[SCSI] arm: convert to accessors and !use_sg cleanup

 - convert to accessors and !use_sg cleanup

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Tested-by: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

2 files changed, 58 insertions, 43 deletions

diff --git a/drivers/scsi/arm/acornscsi.c b/drivers/scsi/arm/acornscsi.c
index eceacf6d49e..3bedf2466bd 100644
--- a/drivers/scsi/arm/acornscsi.c
+++ b/drivers/scsi/arm/acornscsi.c
@@ -1790,7 +1790,7 @@ int acornscsi_starttransfer(AS_Host *host)
         return 0;
     }
 
-    residual = host->SCpnt->request_bufflen - host->scsi.SCp.scsi_xferred;
+    residual = scsi_bufflen(host->SCpnt) - host->scsi.SCp.scsi_xferred;
 
     sbic_arm_write(host->scsi.io_port, SBIC_SYNCHTRANSFER, host->device[host->SCpnt->device->id].sync_xfer);
     sbic_arm_writenext(host->scsi.io_port, residual >> 16);
@@ -2270,7 +2270,7 @@ intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
         case 0x4b:                      /* -> PHASE_STATUSIN                            */
         case 0x8b:                      /* -> PHASE_STATUSIN                            */
             /* DATA IN -> STATUS */
-            host->scsi.SCp.scsi_xferred = host->SCpnt->request_bufflen -
+            host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
                                           acornscsi_sbic_xfcount(host);
             acornscsi_dma_stop(host);
             acornscsi_readstatusbyte(host);
@@ -2281,7 +2281,7 @@ intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
         case 0x4e:                      /* -> PHASE_MSGOUT                              */
         case 0x8e:                      /* -> PHASE_MSGOUT                              */
             /* DATA IN -> MESSAGE OUT */
-            host->scsi.SCp.scsi_xferred = host->SCpnt->request_bufflen -
+            host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
                                           acornscsi_sbic_xfcount(host);
             acornscsi_dma_stop(host);
             acornscsi_sendmessage(host);
@@ -2291,7 +2291,7 @@ intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
         case 0x4f:                      /* message in                                   */
         case 0x8f:                      /* message in                                   */
             /* DATA IN -> MESSAGE IN */
-            host->scsi.SCp.scsi_xferred = host->SCpnt->request_bufflen -
+            host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
                                           acornscsi_sbic_xfcount(host);
             acornscsi_dma_stop(host);
             acornscsi_message(host);    /* -> PHASE_MSGIN, PHASE_DISCONNECT             */
@@ -2319,7 +2319,7 @@ intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
         case 0x4b:                      /* -> PHASE_STATUSIN                            */
         case 0x8b:                      /* -> PHASE_STATUSIN                            */
             /* DATA OUT -> STATUS */
-            host->scsi.SCp.scsi_xferred = host->SCpnt->request_bufflen -
+            host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
                                           acornscsi_sbic_xfcount(host);
             acornscsi_dma_stop(host);
             acornscsi_dma_adjust(host);
@@ -2331,7 +2331,7 @@ intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
         case 0x4e:                      /* -> PHASE_MSGOUT                              */
         case 0x8e:                      /* -> PHASE_MSGOUT                              */
             /* DATA OUT -> MESSAGE OUT */
-            host->scsi.SCp.scsi_xferred = host->SCpnt->request_bufflen -
+            host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
                                           acornscsi_sbic_xfcount(host);
             acornscsi_dma_stop(host);
             acornscsi_dma_adjust(host);
@@ -2342,7 +2342,7 @@ intr_ret_t acornscsi_sbicintr(AS_Host *host, int in_irq)
         case 0x4f:                      /* message in                                   */
         case 0x8f:                      /* message in                                   */
             /* DATA OUT -> MESSAGE IN */
-            host->scsi.SCp.scsi_xferred = host->SCpnt->request_bufflen -
+            host->scsi.SCp.scsi_xferred = scsi_bufflen(host->SCpnt) -
                                           acornscsi_sbic_xfcount(host);
             acornscsi_dma_stop(host);
             acornscsi_dma_adjust(host);
diff --git a/drivers/scsi/arm/scsi.h b/drivers/scsi/arm/scsi.h
index bb6550e3192..138a521ba1a 100644
--- a/drivers/scsi/arm/scsi.h
+++ b/drivers/scsi/arm/scsi.h
@@ -18,17 +18,32 @@
  * The scatter-gather list handling.  This contains all
  * the yucky stuff that needs to be fixed properly.
  */
+
+/*
+ * copy_SCp_to_sg() Assumes contiguous allocation at @sg of at-most @max
+ * entries of uninitialized memory. SCp is from scsi-ml and has a valid
+ * (possibly chained) sg-list
+ */
 static inline int copy_SCp_to_sg(struct scatterlist *sg, struct scsi_pointer *SCp, int max)
 {
         int bufs = SCp->buffers_residual;
 
+        /* FIXME: It should be easy for drivers to loop on copy_SCp_to_sg().
+         * and to remove this BUG_ON. Use min() in-its-place
+         */
         BUG_ON(bufs + 1 > max);
 
         sg_set_buf(sg, SCp->ptr, SCp->this_residual);
 
-        if (bufs)
-                memcpy(sg + 1, SCp->buffer + 1,
-                       sizeof(struct scatterlist) * bufs);
+        if (bufs) {
+                struct scatterlist *src_sg;
+                unsigned i;
+
+                for_each_sg(sg_next(SCp->buffer), src_sg, bufs, i)
+                        *(++sg) = *src_sg;
+                sg_mark_end(sg);
+        }
+
         return bufs + 1;
 }
 
@@ -36,7 +51,7 @@ static inline int next_SCp(struct scsi_pointer *SCp)
 {
         int ret = SCp->buffers_residual;
         if (ret) {
-                SCp->buffer++;
+                SCp->buffer = sg_next(SCp->buffer);
                 SCp->buffers_residual--;
                 SCp->ptr = sg_virt(SCp->buffer);
                 SCp->this_residual = SCp->buffer->length;
@@ -68,46 +83,46 @@ static inline void init_SCp(struct scsi_cmnd *SCpnt)
 {
         memset(&SCpnt->SCp, 0, sizeof(struct scsi_pointer));
 
-        if (SCpnt->use_sg) {
+        if (scsi_bufflen(SCpnt)) {
                 unsigned long len = 0;
-                int buf;
 
-                SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->request_buffer;
-                SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
+                SCpnt->SCp.buffer = scsi_sglist(SCpnt);
+                SCpnt->SCp.buffers_residual = scsi_sg_count(SCpnt) - 1;
                 SCpnt->SCp.ptr = sg_virt(SCpnt->SCp.buffer);
                 SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
-                SCpnt->SCp.phase = SCpnt->request_bufflen;
+                SCpnt->SCp.phase = scsi_bufflen(SCpnt);
 
 #ifdef BELT_AND_BRACES
-                /*
-                 * Calculate correct buffer length.  Some commands
-                 * come in with the wrong request_bufflen.
-                 */
-                for (buf = 0; buf <= SCpnt->SCp.buffers_residual; buf++)
-                        len += SCpnt->SCp.buffer[buf].length;
-
-                if (SCpnt->request_bufflen != len)
-                        printk(KERN_WARNING "scsi%d.%c: bad request buffer "
-                               "length %d, should be %ld\n", SCpnt->device->host->host_no,
-                               '0' + SCpnt->device->id, SCpnt->request_bufflen, len);
-                SCpnt->request_bufflen = len;
+                {       /*
+                         * Calculate correct buffer length.  Some commands
+                         * come in with the wrong scsi_bufflen.
+                         */
+                        struct scatterlist *sg;
+                        unsigned i, sg_count = scsi_sg_count(SCpnt);
+
+                        scsi_for_each_sg(SCpnt, sg, sg_count, i)
+                                len += sg->length;
+
+                        if (scsi_bufflen(SCpnt) != len) {
+                                printk(KERN_WARNING
+                                       "scsi%d.%c: bad request buffer "
+                                       "length %d, should be %ld\n",
+                                        SCpnt->device->host->host_no,
+                                        '0' + SCpnt->device->id,
+                                        scsi_bufflen(SCpnt), len);
+                                /*
+                                 * FIXME: Totaly naive fixup. We should abort
+                                 * with error
+                                 */
+                                SCpnt->SCp.phase =
+                                        min_t(unsigned long, len,
+                                              scsi_bufflen(SCpnt));
+                        }
+                }
 #endif
         } else {
-                SCpnt->SCp.ptr = (unsigned char *)SCpnt->request_buffer;
-                SCpnt->SCp.this_residual = SCpnt->request_bufflen;
-                SCpnt->SCp.phase = SCpnt->request_bufflen;
-        }
-
-        /*
-         * If the upper SCSI layers pass a buffer, but zero length,
-         * we aren't interested in the buffer pointer.
-         */
-        if (SCpnt->SCp.this_residual == 0 && SCpnt->SCp.ptr) {
-#if 0 //def BELT_AND_BRACES
-                printk(KERN_WARNING "scsi%d.%c: zero length buffer passed for "
-                       "command ", SCpnt->host->host_no, '0' + SCpnt->target);
-                __scsi_print_command(SCpnt->cmnd);
-#endif
                 SCpnt->SCp.ptr = NULL;
+                SCpnt->SCp.this_residual = 0;
+                SCpnt->SCp.phase = 0;
         }
 }