stex: Add hotplug support

1. Add hotplug support. Pegasus support surprise removal. To this end, I
   use return_abnormal_state function to return DID_NO_CONNECT for all
   commands which sent to driver.

2. Remove stex_hba_stop in stex_remove because we cannot send command to
   device after hotplug.

3. Add new device status: MU_STATE_STOP, MU_STATE_NOCONNECT,
   MU_STATE_STOP. MU_STATE_STOP is currently not referenced.
   MU_STATE_NOCONNECT represent that device is plugged out from the
   host.

4. Use return_abnormal_function() to substitute part of code in
   stex_do_reset.

Signed-off-by: Charles Chiou <charles.chiou@tw.promise.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 34 insertions, 19 deletions

diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index 495d6322bb21..19946031fa9a 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -84,6 +84,8 @@ enum {
         MU_STATE_STARTED                        = 2,
         MU_STATE_RESETTING                      = 3,
         MU_STATE_FAILED                         = 4,
+        MU_STATE_STOP                           = 5,
+        MU_STATE_NOCONNECT                      = 6,
 
         MU_MAX_DELAY                            = 120,
         MU_HANDSHAKE_SIGNATURE                  = 0x55aaaa55,
@@ -537,6 +539,27 @@ stex_ss_send_cmd(struct st_hba *hba, struct req_msg *req, u16 tag)
         readl(hba->mmio_base + YH2I_REQ); /* flush */
 }
 
+static void return_abnormal_state(struct st_hba *hba, int status)
+{
+        struct st_ccb *ccb;
+        unsigned long flags;
+        u16 tag;
+
+        spin_lock_irqsave(hba->host->host_lock, flags);
+        for (tag = 0; tag < hba->host->can_queue; tag++) {
+                ccb = &hba->ccb[tag];
+                if (ccb->req == NULL)
+                        continue;
+                ccb->req = NULL;
+                if (ccb->cmd) {
+                        scsi_dma_unmap(ccb->cmd);
+                        ccb->cmd->result = status << 16;
+                        ccb->cmd->scsi_done(ccb->cmd);
+                        ccb->cmd = NULL;
+                }
+        }
+        spin_unlock_irqrestore(hba->host->host_lock, flags);
+}
 static int
 stex_slave_config(struct scsi_device *sdev)
 {
@@ -560,8 +583,12 @@ stex_queuecommand_lck(struct scsi_cmnd *cmd, void (*done)(struct scsi_cmnd *))
         id = cmd->device->id;
         lun = cmd->device->lun;
         hba = (struct st_hba *) &host->hostdata[0];
-
-        if (unlikely(hba->mu_status == MU_STATE_RESETTING))
+        if (hba->mu_status == MU_STATE_NOCONNECT) {
+                cmd->result = DID_NO_CONNECT;
+                done(cmd);
+                return 0;
+        }
+        if (unlikely(hba->mu_status != MU_STATE_STARTED))
                 return SCSI_MLQUEUE_HOST_BUSY;
 
         switch (cmd->cmnd[0]) {
@@ -1260,10 +1287,8 @@ static void stex_ss_reset(struct st_hba *hba)
 
 static int stex_do_reset(struct st_hba *hba)
 {
-        struct st_ccb *ccb;
         unsigned long flags;
         unsigned int mu_status = MU_STATE_RESETTING;
-        u16 tag;
 
         spin_lock_irqsave(hba->host->host_lock, flags);
         if (hba->mu_status == MU_STATE_STARTING) {
@@ -1297,20 +1322,8 @@ static int stex_do_reset(struct st_hba *hba)
         else if (hba->cardtype == st_yel)
                 stex_ss_reset(hba);
 
-        spin_lock_irqsave(hba->host->host_lock, flags);
-        for (tag = 0; tag < hba->host->can_queue; tag++) {
-                ccb = &hba->ccb[tag];
-                if (ccb->req == NULL)
-                        continue;
-                ccb->req = NULL;
-                if (ccb->cmd) {
-                        scsi_dma_unmap(ccb->cmd);
-                        ccb->cmd->result = DID_RESET << 16;
-                        ccb->cmd->scsi_done(ccb->cmd);
-                        ccb->cmd = NULL;
-                }
-        }
-        spin_unlock_irqrestore(hba->host->host_lock, flags);
+
+        return_abnormal_state(hba, DID_RESET);
 
         if (stex_handshake(hba) == 0)
                 return 0;
@@ -1771,9 +1784,11 @@ static void stex_remove(struct pci_dev *pdev)
 {
         struct st_hba *hba = pci_get_drvdata(pdev);
 
+        hba->mu_status = MU_STATE_NOCONNECT;
+        return_abnormal_state(hba, DID_NO_CONNECT);
         scsi_remove_host(hba->host);
 
-        stex_hba_stop(hba);
+        scsi_block_requests(hba->host);
 
         stex_hba_free(hba);