[POWERPC] convert string i/o operations to C

This produces essentially the same code and will make the iSeries i/o
consolidation easier.

The count parameter is changed to long since that will produce the same
(better) code on 32 and 64 bit builds.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
diff --git a/arch/powerpc/kernel/io.c b/arch/powerpc/kernel/io.c
new file mode 100644
index 0000000..80a3209
--- /dev/null
+++ b/arch/powerpc/kernel/io.c
@@ -0,0 +1,117 @@
+/*
+ * I/O string operations
+ *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
+ *    Copyright (C) 2006 IBM Corporation
+ *
+ * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
+ * and Paul Mackerras.
+ *
+ * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
+ * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
+ *
+ * Rewritten in C by Stephen Rothwell.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/compiler.h>
+#include <linux/module.h>
+
+#include <asm/io.h>
+
+void _insb(volatile u8 __iomem *port, void *buf, long count)
+{
+	u8 *tbuf = buf;
+	u8 tmp;
+
+	if (unlikely(count <= 0))
+		return;
+	asm volatile("sync");
+	do {
+		tmp = *port;
+		asm volatile("eieio");
+		*tbuf++ = tmp;
+	} while (--count != 0);
+	asm volatile("twi 0,%0,0; isync" : : "r" (tmp));
+}
+EXPORT_SYMBOL(_insb);
+
+void _outsb(volatile u8 __iomem *port, const void *buf, long count)
+{
+	const u8 *tbuf = buf;
+
+	if (unlikely(count <= 0))
+		return;
+	asm volatile("sync");
+	do {
+		*port = *tbuf++;
+	} while (--count != 0);
+	asm volatile("sync");
+}
+EXPORT_SYMBOL(_outsb);
+
+void _insw_ns(volatile u16 __iomem *port, void *buf, long count)
+{
+	u16 *tbuf = buf;
+	u16 tmp;
+
+	if (unlikely(count <= 0))
+		return;
+	asm volatile("sync");
+	do {
+		tmp = *port;
+		asm volatile("eieio");
+		*tbuf++ = tmp;
+	} while (--count != 0);
+	asm volatile("twi 0,%0,0; isync" : : "r" (tmp));
+}
+EXPORT_SYMBOL(_insw_ns);
+
+void _outsw_ns(volatile u16 __iomem *port, const void *buf, long count)
+{
+	const u16 *tbuf = buf;
+
+	if (unlikely(count <= 0))
+		return;
+	asm volatile("sync");
+	do {
+		*port = *tbuf++;
+	} while (--count != 0);
+	asm volatile("sync");
+}
+EXPORT_SYMBOL(_outsw_ns);
+
+void _insl_ns(volatile u32 __iomem *port, void *buf, long count)
+{
+	u32 *tbuf = buf;
+	u32 tmp;
+
+	if (unlikely(count <= 0))
+		return;
+	asm volatile("sync");
+	do {
+		tmp = *port;
+		asm volatile("eieio");
+		*tbuf++ = tmp;
+	} while (--count != 0);
+	asm volatile("twi 0,%0,0; isync" : : "r" (tmp));
+}
+EXPORT_SYMBOL(_insl_ns);
+
+void _outsl_ns(volatile u32 __iomem *port, const void *buf, long count)
+{
+	const u32 *tbuf = buf;
+
+	if (unlikely(count <= 0))
+		return;
+	asm volatile("sync");
+	do {
+		*port = *tbuf++;
+	} while (--count != 0);
+	asm volatile("sync");
+}
+EXPORT_SYMBOL(_outsl_ns);