drivers/scsi/sd_dif.c

   1 /*
   2  * sd_dif.c - SCSI Data Integrity Field
   3  *
   4  * Copyright (C) 2007, 2008 Oracle Corporation
   5  * Written by: Martin K. Petersen <martin.petersen@oracle.com>
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License version
   9  * 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; see the file COPYING.  If not, write to
  18  * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
  19  * USA.
  20  *
  21  */
  22
  23 #include <linux/blkdev.h>
  24 #include <linux/t10-pi.h>
  25
  26 #include <scsi/scsi.h>
  27 #include <scsi/scsi_cmnd.h>
  28 #include <scsi/scsi_dbg.h>
  29 #include <scsi/scsi_device.h>
  30 #include <scsi/scsi_driver.h>
  31 #include <scsi/scsi_eh.h>
  32 #include <scsi/scsi_host.h>
  33 #include <scsi/scsi_ioctl.h>
  34 #include <scsi/scsicam.h>
  35
  36 #include "sd.h"
  37
  38 /*
  39  * Configure exchange of protection information between OS and HBA.
  40  */
  41 void sd_dif_config_host(struct scsi_disk *sdkp)
  42 {
  43         struct scsi_device *sdp = sdkp->device;
  44         struct gendisk *disk = sdkp->disk;
  45         u8 type = sdkp->protection_type;
  46         struct blk_integrity bi;
  47         int dif, dix;
  48
  49         dif = scsi_host_dif_capable(sdp->host, type);
  50         dix = scsi_host_dix_capable(sdp->host, type);
  51
  52         if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
  53                 dif = 0; dix = 1;
  54         }
  55
  56         if (!dix)
  57                 return;
  58
  59         memset(&bi, 0, sizeof(bi));
  60
  61         /* Enable DMA of protection information */
  62         if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) {
  63                 if (type == T10_PI_TYPE3_PROTECTION)
  64                         bi.profile = &t10_pi_type3_ip;
  65                 else
  66                         bi.profile = &t10_pi_type1_ip;
  67
  68                 bi.flags |= BLK_INTEGRITY_IP_CHECKSUM;
  69         } else
  70                 if (type == T10_PI_TYPE3_PROTECTION)
  71                         bi.profile = &t10_pi_type3_crc;
  72                 else
  73                         bi.profile = &t10_pi_type1_crc;
  74
  75         bi.tuple_size = sizeof(struct t10_pi_tuple);
  76         sd_printk(KERN_NOTICE, sdkp,
  77                   "Enabling DIX %s protection\n", bi.profile->name);
  78
  79         if (dif && type) {
  80                 bi.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
  81
  82                 if (!sdkp->ATO)
  83                         goto out;
  84
  85                 if (type == T10_PI_TYPE3_PROTECTION)
  86                         bi.tag_size = sizeof(u16) + sizeof(u32);
  87                 else
  88                         bi.tag_size = sizeof(u16);
  89
  90                 sd_printk(KERN_NOTICE, sdkp, "DIF application tag size %u\n",
  91                           bi.tag_size);
  92         }
  93
  94 out:
  95         blk_integrity_register(disk, &bi);
  96 }
  97