From 3c851001cbd55b080eaaa1c89ae033d8129cac28 Mon Sep 17 00:00:00 2001
From: Jesse Gross <jesse@nicira.com>
Date: Mon, 16 Dec 2013 00:44:05 -0800
Subject: [PATCH] datapath: Backport for architecture hash library.
The architecture-specific hash library automatically selects either
jhash or CRC32 if it is available on the current processor.
Signed-off-by: Jesse Gross <jesse@nicira.com>
---
datapath/linux/Modules.mk | 4 +
datapath/linux/compat/hash-x86.c | 95 ++++++++++++++++++++++
datapath/linux/compat/hash.c | 51 ++++++++++++
datapath/linux/compat/include/asm/hash.h | 18 ++++
datapath/linux/compat/include/linux/hash.h | 45 ++++++++++
5 files changed, 213 insertions(+)
create mode 100644 datapath/linux/compat/hash-x86.c
create mode 100644 datapath/linux/compat/hash.c
create mode 100644 datapath/linux/compat/include/asm/hash.h
create mode 100644 datapath/linux/compat/include/linux/hash.h
diff --git a/datapath/linux/Modules.mk b/datapath/linux/Modules.mk
index fee132e6e..2f4a9c223 100644
--- a/datapath/linux/Modules.mk
+++ b/datapath/linux/Modules.mk
@@ -6,6 +6,8 @@ openvswitch_sources += \
linux/compat/gre.c \
linux/compat/gso.c \
linux/compat/genetlink-openvswitch.c \
+ linux/compat/hash.c \
+ linux/compat/hash-x86.c \
linux/compat/ip_tunnels_core.c \
linux/compat/netdevice.c \
linux/compat/net_namespace.c \
@@ -15,6 +17,7 @@ openvswitch_sources += \
linux/compat/utils.c
openvswitch_headers += \
linux/compat/gso.h \
+ linux/compat/include/asm/hash.h \
linux/compat/include/asm/percpu.h \
linux/compat/include/linux/compiler.h \
linux/compat/include/linux/compiler-gcc.h \
@@ -22,6 +25,7 @@ openvswitch_headers += \
linux/compat/include/linux/err.h \
linux/compat/include/linux/etherdevice.h \
linux/compat/include/linux/flex_array.h \
+ linux/compat/include/linux/hash.h \
linux/compat/include/linux/icmp.h \
linux/compat/include/linux/icmpv6.h \
linux/compat/include/linux/if.h \
diff --git a/datapath/linux/compat/hash-x86.c b/datapath/linux/compat/hash-x86.c
new file mode 100644
index 000000000..ca259b910
--- /dev/null
+++ b/datapath/linux/compat/hash-x86.c
@@ -0,0 +1,95 @@
+/*
+ * 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/version.h>
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
+
+#ifdef CONFIG_X86
+
+#include <linux/hash.h>
+
+#include <asm/processor.h>
+#include <asm/cpufeature.h>
+
+static inline u32 crc32_u32(u32 crc, u32 val)
+{
+ asm ("crc32l %1,%0\n" : "+r" (crc) : "rm" (val));
+ 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(*p32++, seed);
+
+ switch (3 - (len & 0x03)) {
+ case 0:
+ tmp |= *((const u8 *) p32 + 2) << 16;
+ /* fallthrough */
+ case 1:
+ tmp |= *((const u8 *) p32 + 1) << 8;
+ /* fallthrough */
+ case 2:
+ tmp |= *((const u8 *) p32);
+ seed = crc32_u32(tmp, seed);
+ default:
+ 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(*p32++, seed);
+
+ return seed;
+}
+
+void 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;
+ }
+}
+
+#endif /* CONFIG_X86 */
+#endif /* < 3.14 */
diff --git a/datapath/linux/compat/hash.c b/datapath/linux/compat/hash.c
new file mode 100644
index 000000000..5e0d32425
--- /dev/null
+++ b/datapath/linux/compat/hash.c
@@ -0,0 +1,51 @@
+/* General purpose hashing library
+ *
+ * That's a start of a kernel hashing library, which can be extended
+ * with further algorithms in future. arch_fast_hash{2,}() will
+ * eventually resolve to an architecture optimized implementation.
+ *
+ * Copyright 2013 Francesco Fusco <ffusco@redhat.com>
+ * Copyright 2013 Daniel Borkmann <dborkman@redhat.com>
+ * Copyright 2013 Thomas Graf <tgraf@redhat.com>
+ * Licensed under the GNU General Public License, version 2.0 (GPLv2)
+ */
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
+
+#include <linux/cache.h>
+#include <linux/compiler.h>
+#include <linux/jhash.h>
+#include <linux/hash.h>
+#include <linux/kernel.h>
+
+static struct fast_hash_ops arch_hash_ops __read_mostly = {
+ .hash = jhash,
+ .hash2 = jhash2,
+};
+
+static bool arch_inited __read_mostly;
+static void init_arch(void)
+{
+ if (likely(arch_inited))
+ return;
+
+ setup_arch_fast_hash(&arch_hash_ops);
+ arch_inited = true;
+}
+
+u32 arch_fast_hash(const void *data, u32 len, u32 seed)
+{
+ init_arch();
+
+ return arch_hash_ops.hash(data, len, seed);
+}
+
+u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed)
+{
+ init_arch();
+
+ return arch_hash_ops.hash2(data, len, seed);
+}
+
+#endif /* < 3.14 */
diff --git a/datapath/linux/compat/include/asm/hash.h b/datapath/linux/compat/include/asm/hash.h
new file mode 100644
index 000000000..2ed5a9b50
--- /dev/null
+++ b/datapath/linux/compat/include/asm/hash.h
@@ -0,0 +1,18 @@
+#ifndef _ASM_HASH_WRAPPER_H
+#define _ASM_HASH_WRAPPER_H
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3,14,0)
+#include_next <asm/hash.h>
+#else
+
+struct fast_hash_ops;
+#ifdef CONFIG_X86
+extern void setup_arch_fast_hash(struct fast_hash_ops *ops);
+#else
+static inline void setup_arch_fast_hash(struct fast_hash_ops *ops) { }
+#endif
+
+#endif /* < 3.14 */
+
+#endif /* _ASM_HASH_WRAPPER_H */
diff --git a/datapath/linux/compat/include/linux/hash.h b/datapath/linux/compat/include/linux/hash.h
new file mode 100644
index 000000000..ac8531b3a
--- /dev/null
+++ b/datapath/linux/compat/include/linux/hash.h
@@ -0,0 +1,45 @@
+#ifndef _LINUX_HASH_WRAPPER_H
+#define _LINUX_HASH_WRAPPER_H
+
+#include_next <linux/hash.h>
+
+#include <linux/version.h>
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3,14,0)
+#include <asm/hash.h>
+
+struct fast_hash_ops {
+ u32 (*hash)(const void *data, u32 len, u32 seed);
+ u32 (*hash2)(const u32 *data, u32 len, u32 seed);
+};
+
+/**
+ * arch_fast_hash - Caclulates a hash over a given buffer that can have
+ * arbitrary size. This function will eventually use an
+ * architecture-optimized hashing implementation if
+ * available, and trades off distribution for speed.
+ *
+ * @data: buffer to hash
+ * @len: length of buffer in bytes
+ * @seed: start seed
+ *
+ * Returns 32bit hash.
+ */
+extern u32 arch_fast_hash(const void *data, u32 len, u32 seed);
+
+/**
+ * arch_fast_hash2 - Caclulates a hash over a given buffer that has a
+ * size that is of a multiple of 32bit words. This
+ * function will eventually use an architecture-
+ * optimized hashing implementation if available,
+ * and trades off distribution for speed.
+ *
+ * @data: buffer to hash (must be 32bit padded)
+ * @len: number of 32bit words
+ * @seed: start seed
+ *
+ * Returns 32bit hash.
+ */
+extern u32 arch_fast_hash2(const u32 *data, u32 len, u32 seed);
+#endif /* < 3.14 */
+
+#endif /* _LINUX_HASH_WRAPPER_H */
--
2.47.0