lib/crc: Move files into lib/crc/

Move all CRC files in lib/ into a subdirectory lib/crc/ to keep them
from cluttering up the main lib/ directory.

Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20250607200454.73587-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>

1 files changed, 59 insertions, 0 deletions

diff --git a/lib/crc/crc32.c b/lib/crc/crc32.c
new file mode 100644
index 000000000000..6811b37df2aa
--- /dev/null
+++ b/lib/crc/crc32.c
@@ -0,0 +1,59 @@
+// 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/module.h>
+#include <linux/types.h>
+
+#include "crc32table.h"
+
+MODULE_AUTHOR("Matt Domsch <Matt_Domsch@dell.com>");
+MODULE_DESCRIPTION("Various CRC32 calculations");
+MODULE_LICENSE("GPL");
+
+u32 crc32_le_base(u32 crc, const u8 *p, size_t len)
+{
+	while (len--)
+		crc = (crc >> 8) ^ crc32table_le[(crc & 255) ^ *p++];
+	return crc;
+}
+EXPORT_SYMBOL(crc32_le_base);
+
+u32 crc32c_base(u32 crc, const u8 *p, size_t len)
+{
+	while (len--)
+		crc = (crc >> 8) ^ crc32ctable_le[(crc & 255) ^ *p++];
+	return crc;
+}
+EXPORT_SYMBOL(crc32c_base);
+
+u32 crc32_be_base(u32 crc, const u8 *p, size_t len)
+{
+	while (len--)
+		crc = (crc << 8) ^ crc32table_be[(crc >> 24) ^ *p++];
+	return crc;
+}
+EXPORT_SYMBOL(crc32_be_base);