xref: /openbmc/linux/drivers/scsi/sd_dif.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * sd_dif.c - SCSI Data Integrity Field
4  *
5  * Copyright (C) 2007, 2008 Oracle Corporation
6  * Written by: Martin K. Petersen <martin.petersen@oracle.com>
7  */
8 
9 #include <linux/blk-integrity.h>
10 #include <linux/t10-pi.h>
11 
12 #include <scsi/scsi.h>
13 #include <scsi/scsi_cmnd.h>
14 #include <scsi/scsi_dbg.h>
15 #include <scsi/scsi_device.h>
16 #include <scsi/scsi_driver.h>
17 #include <scsi/scsi_eh.h>
18 #include <scsi/scsi_host.h>
19 #include <scsi/scsi_ioctl.h>
20 #include <scsi/scsicam.h>
21 
22 #include "sd.h"
23 
24 /*
25  * Configure exchange of protection information between OS and HBA.
26  */
27 void sd_dif_config_host(struct scsi_disk *sdkp)
28 {
29 	struct scsi_device *sdp = sdkp->device;
30 	struct gendisk *disk = sdkp->disk;
31 	u8 type = sdkp->protection_type;
32 	struct blk_integrity bi;
33 	int dif, dix;
34 
35 	dif = scsi_host_dif_capable(sdp->host, type);
36 	dix = scsi_host_dix_capable(sdp->host, type);
37 
38 	if (!dix && scsi_host_dix_capable(sdp->host, 0)) {
39 		dif = 0; dix = 1;
40 	}
41 
42 	if (!dix)
43 		return;
44 
45 	memset(&bi, 0, sizeof(bi));
46 
47 	/* Enable DMA of protection information */
48 	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) {
49 		if (type == T10_PI_TYPE3_PROTECTION)
50 			bi.profile = &t10_pi_type3_ip;
51 		else
52 			bi.profile = &t10_pi_type1_ip;
53 
54 		bi.flags |= BLK_INTEGRITY_IP_CHECKSUM;
55 	} else
56 		if (type == T10_PI_TYPE3_PROTECTION)
57 			bi.profile = &t10_pi_type3_crc;
58 		else
59 			bi.profile = &t10_pi_type1_crc;
60 
61 	bi.tuple_size = sizeof(struct t10_pi_tuple);
62 
63 	if (dif && type) {
64 		bi.flags |= BLK_INTEGRITY_DEVICE_CAPABLE;
65 
66 		if (!sdkp->ATO)
67 			goto out;
68 
69 		if (type == T10_PI_TYPE3_PROTECTION)
70 			bi.tag_size = sizeof(u16) + sizeof(u32);
71 		else
72 			bi.tag_size = sizeof(u16);
73 	}
74 
75 	sd_printk(KERN_NOTICE, sdkp,
76 		  "Enabling DIX %s, application tag size %u bytes\n",
77 		  bi.profile->name, bi.tag_size);
78 out:
79 	blk_integrity_register(disk, &bi);
80 }
81 
82