Revert "dc395x: Fix support for highmem"

It introduces a repeatable oops in the driver, which is a bigger problem
than the patch tries to solve. From the original description:

    Author: Jamie Lenehan <lenehan@twibble.org>
    Date:   Thu Mar 3 14:41:40 2005 +0200

    [PATCH] dc395x: Fix support for highmem

    From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

    Removes the page_to_virt and maps sg lists dynamically.
    This makes the driver work with highmem pages.

    Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
    Signed-off-by: Jamie Lenehan <lenehan@twibble.org>
    Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 35 deletions

diff --git a/drivers/scsi/dc395x.c b/drivers/scsi/dc395x.c
index 929170dcd3cb..600ba1202864 100644
--- a/drivers/scsi/dc395x.c
+++ b/drivers/scsi/dc395x.c
@@ -183,7 +183,7 @@
  * cross a page boundy.
  */
 #define SEGMENTX_LEN    (sizeof(struct SGentry)*DC395x_MAX_SG_LISTENTRY)
-#define VIRTX_LEN       (sizeof(void *) * DC395x_MAX_SG_LISTENTRY)
+
 
 struct SGentry {
         u32 address;            /* bus! address */
@@ -235,7 +235,6 @@ struct ScsiReqBlk {
         u8 sg_count;                    /* No of HW sg entries for this request */
         u8 sg_index;                    /* Index of HW sg entry for this request */
         u32 total_xfer_length;          /* Total number of bytes remaining to be transfered */
-        void **virt_map;
         unsigned char *virt_addr;       /* Virtual address of current transfer position */
 
         /*
@@ -1022,14 +1021,14 @@ static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
                         reqlen, cmd->request_buffer, cmd->use_sg,
                         srb->sg_count);
 
+                srb->virt_addr = page_address(sl->page);
                 for (i = 0; i < srb->sg_count; i++) {
-                        u32 seglen = (u32)sg_dma_len(sl + i);
-                        sgp[i].address = (u32)sg_dma_address(sl + i);
+                        u32 busaddr = (u32)sg_dma_address(&sl[i]);
+                        u32 seglen = (u32)sl[i].length;
+                        sgp[i].address = busaddr;
                         sgp[i].length = seglen;
                         srb->total_xfer_length += seglen;
-                        srb->virt_map[i] = kmap(sl[i].page);
                 }
-                srb->virt_addr = srb->virt_map[0];
                 sgp += srb->sg_count - 1;
 
                 /*
@@ -1976,7 +1975,6 @@ static void sg_update_list(struct ScsiReqBlk *srb, u32 left)
         int segment = cmd->use_sg;
         u32 xferred = srb->total_xfer_length - left; /* bytes transfered */
         struct SGentry *psge = srb->segment_x + srb->sg_index;
-        void **virt = srb->virt_map;
 
         dprintkdbg(DBG_0,
                 "sg_update_list: Transfered %i of %i bytes, %i remain\n",
@@ -2016,16 +2014,16 @@ static void sg_update_list(struct ScsiReqBlk *srb, u32 left)
 
         /* We have to walk the scatterlist to find it */
         sg = (struct scatterlist *)cmd->request_buffer;
-        idx = 0;
         while (segment--) {
                 unsigned long mask =
                     ~((unsigned long)sg->length - 1) & PAGE_MASK;
                 if ((sg_dma_address(sg) & mask) == (psge->address & mask)) {
-                        srb->virt_addr = virt[idx] + (psge->address & ~PAGE_MASK);
+                        srb->virt_addr = (page_address(sg->page)
+                                           + psge->address -
+                                           (psge->address & PAGE_MASK));
                         return;
                 }
                 ++sg;
-                ++idx;
         }
 
         dprintkl(KERN_ERR, "sg_update_list: sg_to_virt failed\n");
@@ -2151,7 +2149,7 @@ static void data_out_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                                 DC395x_read32(acb, TRM_S1040_DMA_CXCNT));
                 }
                 /*
-                 * calculate all the residue data that not yet transfered
+                 * calculate all the residue data that not yet tranfered
                  * SCSI transfer counter + left in SCSI FIFO data
                  *
                  * .....TRM_S1040_SCSI_COUNTER (24bits)
@@ -3269,7 +3267,6 @@ static void pci_unmap_srb(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
         struct scsi_cmnd *cmd = srb->cmd;
         enum dma_data_direction dir = cmd->sc_data_direction;
         if (cmd->use_sg && dir != PCI_DMA_NONE) {
-                int i;
                 /* unmap DC395x SG list */
                 dprintkdbg(DBG_SG, "pci_unmap_srb: list=%08x(%05x)\n",
                         srb->sg_bus_addr, SEGMENTX_LEN);
@@ -3279,8 +3276,6 @@ static void pci_unmap_srb(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
                 dprintkdbg(DBG_SG, "pci_unmap_srb: segs=%i buffer=%p\n",
                         cmd->use_sg, cmd->request_buffer);
                 /* unmap the sg segments */
-                for (i = 0; i < srb->sg_count; i++)
-                        kunmap(virt_to_page(srb->virt_map[i]));
                 pci_unmap_sg(acb->dev,
                              (struct scatterlist *)cmd->request_buffer,
                              cmd->use_sg, dir);
@@ -3327,7 +3322,7 @@ static void srb_done(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
 
         if (cmd->use_sg) {
                 struct scatterlist* sg = (struct scatterlist *)cmd->request_buffer;
-                ptr = (struct ScsiInqData *)(srb->virt_map[0] + sg->offset);
+                ptr = (struct ScsiInqData *)(page_address(sg->page) + sg->offset);
         } else {
                 ptr = (struct ScsiInqData *)(cmd->request_buffer);
         }
@@ -4262,9 +4257,8 @@ static void adapter_sg_tables_free(struct AdapterCtlBlk *acb)
         const unsigned srbs_per_page = PAGE_SIZE/SEGMENTX_LEN;
 
         for (i = 0; i < DC395x_MAX_SRB_CNT; i += srbs_per_page)
-                kfree(acb->srb_array[i].segment_x);
-
-        vfree(acb->srb_array[0].virt_map);
+                if (acb->srb_array[i].segment_x)
+                        kfree(acb->srb_array[i].segment_x);
 }
 
 
@@ -4280,12 +4274,9 @@ static int __devinit adapter_sg_tables_alloc(struct AdapterCtlBlk *acb)
         int srb_idx = 0;
         unsigned i = 0;
         struct SGentry *ptr;
-        void **virt_array;
 
-        for (i = 0; i < DC395x_MAX_SRB_CNT; i++) {
+        for (i = 0; i < DC395x_MAX_SRB_CNT; i++)
                 acb->srb_array[i].segment_x = NULL;
-                acb->srb_array[i].virt_map = NULL;
-        }
 
         dprintkdbg(DBG_1, "Allocate %i pages for SG tables\n", pages);
         while (pages--) {
@@ -4306,19 +4297,6 @@ static int __devinit adapter_sg_tables_alloc(struct AdapterCtlBlk *acb)
                     ptr + (i * DC395x_MAX_SG_LISTENTRY);
         else
                 dprintkl(KERN_DEBUG, "No space for tmsrb SG table reserved?!\n");
-
-        virt_array = vmalloc((DC395x_MAX_SRB_CNT + 1) * DC395x_MAX_SG_LISTENTRY * sizeof(void*));
-
-        if (!virt_array) {
-                adapter_sg_tables_free(acb);
-                return 1;
-        }
-
-        for (i = 0; i < DC395x_MAX_SRB_CNT + 1; i++) {
-                acb->srb_array[i].virt_map = virt_array;
-                virt_array += DC395x_MAX_SG_LISTENTRY;
-        }
-
         return 0;
 }