3 files changed, 138 insertions, 1 deletions
diff --git a/arch/loongarch/lib/Makefile b/arch/loongarch/lib/Makefile
index ccea3bbd4353..fae77809048b 100644
--- a/arch/loongarch/lib/Makefile
+++ b/arch/loongarch/lib/Makefile
@@ -11,3 +11,5 @@ obj-$(CONFIG_ARCH_SUPPORTS_INT128) += tishift.o
 obj-$(CONFIG_CPU_HAS_LSX) += xor_simd.o xor_simd_glue.o
 
 obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
+
+obj-$(CONFIG_CRC32_ARCH) += crc32-loongarch.o
diff --git a/arch/loongarch/lib/crc32-loongarch.c b/arch/loongarch/lib/crc32-loongarch.c
new file mode 100644
index 000000000000..c44ee4f32557
--- /dev/null
+++ b/arch/loongarch/lib/crc32-loongarch.c
@@ -0,0 +1,135 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * CRC32 and CRC32C using LoongArch crc* instructions
+ *
+ * Module based on mips/crypto/crc32-mips.c
+ *
+ * Copyright (C) 2014 Linaro Ltd <yazen.ghannam@linaro.org>
+ * Copyright (C) 2018 MIPS Tech, LLC
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#include <asm/cpu-features.h>
+#include <linux/crc32.h>
+#include <linux/module.h>
+#include <linux/unaligned.h>
+
+#define _CRC32(crc, value, size, type)			\
+do {							\
+	__asm__ __volatile__(				\
+		#type ".w." #size ".w" " %0, %1, %0\n\t"\
+		: "+r" (crc)				\
+		: "r" (value)				\
+		: "memory");				\
+} while (0)
+
+#define CRC32(crc, value, size)		_CRC32(crc, value, size, crc)
+#define CRC32C(crc, value, size)	_CRC32(crc, value, size, crcc)
+
+static DEFINE_STATIC_KEY_FALSE(have_crc32);
+
+u32 crc32_le_arch(u32 crc, const u8 *p, size_t len)
+{
+	if (!static_branch_likely(&have_crc32))
+		return crc32_le_base(crc, p, len);
+
+	while (len >= sizeof(u64)) {
+		u64 value = get_unaligned_le64(p);
+
+		CRC32(crc, value, d);
+		p += sizeof(u64);
+		len -= sizeof(u64);
+	}
+
+	if (len & sizeof(u32)) {
+		u32 value = get_unaligned_le32(p);
+
+		CRC32(crc, value, w);
+		p += sizeof(u32);
+	}
+
+	if (len & sizeof(u16)) {
+		u16 value = get_unaligned_le16(p);
+
+		CRC32(crc, value, h);
+		p += sizeof(u16);
+	}
+
+	if (len & sizeof(u8)) {
+		u8 value = *p++;
+
+		CRC32(crc, value, b);
+	}
+
+	return crc;
+}
+EXPORT_SYMBOL(crc32_le_arch);
+
+u32 crc32c_arch(u32 crc, const u8 *p, size_t len)
+{
+	if (!static_branch_likely(&have_crc32))
+		return crc32c_base(crc, p, len);
+
+	while (len >= sizeof(u64)) {
+		u64 value = get_unaligned_le64(p);
+
+		CRC32C(crc, value, d);
+		p += sizeof(u64);
+		len -= sizeof(u64);
+	}
+
+	if (len & sizeof(u32)) {
+		u32 value = get_unaligned_le32(p);
+
+		CRC32C(crc, value, w);
+		p += sizeof(u32);
+	}
+
+	if (len & sizeof(u16)) {
+		u16 value = get_unaligned_le16(p);
+
+		CRC32C(crc, value, h);
+		p += sizeof(u16);
+	}
+
+	if (len & sizeof(u8)) {
+		u8 value = *p++;
+
+		CRC32C(crc, value, b);
+	}
+
+	return crc;
+}
+EXPORT_SYMBOL(crc32c_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_loongarch_init(void)
+{
+	if (cpu_has_crc32)
+		static_branch_enable(&have_crc32);
+	return 0;
+}
+arch_initcall(crc32_loongarch_init);
+
+static void __exit crc32_loongarch_exit(void)
+{
+}
+module_exit(crc32_loongarch_exit);
+
+u32 crc32_optimizations(void)
+{
+	if (static_key_enabled(&have_crc32))
+		return CRC32_LE_OPTIMIZATION | CRC32C_OPTIMIZATION;
+	return 0;
+}
+EXPORT_SYMBOL(crc32_optimizations);
+
+MODULE_AUTHOR("Min Zhou <zhoumin@loongson.cn>");
+MODULE_AUTHOR("Huacai Chen <chenhuacai@loongson.cn>");
+MODULE_DESCRIPTION("CRC32 and CRC32C using LoongArch crc* instructions");
+MODULE_LICENSE("GPL v2");
diff --git a/arch/loongarch/lib/csum.c b/arch/loongarch/lib/csum.c
index a5e84b403c3b..df309ae4045d 100644
--- a/arch/loongarch/lib/csum.c
+++ b/arch/loongarch/lib/csum.c
@@ -25,7 +25,7 @@ unsigned int __no_sanitize_address do_csum(const unsigned char *buff, int len)
 	const u64 *ptr;
 	u64 data, sum64 = 0;
 
-	if (unlikely(len == 0))
+	if (unlikely(len <= 0))
 		return 0;
 
 	offset = (unsigned long)buff & 7;