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

Pull CRC updates from Eric Biggers:
 "Cleanups for the kernel's CRC (cyclic redundancy check) code:

   - Use __ro_after_init where appropriate

   - Remove unnecessary static_key on s390

   - Rename some source code files

   - Rename the crc32 and crc32c crypto API modules

   - Use subsys_initcall instead of arch_initcall

   - Restore maintainers for crc_kunit.c

   - Fold crc16_byte() into crc16.c

   - Add some SPDX license identifiers"

* tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux:
  lib/crc32: add SPDX license identifier
  lib/crc16: unexport crc16_table and crc16_byte()
  w1: ds2406: use crc16() instead of crc16_byte() loop
  MAINTAINERS: add crc_kunit.c back to CRC LIBRARY
  lib/crc: make arch-optimized code use subsys_initcall
  crypto: crc32 - remove "generic" from file and module names
  x86/crc: drop "glue" from filenames
  sparc/crc: drop "glue" from filenames
  s390/crc: drop "glue" from filenames
  powerpc/crc: rename crc32-vpmsum_core.S to crc-vpmsum-template.S
  powerpc/crc: drop "glue" from filenames
  arm64/crc: drop "glue" from filenames
  arm/crc: drop "glue" from filenames
  s390/crc32: Remove no-op module init and exit functions
  s390/crc32: Remove have_vxrs static key
  lib/crc: make the CPU feature static keys __ro_after_init

1 files changed, 83 insertions, 0 deletions

diff --git a/arch/powerpc/lib/crc-t10dif.c b/arch/powerpc/lib/crc-t10dif.c
new file mode 100644
index 000000000000..4253842cc50d
--- /dev/null
+++ b/arch/powerpc/lib/crc-t10dif.c
@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Calculate a CRC T10-DIF with vpmsum acceleration
+ *
+ * Copyright 2017, Daniel Axtens, IBM Corporation.
+ * [based on crc32c-vpmsum_glue.c]
+ */
+
+#include <linux/crc-t10dif.h>
+#include <crypto/internal/simd.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/cpufeature.h>
+#include <asm/simd.h>
+#include <asm/switch_to.h>
+
+#define VMX_ALIGN		16
+#define VMX_ALIGN_MASK		(VMX_ALIGN-1)
+
+#define VECTOR_BREAKPOINT	64
+
+static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_vec_crypto);
+
+u32 __crct10dif_vpmsum(u32 crc, unsigned char const *p, size_t len);
+
+u16 crc_t10dif_arch(u16 crci, const u8 *p, size_t len)
+{
+	unsigned int prealign;
+	unsigned int tail;
+	u32 crc = crci;
+
+	if (len < (VECTOR_BREAKPOINT + VMX_ALIGN) ||
+	    !static_branch_likely(&have_vec_crypto) || !crypto_simd_usable())
+		return crc_t10dif_generic(crc, p, len);
+
+	if ((unsigned long)p & VMX_ALIGN_MASK) {
+		prealign = VMX_ALIGN - ((unsigned long)p & VMX_ALIGN_MASK);
+		crc = crc_t10dif_generic(crc, p, prealign);
+		len -= prealign;
+		p += prealign;
+	}
+
+	if (len & ~VMX_ALIGN_MASK) {
+		crc <<= 16;
+		preempt_disable();
+		pagefault_disable();
+		enable_kernel_altivec();
+		crc = __crct10dif_vpmsum(crc, p, len & ~VMX_ALIGN_MASK);
+		disable_kernel_altivec();
+		pagefault_enable();
+		preempt_enable();
+		crc >>= 16;
+	}
+
+	tail = len & VMX_ALIGN_MASK;
+	if (tail) {
+		p += len & ~VMX_ALIGN_MASK;
+		crc = crc_t10dif_generic(crc, p, tail);
+	}
+
+	return crc & 0xffff;
+}
+EXPORT_SYMBOL(crc_t10dif_arch);
+
+static int __init crc_t10dif_powerpc_init(void)
+{
+	if (cpu_has_feature(CPU_FTR_ARCH_207S) &&
+	    (cur_cpu_spec->cpu_user_features2 & PPC_FEATURE2_VEC_CRYPTO))
+		static_branch_enable(&have_vec_crypto);
+	return 0;
+}
+subsys_initcall(crc_t10dif_powerpc_init);
+
+static void __exit crc_t10dif_powerpc_exit(void)
+{
+}
+module_exit(crc_t10dif_powerpc_exit);
+
+MODULE_AUTHOR("Daniel Axtens <dja@axtens.net>");
+MODULE_DESCRIPTION("CRCT10DIF using vector polynomial multiply-sum instructions");
+MODULE_LICENSE("GPL");