3 files changed, 72 insertions, 24 deletions

diff --git a/arch/sparc/kernel/prom_common.c b/arch/sparc/kernel/prom_common.c
index fe84d56b7c5a..ed25834328f4 100644
--- a/arch/sparc/kernel/prom_common.c
+++ b/arch/sparc/kernel/prom_common.c
@@ -118,11 +118,45 @@ int of_find_in_proplist(const char *list, const char *match, int len)
 }
 EXPORT_SYMBOL(of_find_in_proplist);
 
+/*
+ * SPARC32 and SPARC64's prom_nextprop() do things differently
+ * here, despite sharing the same interface.  SPARC32 doesn't fill in 'buf',
+ * returning NULL on an error.  SPARC64 fills in 'buf', but sets it to an
+ * empty string upon error.
+ */
+static int __init handle_nextprop_quirks(char *buf, const char *name)
+{
+        if (!name || strlen(name) == 0)
+                return -1;
+
+#ifdef CONFIG_SPARC32
+        strcpy(buf, name);
+#endif
+        return 0;
+}
+
+static int __init prom_common_nextprop(phandle node, char *prev, char *buf)
+{
+        const char *name;
+
+        buf[0] = '\0';
+        name = prom_nextprop(node, prev, buf);
+        return handle_nextprop_quirks(buf, name);
+}
+
 unsigned int prom_early_allocated __initdata;
 
+static struct of_pdt_ops prom_sparc_ops __initdata = {
+        .nextprop = prom_common_nextprop,
+        .getproplen = prom_getproplen,
+        .getproperty = prom_getproperty,
+        .getchild = prom_getchild,
+        .getsibling = prom_getsibling,
+};
+
 void __init prom_build_devicetree(void)
 {
-        of_pdt_build_devicetree(prom_root_node);
+        of_pdt_build_devicetree(prom_root_node, &prom_sparc_ops);
         of_console_init();
 
         pr_info("PROM: Built device tree with %u bytes of memory.\n",
diff --git a/drivers/of/pdt.c b/drivers/of/pdt.c
index 2fdb1b478d6f..fd02fc1dd891 100644
--- a/drivers/of/pdt.c
+++ b/drivers/of/pdt.c
@@ -23,7 +23,8 @@
 #include <linux/of.h>
 #include <linux/of_pdt.h>
 #include <asm/prom.h>
-#include <asm/oplib.h>
+
+static struct of_pdt_ops *of_pdt_prom_ops __initdata;
 
 void __initdata (*prom_build_more)(struct device_node *dp,
                 struct device_node ***nextp);
@@ -59,7 +60,7 @@ static struct property * __init build_one_prop(phandle node, char *prev,
 {
         static struct property *tmp = NULL;
         struct property *p;
-        const char *name;
+        int err;
 
         if (tmp) {
                 p = tmp;
@@ -77,28 +78,20 @@ static struct property * __init build_one_prop(phandle node, char *prev,
                 p->value = prom_early_alloc(special_len);
                 memcpy(p->value, special_val, special_len);
         } else {
-                if (prev == NULL) {
-                        name = prom_firstprop(node, p->name);
-                } else {
-                        name = prom_nextprop(node, prev, p->name);
-                }
-
-                if (!name || strlen(name) == 0) {
+                err = of_pdt_prom_ops->nextprop(node, prev, p->name);
+                if (err) {
                         tmp = p;
                         return NULL;
                 }
-#ifdef CONFIG_SPARC32
-                strcpy(p->name, name);
-#endif
-                p->length = prom_getproplen(node, p->name);
+                p->length = of_pdt_prom_ops->getproplen(node, p->name);
                 if (p->length <= 0) {
                         p->length = 0;
                 } else {
                         int len;
 
                         p->value = prom_early_alloc(p->length + 1);
-                        len = prom_getproperty(node, p->name, p->value,
-                                               p->length);
+                        len = of_pdt_prom_ops->getproperty(node, p->name,
+                                        p->value, p->length);
                         if (len <= 0)
                                 p->length = 0;
                         ((unsigned char *)p->value)[p->length] = '\0';
@@ -130,10 +123,10 @@ static char * __init get_one_property(phandle node, const char *name)
         char *buf = "<NULL>";
         int len;
 
-        len = prom_getproplen(node, name);
+        len = of_pdt_prom_ops->getproplen(node, name);
         if (len > 0) {
                 buf = prom_early_alloc(len);
-                len = prom_getproperty(node, name, buf, len);
+                len = of_pdt_prom_ops->getproperty(node, name, buf, len);
         }
 
         return buf;
@@ -211,21 +204,25 @@ static struct device_node * __init prom_build_tree(struct device_node *parent,
 #endif
                 dp->full_name = build_full_name(dp);
 
-                dp->child = prom_build_tree(dp, prom_getchild(node), nextp);
+                dp->child = prom_build_tree(dp,
+                                of_pdt_prom_ops->getchild(node), nextp);
 
                 if (prom_build_more)
                         prom_build_more(dp, nextp);
 
-                node = prom_getsibling(node);
+                node = of_pdt_prom_ops->getsibling(node);
         }
 
         return ret;
 }
 
-void __init of_pdt_build_devicetree(phandle root_node)
+void __init of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops)
 {
         struct device_node **nextp;
 
+        BUG_ON(!ops);
+        of_pdt_prom_ops = ops;
+
         allnodes = prom_create_node(root_node, NULL);
 #if defined(CONFIG_SPARC)
         allnodes->path_component_name = "";
@@ -234,6 +231,5 @@ void __init of_pdt_build_devicetree(phandle root_node)
 
         nextp = &allnodes->allnext;
         allnodes->child = prom_build_tree(allnodes,
-                                          prom_getchild(allnodes->phandle),
-                                          &nextp);
+                        of_pdt_prom_ops->getchild(allnodes->phandle), &nextp);
 }
diff --git a/include/linux/of_pdt.h b/include/linux/of_pdt.h
index c0a8774e45d0..303c5ffae9b4 100644
--- a/include/linux/of_pdt.h
+++ b/include/linux/of_pdt.h
@@ -13,10 +13,28 @@
 #ifndef _LINUX_OF_PDT_H
 #define _LINUX_OF_PDT_H
 
+/* overridable operations for calling into the PROM */
+struct of_pdt_ops {
+        /*
+         * buf should be 32 bytes; return 0 on success.
+         * If prev is NULL, the first property will be returned.
+         */
+        int (*nextprop)(phandle node, char *prev, char *buf);
+
+        /* for both functions, return proplen on success; -1 on error */
+        int (*getproplen)(phandle node, const char *prop);
+        int (*getproperty)(phandle node, const char *prop, char *buf,
+                        int bufsize);
+
+        /* phandles are 0 if no child or sibling exists */
+        phandle (*getchild)(phandle parent);
+        phandle (*getsibling)(phandle node);
+};
+
 extern void *prom_early_alloc(unsigned long size);
 
 /* for building the device tree */
-extern void of_pdt_build_devicetree(phandle root_node);
+extern void of_pdt_build_devicetree(phandle root_node, struct of_pdt_ops *ops);
 
 extern void (*prom_build_more)(struct device_node *dp,
                 struct device_node ***nextp);