of: reserved_mem: Remove the use of phandle from the reserved_mem APIs

The __find_rmem() function is the only place that references the phandle
field of the reserved_mem struct. __find_rmem() is used to match a
device_node object to its corresponding entry in the reserved_mem array
using its phandle value. But, there is already a function called
of_reserved_mem_lookup() which carries out the same action using the
name of the node.

Using the of_reserved_mem_lookup() function is more reliable because
every node is guaranteed to have a name, but not all nodes will have a
phandle.

Nodes are only assigned a phandle if they are explicitly defined in the
DT using "phandle = <phandle_number>", or if they are referenced by
another node in the DT. Hence, If the phandle field is empty, then
__find_rmem() will return a false negative.

Hence, delete the __find_rmem() function and switch to using the
of_reserved_mem_lookup() function to find the corresponding entry of a
device_node in the reserved_mem array. Since the phandle field of the
reserved_mem struct is now unused, delete that as well.

Signed-off-by: Oreoluwa Babatunde <quic_obabatun@quicinc.com>
Link: https://lore.kernel.org/r/20240502192403.3307277-1-quic_obabatun@quicinc.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>

diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c
index 8236ecae29533694ae4efbc4251a0182c4af99d6..46e1c3fbc7692cb1beb06506204e40f35c8e6783 100644 (file)
--- a/drivers/of/of_reserved_mem.c
+++ b/drivers/of/of_reserved_mem.c
@@ -437,17 +437,10 @@ void __init fdt_init_reserved_mem(void)
        for (i = 0; i < reserved_mem_count; i++) {
                struct reserved_mem *rmem = &reserved_mem[i];
                unsigned long node = rmem->fdt_node;
-               int len;
-               const __be32 *prop;
                int err = 0;
                bool nomap;
 
                nomap = of_get_flat_dt_prop(node, "no-map", NULL) != NULL;
-               prop = of_get_flat_dt_prop(node, "phandle", &len);
-               if (!prop)
-                       prop = of_get_flat_dt_prop(node, "linux,phandle", &len);
-               if (prop)
-                       rmem->phandle = of_read_number(prop, len/4);
 
                if (rmem->size == 0)
                        err = __reserved_mem_alloc_size(node, rmem->name,
@@ -477,19 +470,6 @@ void __init fdt_init_reserved_mem(void)
        }
 }
 
-static inline struct reserved_mem *__find_rmem(struct device_node *node)
-{
-       unsigned int i;
-
-       if (!node->phandle)
-               return NULL;
-
-       for (i = 0; i < reserved_mem_count; i++)
-               if (reserved_mem[i].phandle == node->phandle)
-                       return &reserved_mem[i];
-       return NULL;
-}
-
 struct rmem_assigned_device {
        struct device *dev;
        struct reserved_mem *rmem;
@@ -534,7 +514,7 @@ int of_reserved_mem_device_init_by_idx(struct device *dev,
                return 0;
        }
 
-       rmem = __find_rmem(target);
+       rmem = of_reserved_mem_lookup(target);
        of_node_put(target);
 
        if (!rmem || !rmem->ops || !rmem->ops->device_init)

diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
index 4de2a24cadc9bfdae74fb960ff37b57524bcba04..e338282da65202999a5baea62949e546998e9978 100644 (file)
--- a/include/linux/of_reserved_mem.h
+++ b/include/linux/of_reserved_mem.h
@@ -11,7 +11,6 @@ struct reserved_mem_ops;
 struct reserved_mem {
        const char                      *name;
        unsigned long                   fdt_node;
-       unsigned long                   phandle;
        const struct reserved_mem_ops   *ops;
        phys_addr_t                     base;
        phys_addr_t                     size;