[PATCH v4 3/3] of: Respect #{iommu,msi}-cells in maps

Vijayanand Jitta posted 3 patches 1 month, 1 week ago
There is a newer version of this series
[PATCH v4 3/3] of: Respect #{iommu,msi}-cells in maps
Posted by Vijayanand Jitta 1 month, 1 week ago
From: Robin Murphy <robin.murphy@arm.com>

So far our parsing of {iommu,msi}-map properites has always blindly
asusmed 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: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
---
 drivers/iommu/of_iommu.c |   4 +-
 drivers/of/base.c        | 114 +++++++++++++++++++++++++++++++--------
 include/linux/of.h       |  16 +++---
 3 files changed, 101 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 646ac5a67475..768eaddf927b 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -46,9 +46,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
 				     const u32 *id)
 {
 	struct of_map_id_arg arg = {
-		.map_args = {
-			.args_count = 1,
-		},
+		.map_args = {},
 	};
 	int err;
 
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 9f327c6b4f6b..f0507ddb6dae 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -2045,11 +2045,38 @@ 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: contains the optional params, wrapped in a struct of_phandle_args,
  *	which includes:
@@ -2067,18 +2094,19 @@ 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,
-	       struct of_map_id_arg *arg)
+int of_map_id(const struct device_node *np, u32 id, const char *map_name,
+	      const char *cells_name, const char *map_mask_name,
+	      struct of_map_id_arg *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->map_args.np)
 			return -ENODEV;
@@ -2087,11 +2115,9 @@ 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;
@@ -2104,27 +2130,64 @@ 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,
+			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);
+			return -EINVAL;
+		}
+
+		if (map_len - offset < 3 + cells)
+			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);
+			return -EINVAL;
+		}
+		id_off = masked_id - id_base;
+		if (masked_id < id_base || id_off >= id_len)
+			continue;
+
 		if (arg->map_args.np)
 			of_node_put(phandle_node);
 		else
@@ -2133,11 +2196,14 @@ int of_map_id(const struct device_node *np, u32 id,
 		if (arg->map_args.np != phandle_node)
 			continue;
 
-		arg->map_args.args[0] = masked_id - id_base + out_base;
+		for (int i = 0; i < cells; i++)
+			arg->map_args.args[i] = (id_off + be32_to_cpu(out_base[i]));
+
+		arg->map_args.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;
 	}
 
@@ -2147,5 +2213,9 @@ int of_map_id(const struct device_node *np, u32 id,
 	/* Bypasses translation */
 	arg->map_args.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);
diff --git a/include/linux/of.h b/include/linux/of.h
index 0b0d545b80a3..ee07e8642133 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -460,9 +460,9 @@ 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,
-	       struct of_map_id_arg *arg);
+int of_map_id(const struct device_node *np, u32 id, const char *map_name,
+	      const char *cells_name, const char *map_mask_name,
+	      struct of_map_id_arg *arg);
 
 phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
 
@@ -909,9 +909,9 @@ 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 of_map_id_arg *arg)
+static inline int of_map_id(const struct device_node *np, u32 id, const char *map_name,
+			    const char *cells_name, const char *map_mask_name,
+			    struct of_map_id_arg *arg);
 {
 	return -EINVAL;
 }
@@ -1442,7 +1442,7 @@ static inline int of_property_read_s32(const struct device_node *np,
 static inline int of_map_iommu_id(const struct device_node *np, u32 id,
 				  struct of_map_id_arg *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);
 }
 
 static inline int of_map_msi_id(const struct device_node *np, u32 id,
@@ -1456,7 +1456,7 @@ static inline int of_map_msi_id(const struct device_node *np, u32 id,
 		},
 	};
 
-	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);
 }
 
 #define of_for_each_phandle(it, err, np, ln, cn, cc)			\
-- 
2.34.1
Re: [PATCH v4 3/3] of: Respect #{iommu,msi}-cells in maps
Posted by Vijayanand Jitta 1 month ago

On 12/31/2025 5:12 PM, Vijayanand Jitta wrote:
> From: Robin Murphy <robin.murphy@arm.com>
> 
> So far our parsing of {iommu,msi}-map properites has always blindly
> asusmed 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: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
> ---
>  drivers/iommu/of_iommu.c |   4 +-
>  drivers/of/base.c        | 114 +++++++++++++++++++++++++++++++--------
>  include/linux/of.h       |  16 +++---
>  3 files changed, 101 insertions(+), 33 deletions(-)
> 
> diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
> index 646ac5a67475..768eaddf927b 100644
> --- a/drivers/iommu/of_iommu.c
> +++ b/drivers/iommu/of_iommu.c
> @@ -46,9 +46,7 @@ static int of_iommu_configure_dev_id(struct device_node *master_np,
>  				     const u32 *id)
>  {
>  	struct of_map_id_arg arg = {
> -		.map_args = {
> -			.args_count = 1,
> -		},
> +		.map_args = {},
>  	};
>  	int err;
>  
> diff --git a/drivers/of/base.c b/drivers/of/base.c
> index 9f327c6b4f6b..f0507ddb6dae 100644
> --- a/drivers/of/base.c
> +++ b/drivers/of/base.c
> @@ -2045,11 +2045,38 @@ 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: contains the optional params, wrapped in a struct of_phandle_args,
>   *	which includes:
> @@ -2067,18 +2094,19 @@ 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,
> -	       struct of_map_id_arg *arg)
> +int of_map_id(const struct device_node *np, u32 id, const char *map_name,
> +	      const char *cells_name, const char *map_mask_name,
> +	      struct of_map_id_arg *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->map_args.np)
>  			return -ENODEV;
> @@ -2087,11 +2115,9 @@ 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;
> @@ -2104,27 +2130,64 @@ 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,
> +			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);
> +			return -EINVAL;
> +		}
> +
> +		if (map_len - offset < 3 + cells)
> +			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);
> +			return -EINVAL;
> +		}
> +		id_off = masked_id - id_base;
> +		if (masked_id < id_base || id_off >= id_len)
> +			continue;
> +
>  		if (arg->map_args.np)
>  			of_node_put(phandle_node);
>  		else
> @@ -2133,11 +2196,14 @@ int of_map_id(const struct device_node *np, u32 id,
>  		if (arg->map_args.np != phandle_node)
>  			continue;
>  
> -		arg->map_args.args[0] = masked_id - id_base + out_base;
> +		for (int i = 0; i < cells; i++)
> +			arg->map_args.args[i] = (id_off + be32_to_cpu(out_base[i]));
> +
> +		arg->map_args.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;
>  	}
>  
> @@ -2147,5 +2213,9 @@ int of_map_id(const struct device_node *np, u32 id,
>  	/* Bypasses translation */
>  	arg->map_args.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);
> diff --git a/include/linux/of.h b/include/linux/of.h
> index 0b0d545b80a3..ee07e8642133 100644
> --- a/include/linux/of.h
> +++ b/include/linux/of.h
> @@ -460,9 +460,9 @@ 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,
> -	       struct of_map_id_arg *arg);
> +int of_map_id(const struct device_node *np, u32 id, const char *map_name,
> +	      const char *cells_name, const char *map_mask_name,
> +	      struct of_map_id_arg *arg);
>  
>  phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
>  
> @@ -909,9 +909,9 @@ 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 of_map_id_arg *arg)
> +static inline int of_map_id(const struct device_node *np, u32 id, const char *map_name,
> +			    const char *cells_name, const char *map_mask_name,
> +			    struct of_map_id_arg *arg);
>  {
>  	return -EINVAL;
>  }
> @@ -1442,7 +1442,7 @@ static inline int of_property_read_s32(const struct device_node *np,
>  static inline int of_map_iommu_id(const struct device_node *np, u32 id,
>  				  struct of_map_id_arg *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);
>  }
>  
>  static inline int of_map_msi_id(const struct device_node *np, u32 id,
> @@ -1456,7 +1456,7 @@ static inline int of_map_msi_id(const struct device_node *np, u32 id,
>  		},
>  	};
>  
> -	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);
>  }
>  
>  #define of_for_each_phandle(it, err, np, ln, cn, cc)			\

Rob, 

Gentle ping, could you please let me know if the latest patchset looks good enough
to be considered for the next merge window?

Thanks,
Vijay
Re: [PATCH v4 3/3] of: Respect #{iommu,msi}-cells in maps
Posted by Konrad Dybcio 1 month ago
On 1/7/26 6:31 AM, Vijayanand Jitta wrote:
> 
> 
> On 12/31/2025 5:12 PM, Vijayanand Jitta wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>>
>> So far our parsing of {iommu,msi}-map properites has always blindly
>> asusmed 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: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
>> ---

[...]

> Rob, 
> 
> Gentle ping, could you please let me know if the latest patchset looks good enough
> to be considered for the next merge window?

You have an outstanding build warning:

<202601062128.BCmw1wNO-lkp@intel.com>

Konrad
Re: [PATCH v4 3/3] of: Respect #{iommu,msi}-cells in maps
Posted by Vijayanand Jitta 3 weeks, 1 day ago

On 1/7/2026 4:30 PM, Konrad Dybcio wrote:
> On 1/7/26 6:31 AM, Vijayanand Jitta wrote:
>>
>>
>> On 12/31/2025 5:12 PM, Vijayanand Jitta wrote:
>>> From: Robin Murphy <robin.murphy@arm.com>
>>>
>>> So far our parsing of {iommu,msi}-map properites has always blindly
>>> asusmed 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: Vijayanand Jitta <vijayanand.jitta@oss.qualcomm.com>
>>> ---
> 
> [...]
> 
>> Rob, 
>>
>> Gentle ping, could you please let me know if the latest patchset looks good enough
>> to be considered for the next merge window?
> 
> You have an outstanding build warning:
> 
> <202601062128.BCmw1wNO-lkp@intel.com>
> 
> Konrad


Thanks, I have fixed those and sent out V5. Please review.

Thanks,
Vijay