1 files changed, 105 insertions, 0 deletions
diff --git a/lib/crc/crc32-main.c b/lib/crc/crc32-main.c
new file mode 100644
index 000000000000..fbb90c9006e5
--- /dev/null
+++ b/lib/crc/crc32-main.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Aug 8, 2011 Bob Pearson with help from Joakim Tjernlund and George Spelvin
+ * cleaned up code to current version of sparse and added the slicing-by-8
+ * algorithm to the closely similar existing slicing-by-4 algorithm.
+ *
+ * Oct 15, 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * Nicer crc32 functions/docs submitted by linux@horizon.com.  Thanks!
+ * Code was from the public domain, copyright abandoned.  Code was
+ * subsequently included in the kernel, thus was re-licensed under the
+ * GNU GPL v2.
+ *
+ * Oct 12, 2000 Matt Domsch <Matt_Domsch@dell.com>
+ * Same crc32 function was used in 5 other places in the kernel.
+ * I made one version, and deleted the others.
+ * There are various incantations of crc32().  Some use a seed of 0 or ~0.
+ * Some xor at the end with ~0.  The generic crc32() function takes
+ * seed as an argument, and doesn't xor at the end.  Then individual
+ * users can do whatever they need.
+ *   drivers/net/smc9194.c uses seed ~0, doesn't xor with ~0.
+ *   fs/jffs2 uses seed 0, doesn't xor with ~0.
+ *   fs/partitions/efi.c uses seed ~0, xor's with ~0.
+ */
+
+/* see: Documentation/staging/crc32.rst for a description of algorithms */
+
+#include <linux/crc32.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+#include "crc32table.h"
+
+static inline u32 __maybe_unused
+crc32_le_base(u32 crc, const u8 *p, size_t len)
+{
+	while (len--)
+		crc = (crc >> 8) ^ crc32table_le[(crc & 255) ^ *p++];
+	return crc;
+}
+
+static inline u32 __maybe_unused
+crc32_be_base(u32 crc, const u8 *p, size_t len)
+{
+	while (len--)
+		crc = (crc << 8) ^ crc32table_be[(crc >> 24) ^ *p++];
+	return crc;
+}
+
+static inline u32 __maybe_unused
+crc32c_base(u32 crc, const u8 *p, size_t len)
+{
+	while (len--)
+		crc = (crc >> 8) ^ crc32ctable_le[(crc & 255) ^ *p++];
+	return crc;
+}
+
+#ifdef CONFIG_CRC32_ARCH
+#include "crc32.h" /* $(SRCARCH)/crc32.h */
+
+u32 crc32_optimizations(void)
+{
+	return crc32_optimizations_arch();
+}
+EXPORT_SYMBOL(crc32_optimizations);
+#else
+#define crc32_le_arch crc32_le_base
+#define crc32_be_arch crc32_be_base
+#define crc32c_arch crc32c_base
+#endif
+
+u32 crc32_le(u32 crc, const void *p, size_t len)
+{
+	return crc32_le_arch(crc, p, len);
+}
+EXPORT_SYMBOL(crc32_le);
+
+u32 crc32_be(u32 crc, const void *p, size_t len)
+{
+	return crc32_be_arch(crc, p, len);
+}
+EXPORT_SYMBOL(crc32_be);
+
+u32 crc32c(u32 crc, const void *p, size_t len)
+{
+	return crc32c_arch(crc, p, len);
+}
+EXPORT_SYMBOL(crc32c);
+
+#ifdef crc32_mod_init_arch
+static int __init crc32_mod_init(void)
+{
+	crc32_mod_init_arch();
+	return 0;
+}
+subsys_initcall(crc32_mod_init);
+
+static void __exit crc32_mod_exit(void)
+{
+}
+module_exit(crc32_mod_exit);
+#endif
+
+MODULE_DESCRIPTION("CRC32 library functions");
+MODULE_LICENSE("GPL");