Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

Pull CRC updates from Eric Biggers:

 - Reorganize the architecture-optimized CRC code

   It now lives in lib/crc/$(SRCARCH)/ rather than arch/$(SRCARCH)/lib/,
   and it is no longer artificially split into separate generic and arch
   modules. This allows better inlining and dead code elimination

   The generic CRC code is also no longer exported, simplifying the API.
   (This mirrors the similar changes to SHA-1 and SHA-2 in lib/crypto/,
   which can be found in the "Crypto library updates" pull request)

 - Improve crc32c() performance on newer x86_64 CPUs on long messages by
   enabling the VPCLMULQDQ optimized code

 - Simplify the crypto_shash wrappers for crc32_le() and crc32c()

   Register just one shash algorithm for each that uses the (fully
   optimized) library functions, instead of unnecessarily providing
   direct access to the generic CRC code

 - Remove unused and obsolete drivers for hardware CRC engines

 - Remove CRC-32 combination functions that are no longer used

 - Add kerneldoc for crc32_le(), crc32_be(), and crc32c()

 - Convert the crc32() macro to an inline function

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: (26 commits)
  lib/crc: x86/crc32c: Enable VPCLMULQDQ optimization where beneficial
  lib/crc: x86: Reorganize crc-pclmul static_call initialization
  lib/crc: crc64: Add include/linux/crc64.h to kernel-api.rst
  lib/crc: crc32: Change crc32() from macro to inline function and remove cast
  nvmem: layouts: Switch from crc32() to crc32_le()
  lib/crc: crc32: Document crc32_le(), crc32_be(), and crc32c()
  lib/crc: Explicitly include <linux/export.h>
  lib/crc: Remove ARCH_HAS_* kconfig symbols
  lib/crc: x86: Migrate optimized CRC code into lib/crc/
  lib/crc: sparc: Migrate optimized CRC code into lib/crc/
  lib/crc: s390: Migrate optimized CRC code into lib/crc/
  lib/crc: riscv: Migrate optimized CRC code into lib/crc/
  lib/crc: powerpc: Migrate optimized CRC code into lib/crc/
  lib/crc: mips: Migrate optimized CRC code into lib/crc/
  lib/crc: loongarch: Migrate optimized CRC code into lib/crc/
  lib/crc: arm64: Migrate optimized CRC code into lib/crc/
  lib/crc: arm: Migrate optimized CRC code into lib/crc/
  lib/crc: Prepare for arch-optimized code in subdirs of lib/crc/
  lib/crc: Move files into lib/crc/
  lib/crc32: Remove unused combination support
  ...

1 files changed, 66 insertions, 0 deletions

diff --git a/lib/crc/crc-ccitt.c b/lib/crc/crc-ccitt.c
new file mode 100644
index 000000000000..f8692c3de101
--- /dev/null
+++ b/lib/crc/crc-ccitt.c
@@ -0,0 +1,66 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/crc-ccitt.h>
+#include <linux/export.h>
+#include <linux/module.h>
+#include <linux/types.h>
+
+/*
+ * This mysterious table is just the CRC of each possible byte. It can be
+ * computed using the standard bit-at-a-time methods. The polynomial can
+ * be seen in entry 128, 0x8408. This corresponds to x^0 + x^5 + x^12.
+ * Add the implicit x^16, and you have the standard CRC-CCITT.
+ */
+u16 const crc_ccitt_table[256] = {
+	0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
+	0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
+	0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
+	0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
+	0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
+	0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
+	0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
+	0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
+	0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
+	0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
+	0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
+	0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
+	0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
+	0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
+	0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
+	0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
+	0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
+	0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
+	0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
+	0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
+	0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
+	0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
+	0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
+	0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
+	0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
+	0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
+	0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
+	0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
+	0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
+	0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
+	0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
+	0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
+};
+EXPORT_SYMBOL(crc_ccitt_table);
+
+/**
+ *	crc_ccitt - recompute the CRC (CRC-CCITT variant) for the data
+ *	buffer
+ *	@crc: previous CRC value
+ *	@buffer: data pointer
+ *	@len: number of bytes in the buffer
+ */
+u16 crc_ccitt(u16 crc, u8 const *buffer, size_t len)
+{
+	while (len--)
+		crc = crc_ccitt_byte(crc, *buffer++);
+	return crc;
+}
+EXPORT_SYMBOL(crc_ccitt);
+
+MODULE_DESCRIPTION("CRC-CCITT calculations");
+MODULE_LICENSE("GPL");