[SCSI] mpt2sas : While enabling phy, read the current port number from sas iounit page 0 instead of page 1

The port number is changing after disabling/enabling phys using the SysFS
interface This is because the firmware behavour changed where it would read
the the port number then set it to some different value even though Auto Port
Config is turned on.  With this change of behavour in FW, it is possible that
the expanders are moved from one port to another after disabling /enabling
phys. This is occuring because the port number in sas iounit page 1 is not
matching up to the current port in page 0. In order to fix this the driver is
modified to read the current port number from sas iounit page 0 instead of
page 1.  Also copy the port and phy flags over from page 0 to page 1.

Signed-off-by: Nagalakshmi Nandigama <nagalakshmi.nandigama@lsi.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

drivers/scsi/mpt2sas/mpt2sas_transport.c

@@ -1639,11 +1639,13 @@ _transport_phy_enable(struct sas_phy *phy, int enable)
 {
 	struct MPT2SAS_ADAPTER *ioc = phy_to_ioc(phy);
 	Mpi2SasIOUnitPage1_t *sas_iounit_pg1 = NULL;
+	Mpi2SasIOUnitPage0_t *sas_iounit_pg0 = NULL;
 	Mpi2ConfigReply_t mpi_reply;
 	u16 ioc_status;
 	u16 sz;
 	int rc = 0;
 	unsigned long flags;
+	int i, discovery_active;
 
 	spin_lock_irqsave(&ioc->sas_node_lock, flags);
 	if (_transport_sas_node_find_by_sas_address(ioc,
@@ -1661,7 +1663,50 @@ _transport_phy_enable(struct sas_phy *phy, int enable)
 
 	/* handle hba phys */
 
-	/* sas_iounit page 1 */
+	/* read sas_iounit page 0 */
+	sz = offsetof(Mpi2SasIOUnitPage0_t, PhyData) + (ioc->sas_hba.num_phys *
+	    sizeof(Mpi2SasIOUnit0PhyData_t));
+	sas_iounit_pg0 = kzalloc(sz, GFP_KERNEL);
+	if (!sas_iounit_pg0) {
+		printk(MPT2SAS_ERR_FMT "failure at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+		rc = -ENOMEM;
+		goto out;
+	}
+	if ((mpt2sas_config_get_sas_iounit_pg0(ioc, &mpi_reply,
+	    sas_iounit_pg0, sz))) {
+		printk(MPT2SAS_ERR_FMT "failure at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+		rc = -ENXIO;
+		goto out;
+	}
+	ioc_status = le16_to_cpu(mpi_reply.IOCStatus) &
+	    MPI2_IOCSTATUS_MASK;
+	if (ioc_status != MPI2_IOCSTATUS_SUCCESS) {
+		printk(MPT2SAS_ERR_FMT "failure at %s:%d/%s()!\n",
+		    ioc->name, __FILE__, __LINE__, __func__);
+		rc = -EIO;
+		goto out;
+	}
+
+	/* unable to enable/disable phys when when discovery is active */
+	for (i = 0, discovery_active = 0; i < ioc->sas_hba.num_phys ; i++) {
+		if (sas_iounit_pg0->PhyData[i].PortFlags &
+		    MPI2_SASIOUNIT0_PORTFLAGS_DISCOVERY_IN_PROGRESS) {
+			printk(MPT2SAS_ERR_FMT "discovery is active on "
+			    "port = %d, phy = %d: unable to enable/disable "
+			    "phys, try again later!\n", ioc->name,
+			    sas_iounit_pg0->PhyData[i].Port, i);
+			discovery_active = 1;
+		}
+	}
+
+	if (discovery_active) {
+		rc = -EAGAIN;
+		goto out;
+	}
+
+	/* read sas_iounit page 1 */
 	sz = offsetof(Mpi2SasIOUnitPage1_t, PhyData) + (ioc->sas_hba.num_phys *
 	    sizeof(Mpi2SasIOUnit1PhyData_t));
 	sas_iounit_pg1 = kzalloc(sz, GFP_KERNEL);
@@ -1686,7 +1731,18 @@ _transport_phy_enable(struct sas_phy *phy, int enable)
 		rc = -EIO;
 		goto out;
 	}
-
+	/* copy Port/PortFlags/PhyFlags from page 0 */
+	for (i = 0; i < ioc->sas_hba.num_phys ; i++) {
+		sas_iounit_pg1->PhyData[i].Port =
+		    sas_iounit_pg0->PhyData[i].Port;
+		sas_iounit_pg1->PhyData[i].PortFlags =
+		    (sas_iounit_pg0->PhyData[i].PortFlags &
+		    MPI2_SASIOUNIT0_PORTFLAGS_AUTO_PORT_CONFIG);
+		sas_iounit_pg1->PhyData[i].PhyFlags =
+		    (sas_iounit_pg0->PhyData[i].PhyFlags &
+		    (MPI2_SASIOUNIT0_PHYFLAGS_ZONING_ENABLED +
+		    MPI2_SASIOUNIT0_PHYFLAGS_PHY_DISABLED));
+	}
 	if (enable)
 		sas_iounit_pg1->PhyData[phy->number].PhyFlags
 		    &= ~MPI2_SASIOUNIT1_PHYFLAGS_PHY_DISABLE;
@@ -1702,6 +1758,7 @@ _transport_phy_enable(struct sas_phy *phy, int enable)
 
  out:
 	kfree(sas_iounit_pg1);
+	kfree(sas_iounit_pg0);
 	return rc;
 }