[SCSI] isd200: use one-element sg list in issuing commands

  - This patch should be commited before:
    usb: transport - convert to accessors and !use_sg code path removal

  - isd200_action() was still using direct liniar pointers in issuing
    commands to the USB transport level. This is no longer supported,
    use one-element scatterlist instead.
  - Adjustment of command's length in the case of scsi-to-ata translation
    is now restored before return to queuecommand, since other wise it can
    leak BIOs.
  - isd200_action() return Error on unknown requests. Used to print an error
    but still try to send garbage cdb.
  - convert few places to scsi data accessors.
  - Todo: This file will need to be changed when scsi_cmnd changes to
    scsi_data_buffer or any other solution.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Acked-by: Matthew Dharm <mdharm-scsi@one-eyed-alien.net>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 46 insertions, 20 deletions

diff --git a/drivers/usb/storage/isd200.c b/drivers/usb/storage/isd200.c
index 49ba6c0ff1e8..178e8c2a8a2f 100644
--- a/drivers/usb/storage/isd200.c
+++ b/drivers/usb/storage/isd200.c
@@ -49,6 +49,7 @@
 #include <linux/slab.h>
 #include <linux/hdreg.h>
 #include <linux/ide.h>
+#include <linux/scatterlist.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -287,6 +288,7 @@ struct isd200_info {
         /* maximum number of LUNs supported */
         unsigned char MaxLUNs;
         struct scsi_cmnd srb;
+        struct scatterlist sg;
 };
 
 
@@ -398,6 +400,31 @@ static void isd200_build_sense(struct us_data *us, struct scsi_cmnd *srb)
  * Transport routines
  ***********************************************************************/
 
+/**************************************************************************
+ *  isd200_set_srb(), isd200_srb_set_bufflen()
+ *
+ * Two helpers to facilitate in initialization of scsi_cmnd structure
+ * Will need to change when struct scsi_cmnd changes
+ */
+static void isd200_set_srb(struct isd200_info *info,
+        enum dma_data_direction dir, void* buff, unsigned bufflen)
+{
+        struct scsi_cmnd *srb = &info->srb;
+
+        if (buff)
+                sg_init_one(&info->sg, buff, bufflen);
+
+        srb->sc_data_direction = dir;
+        srb->request_buffer = buff ? &info->sg : NULL;
+        srb->request_bufflen = bufflen;
+        srb->use_sg = buff ? 1 : 0;
+}
+
+static void isd200_srb_set_bufflen(struct scsi_cmnd *srb, unsigned bufflen)
+{
+        srb->request_bufflen = bufflen;
+}
+
 
 /**************************************************************************
  *  isd200_action
@@ -432,9 +459,7 @@ static int isd200_action( struct us_data *us, int action,
                 ata.generic.RegisterSelect =
                   REG_CYLINDER_LOW | REG_CYLINDER_HIGH |
                   REG_STATUS | REG_ERROR;
-                srb->sc_data_direction = DMA_FROM_DEVICE;
-                srb->request_buffer = pointer;
-                srb->request_bufflen = value;
+                isd200_set_srb(info, DMA_FROM_DEVICE, pointer, value);
                 break;
 
         case ACTION_ENUM:
@@ -444,7 +469,7 @@ static int isd200_action( struct us_data *us, int action,
                                            ACTION_SELECT_5;
                 ata.generic.RegisterSelect = REG_DEVICE_HEAD;
                 ata.write.DeviceHeadByte = value;
-                srb->sc_data_direction = DMA_NONE;
+                isd200_set_srb(info, DMA_NONE, NULL, 0);
                 break;
 
         case ACTION_RESET:
@@ -453,7 +478,7 @@ static int isd200_action( struct us_data *us, int action,
                                            ACTION_SELECT_3|ACTION_SELECT_4;
                 ata.generic.RegisterSelect = REG_DEVICE_CONTROL;
                 ata.write.DeviceControlByte = ATA_DC_RESET_CONTROLLER;
-                srb->sc_data_direction = DMA_NONE;
+                isd200_set_srb(info, DMA_NONE, NULL, 0);
                 break;
 
         case ACTION_REENABLE:
@@ -462,7 +487,7 @@ static int isd200_action( struct us_data *us, int action,
                                            ACTION_SELECT_3|ACTION_SELECT_4;
                 ata.generic.RegisterSelect = REG_DEVICE_CONTROL;
                 ata.write.DeviceControlByte = ATA_DC_REENABLE_CONTROLLER;
-                srb->sc_data_direction = DMA_NONE;
+                isd200_set_srb(info, DMA_NONE, NULL, 0);
                 break;
 
         case ACTION_SOFT_RESET:
@@ -471,21 +496,20 @@ static int isd200_action( struct us_data *us, int action,
                 ata.generic.RegisterSelect = REG_DEVICE_HEAD | REG_COMMAND;
                 ata.write.DeviceHeadByte = info->DeviceHead;
                 ata.write.CommandByte = WIN_SRST;
-                srb->sc_data_direction = DMA_NONE;
+                isd200_set_srb(info, DMA_NONE, NULL, 0);
                 break;
 
         case ACTION_IDENTIFY:
                 US_DEBUGP("   isd200_action(IDENTIFY)\n");
                 ata.generic.RegisterSelect = REG_COMMAND;
                 ata.write.CommandByte = WIN_IDENTIFY;
-                srb->sc_data_direction = DMA_FROM_DEVICE;
-                srb->request_buffer = (void *) info->id;
-                srb->request_bufflen = sizeof(struct hd_driveid);
+                isd200_set_srb(info, DMA_FROM_DEVICE, info->id,
+                                                sizeof(struct hd_driveid));
                 break;
 
         default:
                 US_DEBUGP("Error: Undefined action %d\n",action);
-                break;
+                return ISD200_ERROR;
         }
 
         memcpy(srb->cmnd, &ata, sizeof(ata.generic));
@@ -590,7 +614,7 @@ static void isd200_invoke_transport( struct us_data *us,
                 return;
         }
 
-        if ((srb->resid > 0) &&
+        if ((scsi_get_resid(srb) > 0) &&
             !((srb->cmnd[0] == REQUEST_SENSE) ||
               (srb->cmnd[0] == INQUIRY) ||
               (srb->cmnd[0] == MODE_SENSE) ||
@@ -1217,7 +1241,6 @@ static int isd200_get_inquiry_data( struct us_data *us )
         return(retStatus);
 }
 
-
 /**************************************************************************
  * isd200_scsi_to_ata
  *                                                                       
@@ -1266,7 +1289,7 @@ static int isd200_scsi_to_ata(struct scsi_cmnd *srb, struct us_data *us,
                         ataCdb->generic.TransferBlockSize = 1;
                         ataCdb->generic.RegisterSelect = REG_COMMAND;
                         ataCdb->write.CommandByte = ATA_COMMAND_GET_MEDIA_STATUS;
-                        srb->request_bufflen = 0;
+                        isd200_srb_set_bufflen(srb, 0);
                 } else {
                         US_DEBUGP("   Media Status not supported, just report okay\n");
                         srb->result = SAM_STAT_GOOD;
@@ -1284,7 +1307,7 @@ static int isd200_scsi_to_ata(struct scsi_cmnd *srb, struct us_data *us,
                         ataCdb->generic.TransferBlockSize = 1;
                         ataCdb->generic.RegisterSelect = REG_COMMAND;
                         ataCdb->write.CommandByte = ATA_COMMAND_GET_MEDIA_STATUS;
-                        srb->request_bufflen = 0;
+                        isd200_srb_set_bufflen(srb, 0);
                 } else {
                         US_DEBUGP("   Media Status not supported, just report okay\n");
                         srb->result = SAM_STAT_GOOD;
@@ -1390,7 +1413,7 @@ static int isd200_scsi_to_ata(struct scsi_cmnd *srb, struct us_data *us,
                         ataCdb->generic.RegisterSelect = REG_COMMAND;
                         ataCdb->write.CommandByte = (srb->cmnd[4] & 0x1) ?
                                 WIN_DOORLOCK : WIN_DOORUNLOCK;
-                        srb->request_bufflen = 0;
+                        isd200_srb_set_bufflen(srb, 0);
                 } else {
                         US_DEBUGP("   Not removeable media, just report okay\n");
                         srb->result = SAM_STAT_GOOD;
@@ -1416,7 +1439,7 @@ static int isd200_scsi_to_ata(struct scsi_cmnd *srb, struct us_data *us,
                         ataCdb->generic.TransferBlockSize = 1;
                         ataCdb->generic.RegisterSelect = REG_COMMAND;
                         ataCdb->write.CommandByte = ATA_COMMAND_GET_MEDIA_STATUS;
-                        srb->request_bufflen = 0;
+                        isd200_srb_set_bufflen(srb, 0);
                 } else {
                         US_DEBUGP("   Nothing to do, just report okay\n");
                         srb->result = SAM_STAT_GOOD;
@@ -1525,7 +1548,7 @@ int isd200_Initialization(struct us_data *us)
 
 void isd200_ata_command(struct scsi_cmnd *srb, struct us_data *us)
 {
-        int sendToTransport = 1;
+        int sendToTransport = 1, orig_bufflen;
         union ata_cdb ataCdb;
 
         /* Make sure driver was initialized */
@@ -1533,11 +1556,14 @@ void isd200_ata_command(struct scsi_cmnd *srb, struct us_data *us)
         if (us->extra == NULL)
                 US_DEBUGP("ERROR Driver not initialized\n");
 
-        /* Convert command */
-        srb->resid = 0;
+        scsi_set_resid(srb, 0);
+        /* scsi_bufflen might change in protocol translation to ata */
+        orig_bufflen = scsi_bufflen(srb);
         sendToTransport = isd200_scsi_to_ata(srb, us, &ataCdb);
 
         /* send the command to the transport layer */
         if (sendToTransport)
                 isd200_invoke_transport(us, srb, &ataCdb);
+
+        isd200_srb_set_bufflen(srb, orig_bufflen);
 }