1 files changed, 92 insertions, 0 deletions

diff --git a/arch/x86/lib/hash.c b/arch/x86/lib/hash.c
new file mode 100644
index 000000000000..ff4fa51a5b1f
--- /dev/null
+++ b/arch/x86/lib/hash.c
@@ -0,0 +1,92 @@
+/*
+ * Some portions derived from code covered by the following notice:
+ *
+ * Copyright (c) 2010-2013 Intel Corporation. All rights reserved.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in
+ *     the documentation and/or other materials provided with the
+ *     distribution.
+ *   * Neither the name of Intel Corporation nor the names of its
+ *     contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <linux/hash.h>
+#include <linux/init.h>
+
+#include <asm/processor.h>
+#include <asm/cpufeature.h>
+#include <asm/hash.h>
+
+static inline u32 crc32_u32(u32 crc, u32 val)
+{
+#ifdef CONFIG_AS_CRC32
+        asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val));
+#else
+        asm (".byte 0xf2, 0x0f, 0x38, 0xf1, 0xc1" : "+a" (crc) : "c" (val));
+#endif
+        return crc;
+}
+
+static u32 intel_crc4_2_hash(const void *data, u32 len, u32 seed)
+{
+        const u32 *p32 = (const u32 *) data;
+        u32 i, tmp = 0;
+
+        for (i = 0; i < len / 4; i++)
+                seed = crc32_u32(seed, *p32++);
+
+        switch (len & 3) {
+        case 3:
+                tmp |= *((const u8 *) p32 + 2) << 16;
+                /* fallthrough */
+        case 2:
+                tmp |= *((const u8 *) p32 + 1) << 8;
+                /* fallthrough */
+        case 1:
+                tmp |= *((const u8 *) p32);
+                seed = crc32_u32(seed, tmp);
+                break;
+        }
+
+        return seed;
+}
+
+static u32 intel_crc4_2_hash2(const u32 *data, u32 len, u32 seed)
+{
+        const u32 *p32 = (const u32 *) data;
+        u32 i;
+
+        for (i = 0; i < len; i++)
+                seed = crc32_u32(seed, *p32++);
+
+        return seed;
+}
+
+void __init setup_arch_fast_hash(struct fast_hash_ops *ops)
+{
+        if (cpu_has_xmm4_2) {
+                ops->hash  = intel_crc4_2_hash;
+                ops->hash2 = intel_crc4_2_hash2;
+        }
+}