scsi: mpt3sas: Add sysfs to know supported features

Currently with sysfs parameter "drv_support_bitmap" driver exposes whether
driver supports toolbox memory move command or not.

And application should issue the toolbox memory move command only if driver
tell that memory move tool box command is supported through this sysfs
parameter.

In future we can utilize this sysfs parameter if any new feature is added
and need to notify the same to applications.
Signed-off-by: Suganath Prabu <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.h

@@ -1047,6 +1047,7 @@ typedef void (*MPT3SAS_FLUSH_RUNNING_CMDS)(struct MPT3SAS_ADAPTER *ioc);
  * @schedule_dead_ioc_flush_running_cmds: callback to flush pending commands
  * @thresh_hold: Max number of reply descriptors processed
  *				before updating Host Index
+ * @drv_support_bitmap: driver's supported feature bit map
  * @scsi_io_cb_idx: shost generated commands
  * @tm_cb_idx: task management commands
  * @scsih_cb_idx: scsih internal commands
@@ -1230,6 +1231,7 @@ struct MPT3SAS_ADAPTER {
 	bool            msix_load_balance;
 	u16		thresh_hold;
 	u8		high_iops_queues;
+	u32		drv_support_bitmap;
 
 	/* internal commands, callback index */
 	u8		scsi_io_cb_idx;
@@ -1454,6 +1456,8 @@ struct MPT3SAS_ADAPTER {
 	GET_MSIX_INDEX get_msix_index_for_smlio;
 };
 
+#define MPT_DRV_SUPPORT_BITMAP_MEMMOVE 0x00000001
+
 typedef u8 (*MPT_CALLBACK)(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
 	u32 reply);
 

drivers/scsi/mpt3sas/mpt3sas_ctl.c

@@ -3382,6 +3382,24 @@ static DEVICE_ATTR_RW(diag_trigger_mpi);
 
 /*****************************************/
 
+/**
+ * drv_support_bitmap_show - driver supported feature bitmap
+ * @cdev - pointer to embedded class device
+ * @buf - the buffer returned
+ *
+ * A sysfs 'read-only' shost attribute.
+ */
+static ssize_t
+drv_support_bitmap_show(struct device *cdev,
+	struct device_attribute *attr, char *buf)
+{
+	struct Scsi_Host *shost = class_to_shost(cdev);
+	struct MPT3SAS_ADAPTER *ioc = shost_priv(shost);
+
+	return snprintf(buf, PAGE_SIZE, "0x%08x\n", ioc->drv_support_bitmap);
+}
+static DEVICE_ATTR_RO(drv_support_bitmap);
+
 struct device_attribute *mpt3sas_host_attrs[] = {
 	&dev_attr_version_fw,
 	&dev_attr_version_bios,
@@ -3407,6 +3425,7 @@ struct device_attribute *mpt3sas_host_attrs[] = {
 	&dev_attr_diag_trigger_event,
 	&dev_attr_diag_trigger_scsi,
 	&dev_attr_diag_trigger_mpi,
+	&dev_attr_drv_support_bitmap,
 	&dev_attr_BRM_status,
 	NULL,
 };

drivers/scsi/mpt3sas/mpt3sas_scsih.c

@@ -10500,6 +10500,10 @@ _scsih_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	ioc->tm_sas_control_cb_idx = tm_sas_control_cb_idx;
 	ioc->logging_level = logging_level;
 	ioc->schedule_dead_ioc_flush_running_cmds = &_scsih_flush_running_cmds;
+	/*
+	 * Enable MEMORY MOVE support flag.
+	 */
+	ioc->drv_support_bitmap |= MPT_DRV_SUPPORT_BITMAP_MEMMOVE;
 	/* misc semaphores and spin locks */
 	mutex_init(&ioc->reset_in_progress_mutex);
 	/* initializing pci_access_mutex lock */