freebsd-nq/sys/cam/ctl/ctl_ser_table.c
Alexander Motin ab55ae255a Implement control over command reordering via options and control mode page.
It allows to bypass range checks between UNMAP and READ/WRITE commands,
which may introduce additional delays while waiting for UNMAP parameters.
READ and WRITE commands are always processed in safe order since their
range checks are almost free.
2014-09-13 10:34:23 +00:00

81 lines
4.2 KiB
C

/*-
* Copyright (c) 2003 Silicon Graphics International Corp.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce at minimum a disclaimer
* substantially similar to the "NO WARRANTY" disclaimer below
* ("Disclaimer") and any redistribution must be conditioned upon
* including a substantially similar Disclaimer requirement for further
* binary redistribution.
*
* NO WARRANTY
* 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 MERCHANTIBILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR 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 DAMAGES.
*
* $Id: //depot/users/kenm/FreeBSD-test2/sys/cam/ctl/ctl_ser_table.c#1 $
* $FreeBSD$
*/
/*
* CAM Target Layer command serialization table.
*
* Author: Kim Le
*/
/****************************************************************************/
/* TABLE ctlSerTbl */
/* */
/* The matrix which drives the serialization algorithm. The major index */
/* (the first) into this table is the command being checked and the minor */
/* index is the command against which the first command is being checked. */
/* i.e., the major index (row) command is ahead of the minor index command */
/* (column) in the queue. This allows the code to optimize by capturing */
/* the result of the first indexing operation into a pointer. */
/* */
/* Whenever a new value is added to the IDX_T type, this matrix must be */
/* expanded by one row AND one column -- Because of this, some effort */
/* should be made to re-use the indexes whenever possible. */
/* */
/****************************************************************************/
#define sK CTL_SER_SKIP /* Skip */
#define pS CTL_SER_PASS /* Pass */
#define bK CTL_SER_BLOCK /* Blocked */
#define bO CTL_SER_BLOCKOPT /* Optional block */
#define xT CTL_SER_EXTENT /* Extent check */
#define xO CTL_SER_EXTENTOPT /* Optional extent check */
static ctl_serialize_action
ctl_serialize_table[CTL_SERIDX_COUNT][CTL_SERIDX_COUNT] = {
/**>IDX_ :: 2nd:TUR RD WRT UNM MDSN MDSL RQSN INQ RDCP RES LSNS FMT STR*/
/*TUR */{ pS, pS, pS, pS, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*READ */{ pS, pS, xT, bO, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*WRITE */{ pS, xT, xT, bO, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*UNMAP */{ pS, xO, xO, pS, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*MD_SNS */{ bK, bK, bK, bK, pS, bK, bK, pS, pS, bK, pS, bK, bK},
/*MD_SEL */{ bK, bK, bK, bK, bK, bK, bK, pS, pS, bK, pS, bK, bK},
/*RQ_SNS */{ pS, pS, pS, pS, pS, pS, bK, pS, pS, bK, pS, bK, bK},
/*INQ */{ pS, pS, pS, pS, pS, pS, bK, pS, pS, pS, pS, bK, bK},
/*RD_CAP */{ pS, pS, pS, pS, pS, pS, bK, pS, pS, pS, pS, bK, pS},
/*RES */{ bK, bK, bK, bK, bK, bK, bK, pS, bK, bK, bK, bK, bK},
/*LOG_SNS */{ pS, pS, pS, pS, pS, bK, bK, pS, pS, bK, pS, bK, bK},
/*FORMAT */{ pS, bK, bK, bK, bK, bK, pS, pS, bK, bK, bK, bK, bK},
/*START */{ bK, bK, bK, bK, bK, bK, bK, pS, bK, bK, bK, bK, bK},
};