of/address: Fix WARN when attempting translating non-translatable addresses

The recently added WARN() for deprecated #address-cells and #size-cells
triggered a WARN when of_platform_populate() (which calls
of_address_to_resource()) is used on nodes with non-translatable
addresses. This case is expected to return an error.

Rework the bus matching to allow no match and make the default require
an #address-cells property. That should be safe to do as any platform
missing #address-cells would have a warning already.

Fixes: 045b14ca5c36 ("of: WARN on deprecated #address-cells/#size-cells handling")
Tested-by: Sean Anderson <sean.anderson@linux.dev>
Link: https://lore.kernel.org/r/20250110215030.3637845-2-robh@kernel.org
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

diff --git a/drivers/of/address.c b/drivers/of/address.c
index c1f1c810e810d09d3ee23545011d4a61dc415143..8770004d9b085f1ff40f693d695d284a6ef3dfde 100644 (file)
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -340,6 +340,15 @@ static int of_bus_default_flags_match(struct device_node *np)
        return of_property_present(np, "#address-cells") && (of_bus_n_addr_cells(np) == 3);
 }
 
+static int of_bus_default_match(struct device_node *np)
+{
+       /*
+        * Check for presence first since of_bus_n_addr_cells() will warn when
+        * walking parent nodes.
+        */
+       return of_property_present(np, "#address-cells");
+}
+
 /*
  * Array of bus specific translators
  */
@@ -384,7 +393,7 @@ static const struct of_bus of_busses[] = {
        {
                .name = "default",
                .addresses = "reg",
-               .match = NULL,
+               .match = of_bus_default_match,
                .count_cells = of_bus_default_count_cells,
                .map = of_bus_default_map,
                .translate = of_bus_default_translate,
@@ -399,7 +408,6 @@ static const struct of_bus *of_match_bus(struct device_node *np)
        for (i = 0; i < ARRAY_SIZE(of_busses); i++)
                if (!of_busses[i].match || of_busses[i].match(np))
                        return &of_busses[i];
-       BUG();
        return NULL;
 }
 
@@ -521,6 +529,8 @@ static u64 __of_translate_address(struct device_node *node,
        if (parent == NULL)
                return OF_BAD_ADDR;
        bus = of_match_bus(parent);
+       if (!bus)
+               return OF_BAD_ADDR;
 
        /* Count address cells & copy address locally */
        bus->count_cells(dev, &na, &ns);
@@ -564,6 +574,8 @@ static u64 __of_translate_address(struct device_node *node,
 
                /* Get new parent bus and counts */
                pbus = of_match_bus(parent);
+               if (!pbus)
+                       return OF_BAD_ADDR;
                pbus->count_cells(dev, &pna, &pns);
                if (!OF_CHECK_COUNTS(pna, pns)) {
                        pr_err("Bad cell count for %pOF\n", dev);
@@ -703,7 +715,7 @@ const __be32 *__of_get_address(struct device_node *dev, int index, int bar_no,
 
        /* match the parent's bus type */
        bus = of_match_bus(parent);
-       if (strcmp(bus->name, "pci") && (bar_no >= 0))
+       if (!bus || (strcmp(bus->name, "pci") && (bar_no >= 0)))
                return NULL;
 
        /* Get "reg" or "assigned-addresses" property */