[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>

1 files changed, 56 insertions, 0 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: