,
i.e., "of: Factor arguments ..."

> Robin Murphy (2):
>       of: Add convenience wrappers for of_map_id()
>       of: Respect #{iommu,msi}-cells in maps

Re: [PATCH v10 0/3] of: parsing of multi #{iommu,msi}-cells in maps

[Vijayanand Jitta]

On 3/10/2026 2:35 AM, Bjorn Helgaas wrote:
> On Mon, Mar 09, 2026 at 01:03:36AM +0530, Vijayanand Jitta wrote:
>> ...
> 
>> Charan Teja Kalla (1):
>>       of: factor arguments passed to of_map_id() into a struct
> 
> Please make this subject line match the capitalization of those below,
> i.e., "of: Factor arguments ..."
> 

Sure, I'll update it.

Thanks,
Vijay

>> Robin Murphy (2):
>>       of: Add convenience wrappers for of_map_id()
>>       of: Respect #{iommu,msi}-cells in maps