2 files changed, 51 insertions, 0 deletions

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index e0bd3f790fca..04c2a278076e 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -246,6 +246,43 @@ show_shost_active_mode(struct device *dev,
 
 static DEVICE_ATTR(active_mode, S_IRUGO | S_IWUSR, show_shost_active_mode, NULL);
 
+static int check_reset_type(char *str)
+{
+        if (strncmp(str, "adapter", 10) == 0)
+                return SCSI_ADAPTER_RESET;
+        else if (strncmp(str, "firmware", 10) == 0)
+                return SCSI_FIRMWARE_RESET;
+        else
+                return 0;
+}
+
+static ssize_t
+store_host_reset(struct device *dev, struct device_attribute *attr,
+                const char *buf, size_t count)
+{
+        struct Scsi_Host *shost = class_to_shost(dev);
+        struct scsi_host_template *sht = shost->hostt;
+        int ret = -EINVAL;
+        char str[10];
+        int type;
+
+        sscanf(buf, "%s", str);
+        type = check_reset_type(str);
+
+        if (!type)
+                goto exit_store_host_reset;
+
+        if (sht->host_reset)
+                ret = sht->host_reset(shost, type);
+
+exit_store_host_reset:
+        if (ret == 0)
+                ret = count;
+        return ret;
+}
+
+static DEVICE_ATTR(host_reset, S_IWUSR, NULL, store_host_reset);
+
 shost_rd_attr(unique_id, "%u\n");
 shost_rd_attr(host_busy, "%hu\n");
 shost_rd_attr(cmd_per_lun, "%hd\n");
@@ -272,6 +309,7 @@ static struct attribute *scsi_sysfs_shost_attrs[] = {
         &dev_attr_active_mode.attr,
         &dev_attr_prot_capabilities.attr,
         &dev_attr_prot_guard_type.attr,
+        &dev_attr_host_reset.attr,
         NULL
 };
 
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index f1f2644137b8..fc22ad9dba77 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -355,6 +355,19 @@ struct scsi_host_template {
          */
         enum blk_eh_timer_return (*eh_timed_out)(struct scsi_cmnd *);
 
+        /* This is an optional routine that allows transport to initiate
+         * LLD adapter or firmware reset using sysfs attribute.
+         *
+         * Return values: 0 on success, -ve value on failure.
+         *
+         * Status: OPTIONAL
+         */
+
+        int (*host_reset)(struct Scsi_Host *shost, int reset_type);
+#define SCSI_ADAPTER_RESET      1
+#define SCSI_FIRMWARE_RESET     2
+
+
         /*
          * Name of proc directory
          */