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| author | Martin K. Petersen <martin.petersen@oracle.com> | 2010-09-10 20:50:10 +0200 |
|---|---|---|
| committer | Jens Axboe <axboe@carl.home.kernel.dk> | 2010-09-10 20:50:10 +0200 |
| commit | 13f05c8d8e98bbdce89158bfdb2e380940695a88 (patch) | |
| tree | 055215e7e2b1bdc684ead64daa61b30b35eaa3c5 /include/scsi | |
| parent | c8bf1336824ebd698d37b71763e1c43190f2229a (diff) | |
| download | lwn-13f05c8d8e98bbdce89158bfdb2e380940695a88.tar.gz lwn-13f05c8d8e98bbdce89158bfdb2e380940695a88.zip | |
block/scsi: Provide a limit on the number of integrity segments
Some controllers have a hardware limit on the number of protection
information scatter-gather list segments they can handle.
Introduce a max_integrity_segments limit in the block layer and provide
a new scsi_host_template setting that allows HBA drivers to provide a
value suitable for the hardware.
Add support for honoring the integrity segment limit when merging both
bios and requests.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
Diffstat (limited to 'include/scsi')
| -rw-r--r-- | include/scsi/scsi.h | 6 | ||||
| -rw-r--r-- | include/scsi/scsi_host.h | 7 |
2 files changed, 13 insertions, 0 deletions
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h index 8fcb6e0e9e72..d63533a4a59e 100644 --- a/include/scsi/scsi.h +++ b/include/scsi/scsi.h @@ -32,6 +32,12 @@ struct scsi_cmnd; #endif /* + * DIX-capable adapters effectively support infinite chaining for the + * protection information scatterlist + */ +#define SCSI_MAX_PROT_SG_SEGMENTS 0xFFFF + +/* * Special value for scanning to specify scanning or rescanning of all * possible channels, (target) ids, or luns on a given shost. */ diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h index b7bdecb7b76e..d0a6a845f204 100644 --- a/include/scsi/scsi_host.h +++ b/include/scsi/scsi_host.h @@ -388,6 +388,7 @@ struct scsi_host_template { * of scatter-gather. */ unsigned short sg_tablesize; + unsigned short sg_prot_tablesize; /* * Set this if the host adapter has limitations beside segment count. @@ -599,6 +600,7 @@ struct Scsi_Host { int can_queue; short cmd_per_lun; short unsigned int sg_tablesize; + short unsigned int sg_prot_tablesize; short unsigned int max_sectors; unsigned long dma_boundary; /* @@ -823,6 +825,11 @@ static inline unsigned int scsi_host_get_prot(struct Scsi_Host *shost) return shost->prot_capabilities; } +static inline int scsi_host_prot_dma(struct Scsi_Host *shost) +{ + return shost->prot_capabilities >= SHOST_DIX_TYPE0_PROTECTION; +} + static inline unsigned int scsi_host_dif_capable(struct Scsi_Host *shost, unsigned int target_type) { static unsigned char cap[] = { 0, |