refactor(hw_crc32): renamed hw_crc32 to tf_crc32

Renamed hw_crc32 to tf_crc32 to make the file and function
name more generic so that the same name can be used in upcoming
software CRC32 implementation.

Change-Id: Idff8f70c50ca700a4328a27b49d5e1f14d2095eb
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/common/tf_crc32.c b/common/tf_crc32.c
new file mode 100644
index 0000000..b33d36e
--- /dev/null
+++ b/common/tf_crc32.c
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2021, Arm Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdarg.h>
+#include <assert.h>
+
+#include <arm_acle.h>
+#include <common/debug.h>
+#include <common/tf_crc32.h>
+
+/* compute CRC using Arm intrinsic function
+ *
+ * This function is useful for the platforms with the CPU ARMv8.0
+ * (with CRC instructions supported), and onwards.
+ * Platforms with CPU ARMv8.0 should make sure to add a compile switch
+ * '-march=armv8-a+crc" for successful compilation of this file.
+ *
+ * @crc: previous accumulated CRC
+ * @buf: buffer base address
+ * @size: the size of the buffer
+ *
+ * Return calculated CRC value
+ */
+uint32_t tf_crc32(uint32_t crc, const unsigned char *buf, size_t size)
+{
+	assert(buf != NULL);
+
+	uint32_t calc_crc = ~crc;
+	const unsigned char *local_buf = buf;
+	size_t local_size = size;
+
+	/*
+	 * calculate CRC over byte data
+	 */
+	while (local_size != 0UL) {
+		calc_crc = __crc32b(calc_crc, *local_buf);
+		local_buf++;
+		local_size--;
+	}
+
+	return ~calc_crc;
+}