[JFFS2] Fix cross-endian build.

When compiling a LE-capable JFFS2 on PowerPC, wbuf.c fails to compile:

fs/jffs2/wbuf.c:973: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:973: error: initializer element is not constant
fs/jffs2/wbuf.c:973: error: (near initialization for ‘oob_cleanmarker.magic’)
fs/jffs2/wbuf.c:974: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:974: error: initializer element is not constant
fs/jffs2/wbuf.c:974: error: (near initialization for ‘oob_cleanmarker.nodetype’)
fs/jffs2/wbuf.c:975: error: braced-group within expression allowed only inside a function
fs/jffs2/wbuf.c:976: error: initializer element is not constant
fs/jffs2/wbuf.c:976: error: (near initialization for ‘oob_cleanmarker.totlen’)

Provide constant_cpu_to_je{16,32} functions, and use them for initialising the
offending structure.
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

fs/jffs2/nodelist.h

@@ -40,6 +40,9 @@
 #define cpu_to_je32(x) ((jint32_t){x})
 #define cpu_to_jemode(x) ((jmode_t){os_to_jffs2_mode(x)})
 
+#define constant_cpu_to_je16(x) ((jint16_t){x})
+#define constant_cpu_to_je32(x) ((jint32_t){x})
+
 #define je16_to_cpu(x) ((x).v16)
 #define je32_to_cpu(x) ((x).v32)
 #define jemode_to_cpu(x) (jffs2_to_os_mode((x).m))
@@ -48,6 +51,9 @@
 #define cpu_to_je32(x) ((jint32_t){cpu_to_be32(x)})
 #define cpu_to_jemode(x) ((jmode_t){cpu_to_be32(os_to_jffs2_mode(x))})
 
+#define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_be16(x)})
+#define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_be32(x)})
+
 #define je16_to_cpu(x) (be16_to_cpu(x.v16))
 #define je32_to_cpu(x) (be32_to_cpu(x.v32))
 #define jemode_to_cpu(x) (be32_to_cpu(jffs2_to_os_mode((x).m)))
@@ -56,6 +62,9 @@
 #define cpu_to_je32(x) ((jint32_t){cpu_to_le32(x)})
 #define cpu_to_jemode(x) ((jmode_t){cpu_to_le32(os_to_jffs2_mode(x))})
 
+#define constant_cpu_to_je16(x) ((jint16_t){__constant_cpu_to_le16(x)})
+#define constant_cpu_to_je32(x) ((jint32_t){__constant_cpu_to_le32(x)})
+
 #define je16_to_cpu(x) (le16_to_cpu(x.v16))
 #define je32_to_cpu(x) (le32_to_cpu(x.v32))
 #define jemode_to_cpu(x) (le32_to_cpu(jffs2_to_os_mode((x).m)))

fs/jffs2/wbuf.c

@@ -970,9 +970,9 @@ int jffs2_flash_read(struct jffs2_sb_info *c, loff_t ofs, size_t len, size_t *re
 
 static const struct jffs2_unknown_node oob_cleanmarker =
 {
-	.magic = cpu_to_je16(JFFS2_MAGIC_BITMASK),
-	.nodetype = cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER),
-	.totlen = cpu_to_je32(8)
+	.magic = constant_cpu_to_je16(JFFS2_MAGIC_BITMASK),
+	.nodetype = constant_cpu_to_je16(JFFS2_NODETYPE_CLEANMARKER),
+	.totlen = constant_cpu_to_je32(8)
 };
 
 /*