usb: early: xhci-dbc: Move cpu_to_le16_array() to core

It's used in USB but it might be useful for other drivers as well.
While at it, introduce a counterpart helper, i.e. le16_to_cpu_array().

Make them available through byteorder/generic.h.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/usb/early/xhci-dbc.c

@@ -9,6 +9,7 @@
 
 #define pr_fmt(fmt)	KBUILD_MODNAME ":%s: " fmt, __func__
 
+#include <linux/byteorder/generic.h>
 #include <linux/console.h>
 #include <linux/pci_regs.h>
 #include <linux/pci_ids.h>
@@ -200,14 +201,6 @@ static void xdbc_reset_ring(struct xdbc_ring *ring)
 	}
 }
 
-static inline void xdbc_put_utf16(u16 *s, const char *c, size_t size)
-{
-	int i;
-
-	for (i = 0; i < size; i++)
-		s[i] = cpu_to_le16(c[i]);
-}
-
 static void xdbc_mem_init(void)
 {
 	struct xdbc_ep_context *ep_in, *ep_out;
@@ -263,7 +256,7 @@ static void xdbc_mem_init(void)
 	s_desc->bLength		= (strlen(XDBC_STRING_SERIAL) + 1) * 2;
 	s_desc->bDescriptorType	= USB_DT_STRING;
 
-	xdbc_put_utf16(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
+	cpu_to_le16_array(s_desc->wData, XDBC_STRING_SERIAL, strlen(XDBC_STRING_SERIAL));
 	string_length = s_desc->bLength;
 	string_length <<= 8;
 
@@ -272,7 +265,7 @@ static void xdbc_mem_init(void)
 	s_desc->bLength		= (strlen(XDBC_STRING_PRODUCT) + 1) * 2;
 	s_desc->bDescriptorType	= USB_DT_STRING;
 
-	xdbc_put_utf16(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
+	cpu_to_le16_array(s_desc->wData, XDBC_STRING_PRODUCT, strlen(XDBC_STRING_PRODUCT));
 	string_length += s_desc->bLength;
 	string_length <<= 8;
 
@@ -281,7 +274,7 @@ static void xdbc_mem_init(void)
 	s_desc->bLength		= (strlen(XDBC_STRING_MANUFACTURER) + 1) * 2;
 	s_desc->bDescriptorType	= USB_DT_STRING;
 
-	xdbc_put_utf16(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
+	cpu_to_le16_array(s_desc->wData, XDBC_STRING_MANUFACTURER, strlen(XDBC_STRING_MANUFACTURER));
 	string_length += s_desc->bLength;
 	string_length <<= 8;
 

include/linux/byteorder/generic.h

@@ -156,6 +156,22 @@ static inline void le64_add_cpu(__le64 *var, u64 val)
 	*var = cpu_to_le64(le64_to_cpu(*var) + val);
 }
 
+static inline void cpu_to_le16_array(__le16 *dst, const u16 *src, size_t len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		dst[i] = cpu_to_le16(src[i]);
+}
+
+static inline void le16_to_cpu_array(u16 *dst, const __le16 *src, size_t len)
+{
+	int i;
+
+	for (i = 0; i < len; i++)
+		dst[i] = le16_to_cpu(src[i]);
+}
+
 /* XXX: this stuff can be optimized */
 static inline void le32_to_cpu_array(u32 *buf, unsigned int words)
 {