[SCSI] mpt fusion: Added support for MPT discovery completion check

sas_discovery_quiesce_io flag is used to control IO start/resume functionality.
IO will be stoped while doing discovery of topology. Once discovery is completed
It will resume IO. Resending patch including James review.

Signed-off-by: Kashyap Desai <kadesai@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 80 insertions, 2 deletions

diff --git a/drivers/message/fusion/mptbase.c b/drivers/message/fusion/mptbase.c
index a66369218c97..54326e09629c 100644
--- a/drivers/message/fusion/mptbase.c
+++ b/drivers/message/fusion/mptbase.c
@@ -277,6 +277,56 @@ mpt_get_cb_idx(MPT_DRIVER_CLASS dclass)
 }
 
 /**
+ * mpt_is_discovery_complete - determine if discovery has completed
+ * @ioc: per adatper instance
+ *
+ * Returns 1 when discovery completed, else zero.
+ */
+static int
+mpt_is_discovery_complete(MPT_ADAPTER *ioc)
+{
+        ConfigExtendedPageHeader_t hdr;
+        CONFIGPARMS cfg;
+        SasIOUnitPage0_t *buffer;
+        dma_addr_t dma_handle;
+        int rc = 0;
+
+        memset(&hdr, 0, sizeof(ConfigExtendedPageHeader_t));
+        memset(&cfg, 0, sizeof(CONFIGPARMS));
+        hdr.PageVersion = MPI_SASIOUNITPAGE0_PAGEVERSION;
+        hdr.PageType = MPI_CONFIG_PAGETYPE_EXTENDED;
+        hdr.ExtPageType = MPI_CONFIG_EXTPAGETYPE_SAS_IO_UNIT;
+        cfg.cfghdr.ehdr = &hdr;
+        cfg.action = MPI_CONFIG_ACTION_PAGE_HEADER;
+
+        if ((mpt_config(ioc, &cfg)))
+                goto out;
+        if (!hdr.ExtPageLength)
+                goto out;
+
+        buffer = pci_alloc_consistent(ioc->pcidev, hdr.ExtPageLength * 4,
+            &dma_handle);
+        if (!buffer)
+                goto out;
+
+        cfg.physAddr = dma_handle;
+        cfg.action = MPI_CONFIG_ACTION_PAGE_READ_CURRENT;
+
+        if ((mpt_config(ioc, &cfg)))
+                goto out_free_consistent;
+
+        if (!(buffer->PhyData[0].PortFlags &
+            MPI_SAS_IOUNIT0_PORT_FLAGS_DISCOVERY_IN_PROGRESS))
+                rc = 1;
+
+ out_free_consistent:
+        pci_free_consistent(ioc->pcidev, hdr.ExtPageLength * 4,
+            buffer, dma_handle);
+ out:
+        return rc;
+}
+
+/**
  *      mpt_fault_reset_work - work performed on workq after ioc fault
  *      @work: input argument, used to derive ioc
  *
@@ -307,6 +357,12 @@ mpt_fault_reset_work(struct work_struct *work)
                         printk(MYIOC_s_WARN_FMT "IOC is in FAULT state after "
                             "reset (%04xh)\n", ioc->name, ioc_raw_state &
                             MPI_DOORBELL_DATA_MASK);
+        } else if (ioc->bus_type == SAS && ioc->sas_discovery_quiesce_io) {
+                if ((mpt_is_discovery_complete(ioc))) {
+                        devtprintk(ioc, printk(MYIOC_s_DEBUG_FMT "clearing "
+                            "discovery_quiesce_io flag\n", ioc->name));
+                        ioc->sas_discovery_quiesce_io = 0;
+                }
         }
 
  out:
diff --git a/drivers/message/fusion/mptbase.h b/drivers/message/fusion/mptbase.h
index 4a606764e317..8cd0a16cdfac 100644
--- a/drivers/message/fusion/mptbase.h
+++ b/drivers/message/fusion/mptbase.h
@@ -706,6 +706,7 @@ typedef struct _MPT_ADAPTER
         struct mutex             sas_discovery_mutex;
         u8                       sas_discovery_runtime;
         u8                       sas_discovery_ignore_events;
+        u8                       sas_discovery_quiesce_io;
         int                      sas_index; /* index refrencing */
         MPT_SAS_MGMT             sas_mgmt;
         struct work_struct       sas_persist_task;
diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c
index b162f7a1c563..40dbaaaf49e1 100644
--- a/drivers/message/fusion/mptsas.c
+++ b/drivers/message/fusion/mptsas.c
@@ -1008,6 +1008,8 @@ mptsas_slave_alloc(struct scsi_device *sdev)
 static int
 mptsas_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
 {
+        MPT_SCSI_HOST   *hd;
+        MPT_ADAPTER     *ioc;
         VirtDevice      *vdevice = SCpnt->device->hostdata;
 
         if (!vdevice || !vdevice->vtarget || vdevice->vtarget->deleted) {
@@ -1016,6 +1018,12 @@ mptsas_qcmd(struct scsi_cmnd *SCpnt, void (*done)(struct scsi_cmnd *))
                 return 0;
         }
 
+        hd = shost_priv(SCpnt->device->host);
+        ioc = hd->ioc;
+
+        if (ioc->sas_discovery_quiesce_io)
+                return SCSI_MLQUEUE_HOST_BUSY;
+
 //      scsi_print_command(SCpnt);
 
         return mptscsih_qcmd(SCpnt,done);
@@ -3009,6 +3017,7 @@ mptsas_send_discovery_event(MPT_ADAPTER *ioc,
         EVENT_DATA_SAS_DISCOVERY *discovery_data)
 {
         struct mptsas_discovery_event *ev;
+        u32 discovery_status;
 
         /*
          * DiscoveryStatus
@@ -3017,7 +3026,9 @@ mptsas_send_discovery_event(MPT_ADAPTER *ioc,
          * kicks off discovery, and return to zero
          * once its completed.
          */
-        if (discovery_data->DiscoveryStatus)
+        discovery_status = le32_to_cpu(discovery_data->DiscoveryStatus);
+        ioc->sas_discovery_quiesce_io = discovery_status ? 1 : 0;
+        if (discovery_status)
                 return;
 
         ev = kzalloc(sizeof(*ev), GFP_ATOMIC);
@@ -3299,12 +3310,22 @@ mptsas_probe(struct pci_dev *pdev, const struct pci_device_id *id)
         return error;
 }
 
+void
+mptsas_shutdown(struct pci_dev *pdev)
+{
+        MPT_ADAPTER *ioc = pci_get_drvdata(pdev);
+
+        ioc->sas_discovery_quiesce_io = 0;
+}
+
 static void __devexit mptsas_remove(struct pci_dev *pdev)
 {
         MPT_ADAPTER *ioc = pci_get_drvdata(pdev);
         struct mptsas_portinfo *p, *n;
         int i;
 
+        mptsas_shutdown(pdev);
+
         ioc->sas_discovery_ignore_events = 1;
         sas_remove_host(ioc->sh);
 
@@ -3342,7 +3363,7 @@ static struct pci_driver mptsas_driver = {
         .id_table       = mptsas_pci_table,
         .probe          = mptsas_probe,
         .remove         = __devexit_p(mptsas_remove),
-        .shutdown       = mptscsih_shutdown,
+        .shutdown       = mptsas_shutdown,
 #ifdef CONFIG_PM
         .suspend        = mptscsih_suspend,
         .resume         = mptscsih_resume,