mpt3sas: sysfs attribute to report Backup Rail Monitor Status

A new sysfs shost attribute called "BMR_status" is implemented to report
Backup Rail Monitor status.

This attribute is located in:

        /sys/class/scsi_host/host#/BMR_status

When reading this adapter attribute, the driver will output the state of
GPIO[24]. It returns "0" if BMR is healthy and "1" for failure.

If it returns an empty string then it means that there was an error
while obtaining the BMR status. Check dmesg for what error has occurred.

This sysfs shost attribute is mainly for WarpDrive controllers.

This commit is a port of 6c265660c262 ("mpt2sas: Provide sysfs attribute
to report Backup Rail Monitor Status").

Signed-off-by: Sreekanth Reddy <Sreekanth.Reddy@avagotech.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/drivers/scsi/mpt3sas/mpt3sas_config.c b/drivers/scsi/mpt3sas/mpt3sas_config.c
index 53eb70130621..2bbb0346b462 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_config.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_config.c
@@ -865,6 +865,44 @@ mpt3sas_config_set_iounit_pg1(struct MPT3SAS_ADAPTER *ioc,
 	return r;
 }
 
+#ifdef SCSI_MPT2SAS
+/**
+ * mpt3sas_config_get_iounit_pg3 - obtain iounit page 3
+ * @ioc: per adapter object
+ * @mpi_reply: reply mf payload returned from firmware
+ * @config_page: contents of the config page
+ * @sz: size of buffer passed in config_page
+ * Context: sleep.
+ *
+ * Returns 0 for success, non-zero for failure.
+ */
+int
+mpt3sas_config_get_iounit_pg3(struct MPT3SAS_ADAPTER *ioc,
+	Mpi2ConfigReply_t *mpi_reply, Mpi2IOUnitPage3_t *config_page, u16 sz)
+{
+	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 = 3;
+	mpi_request.Header.PageVersion = MPI2_IOUNITPAGE3_PAGEVERSION;
+	ioc->build_zero_len_sge_mpi(ioc, &mpi_request.PageBufferSGE);
+	r = _config_request(ioc, &mpi_request, mpi_reply,
+	    MPT3_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,
+	    MPT3_CONFIG_PAGE_DEFAULT_TIMEOUT, config_page, sz);
+ out:
+	return r;
+}
+#endif
+
 /**
  * mpt3sas_config_get_iounit_pg8 - obtain iounit page 8
  * @ioc: per adapter object