xref: /openbmc/linux/drivers/scsi/sd_dif.c (revision ebd09753)
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 
98