1 files changed, 83 insertions, 0 deletions
diff --git a/arch/powerpc/lib/crc-t10dif-glue.c b/arch/powerpc/lib/crc-t10dif-glue.c
new file mode 100644
index 000000000000..f411b0120cc5
--- /dev/null
+++ b/arch/powerpc/lib/crc-t10dif-glue.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 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;
+}
+arch_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");