[POWERPC] Define of_read_ulong helper

There are various places where we want to extract an unsigned long
value from a device-tree property that can be 1 or 2 cells in length.
This replaces some open-coded calculations, and one place where we
assumed without checking that properties were the length we wanted,
with a little of_read_ulong() helper.

Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 11 insertions, 25 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index bf2005b2feb..eb913f80bfb 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -757,24 +757,9 @@ static int __init early_init_dt_scan_root(unsigned long node,
 static unsigned long __init dt_mem_next_cell(int s, cell_t **cellp)
 {
         cell_t *p = *cellp;
-        unsigned long r;
 
-        /* Ignore more than 2 cells */
-        while (s > sizeof(unsigned long) / 4) {
-                p++;
-                s--;
-        }
-        r = *p++;
-#ifdef CONFIG_PPC64
-        if (s > 1) {
-                r <<= 32;
-                r |= *(p++);
-                s--;
-        }
-#endif
-
-        *cellp = p;
-        return r;
+        *cellp = p + s;
+        return of_read_ulong(p, s);
 }
 
 
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 465e7435efb..0af3fc1bdcc 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -304,18 +304,21 @@ struct seq_operations cpuinfo_op = {
 void __init check_for_initrd(void)
 {
 #ifdef CONFIG_BLK_DEV_INITRD
-        const unsigned long *prop;
+        const unsigned int *prop;
+        int len;
 
         DBG(" -> check_for_initrd()\n");
 
         if (of_chosen) {
-                prop = get_property(of_chosen, "linux,initrd-start", NULL);
+                prop = get_property(of_chosen, "linux,initrd-start", &len);
                 if (prop != NULL) {
-                        initrd_start = (unsigned long)__va(*prop);
+                        initrd_start = (unsigned long)
+                                __va(of_read_ulong(prop, len / 4));
                         prop = get_property(of_chosen,
-                                        "linux,initrd-end", NULL);
+                                        "linux,initrd-end", &len);
                         if (prop != NULL) {
-                                initrd_end = (unsigned long)__va(*prop);
+                                initrd_end = (unsigned long)
+                                        __va(of_read_ulong(prop, len / 4));
                                 initrd_below_start_ok = 1;
                         } else
                                 initrd_start = 0;
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index b9a2061cfdb..7a3c3f791ad 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -870,9 +870,7 @@ static int __init get_freq(char *name, int cells, unsigned long *val)
                 fp = get_property(cpu, name, NULL);
                 if (fp) {
                         found = 1;
-                        *val = 0;
-                        while (cells--)
-                                *val = (*val << 32) | *fp++;
+                        *val = of_read_ulong(fp, cells);
                 }
 
                 of_node_put(cpu);