path: root/drivers/s390/scsi
diff options
authorFedor Loshakov <loshakov@linux.ibm.com>2018-11-29 13:09:56 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2018-12-07 21:36:40 -0500
commit636db60b8e910760c283b7aa928efcc580c1f574 (patch)
tree5fcb77acc5bbdff913c0fbc7f304a25b60c50ddf /drivers/s390/scsi
parentscsi: BusLogic: mark expected switch fall-through (diff)
scsi: zfcp: make DIX experimental, disabled, and independent of DIF
Introduce separate zfcp module parameters to individually select support for: DIF which should work (zfcp.dif, which used to be DIF+DIX, disabled) or DIX+DIF which can cause trouble (zfcp.dix, new, disabled). If DIX is enabled, we warn on zfcp driver initialization. As before, this also reduces the maximum I/O request size to half, to support the worst case of merged single sector requests with one protection data scatter gather element per sector. This can impact the maximum throughput. In DIF-only mode (zfcp.dif=1 zfcp.dix=0), we can use the full maximum I/O request size as there is no protection data for zfcp. Signed-off-by: Steffen Maier <maier@linux.ibm.com> Signed-off-by: Fedor Loshakov <loshakov@linux.ibm.com> Reviewed-by: Jens Remus <jremus@linux.ibm.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/s390/scsi')
3 files changed, 11 insertions, 3 deletions
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 89657146f832..df10f4e07a4a 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -124,6 +124,9 @@ static int __init zfcp_module_init(void)
int retval = -ENOMEM;
+ if (zfcp_experimental_dix)
+ pr_warn("DIX is enabled. It is experimental and might cause problems\n");
zfcp_fsf_qtcb_cache = zfcp_cache_hw_align("zfcp_fsf_qtcb",
sizeof(struct fsf_qtcb));
if (!zfcp_fsf_qtcb_cache)
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index d74dd8bb175c..3fce47b0b21b 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -146,6 +146,7 @@ extern void zfcp_qdio_close(struct zfcp_qdio *);
extern void zfcp_qdio_siosl(struct zfcp_adapter *);
/* zfcp_scsi.c */
+extern bool zfcp_experimental_dix;
extern struct scsi_transport_template *zfcp_scsi_transport_template;
extern int zfcp_scsi_adapter_register(struct zfcp_adapter *);
extern void zfcp_scsi_adapter_unregister(struct zfcp_adapter *);
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index 82dbe2677fc1..a8b53ed61c1e 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -27,7 +27,11 @@ MODULE_PARM_DESC(queue_depth, "Default queue depth for new SCSI devices");
static bool enable_dif;
module_param_named(dif, enable_dif, bool, 0400);
-MODULE_PARM_DESC(dif, "Enable DIF/DIX data integrity support");
+MODULE_PARM_DESC(dif, "Enable DIF data integrity support (default off)");
+bool zfcp_experimental_dix;
+module_param_named(dix, zfcp_experimental_dix, bool, 0400);
+MODULE_PARM_DESC(dix, "Enable experimental DIX (data integrity extension) support which implies DIF support (default off)");
static bool allow_lun_scan = true;
module_param(allow_lun_scan, bool, 0600);
@@ -790,11 +794,11 @@ void zfcp_scsi_set_prot(struct zfcp_adapter *adapter)
data_div = atomic_read(&adapter->status) &
- if (enable_dif &&
+ if ((enable_dif || zfcp_experimental_dix) &&
adapter->adapter_features & FSF_FEATURE_DIF_PROT_TYPE1)
- if (enable_dif && data_div &&
+ if (zfcp_experimental_dix && data_div &&
adapter->adapter_features & FSF_FEATURE_DIX_PROT_TCPIP) {
scsi_host_set_guard(shost, SHOST_DIX_GUARD_IP);