of: assume big-endian properties, adding conversions where necessary

Properties in the device tree are specified as big-endian. At present,
the only platforms to support device trees are also big-endian, so we've
been acessing the properties as raw values.

We'd like to add device tree support to little-endian platforms too, so
add endian conversion to the sites where we access property values in
the common of code.

Compiled on powerpc (ppc44x_defconfig & ppc64_defconfig) and arm (fdt
support only for now).

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 25 insertions, 20 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 968a86af530..5c5f03ef7f0 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -51,7 +51,7 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node,
         int depth = -1;
 
         do {
-                u32 tag = *((u32 *)p);
+                u32 tag = be32_to_cpup((__be32 *)p);
                 char *pathp;
 
                 p += 4;
@@ -64,7 +64,7 @@ int __init of_scan_flat_dt(int (*it)(unsigned long node,
                 if (tag == OF_DT_END)
                         break;
                 if (tag == OF_DT_PROP) {
-                        u32 sz = *((u32 *)p);
+                        u32 sz = be32_to_cpup((__be32 *)p);
                         p += 8;
                         if (initial_boot_params->version < 0x10)
                                 p = _ALIGN(p, sz >= 8 ? 8 : 4);
@@ -103,9 +103,9 @@ unsigned long __init of_get_flat_dt_root(void)
         unsigned long p = ((unsigned long)initial_boot_params) +
                 initial_boot_params->off_dt_struct;
 
-        while (*((u32 *)p) == OF_DT_NOP)
+        while (be32_to_cpup((__be32 *)p) == OF_DT_NOP)
                 p += 4;
-        BUG_ON(*((u32 *)p) != OF_DT_BEGIN_NODE);
+        BUG_ON(be32_to_cpup((__be32 *)p) != OF_DT_BEGIN_NODE);
         p += 4;
         return _ALIGN(p + strlen((char *)p) + 1, 4);
 }
@@ -122,7 +122,7 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
         unsigned long p = node;
 
         do {
-                u32 tag = *((u32 *)p);
+                u32 tag = be32_to_cpup((__be32 *)p);
                 u32 sz, noff;
                 const char *nstr;
 
@@ -132,8 +132,8 @@ void *__init of_get_flat_dt_prop(unsigned long node, const char *name,
                 if (tag != OF_DT_PROP)
                         return NULL;
 
-                sz = *((u32 *)p);
-                noff = *((u32 *)(p + 4));
+                sz = be32_to_cpup((__be32 *)p);
+                noff = be32_to_cpup((__be32 *)(p + 4));
                 p += 8;
                 if (initial_boot_params->version < 0x10)
                         p = _ALIGN(p, sz >= 8 ? 8 : 4);
@@ -210,7 +210,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
         int has_name = 0;
         int new_format = 0;
 
-        tag = *((u32 *)(*p));
+        tag = be32_to_cpup((__be32 *)(*p));
         if (tag != OF_DT_BEGIN_NODE) {
                 pr_err("Weird tag at start of node: %x\n", tag);
                 return mem;
@@ -285,7 +285,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
                 u32 sz, noff;
                 char *pname;
 
-                tag = *((u32 *)(*p));
+                tag = be32_to_cpup((__be32 *)(*p));
                 if (tag == OF_DT_NOP) {
                         *p += 4;
                         continue;
@@ -293,8 +293,8 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
                 if (tag != OF_DT_PROP)
                         break;
                 *p += 4;
-                sz = *((u32 *)(*p));
-                noff = *((u32 *)((*p) + 4));
+                sz = be32_to_cpup((__be32 *)(*p));
+                noff = be32_to_cpup((__be32 *)((*p) + 4));
                 *p += 8;
                 if (initial_boot_params->version < 0x10)
                         *p = _ALIGN(*p, sz >= 8 ? 8 : 4);
@@ -367,7 +367,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
         }
         while (tag == OF_DT_BEGIN_NODE) {
                 mem = unflatten_dt_node(mem, p, np, allnextpp, fpsize);
-                tag = *((u32 *)(*p));
+                tag = be32_to_cpup((__be32 *)(*p));
         }
         if (tag != OF_DT_END_NODE) {
                 pr_err("Weird tag at end of node: %x\n", tag);
@@ -385,7 +385,7 @@ unsigned long __init unflatten_dt_node(unsigned long mem,
 void __init early_init_dt_check_for_initrd(unsigned long node)
 {
         unsigned long start, end, len;
-        u32 *prop;
+        __be32 *prop;
 
         pr_debug("Looking for initrd properties... ");
 
@@ -414,17 +414,22 @@ inline void early_init_dt_check_for_initrd(unsigned long node)
 int __init early_init_dt_scan_root(unsigned long node, const char *uname,
                                    int depth, void *data)
 {
-        u32 *prop;
+        __be32 *prop;
 
         if (depth != 0)
                 return 0;
 
+        dt_root_size_cells = OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+        dt_root_addr_cells = OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+
         prop = of_get_flat_dt_prop(node, "#size-cells", NULL);
-        dt_root_size_cells = prop ? *prop : OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
+        if (prop)
+                dt_root_size_cells = be32_to_cpup(prop);
         pr_debug("dt_root_size_cells = %x\n", dt_root_size_cells);
 
         prop = of_get_flat_dt_prop(node, "#address-cells", NULL);
-        dt_root_addr_cells = prop ? *prop : OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
+        if (prop)
+                dt_root_addr_cells = be32_to_cpup(prop);
         pr_debug("dt_root_addr_cells = %x\n", dt_root_addr_cells);
 
         /* break now */
@@ -549,7 +554,7 @@ void __init unflatten_device_tree(void)
         mem = lmb_alloc(size + 4, __alignof__(struct device_node));
         mem = (unsigned long) __va(mem);
 
-        ((u32 *)mem)[size / 4] = 0xdeadbeef;
+        ((__be32 *)mem)[size / 4] = cpu_to_be32(0xdeadbeef);
 
         pr_debug("  unflattening %lx...\n", mem);
 
@@ -557,11 +562,11 @@ void __init unflatten_device_tree(void)
         start = ((unsigned long)initial_boot_params) +
                 initial_boot_params->off_dt_struct;
         unflatten_dt_node(mem, &start, NULL, &allnextp, 0);
-        if (*((u32 *)start) != OF_DT_END)
+        if (be32_to_cpup((__be32 *)start) != OF_DT_END)
                 pr_warning("Weird tag at end of tree: %08x\n", *((u32 *)start));
-        if (((u32 *)mem)[size / 4] != 0xdeadbeef)
+        if (be32_to_cpu(((__be32 *)mem)[size / 4]) != 0xdeadbeef)
                 pr_warning("End of tree marker overwritten: %08x\n",
-                           ((u32 *)mem)[size / 4]);
+                           be32_to_cpu(((__be32 *)mem)[size / 4]));
         *allnextp = NULL;
 
         /* Get pointer to OF "/chosen" node for use everywhere */