usr/scsi.c

   1 /*
   2  * The following is from the linux kernel scsi_error.c
   3  *
   4  *  scsi_error.c Copyright (C) 1997 Eric Youngdale
   5  *
   6  *  SCSI error/timeout handling
   7  *      Initial versions: Eric Youngdale.  Based upon conversations with
   8  *                        Leonard Zubkoff and David Miller at Linux Expo,
   9  *                        ideas originating from all over the place.
  10  *
  11  *      Restructured scsi_unjam_host and associated functions.
  12  *      September 04, 2002 Mike Anderson (andmike@us.ibm.com)
  13  *
  14  *      Forward port of Russell King's (rmk@arm.linux.org.uk) changes and
  15  *      minor  cleanups.
  16  *      September 30, 2002 Mike Anderson (andmike@us.ibm.com)
  17  */
  18
  19 #include <string.h>
  20 #include "scsi.h"
  21
  22 /**
  23  * scsi_normalize_sense - normalize main elements from either fixed or
  24  *                      descriptor sense data format into a common format.
  25  *
  26  * @sense_buffer:       byte array containing sense data returned by device
  27  * @sb_len:             number of valid bytes in sense_buffer
  28  * @sshdr:              pointer to instance of structure that common
  29  *                      elements are written to.
  30  *
  31  * Notes:
  32  *      The "main elements" from sense data are: response_code, sense_key,
  33  *      asc, ascq and additional_length (only for descriptor format).
  34  *
  35  *      Typically this function can be called after a device has
  36  *      responded to a SCSI command with the CHECK_CONDITION status.
  37  *
  38  * Return value:
  39  *      1 if valid sense data information found, else 0;
  40  **/
  41 int scsi_normalize_sense(const uint8_t *sense_buffer, int sb_len,
  42                          struct scsi_sense_hdr *sshdr)
  43 {
  44         if (!sense_buffer || !sb_len)
  45                 return 0;
  46
  47         memset(sshdr, 0, sizeof(struct scsi_sense_hdr));
  48
  49         sshdr->response_code = (sense_buffer[0] & 0x7f);
  50
  51         if (!scsi_sense_valid(sshdr))
  52                 return 0;
  53
  54         if (sshdr->response_code >= 0x72) {
  55                 /*
  56                  * descriptor format
  57                  */
  58                 if (sb_len > 1)
  59                         sshdr->sense_key = (sense_buffer[1] & 0xf);
  60                 if (sb_len > 2)
  61                         sshdr->asc = sense_buffer[2];
  62                 if (sb_len > 3)
  63                         sshdr->ascq = sense_buffer[3];
  64                 if (sb_len > 7)
  65                         sshdr->additional_length = sense_buffer[7];
  66         } else {
  67                 /*
  68                  * fixed format
  69                  */
  70                 if (sb_len > 2)
  71                         sshdr->sense_key = (sense_buffer[2] & 0xf);
  72                 if (sb_len > 7) {
  73                         sb_len = (sb_len < (sense_buffer[7] + 8)) ?
  74                                          sb_len : (sense_buffer[7] + 8);
  75                         if (sb_len > 12)
  76                                 sshdr->asc = sense_buffer[12];
  77                         if (sb_len > 13)
  78                                 sshdr->ascq = sense_buffer[13];
  79                 }
  80         }
  81
  82         return 1;
  83 }