[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 a66369218c9..54326e09629 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: