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, 2 insertions, 6 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 9cc14ab35297..70fc4e7cc5a0 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2029,14 +2029,10 @@ static int btrfs_init_csum_hash(struct btrfs_fs_info *fs_info, u16 csum_type)
 
 	fs_info->csum_shash = csum_shash;
 
-	/*
-	 * Check if the checksum implementation is a fast accelerated one.
-	 * As-is this is a bit of a hack and should be replaced once the csum
-	 * implementations provide that information themselves.
-	 */
+	/* Check if the checksum implementation is a fast accelerated one. */
 	switch (csum_type) {
 	case BTRFS_CSUM_TYPE_CRC32:
-		if (!strstr(crypto_shash_driver_name(csum_shash), "generic"))
+		if (crc32_optimizations() & CRC32C_OPTIMIZATION)
 			set_bit(BTRFS_FS_CSUM_IMPL_FAST, &fs_info->flags);
 		break;
 	case BTRFS_CSUM_TYPE_XXHASH: