Commit e0597d70 authored by Martin K. Petersen's avatar Martin K. Petersen Committed by James Bottomley
Browse files

[SCSI] sd: Identify DIF protection type and application tag ownership 



If a disk is formatted with protection information (Inquiry bit
PROTECT=1) it is required to support Read Capacity(16).  Force use of
the 16-bit command in this case and extract the P_TYPE field which
indicates whether the disk is formatted using DIF Type 1, 2 or 3.

The ATO (App Tag Own) bit in the Control Mode Page indicates whether
the storage device or the initiator own the contents of the
DIF application tag.

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 511e44f4

drivers/scsi/sd.c

+118 −4
Original line number Diff line number Diff line
@@ -233,6 +233,24 @@ sd_show_allow_restart(struct device *dev, struct device_attribute *attr, 
	return snprintf(buf, 40, "%d\n", sdkp->device->allow_restart);

}



static ssize_t

sd_show_protection_type(struct device *dev, struct device_attribute *attr,

			char *buf)

{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->protection_type);

}



static ssize_t

sd_show_app_tag_own(struct device *dev, struct device_attribute *attr,

		    char *buf)

{

	struct scsi_disk *sdkp = to_scsi_disk(dev);



	return snprintf(buf, 20, "%u\n", sdkp->ATO);

}



static struct device_attribute sd_disk_attrs[] = {

	__ATTR(cache_type, S_IRUGO|S_IWUSR, sd_show_cache_type,

	       sd_store_cache_type),
@@ -241,6 +259,8 @@ static struct device_attribute sd_disk_attrs[] = { 
	       sd_store_allow_restart),

	__ATTR(manage_start_stop, S_IRUGO|S_IWUSR, sd_show_manage_start_stop,

	       sd_store_manage_start_stop),

	__ATTR(protection_type, S_IRUGO, sd_show_protection_type, NULL),

	__ATTR(app_tag_own, S_IRUGO, sd_show_app_tag_own, NULL),

	__ATTR_NULL,

};
@@ -1164,6 +1184,49 @@ sd_spinup_disk(struct scsi_disk *sdkp) 
	}

}





/*

 * Determine whether disk supports Data Integrity Field.

 */

void sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer)

{

	struct scsi_device *sdp = sdkp->device;

	u8 type;



	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)

		type = 0;

	else

		type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */



	switch (type) {

	case SD_DIF_TYPE0_PROTECTION:

		sdkp->protection_type = 0;

		break;



	case SD_DIF_TYPE1_PROTECTION:

	case SD_DIF_TYPE3_PROTECTION:

		sdkp->protection_type = type;

		break;



	case SD_DIF_TYPE2_PROTECTION:

		sd_printk(KERN_ERR, sdkp, "formatted with DIF Type 2 "	\

			  "protection which is currently unsupported. "	\

			  "Disabling disk!\n");

		goto disable;



	default:

		sd_printk(KERN_ERR, sdkp, "formatted with unknown "	\

			  "protection type %d. Disabling disk!\n", type);

		goto disable;

	}



	return;



disable:

	sdkp->protection_type = 0;

	sdkp->capacity = 0;

}



/*

 * read disk capacity

 */
@@ -1173,7 +1236,8 @@ sd_read_capacity(struct scsi_disk *sdkp, unsigned char *buffer) 
	unsigned char cmd[16];

	int the_result, retries;

	int sector_size = 0;

	int longrc = 0;

	/* Force READ CAPACITY(16) when PROTECT=1 */

	int longrc = scsi_device_protection(sdkp->device) ? 1 : 0;

	struct scsi_sense_hdr sshdr;

	int sense_valid = 0;

	struct scsi_device *sdp = sdkp->device;
@@ -1185,8 +1249,8 @@ repeat: 
			memset((void *) cmd, 0, 16);

			cmd[0] = SERVICE_ACTION_IN;

			cmd[1] = SAI_READ_CAPACITY_16;

			cmd[13] = 12;

			memset((void *) buffer, 0, 12);

			cmd[13] = 13;

			memset((void *) buffer, 0, 13);

		} else {

			cmd[0] = READ_CAPACITY;

			memset((void *) &cmd[1], 0, 9);
@@ -1194,7 +1258,7 @@ repeat: 
		}

		

		the_result = scsi_execute_req(sdp, cmd, DMA_FROM_DEVICE,

					      buffer, longrc ? 12 : 8, &sshdr,

					      buffer, longrc ? 13 : 8, &sshdr,

					      SD_TIMEOUT, SD_MAX_RETRIES);



		if (media_not_present(sdkp, &sshdr))
@@ -1269,6 +1333,8 @@ repeat: 
			

		sector_size = (buffer[8] << 24) |

			(buffer[9] << 16) | (buffer[10] << 8) | buffer[11];



		sd_read_protection_type(sdkp, buffer);

	}	



	/* Some devices return the total number of sectors, not the
@@ -1530,6 +1596,52 @@ defaults: 
	sdkp->DPOFUA = 0;

}



/*

 * The ATO bit indicates whether the DIF application tag is available

 * for use by the operating system.

 */

void sd_read_app_tag_own(struct scsi_disk *sdkp, unsigned char *buffer)

{

	int res, offset;

	struct scsi_device *sdp = sdkp->device;

	struct scsi_mode_data data;

	struct scsi_sense_hdr sshdr;



	if (sdp->type != TYPE_DISK)

		return;



	if (sdkp->protection_type == 0)

		return;



	res = scsi_mode_sense(sdp, 1, 0x0a, buffer, 36, SD_TIMEOUT,

			      SD_MAX_RETRIES, &data, &sshdr);



	if (!scsi_status_is_good(res) || !data.header_length ||

	    data.length < 6) {

		sd_printk(KERN_WARNING, sdkp,

			  "getting Control mode page failed, assume no ATO\n");



		if (scsi_sense_valid(&sshdr))

			sd_print_sense_hdr(sdkp, &sshdr);



		return;

	}



	offset = data.header_length + data.block_descriptor_length;



	if ((buffer[offset] & 0x3f) != 0x0a) {

		sd_printk(KERN_ERR, sdkp, "ATO Got wrong page\n");

		return;

	}



	if ((buffer[offset + 5] & 0x80) == 0)

		return;



	sdkp->ATO = 1;



	return;

}



/**

 *	sd_revalidate_disk - called the first time a new disk is seen,

 *	performs disk spin up, read_capacity, etc.
@@ -1566,6 +1678,7 @@ static int sd_revalidate_disk(struct gendisk *disk) 
	sdkp->write_prot = 0;

	sdkp->WCE = 0;

	sdkp->RCD = 0;

	sdkp->ATO = 0;



	sd_spinup_disk(sdkp);
@@ -1577,6 +1690,7 @@ static int sd_revalidate_disk(struct gendisk *disk) 
		sd_read_capacity(sdkp, buffer);

		sd_read_write_protect_flag(sdkp, buffer);

		sd_read_cache_type(sdkp, buffer);

		sd_read_app_tag_own(sdkp, buffer);

	}



	/*

drivers/scsi/sd.h

+23 −0
Original line number Diff line number Diff line
@@ -41,7 +41,9 @@ struct scsi_disk { 
	u32		index;

	u8		media_present;

	u8		write_prot;

	u8		protection_type;/* Data Integrity Field */

	unsigned	previous_state : 1;

	unsigned	ATO : 1;	/* state of disk ATO bit */

	unsigned	WCE : 1;	/* state of disk WCE bit */

	unsigned	RCD : 1;	/* state of disk RCD bit, unused */

	unsigned	DPOFUA : 1;	/* state of disk DPOFUA bit */
@@ -59,4 +61,25 @@ static inline struct scsi_disk *scsi_disk(struct gendisk *disk) 
		    (sdsk)->disk->disk_name, ##a) :			\

	sdev_printk(prefix, (sdsk)->device, fmt, ##a)



/*

 * A DIF-capable target device can be formatted with different

 * protection schemes.  Currently 0 through 3 are defined:

 *

 * Type 0 is regular (unprotected) I/O

 *

 * Type 1 defines the contents of the guard and reference tags

 *

 * Type 2 defines the contents of the guard and reference tags and

 * uses 32-byte commands to seed the latter

 *

 * Type 3 defines the contents of the guard tag only

 */



enum sd_dif_target_protection_types {

	SD_DIF_TYPE0_PROTECTION = 0x0,

	SD_DIF_TYPE1_PROTECTION = 0x1,

	SD_DIF_TYPE2_PROTECTION = 0x2,

	SD_DIF_TYPE3_PROTECTION = 0x3,

};



#endif /* _SCSI_DISK_H */

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