arch/tile: support building big-endian kernel

The toolchain supports big-endian mode now, so add support for building
the kernel to run big-endian as well.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
diff --git a/arch/tile/kernel/module.c b/arch/tile/kernel/module.c
index 98d4769..001cbfa 100644
--- a/arch/tile/kernel/module.c
+++ b/arch/tile/kernel/module.c
@@ -159,7 +159,17 @@
 
 		switch (ELF_R_TYPE(rel[i].r_info)) {
 
-#define MUNGE(func) (*location = ((*location & ~func(-1)) | func(value)))
+#ifdef __LITTLE_ENDIAN
+# define MUNGE(func) \
+	(*location = ((*location & ~func(-1)) | func(value)))
+#else
+/*
+ * Instructions are always little-endian, so when we read them as data,
+ * we have to swap them around before and after modifying them.
+ */
+# define MUNGE(func) \
+	(*location = swab64((swab64(*location) & ~func(-1)) | func(value)))
+#endif
 
 #ifndef __tilegx__
 		case R_TILE_32:
diff --git a/arch/tile/kernel/single_step.c b/arch/tile/kernel/single_step.c
index 89529c9..27742e8 100644
--- a/arch/tile/kernel/single_step.c
+++ b/arch/tile/kernel/single_step.c
@@ -172,9 +172,6 @@
 		return (tilepro_bundle_bits) 0;
 	}
 
-#ifndef __LITTLE_ENDIAN
-# error We assume little-endian representation with copy_xx_user size 2 here
-#endif
 	/* Handle unaligned load/store */
 	if (mem_op == MEMOP_LOAD || mem_op == MEMOP_LOAD_POSTINCR) {
 		unsigned short val_16;
@@ -195,8 +192,19 @@
 			state->update = 1;
 		}
 	} else {
+		unsigned short val_16;
 		val = (val_reg == TREG_ZERO) ? 0 : regs->regs[val_reg];
-		err = copy_to_user(addr, &val, size);
+		switch (size) {
+		case 2:
+			val_16 = val;
+			err = copy_to_user(addr, &val_16, sizeof(val_16));
+			break;
+		case 4:
+			err = copy_to_user(addr, &val, sizeof(val));
+			break;
+		default:
+			BUG();
+		}
 	}
 
 	if (err) {