ARM: import memcpy_from/toio and memset_io from linux

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/include/asm/io.h

@@ -3,4 +3,11 @@
 
 #include <asm-generic/io.h>
 
+/*
+ * String version of IO memory access ops:
+ */
+extern void memcpy_fromio(void *, const volatile void __iomem *, size_t);
+extern void memcpy_toio(volatile void __iomem *, const void *, size_t);
+extern void memset_io(volatile void __iomem *, int, size_t);
+
 #endif	/* __ASM_ARM_IO_H */

arch/arm/lib/Makefile

@@ -5,6 +5,7 @@ obj-$(CONFIG_CMD_BOOTU)	+= bootu.o
 obj-y	+= div0.o
 obj-y	+= findbit.o
 obj-y	+= arm.o
+obj-y	+= io.o
 obj-y	+= io-readsb.o
 obj-y	+= io-readsw-armv4.o
 obj-y	+= io-readsl.o

arch/arm/lib/io.c

@@ -0,0 +1,50 @@
+#include <module.h>
+#include <linux/types.h>
+#include <io.h>
+
+/*
+ * Copy data from IO memory space to "real" memory space.
+ * This needs to be optimized.
+ */
+void memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
+{
+	unsigned char *t = to;
+	while (count) {
+		count--;
+		*t = readb(from);
+		t++;
+		from++;
+	}
+}
+
+/*
+ * Copy data from "real" memory space to IO memory space.
+ * This needs to be optimized.
+ */
+void memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
+{
+	const unsigned char *f = from;
+	while (count) {
+		count--;
+		writeb(*f, to);
+		f++;
+		to++;
+	}
+}
+
+/*
+ * "memset" on IO memory space.
+ * This needs to be optimized.
+ */
+void memset_io(volatile void __iomem *dst, int c, size_t count)
+{
+	while (count) {
+		count--;
+		writeb(c, dst);
+		dst++;
+	}
+}
+
+EXPORT_SYMBOL(memcpy_fromio);
+EXPORT_SYMBOL(memcpy_toio);
+EXPORT_SYMBOL(memset_io);