powerpc/boot: Add PROM_ERROR define in oflib

This is mostly useful to make to the boot wrapper code closer with
the kernel code in prom_init.

Signed-off-by: Cédric Le Goater <clg@fr.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

2 files changed, 5 insertions, 3 deletions

diff --git a/arch/powerpc/boot/of.h b/arch/powerpc/boot/of.h
index 40d95bf7402b..0f058ef69521 100644
--- a/arch/powerpc/boot/of.h
+++ b/arch/powerpc/boot/of.h
@@ -23,4 +23,6 @@ typedef u32			__be32;
 #define cpu_to_be32(x) (x)
 #define be32_to_cpu(x) (x)
 
+#define PROM_ERROR (-1u)
+
 #endif /* _PPC_BOOT_OF_H_ */
diff --git a/arch/powerpc/boot/oflib.c b/arch/powerpc/boot/oflib.c
index 0f72b1a42133..7f61f2eb5653 100644
--- a/arch/powerpc/boot/oflib.c
+++ b/arch/powerpc/boot/oflib.c
@@ -55,7 +55,7 @@ int of_call_prom(const char *service, int nargs, int nret, ...)
                 args.args[nargs+i] = 0;
 
         if (prom(&args) < 0)
-                return -1;
+                return PROM_ERROR;
 
         return (nret > 0) ? be32_to_cpu(args.args[nargs]) : 0;
 }
@@ -80,9 +80,9 @@ static int of_call_prom_ret(const char *service, int nargs, int nret,
                 args.args[nargs+i] = 0;
 
         if (prom(&args) < 0)
-                return -1;
+                return PROM_ERROR;
 
-        if (rets != (void *) 0)
+        if (rets != NULL)
                 for (i = 1; i < nret; ++i)
                         rets[i-1] = be32_to_cpu(args.args[nargs+i]);