mpt2sas, mpt3sas: log exceeded temperature thresholds

This patch will log a message when driver receives "Temperature Threshold
exceeded" event from any temperature sensor.

The message will look similar to like:
mpt3sas0: Temperature Threshold flags a b c d exceeded for Sensor: x !!!
mpt3sas0: Current Temp In Celsius: y

where a b c d are threshold flags 0 1 2 3

Change_set:
1. Get the number of sensor count of this IOC by reading IO Unit page 8 at
   driver initialization time.
2. Also unmask the Temperature Threshold Event at driver initialization
   time
3. Whenever a MPI2_EVENT_TEMP_THRESHOLD event is received from the
   firmware, then print the sensor number, the maximum threshold number it
   has exceed and the current temperature of this sensor.

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_config.c b/drivers/scsi/mpt2sas/mpt2sas_config.c
index c72a2ff..41a8f84 100644
--- a/drivers/scsi/mpt2sas/mpt2sas_config.c
+++ b/drivers/scsi/mpt2sas/mpt2sas_config.c
@@ -719,6 +719,42 @@
 }
 
 /**
+ * mpt2sas_config_get_iounit_pg8 - obtain iounit page 8
+ * @ioc: per adapter object
+ * @mpi_reply: reply mf payload returned from firmware
+ * @config_page: contents of the config page
+ * Context: sleep.
+ *
+ * Returns 0 for success, non-zero for failure.
+ */
+int
+mpt2sas_config_get_iounit_pg8(struct MPT2SAS_ADAPTER *ioc,
+	Mpi2ConfigReply_t *mpi_reply, Mpi2IOUnitPage8_t *config_page)
+{
+	Mpi2ConfigRequest_t mpi_request;
+	int r;
+
+	memset(&mpi_request, 0, sizeof(Mpi2ConfigRequest_t));
+	mpi_request.Function = MPI2_FUNCTION_CONFIG;
+	mpi_request.Action = MPI2_CONFIG_ACTION_PAGE_HEADER;
+	mpi_request.Header.PageType = MPI2_CONFIG_PAGETYPE_IO_UNIT;
+	mpi_request.Header.PageNumber = 8;
+	mpi_request.Header.PageVersion = MPI2_IOUNITPAGE8_PAGEVERSION;
+	mpt2sas_base_build_zero_len_sge(ioc, &mpi_request.PageBufferSGE);
+	r = _config_request(ioc, &mpi_request, mpi_reply,
+	    MPT2_CONFIG_PAGE_DEFAULT_TIMEOUT, NULL, 0);
+	if (r)
+		goto out;
+
+	mpi_request.Action = MPI2_CONFIG_ACTION_PAGE_READ_CURRENT;
+	r = _config_request(ioc, &mpi_request, mpi_reply,
+	    MPT2_CONFIG_PAGE_DEFAULT_TIMEOUT, config_page,
+	    sizeof(*config_page));
+ out:
+	return r;
+}
+
+/**
  * mpt2sas_config_get_ioc_pg8 - obtain ioc page 8
  * @ioc: per adapter object
  * @mpi_reply: reply mf payload returned from firmware