usr/src/uts/i86pc/cpu/amd_opteron/ao_poll.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 /*
  30  * AMD Athlon64/Opteron Model-Specific Poller Implementation
  31  */
  32
  33 #include <sys/types.h>
  34
  35 #include "ao.h"
  36
  37 /*
  38  * Decide whether the caller should poll the NB.  The decision is made
  39  * and any poll is performed under protection of the chip-wide mutex
  40  * enforced at the caller's level.  That mutex already ensures that all
  41  * pollers on a chip are serialized - the following is simply to
  42  * avoid the NB poll ping-ponging between different detectors.
  43  */
  44 uint64_t
  45 ao_ms_poll_ownermask(cmi_hdl_t hdl, hrtime_t pintvl)
  46 {
  47         ao_ms_data_t *ao = cms_hdl_getcmsdata(hdl);
  48         hrtime_t now = gethrtime_waitfree();
  49         hrtime_t last = ao->ao_ms_shared->aos_nb_poll_timestamp;
  50         int dopoll = 0;
  51
  52         if (now - last > 2 * pintvl || last == 0) {
  53                 /*
  54                  * If no last value has been recorded assume ownership.
  55                  * Otherwise only take over if the current "owner" seems
  56                  * to be making little progress.
  57                  */
  58                 ao->ao_ms_shared->aos_nb_poll_owner = hdl;
  59                 dopoll = 1;
  60         } else if (ao->ao_ms_shared->aos_nb_poll_owner == hdl) {
  61                 /*
  62                  * This is the current owner and it is making progress.
  63                  */
  64                 dopoll = 1;
  65         }
  66
  67         if (dopoll)
  68                 ao->ao_ms_shared->aos_nb_poll_timestamp = now;
  69
  70         return (dopoll ? -1ULL : ~(1 << AMD_MCA_BANK_NB));
  71 }