Commit 4469f987 authored by Martin K. Petersen's avatar Martin K. Petersen Committed by James Bottomley
Browse files

[SCSI] Host protection capabilities 



Controllers that support protection information must indicate this to
the SCSI midlayer so that the ULD can prepare scsi_cmnds accordingly.

This patch implements a host mask and various types of protection:

 - DIF Type 1-3 (between HBA and disk)
 - DIX Type 0-3 (between OS and HBA)

The patch also allows the HBA to set the guard type to something
different than the T10-mandated CRC.

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent 7c32c7a2

drivers/scsi/scsi_sysfs.c

+4 −0
Original line number Diff line number Diff line
@@ -249,6 +249,8 @@ shost_rd_attr(cmd_per_lun, "%hd\n"); 
shost_rd_attr(can_queue, "%hd\n");

shost_rd_attr(sg_tablesize, "%hu\n");

shost_rd_attr(unchecked_isa_dma, "%d\n");

shost_rd_attr(prot_capabilities, "%u\n");

shost_rd_attr(prot_guard_type, "%hd\n");

shost_rd_attr2(proc_name, hostt->proc_name, "%s\n");



static struct attribute *scsi_sysfs_shost_attrs[] = {
@@ -263,6 +265,8 @@ static struct attribute *scsi_sysfs_shost_attrs[] = { 
	&dev_attr_hstate.attr,

	&dev_attr_supported_mode.attr,

	&dev_attr_active_mode.attr,

	&dev_attr_prot_capabilities.attr,

	&dev_attr_prot_guard_type.attr,

	NULL

};

include/scsi/scsi_host.h

+84 −0
Original line number Diff line number Diff line
@@ -636,6 +636,10 @@ struct Scsi_Host { 
	 */

	unsigned int max_host_blocked;



	/* Protection Information */

	unsigned int prot_capabilities;

	unsigned char prot_guard_type;



	/*

	 * q used for scsi_tgt msgs, async events or any other requests that

	 * need to be processed in userspace
@@ -756,6 +760,86 @@ extern struct request_queue *__scsi_alloc_queue(struct Scsi_Host *shost, 
extern void scsi_free_host_dev(struct scsi_device *);

extern struct scsi_device *scsi_get_host_dev(struct Scsi_Host *);



/*

 * DIF defines the exchange of protection information between

 * initiator and SBC block device.

 *

 * DIX defines the exchange of protection information between OS and

 * initiator.

 */

enum scsi_host_prot_capabilities {

	SHOST_DIF_TYPE1_PROTECTION = 1 << 0, /* T10 DIF Type 1 */

	SHOST_DIF_TYPE2_PROTECTION = 1 << 1, /* T10 DIF Type 2 */

	SHOST_DIF_TYPE3_PROTECTION = 1 << 2, /* T10 DIF Type 3 */



	SHOST_DIX_TYPE0_PROTECTION = 1 << 3, /* DIX between OS and HBA only */

	SHOST_DIX_TYPE1_PROTECTION = 1 << 4, /* DIX with DIF Type 1 */

	SHOST_DIX_TYPE2_PROTECTION = 1 << 5, /* DIX with DIF Type 2 */

	SHOST_DIX_TYPE3_PROTECTION = 1 << 6, /* DIX with DIF Type 3 */

};



/*

 * SCSI hosts which support the Data Integrity Extensions must

 * indicate their capabilities by setting the prot_capabilities using

 * this call.

 */

static inline void scsi_host_set_prot(struct Scsi_Host *shost, unsigned int mask)

{

	shost->prot_capabilities = mask;

}



static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost)

{

	return shost->prot_capabilities;

}



static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type)

{

	switch (target_type) {

	case 1: return shost->prot_capabilities & SHOST_DIF_TYPE1_PROTECTION;

	case 2: return shost->prot_capabilities & SHOST_DIF_TYPE2_PROTECTION;

	case 3: return shost->prot_capabilities & SHOST_DIF_TYPE3_PROTECTION;

	}



	return 0;

}



static inline unsigned int scsi_host_dix_capable(struct Scsi_Host *shost, unsigned int target_type)

{

	switch (target_type) {

	case 0: return shost->prot_capabilities & SHOST_DIX_TYPE0_PROTECTION;

	case 1: return shost->prot_capabilities & SHOST_DIX_TYPE1_PROTECTION;

	case 2: return shost->prot_capabilities & SHOST_DIX_TYPE2_PROTECTION;

	case 3: return shost->prot_capabilities & SHOST_DIX_TYPE3_PROTECTION;

	}



	return 0;

}



/*

 * All DIX-capable initiators must support the T10-mandated CRC

 * checksum.  Controllers can optionally implement the IP checksum

 * scheme which has much lower impact on system performance.  Note

 * that the main rationale for the checksum is to match integrity

 * metadata with data.  Detecting bit errors are a job for ECC memory

 * and buses.

 */



enum scsi_host_guard_type {

	SHOST_DIX_GUARD_CRC = 1 << 0,

	SHOST_DIX_GUARD_IP  = 1 << 1,

};



static inline void scsi_host_set_guard(struct Scsi_Host *shost, unsigned char type)

{

	shost->prot_guard_type = type;

}



static inline unsigned char scsi_host_get_guard(struct Scsi_Host *shost)

{

	return shost->prot_guard_type;

}



/* legacy interfaces */

extern struct Scsi_Host *scsi_register(struct scsi_host_template *, int);

extern void scsi_unregister(struct Scsi_Host *);

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