Merge branch 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block

* 'for-linus' of git://git.kernel.dk/data/git/linux-2.6-block:
  [SCSI] Remove full sg table memset()
  [SCSI] ide-scsi: remove usage of sg_last()
  Fix loop terminating conditions in fill_sg().
  [BLOCK] Clear sg entry before filling in blk_rq_map_sg()
  IA64: iommu uses sg_next with an invalid sg element
  cciss: disable DMA refetch on Smart Array P600
  swiotlb: fix map_sg failure handling
  SPARC64: fix iommu sg chaining
  [SCSI] ide-scsi: use scsi_sg_count() instead of ->use_sg

3 files changed, 12 insertions, 9 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index ca56a0e5cd5e..7c2cfde08f18 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3076,15 +3076,20 @@ static int cciss_pci_init(ctlr_info_t *c, struct pci_dev *pdev)
         }
 #endif
 
-        /* Disabling DMA prefetch for the P600
-         * An ASIC bug may result in a prefetch beyond
-         * physical memory.
+        /* Disabling DMA prefetch and refetch for the P600.
+         * An ASIC bug may result in accesses to invalid memory addresses.
+         * We've disabled prefetch for some time now. Testing with XEN
+         * kernels revealed a bug in the refetch if dom0 resides on a P600.
          */
         if(board_id == 0x3225103C) {
                 __u32 dma_prefetch;
+                __u32 dma_refetch;
                 dma_prefetch = readl(c->vaddr + I2O_DMA1_CFG);
                 dma_prefetch |= 0x8000;
                 writel(dma_prefetch, c->vaddr + I2O_DMA1_CFG);
+                pci_read_config_dword(pdev, PCI_COMMAND_PARITY, &dma_refetch);
+                dma_refetch |= 0x1;
+                pci_write_config_dword(pdev, PCI_COMMAND_PARITY, dma_refetch);
         }
 
 #ifdef CCISS_DEBUG
diff --git a/drivers/scsi/ide-scsi.c b/drivers/scsi/ide-scsi.c
index d297f64cd432..fa7ba64483fb 100644
--- a/drivers/scsi/ide-scsi.c
+++ b/drivers/scsi/ide-scsi.c
@@ -70,7 +70,7 @@ typedef struct idescsi_pc_s {
         u8 *buffer;                             /* Data buffer */
         u8 *current_position;                   /* Pointer into the above buffer */
         struct scatterlist *sg;                 /* Scatter gather table */
-        struct scatterlist *last_sg;            /* Last sg element */
+        unsigned int sg_cnt;                    /* Number of entries in sg */
         int b_count;                            /* Bytes transferred from current entry */
         struct scsi_cmnd *scsi_cmd;             /* SCSI command */
         void (*done)(struct scsi_cmnd *);       /* Scsi completion routine */
@@ -192,7 +192,7 @@ static void idescsi_input_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsigne
                 }
                 bcount -= count; pc->b_count += count;
                 if (pc->b_count == pc->sg->length) {
-                        if (pc->sg == pc->last_sg)
+                        if (!--pc->sg_cnt)
                                 break;
                         pc->sg = sg_next(pc->sg);
                         pc->b_count = 0;
@@ -229,7 +229,7 @@ static void idescsi_output_buffers (ide_drive_t *drive, idescsi_pc_t *pc, unsign
                 }
                 bcount -= count; pc->b_count += count;
                 if (pc->b_count == pc->sg->length) {
-                        if (pc->sg == pc->last_sg)
+                        if (!--pc->sg_cnt)
                                 break;
                         pc->sg = sg_next(pc->sg);
                         pc->b_count = 0;
@@ -807,7 +807,7 @@ static int idescsi_queue (struct scsi_cmnd *cmd,
         memcpy (pc->c, cmd->cmnd, cmd->cmd_len);
         pc->buffer = NULL;
         pc->sg = scsi_sglist(cmd);
-        pc->last_sg = sg_last(pc->sg, cmd->use_sg);
+        pc->sg_cnt = scsi_sg_count(cmd);
         pc->b_count = 0;
         pc->request_transfer = pc->buffer_size = scsi_bufflen(cmd);
         pc->scsi_cmd = cmd;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index aac8a02cbe80..0c86be71bb33 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -764,8 +764,6 @@ struct scatterlist *scsi_alloc_sgtable(struct scsi_cmnd *cmd, gfp_t gfp_mask)
                 if (unlikely(!sgl))
                         goto enomem;
 
-                memset(sgl, 0, sizeof(*sgl) * sgp->size);
-
                 /*
                  * first loop through, set initial index and return value
                  */