mpt2sas, mpt3sas: fix upper bound for the module parameter max_sgl_entries

Change Set:

1. Extended the upper boundary restriction for the module parameter
   max_sgl_entries. Earlier, the max_sgl_entries was capped at the
   SCSI_MAX_SG_SEGMENTS kernel definition. With this change, the user
   would be able to set the max_sgl_entries to any value which is
   greater than SCSI_MAX_SG_SEGMENTS and less than the minimum of
   SCSI_MAX_SG_CHAIN_SEGMENTS & hardware limit (Calculated using
   IOCFacts's MaxChainDepth).

2. Added a print for the message log whenever the user sets the
   max_sgl_entries to a value greater than SCSI_MAX_SG_SEGMENTS to
   warn about the kernel definition overriding.

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/scsi/mpt2sas/mpt2sas_base.c b/drivers/scsi/mpt2sas/mpt2sas_base.c
index 14ebb54fae33cdf265bf2b7538603bd17ece6b2f..88c80efa7d7bec5cd147ff54ece05741c26ff135 100644 (file)
--- a/drivers/scsi/mpt2sas/mpt2sas_base.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_base.c
@@ -2492,9 +2492,13 @@ _base_allocate_memory_pools(struct MPT2SAS_ADAPTER *ioc,  int sleep_flag)
 
        /* command line tunables  for max sgl entries */
        if (max_sgl_entries != -1) {
-               ioc->shost->sg_tablesize = (max_sgl_entries <
-                   MPT2SAS_SG_DEPTH) ? max_sgl_entries :
-                   MPT2SAS_SG_DEPTH;
+               ioc->shost->sg_tablesize =  min_t(unsigned short,
+                            max_sgl_entries, SCSI_MAX_SG_CHAIN_SEGMENTS);
+               if (ioc->shost->sg_tablesize > MPT2SAS_SG_DEPTH)
+                       printk(MPT2SAS_WARN_FMT
+                        "sg_tablesize(%u) is bigger than kernel defined"
+                        " SCSI_MAX_SG_SEGMENTS(%u)\n", ioc->name,
+                         ioc->shost->sg_tablesize, MPT2SAS_SG_DEPTH);
        } else {
                ioc->shost->sg_tablesize = MPT2SAS_SG_DEPTH;
        }

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 678e1ff33f1e49fc8eedacb8eb7fb57c517d039e..a428fdd43df5182b4ed8b2dda1ac54f115a73d3e 100644 (file)
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -2666,8 +2666,14 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc,  int sleep_flag)
 
        if (sg_tablesize < MPT3SAS_MIN_PHYS_SEGMENTS)
                sg_tablesize = MPT3SAS_MIN_PHYS_SEGMENTS;
-       else if (sg_tablesize > MPT3SAS_MAX_PHYS_SEGMENTS)
-               sg_tablesize = MPT3SAS_MAX_PHYS_SEGMENTS;
+       else if (sg_tablesize > MPT3SAS_MAX_PHYS_SEGMENTS) {
+               sg_tablesize = min_t(unsigned short, sg_tablesize,
+                                     SCSI_MAX_SG_CHAIN_SEGMENTS);
+               pr_warn(MPT3SAS_FMT
+                "sg_tablesize(%u) is bigger than kernel"
+                " defined SCSI_MAX_SG_SEGMENTS(%u)\n", ioc->name,
+                sg_tablesize, MPT3SAS_MAX_PHYS_SEGMENTS);
+       }
        ioc->shost->sg_tablesize = sg_tablesize;
 
        ioc->hi_priority_depth = facts->HighPriorityCredit;