* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
- * version 2 along with this program; If not, see [sun.com URL with a
- * copy of GPLv2].
+ * version 2 along with this program; If not, see
+ * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* GPL HEADER END
*/
/*
- * Copyright 2008 Sun Microsystems, Inc. All rights reserved
+ * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*/
/*
#error Unsupported operating system.
#endif
-#include <lustre/types.h>
#include <lustre/lustre_idl.h>
/*
#define CRCPOLY_LE 0xedb88320
/**
* crc32_le() - Calculate bitwise little-endian Ethernet AUTODIN II CRC32
- * @crc - seed value for computation. ~0 for Ethernet, sometimes 0 for
- * other uses, or the previous crc32 value if computing incrementally.
- * @p - pointer to buffer over which CRC is run
- * @len - length of buffer @p
+ * \param crc seed value for computation. ~0 for Ethernet, sometimes 0 for
+ * other uses, or the previous crc32 value if computing incrementally.
+ * \param p - pointer to buffer over which CRC is run
+ * \param len- length of buffer \a p
*/
static inline __u32 crc32_le(__u32 crc, unsigned char const *p, size_t len)
{
return crc;
}
#endif
+
+#ifdef HAVE_ADLER
+/* Adler-32 is supported */
+#define CHECKSUM_ADLER OBD_CKSUM_ADLER
+#else
+#define CHECKSUM_ADLER 0
+#endif
+
+#ifdef X86_FEATURE_XMM4_2
+/* Call Nehalem+ CRC32C harware acceleration instruction on individual bytes. */
+static inline __u32 crc32c_hw_byte(__u32 crc, unsigned char const *p,
+ size_t bytes)
+{
+ while (bytes--) {
+ __asm__ __volatile__ (
+ ".byte 0xf2, 0xf, 0x38, 0xf0, 0xf1"
+ : "=S"(crc)
+ : "0"(crc), "c"(*p)
+ );
+ p++;
+ }
+
+ return crc;
+}
+
+#if BITS_PER_LONG > 32
+#define WORD_SHIFT 3
+#define WORD_MASK 7
+#define REX "0x48, "
+#else
+#define WORD_SHIFT 2
+#define WORD_MASK 3
+#define REX ""
+#endif
+
+/* Do we need to worry about unaligned input data here? */
+static inline __u32 crc32c_hw(__u32 crc, unsigned char const *p, size_t len)
+{
+ unsigned int words = len >> WORD_SHIFT;
+ unsigned int bytes = len & WORD_MASK;
+ long *ptmp = (long *)p;
+
+ while (words--) {
+ __asm__ __volatile__(
+ ".byte 0xf2, " REX "0xf, 0x38, 0xf1, 0xf1;"
+ : "=S"(crc)
+ : "0"(crc), "c"(*ptmp)
+ );
+ ptmp++;
+ }
+
+ if (bytes)
+ crc = crc32c_hw_byte(crc, (unsigned char *)ptmp, bytes);
+
+ return crc;
+}
+#else
+/* We should never call this unless the CPU has previously been detected to
+ * support this instruction in the SSE4.2 feature set. b=23549 */
+static inline __u32 crc32c_hw(__u32 crc, unsigned char const *p,size_t len)
+{
+ LBUG();
+}
+#endif
static inline __u32 init_checksum(cksum_type_t cksum_type)
{
switch(cksum_type) {
- case OBD_CKSUM_CRC32:
+ case OBD_CKSUM_CRC32C:
return ~0U;
#ifdef HAVE_ADLER
case OBD_CKSUM_ADLER:
return 1U;
#endif
+ case OBD_CKSUM_CRC32:
+ return ~0U;
default:
CERROR("Unknown checksum type (%x)!!!\n", cksum_type);
LBUG();
return 0;
}
+static inline __u32 fini_checksum(__u32 cksum, cksum_type_t cksum_type)
+{
+ if (cksum_type == OBD_CKSUM_CRC32C)
+ return ~cksum;
+ return cksum;
+}
+
static inline __u32 compute_checksum(__u32 cksum, unsigned char const *p,
size_t len, cksum_type_t cksum_type)
{
switch(cksum_type) {
- case OBD_CKSUM_CRC32:
- return crc32_le(cksum, p, len);
+ case OBD_CKSUM_CRC32C:
+ return crc32c_hw(cksum, p, len);
#ifdef HAVE_ADLER
case OBD_CKSUM_ADLER:
return adler32(cksum, p, len);
#endif
+ case OBD_CKSUM_CRC32:
+ return crc32_le(cksum, p, len);
default:
CERROR("Unknown checksum type (%x)!!!\n", cksum_type);
LBUG();
return 0;
}
+/* The OBD_FL_CKSUM_* flags is packed into 5 bits of o_flags, since there can
+ * only be a single checksum type per RPC.
+ *
+ * The OBD_CHECKSUM_* type bits passed in ocd_cksum_types are a 32-bit bitmask
+ * since they need to represent the full range of checksum algorithms that
+ * both the client and server can understand.
+ *
+ * In case of an unsupported types/flags we fall back to CRC32 (even though
+ * it isn't very fast) because that is supported by all clients
+ * checksums, since 1.6.5 (or earlier via patches).
+ *
+ * These flags should be listed in order of descending performance, so that
+ * in case multiple algorithms are supported the best one is used. */
static inline obd_flag cksum_type_pack(cksum_type_t cksum_type)
{
- switch(cksum_type) {
- case OBD_CKSUM_CRC32:
- return OBD_FL_CKSUM_CRC32;
+ if (cksum_type & OBD_CKSUM_CRC32C)
+ return OBD_FL_CKSUM_CRC32C;
#ifdef HAVE_ADLER
- case OBD_CKSUM_ADLER:
+ if (cksum_type & OBD_CKSUM_ADLER)
return OBD_FL_CKSUM_ADLER;
#endif
- default:
+ if (unlikely(cksum_type && !(cksum_type & OBD_CKSUM_CRC32)))
CWARN("unknown cksum type %x\n", cksum_type);
- }
+
return OBD_FL_CKSUM_CRC32;
}
static inline cksum_type_t cksum_type_unpack(obd_flag o_flags)
{
- o_flags &= OBD_FL_CKSUM_ALL;
- if ((o_flags - 1) & o_flags)
- CWARN("several checksum types are set: %x\n", o_flags);
- if (o_flags & OBD_FL_CKSUM_ADLER)
+ switch (o_flags & OBD_FL_CKSUM_ALL) {
+ case OBD_FL_CKSUM_CRC32C:
+ return OBD_CKSUM_CRC32C;
+ case OBD_FL_CKSUM_ADLER:
#ifdef HAVE_ADLER
return OBD_CKSUM_ADLER;
#else
CWARN("checksum type is set to adler32, but adler32 is not "
"supported (%x)\n", o_flags);
+ break;
#endif
+ default:
+ break;
+ }
+
+ /* 1.6.4- only supported CRC32 and didn't set o_flags */
return OBD_CKSUM_CRC32;
}
+/* Return a bitmask of the checksum types supported on this system.
+ *
+ * CRC32 is a required for compatibility (starting with 1.6.5),
+ * after which we could move to Adler as the base checksum type.
+ *
+ * If hardware crc32c support is not available, it is slower than Adler,
+ * so don't include it, even if it could be emulated in software. b=23549 */
+static inline cksum_type_t cksum_types_supported(void)
+{
+ cksum_type_t ret = OBD_CKSUM_CRC32;
+
+#ifdef X86_FEATURE_XMM4_2
+ if (cpu_has_xmm4_2)
+ ret |= OBD_CKSUM_CRC32C;
+#endif
#ifdef HAVE_ADLER
-/* Default preferred checksum algorithm to use (if supported by the server) */
-#define OSC_DEFAULT_CKSUM OBD_CKSUM_ADLER
-/* Adler-32 is supported */
-#define CHECKSUM_ADLER OBD_CKSUM_ADLER
-#else
-#define OSC_DEFAULT_CKSUM OBD_CKSUM_CRC32
-#define CHECKSUM_ADLER 0
+ ret |= OBD_CKSUM_ADLER;
#endif
+ return ret;
+}
-#define OBD_CKSUM_ALL (OBD_CKSUM_CRC32 | CHECKSUM_ADLER)
+/* Select the best checksum algorithm among those supplied in the cksum_types
+ * input.
+ *
+ * Currently, calling cksum_type_pack() with a mask will return the fastest
+ * checksum type due to its ordering, but in the future we might want to
+ * determine this based on benchmarking the different algorithms quickly.
+ * Caution is advised, however, since what is fastest on a single client may
+ * not be the fastest or most efficient algorithm on the server. */
+static inline cksum_type_t cksum_type_select(cksum_type_t cksum_types)
+{
+ return cksum_type_unpack(cksum_type_pack(cksum_types));
+}
/* Checksum algorithm names. Must be defined in the same order as the
* OBD_CKSUM_* flags. */
-#define DECLARE_CKSUM_NAME char *cksum_name[] = {"crc32", "adler"}
+#define DECLARE_CKSUM_NAME char *cksum_name[] = {"crc32", "adler", "crc32c"}
#endif /* __OBD_H */
git://git.whamcloud.com / fs / lustre-release.git / blobdiff