1 files changed, 123 insertions, 0 deletions
diff --git a/arch/arm/lib/crc32-glue.c b/arch/arm/lib/crc32-glue.c
new file mode 100644
index 000000000000..2c30ba3d80e6
--- /dev/null
+++ b/arch/arm/lib/crc32-glue.c
@@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions instructions
+ *
+ * Copyright (C) 2016 Linaro Ltd <ard.biesheuvel@linaro.org>
+ */
+
+#include <linux/cpufeature.h>
+#include <linux/crc32.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <crypto/internal/simd.h>
+
+#include <asm/hwcap.h>
+#include <asm/neon.h>
+#include <asm/simd.h>
+
+static DEFINE_STATIC_KEY_FALSE(have_crc32);
+static DEFINE_STATIC_KEY_FALSE(have_pmull);
+
+#define PMULL_MIN_LEN	64	/* min size of buffer for pmull functions */
+
+asmlinkage u32 crc32_pmull_le(const u8 buf[], u32 len, u32 init_crc);
+asmlinkage u32 crc32_armv8_le(u32 init_crc, const u8 buf[], u32 len);
+
+asmlinkage u32 crc32c_pmull_le(const u8 buf[], u32 len, u32 init_crc);
+asmlinkage u32 crc32c_armv8_le(u32 init_crc, const u8 buf[], u32 len);
+
+static u32 crc32_le_scalar(u32 crc, const u8 *p, size_t len)
+{
+	if (static_branch_likely(&have_crc32))
+		return crc32_armv8_le(crc, p, len);
+	return crc32_le_base(crc, p, len);
+}
+
+u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
+{
+	if (len >= PMULL_MIN_LEN + 15 &&
+	    static_branch_likely(&have_pmull) && crypto_simd_usable()) {
+		size_t n = -(uintptr_t)p & 15;
+
+		/* align p to 16-byte boundary */
+		if (n) {
+			crc = crc32_le_scalar(crc, p, n);
+			p += n;
+			len -= n;
+		}
+		n = round_down(len, 16);
+		kernel_neon_begin();
+		crc = crc32_pmull_le(p, n, crc);
+		kernel_neon_end();
+		p += n;
+		len -= n;
+	}
+	return crc32_le_scalar(crc, p, len);
+}
+EXPORT_SYMBOL(crc32_le_arch);
+
+static u32 crc32c_le_scalar(u32 crc, const u8 *p, size_t len)
+{
+	if (static_branch_likely(&have_crc32))
+		return crc32c_armv8_le(crc, p, len);
+	return crc32c_le_base(crc, p, len);
+}
+
+u32 crc32c_le_arch(u32 crc, const u8 *p, size_t len)
+{
+	if (len >= PMULL_MIN_LEN + 15 &&
+	    static_branch_likely(&have_pmull) && crypto_simd_usable()) {
+		size_t n = -(uintptr_t)p & 15;
+
+		/* align p to 16-byte boundary */
+		if (n) {
+			crc = crc32c_le_scalar(crc, p, n);
+			p += n;
+			len -= n;
+		}
+		n = round_down(len, 16);
+		kernel_neon_begin();
+		crc = crc32c_pmull_le(p, n, crc);
+		kernel_neon_end();
+		p += n;
+		len -= n;
+	}
+	return crc32c_le_scalar(crc, p, len);
+}
+EXPORT_SYMBOL(crc32c_le_arch);
+
+u32 crc32_be_arch(u32 crc, const u8 *p, size_t len)
+{
+	return crc32_be_base(crc, p, len);
+}
+EXPORT_SYMBOL(crc32_be_arch);
+
+static int __init crc32_arm_init(void)
+{
+	if (elf_hwcap2 & HWCAP2_CRC32)
+		static_branch_enable(&have_crc32);
+	if (elf_hwcap2 & HWCAP2_PMULL)
+		static_branch_enable(&have_pmull);
+	return 0;
+}
+arch_initcall(crc32_arm_init);
+
+static void __exit crc32_arm_exit(void)
+{
+}
+module_exit(crc32_arm_exit);
+
+u32 crc32_optimizations(void)
+{
+	if (elf_hwcap2 & (HWCAP2_CRC32 | HWCAP2_PMULL))
+		return CRC32_LE_OPTIMIZATION | CRC32C_OPTIMIZATION;
+	return 0;
+}
+EXPORT_SYMBOL(crc32_optimizations);
+
+MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
+MODULE_DESCRIPTION("Accelerated CRC32(C) using ARM CRC, NEON and Crypto Extensions");
+MODULE_LICENSE("GPL v2");