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Annotation of tme/generic/scsi.c, revision 1.1.1.3

1.1.1.3 ! root        1: /* $Id: scsi.c,v 1.3 2007/01/07 23:27:50 fredette Exp $ */
1.1       root        2: 
                      3: /* generic/scsi.c - generic SCSI implementation support: */
                      4: 
                      5: /*
                      6:  * Copyright (c) 2003 Matt Fredette
                      7:  * All rights reserved.
                      8:  *
                      9:  * Redistribution and use in source and binary forms, with or without
                     10:  * modification, are permitted provided that the following conditions
                     11:  * are met:
                     12:  * 1. Redistributions of source code must retain the above copyright
                     13:  *    notice, this list of conditions and the following disclaimer.
                     14:  * 2. Redistributions in binary form must reproduce the above copyright
                     15:  *    notice, this list of conditions and the following disclaimer in the
                     16:  *    documentation and/or other materials provided with the distribution.
                     17:  * 3. All advertising materials mentioning features or use of this software
                     18:  *    must display the following acknowledgement:
                     19:  *      This product includes software developed by Matt Fredette.
                     20:  * 4. The name of the author may not be used to endorse or promote products
                     21:  *    derived from this software without specific prior written permission.
                     22:  *
                     23:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
                     24:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
                     25:  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
                     26:  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
                     27:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
                     28:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
                     29:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     30:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
                     31:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
                     32:  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
                     33:  * POSSIBILITY OF SUCH DAMAGE.
                     34:  */
                     35: 
                     36: #include <tme/common.h>
1.1.1.3 ! root       37: _TME_RCSID("$Id: scsi.c,v 1.3 2007/01/07 23:27:50 fredette Exp $");
1.1       root       38: 
                     39: /* includes: */
                     40: #include <tme/generic/scsi.h>
1.1.1.3 ! root       41: #include <tme/scsi/scsi-cdb.h>
        !            42: #include <tme/scsi/scsi-msg.h>
1.1       root       43: #include <stdlib.h>
                     44: 
                     45: /* this scores a SCSI connection: */
                     46: int
                     47: tme_scsi_connection_score(struct tme_connection *conn, unsigned int *_score)
                     48: {
                     49:   struct tme_scsi_connection *conn_scsi;
                     50:   struct tme_scsi_connection *conn_scsi_other;
                     51: 
                     52:   /* both sides must be SCSI connections: */
                     53:   assert(conn->tme_connection_type == TME_CONNECTION_SCSI);
                     54:   assert(conn->tme_connection_other->tme_connection_type == TME_CONNECTION_SCSI);
                     55: 
                     56:   /* you cannot connect a bus to a bus, or a device to a device: */
                     57:   conn_scsi
                     58:     = (struct tme_scsi_connection *) conn;
                     59:   conn_scsi_other 
                     60:     = (struct tme_scsi_connection *) conn->tme_connection_other;
1.1.1.2   root       61:   /* XXX we need a way to distinguish a bus from a device: */
1.1       root       62:   *_score
1.1.1.2   root       63:     = 1;
1.1       root       64:   return (TME_OK);
                     65: }
                     66: 
                     67: /* this parses a SCSI ID: */
                     68: int
                     69: tme_scsi_id_parse(const char *id_string)
                     70: {
                     71:   unsigned long id;
                     72:   char *p1;
                     73: 
                     74:   /* catch a NULL string: */
                     75:   if (id_string == NULL) {
                     76:     return (-1);
                     77:   }
                     78: 
                     79:   /* convert the string: */
                     80:   id = strtoul(id_string, &p1, 0);
                     81:   if (p1 == id_string
                     82:       || *p1 != '\0') {
                     83:     return (-1);
                     84:   }
                     85:   return (id);
                     86: }
1.1.1.3 ! root       87: 
        !            88: /* this implements state machines that determine the residual in a
        !            89:    SCSI command or message phase: */
        !            90: tme_uint32_t
        !            91: tme_scsi_phase_resid(tme_scsi_control_t scsi_control,
        !            92:                     tme_uint32_t *_state,
        !            93:                     const tme_shared tme_uint8_t *bytes,
        !            94:                     unsigned long count)
        !            95: {
        !            96: #define _TME_SCSI_PHASE_RESID_STATE_COUNT_MASK         (4095)
        !            97:   tme_uint32_t state;
        !            98:   tme_uint32_t transferred;
        !            99:   tme_uint32_t seen;
        !           100:   tme_uint32_t skip;
        !           101:   tme_uint32_t resid;
        !           102:   tme_uint8_t byte;
        !           103: 
        !           104:   /* get the opaque state, which must not be the value zero (the
        !           105:      opaque stop state): */
        !           106:   state = *_state;
        !           107:   assert (state != 0);
        !           108: 
        !           109:   /* decompose the opaque state.  NB since the opaque start state for
        !           110:      all SCSI bus phases is the value one, and we use internal state
        !           111:      zero to represent the stop state, we subtract one from the bytes
        !           112:      transferred value and add one to the internal state number: */
        !           113:   transferred = (state - 1) & _TME_SCSI_PHASE_RESID_STATE_COUNT_MASK;
        !           114:   state /= (_TME_SCSI_PHASE_RESID_STATE_COUNT_MASK + 1);
        !           115:   seen = state & _TME_SCSI_PHASE_RESID_STATE_COUNT_MASK;
        !           116:   state = (state / (_TME_SCSI_PHASE_RESID_STATE_COUNT_MASK + 1)) + 1;
        !           117: 
        !           118:   /* we can't have transferred more than we've seen: */
        !           119:   assert (transferred <= seen);
        !           120: 
        !           121:   /* start with a residual of the number of bytes that we have already
        !           122:      seen, and skip past those bytes in the buffer: */
        !           123:   resid = seen - transferred;
        !           124:   skip = TME_MIN(resid, count);
        !           125:   bytes += skip;
        !           126:   count -= skip;
        !           127: 
        !           128:   /* loop over the bytes: */
        !           129:   for (; count > 0; ) {
        !           130: 
        !           131:     /* get this next byte: */
        !           132:     byte = *(bytes++);
        !           133:     count--;
        !           134:     seen++;
        !           135: 
        !           136:     /* dispatch on the SCSI bus phase: */
        !           137:     switch (TME_SCSI_PHASE(scsi_control)) {
        !           138: 
        !           139:       /* an unknown bus phase: */
        !           140:     default: assert(FALSE);
        !           141: 
        !           142:     case TME_SCSI_PHASE_COMMAND:
        !           143: 
        !           144:       /* we only have state one.  transfer the number of bytes in the
        !           145:         CDB and move to the stop state: */
        !           146:       assert (state == 1);
        !           147:       switch (byte & TME_SCSI_CDB_GROUP_MASK) {
        !           148:       default: abort();
        !           149:       case TME_SCSI_CDB_GROUP_0: resid += TME_SCSI_CDB_GROUP_0_LEN; break;
        !           150:       case TME_SCSI_CDB_GROUP_1: resid += TME_SCSI_CDB_GROUP_1_LEN; break;
        !           151:       case TME_SCSI_CDB_GROUP_2: resid += TME_SCSI_CDB_GROUP_2_LEN; break;
        !           152:       case TME_SCSI_CDB_GROUP_4: resid += TME_SCSI_CDB_GROUP_4_LEN; break;
        !           153:       case TME_SCSI_CDB_GROUP_5: resid += TME_SCSI_CDB_GROUP_5_LEN; break;
        !           154:       }
        !           155:       state = 0;
        !           156:       break;
        !           157: 
        !           158:     case TME_SCSI_PHASE_MESSAGE_IN:
        !           159:     case TME_SCSI_PHASE_MESSAGE_OUT:
        !           160: 
        !           161:       /* dispatch on the state: */
        !           162:       switch (state) {
        !           163:       default: assert(FALSE);
        !           164: 
        !           165:        /* state one is the first byte of the message: */
        !           166:       case 1:
        !           167: 
        !           168:        /* if this is an extended message: */
        !           169:        if (byte == TME_SCSI_MSG_EXTENDED) {
        !           170: 
        !           171:          /* transfer this first message byte and move to state two: */
        !           172:          resid += 1;
        !           173:          state = 2;
        !           174:        }
        !           175: 
        !           176:        /* otherwise, if this is a two-byte message: */
        !           177:        else if (TME_SCSI_MSG_IS_2(byte)) {
        !           178: 
        !           179:          /* transfer the two message bytes and move to state zero: */
        !           180:          resid += 2;
        !           181:          state = 0;
        !           182:        }
        !           183: 
        !           184:        /* otherwise, this is a one-byte message: */
        !           185:        else {
        !           186: 
        !           187:          /* transfer the one message byte and move to state zero: */
        !           188:          resid += 1;
        !           189:          state = 0;
        !           190:        }
        !           191:        break;
        !           192: 
        !           193:        /* the second byte of an extended message: */
        !           194:       case 2:
        !           195: 
        !           196:        /* transfer this second message byte, followed by the extended
        !           197:           message itself, and move to state zero: */
        !           198:        resid += (byte == 0 ? 1 + 256 : 1 + byte);
        !           199:        state = 0;
        !           200:        break;
        !           201:       }
        !           202:       break;
        !           203:     }
        !           204: 
        !           205:     /* if we've reached state zero, return the opaque stop state and
        !           206:        the detected residual: */
        !           207:     if (state == 0) {
        !           208:       *_state = 0;
        !           209:       return (resid);
        !           210:     }
        !           211:   }
        !           212: 
        !           213:   /* compose the updated opaque state.  NB since the opaque start
        !           214:      state for all SCSI bus phases is the value one, and we use
        !           215:      internal state zero to represent the stop state, we add one from
        !           216:      the bytes transferred value and subtract one to the internal
        !           217:      state number: */
        !           218:   state = (state - 1) * (_TME_SCSI_PHASE_RESID_STATE_COUNT_MASK + 1);
        !           219:   state += seen;
        !           220:   state *= (_TME_SCSI_PHASE_RESID_STATE_COUNT_MASK + 1);
        !           221:   state += (transferred + 1) & _TME_SCSI_PHASE_RESID_STATE_COUNT_MASK;
        !           222:   *_state = state;
        !           223:   return (0);
        !           224: #undef _TME_SCSI_PHASE_RESID_STATE_COUNT_MASK
        !           225: }

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