FDT changes for 64 bit kernel

Use the offset into the device tree from fdtp as the phandle instead
of using pointer into the device tree.  This will make sure that the
phandle fits into a uint32_t type, even when compiled for 64bit.

Reviewed by:	raj, nathanw, marcel

1 files changed, 41 insertions, 30 deletions

diff --git a/sys/dev/ofw/ofw_fdt.c b/sys/dev/ofw/ofw_fdt.c
index 68d3149..806f17c 100644
--- a/sys/dev/ofw/ofw_fdt.c
+++ b/sys/dev/ofw/ofw_fdt.c
@@ -109,22 +109,48 @@ ofw_fdt_init(ofw_t ofw, void *data)
 }
 
 /*
- * Device tree functions
+ * Device tree functions.
+ *
+ * We use the offset from fdtp to the node as the 'phandle' in OF interface.
+ *
+ * phandle is a u32 value, therefore we cannot use the pointer to node as
+ * phandle in 64 bit. We also do not use the usual fdt offset as phandle,
+ * as it can be 0, and the OF interface has special meaning for phandle 0.
  */
 
+static phandle_t
+fdt_offset_phandle(int offset)
+{
+	if (offset < 0)
+		return (0);
+	return ((phandle_t)offset + fdt_off_dt_struct(fdtp));
+}
+
 static int
 fdt_phandle_offset(phandle_t p)
 {
-	const char *dt_struct;
+	int pint = (int)p;
+	int dtoff = fdt_off_dt_struct(fdtp);
+
+	if (pint < dtoff)
+		return (-1);
+	return (pint - dtoff);
+}
+
+static int
+fdt_pointer_offset(const void *ptr)
+{
+	uintptr_t dt_struct, p;
 	int offset;
 
-	dt_struct = (const char *)fdtp + fdt_off_dt_struct(fdtp);
+	p = (uintptr_t)ptr;
+	dt_struct = (uintptr_t)fdtp + fdt_off_dt_struct(fdtp);
 
-	if (((const char *)p < dt_struct) ||
-	    (const char *)p > (dt_struct + fdt_size_dt_struct(fdtp)))
+	if ((p < dt_struct) ||
+	    p > (dt_struct + fdt_size_dt_struct(fdtp)))
 		return (-1);
 
-	offset = (const char *)p - dt_struct;
+	offset = p - dt_struct;
 	if (offset < 0)
 		return (-1);
 
@@ -135,15 +161,13 @@ fdt_phandle_offset(phandle_t p)
 static phandle_t
 ofw_fdt_peer(ofw_t ofw, phandle_t node)
 {
-	phandle_t p;
 	int depth, offset;
 
 	if (node == 0) {
 		/* Find root node */
 		offset = fdt_path_offset(fdtp, "/");
-		p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
 
-		return (p);
+		return (fdt_offset_phandle(offset));
 	}
 
 	offset = fdt_phandle_offset(node);
@@ -155,10 +179,8 @@ ofw_fdt_peer(ofw_t ofw, phandle_t node)
 	    offset = fdt_next_node(fdtp, offset, &depth)) {
 		if (depth < 0)
 			return (0);
-		if (depth == 1) {
-			p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
-			return (p);
-		}
+		if (depth == 1)
+			return (fdt_offset_phandle(offset));
 	}
 
 	return (0);
@@ -168,7 +190,6 @@ ofw_fdt_peer(ofw_t ofw, phandle_t node)
 static phandle_t
 ofw_fdt_child(ofw_t ofw, phandle_t node)
 {
-	phandle_t p;
 	int depth, offset;
 
 	offset = fdt_phandle_offset(node);
@@ -180,10 +201,8 @@ ofw_fdt_child(ofw_t ofw, phandle_t node)
 	    offset = fdt_next_node(fdtp, offset, &depth)) {
 		if (depth < 0)
 			return (0);
-		if (depth == 1) {
-			p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
-			return (p);
-		}
+		if (depth == 1)
+			return (fdt_offset_phandle(offset));
 	}
 
 	return (0);
@@ -193,7 +212,6 @@ ofw_fdt_child(ofw_t ofw, phandle_t node)
 static phandle_t
 ofw_fdt_parent(ofw_t ofw, phandle_t node)
 {
-	phandle_t p;
 	int offset, paroffset;
 
 	offset = fdt_phandle_offset(node);
@@ -201,15 +219,13 @@ ofw_fdt_parent(ofw_t ofw, phandle_t node)
 		return (0);
 
 	paroffset = fdt_parent_offset(fdtp, offset);
-	p = (phandle_t)fdt_offset_ptr(fdtp, paroffset, sizeof(phandle_t));
-	return (p);
+	return (fdt_offset_phandle(paroffset));
 }
 
 /* Return the package handle that corresponds to an instance handle. */
 static phandle_t
 ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
 {
-	phandle_t p;
 	int offset;
 
 	/*
@@ -223,8 +239,7 @@ ofw_fdt_instance_to_package(ofw_t ofw, ihandle_t instance)
 	if (offset < 0)
 		return (-1);
 
-	p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(phandle_t));
-	return (p);
+	return (fdt_offset_phandle(offset));
 }
 
 /* Get the length of a property of a package. */
@@ -343,7 +358,7 @@ ofw_fdt_nextprop(ofw_t ofw, phandle_t package, const char *previous, char *buf,
 	if (prop == NULL)
 		return (-1);
 
-	offset = fdt_phandle_offset((phandle_t)prop);
+	offset = fdt_pointer_offset(prop);
 	rv = fdt_nextprop(offset, buf, size);
 	return (rv);
 }
@@ -374,14 +389,10 @@ ofw_fdt_canon(ofw_t ofw, const char *device, char *buf, size_t len)
 static phandle_t
 ofw_fdt_finddevice(ofw_t ofw, const char *device)
 {
-	phandle_t p;
 	int offset;
 
 	offset = fdt_path_offset(fdtp, device);
-
-	p = (phandle_t)fdt_offset_ptr(fdtp, offset, sizeof(p));
-
-	return (p);
+	return (fdt_offset_phandle(offset));
 }
 
 /* Return the fully qualified pathname corresponding to an instance. */