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authorMartin K. Petersen <martin.petersen@oracle.com>2010-09-10 20:50:10 +0200
committerJens Axboe <axboe@carl.home.kernel.dk>2010-09-10 20:50:10 +0200
commit13f05c8d8e98bbdce89158bfdb2e380940695a88 (patch)
tree055215e7e2b1bdc684ead64daa61b30b35eaa3c5 /include/scsi
parentConsolidate min_not_zero (diff)
downloadlinux-dev-13f05c8d8e98bbdce89158bfdb2e380940695a88.tar.xz
linux-dev-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.h6
-rw-r--r--include/scsi/scsi_host.h7
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,