3 files changed, 176 insertions, 102 deletions

diff --git a/drivers/scsi/dc395x.c b/drivers/scsi/dc395x.c
index cbf825263f3..0c56095f814 100644
--- a/drivers/scsi/dc395x.c
+++ b/drivers/scsi/dc395x.c
@@ -230,13 +230,12 @@ struct ScsiReqBlk {
         struct scsi_cmnd *cmd;
 
         struct SGentry *segment_x;      /* Linear array of hw sg entries (up to 64 entries) */
-        u32 sg_bus_addr;                /* Bus address of sg list (ie, of segment_x) */
+        dma_addr_t sg_bus_addr;         /* Bus address of sg list (ie, of segment_x) */
 
         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 */
-        unsigned char *virt_addr;       /* Virtual address of current transfer position */
-
+        size_t total_xfer_length;       /* Total number of bytes remaining to be transfered */
+        size_t request_length;          /* Total number of bytes in this request */
         /*
          * The sense buffer handling function, request_sense, uses
          * the first hw sg entry (segment_x[0]) and the transfer
@@ -246,8 +245,7 @@ struct ScsiReqBlk {
          * total_xfer_length in xferred. These values are restored in
          * pci_unmap_srb_sense. This is the only place xferred is used.
          */
-        unsigned char *virt_addr_req;   /* Saved virtual address of the request buffer */
-        u32 xferred;                    /* Saved copy of total_xfer_length */
+        size_t xferred;                 /* Saved copy of total_xfer_length */
 
         u16 state;
 
@@ -977,17 +975,6 @@ static void send_srb(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb)
         }
 }
 
-static inline void pio_trigger(void)
-{
-        static int feedback_requested;
-
-        if (!feedback_requested) {
-                feedback_requested = 1;
-                printk(KERN_WARNING "%s: Please, contact <linux-scsi@vger.kernel.org> "
-                       "to help improve support for your system.\n", __FILE__);
-        }
-}
-
 /* Prepare SRB for being sent to Device DCB w/ command *cmd */
 static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
                 struct ScsiReqBlk *srb)
@@ -1001,7 +988,6 @@ static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
         srb->sg_count = 0;
         srb->total_xfer_length = 0;
         srb->sg_bus_addr = 0;
-        srb->virt_addr = NULL;
         srb->sg_index = 0;
         srb->adapter_status = 0;
         srb->target_status = 0;
@@ -1032,7 +1018,6 @@ 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 busaddr = (u32)sg_dma_address(&sl[i]);
                         u32 seglen = (u32)sl[i].length;
@@ -1077,12 +1062,14 @@ static void build_srb(struct scsi_cmnd *cmd, struct DeviceCtlBlk *dcb,
                         srb->total_xfer_length++;
 
                 srb->segment_x[0].length = srb->total_xfer_length;
-                srb->virt_addr = cmd->request_buffer;
+
                 dprintkdbg(DBG_0,
                         "build_srb: [1] len=%d buf=%p use_sg=%d map=%08x\n",
                         srb->total_xfer_length, cmd->request_buffer,
                         cmd->use_sg, srb->segment_x[0].address);
         }
+
+        srb->request_length = srb->total_xfer_length;
 }
 
 
@@ -1414,10 +1401,10 @@ static int dc395x_eh_abort(struct scsi_cmnd *cmd)
         }
         srb = find_cmd(cmd, &dcb->srb_going_list);
         if (srb) {
-                dprintkl(KERN_DEBUG, "eh_abort: Command in progress");
+                dprintkl(KERN_DEBUG, "eh_abort: Command in progress\n");
                 /* XXX: Should abort the command here */
         } else {
-                dprintkl(KERN_DEBUG, "eh_abort: Command not found");
+                dprintkl(KERN_DEBUG, "eh_abort: Command not found\n");
         }
         return FAILED;
 }
@@ -1976,14 +1963,11 @@ static void sg_verify_length(struct ScsiReqBlk *srb)
 
 /*
  * Compute the next Scatter Gather list index and adjust its length
- * and address if necessary; also compute virt_addr
+ * and address if necessary
  */
 static void sg_update_list(struct ScsiReqBlk *srb, u32 left)
 {
         u8 idx;
-        struct scatterlist *sg;
-        struct scsi_cmnd *cmd = srb->cmd;
-        int segment = cmd->use_sg;
         u32 xferred = srb->total_xfer_length - left; /* bytes transfered */
         struct SGentry *psge = srb->segment_x + srb->sg_index;
 
@@ -2016,29 +2000,6 @@ static void sg_update_list(struct ScsiReqBlk *srb, u32 left)
                 psge++;
         }
         sg_verify_length(srb);
-
-        /* we need the corresponding virtual address */
-        if (!segment || (srb->flag & AUTO_REQSENSE)) {
-                srb->virt_addr += xferred;
-                return;
-        }
-
-        /* We have to walk the scatterlist to find it */
-        sg = (struct scatterlist *)cmd->request_buffer;
-        while (segment--) {
-                unsigned long mask =
-                    ~((unsigned long)sg->length - 1) & PAGE_MASK;
-                if ((sg_dma_address(sg) & mask) == (psge->address & mask)) {
-                        srb->virt_addr = (page_address(sg->page)
-                                           + psge->address -
-                                           (psge->address & PAGE_MASK));
-                        return;
-                }
-                ++sg;
-        }
-
-        dprintkl(KERN_ERR, "sg_update_list: sg_to_virt failed\n");
-        srb->virt_addr = NULL;
 }
 
 
@@ -2050,15 +2011,7 @@ static void sg_update_list(struct ScsiReqBlk *srb, u32 left)
  */
 static void sg_subtract_one(struct ScsiReqBlk *srb)
 {
-        srb->total_xfer_length--;
-        srb->segment_x[srb->sg_index].length--;
-        if (srb->total_xfer_length &&
-            !srb->segment_x[srb->sg_index].length) {
-                if (debug_enabled(DBG_PIO))
-                        printk(" (next segment)");
-                srb->sg_index++;
-                sg_update_list(srb, srb->total_xfer_length);
-        }
+        sg_update_list(srb, srb->total_xfer_length - 1);
 }
 
 
@@ -2118,7 +2071,7 @@ static void data_out_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
          * If we need more data, the DMA SG list will be freshly set up, anyway
          */
         dprintkdbg(DBG_PIO, "data_out_phase0: "
-                "DMA{fifcnt=0x%02x fifostat=0x%02x} "
+                "DMA{fifocnt=0x%02x fifostat=0x%02x} "
                 "SCSI{fifocnt=0x%02x cnt=0x%06x status=0x%04x} total=0x%06x\n",
                 DC395x_read8(acb, TRM_S1040_DMA_FIFOCNT),
                 DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT),
@@ -2239,12 +2192,11 @@ static void data_out_phase1(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
         data_io_transfer(acb, srb, XFERDATAOUT);
 }
 
-
 static void data_in_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                 u16 *pscsi_status)
 {
         u16 scsi_status = *pscsi_status;
-        u32 d_left_counter = 0;
+
         dprintkdbg(DBG_0, "data_in_phase0: (pid#%li) <%02i-%i>\n",
                 srb->cmd->pid, srb->cmd->device->id, srb->cmd->device->lun);
 
@@ -2262,6 +2214,9 @@ static void data_in_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
          * seem to be a bad idea, actually.
          */
         if (!(srb->state & SRB_XFERPAD)) {
+                u32 d_left_counter;
+                unsigned int sc, fc;
+
                 if (scsi_status & PARITYERROR) {
                         dprintkl(KERN_INFO, "data_in_phase0: (pid#%li) "
                                 "Parity Error\n", srb->cmd->pid);
@@ -2298,18 +2253,19 @@ static void data_in_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                                 DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT));
                 }
                 /* Now: Check remainig data: The SCSI counters should tell us ... */
-                d_left_counter = DC395x_read32(acb, TRM_S1040_SCSI_COUNTER)
-                    + ((DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) & 0x1f)
+                sc = DC395x_read32(acb, TRM_S1040_SCSI_COUNTER);
+                fc = DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT);
+                d_left_counter = sc + ((fc & 0x1f)
                        << ((srb->dcb->sync_period & WIDE_SYNC) ? 1 :
                            0));
                 dprintkdbg(DBG_KG, "data_in_phase0: "
                         "SCSI{fifocnt=0x%02x%s ctr=0x%08x} "
                         "DMA{fifocnt=0x%02x fifostat=0x%02x ctr=0x%08x} "
                         "Remain{totxfer=%i scsi_fifo+ctr=%i}\n",
-                        DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT),
+                        fc,
                         (srb->dcb->sync_period & WIDE_SYNC) ? "words" : "bytes",
-                        DC395x_read32(acb, TRM_S1040_SCSI_COUNTER),
-                        DC395x_read8(acb, TRM_S1040_DMA_FIFOCNT),
+                        sc,
+                        fc,
                         DC395x_read8(acb, TRM_S1040_DMA_FIFOSTAT),
                         DC395x_read32(acb, TRM_S1040_DMA_CXCNT),
                         srb->total_xfer_length, d_left_counter);
@@ -2317,40 +2273,79 @@ static void data_in_phase0(struct AdapterCtlBlk *acb, struct ScsiReqBlk *srb,
                 /* KG: Less than or equal to 4 bytes can not be transfered via DMA, it seems. */
                 if (d_left_counter
                     && srb->total_xfer_length <= DC395x_LASTPIO) {
+                        size_t left_io = srb->total_xfer_length;
+
                         /*u32 addr = (srb->segment_x[srb->sg_index].address); */
                         /*sg_update_list (srb, d_left_counter); */
-                        dprintkdbg(DBG_PIO, "data_in_phase0: PIO (%i %s) to "
-                                "%p for remaining %i bytes:",
-                                DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) & 0x1f,
+                        dprintkdbg(DBG_PIO, "data_in_phase0: PIO (%i %s) "
+                                   "for remaining %i bytes:",
+                                fc & 0x1f,
                                 (srb->dcb->sync_period & WIDE_SYNC) ?
                                     "words" : "bytes",
-                                srb->virt_addr,
                                 srb->total_xfer_length);
                         if (srb->dcb->sync_period & WIDE_SYNC)
                                 DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2,
                                               CFG2_WIDEFIFO);
-                        while (DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT) != 0x40) {
-                                u8 byte = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
-                                pio_trigger();
-                                *(srb->virt_addr)++ = byte;
-                                if (debug_enabled(DBG_PIO))
-                                        printk(" %02x", byte);
-                                d_left_counter--;
-                                sg_subtract_one(srb);
-                        }
-                        if (srb->dcb->sync_period & WIDE_SYNC) {
-#if 1
-                /* Read the last byte ... */
-                                if (srb->total_xfer_length > 0) {
-                                        u8 byte = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
-                                        pio_trigger();
-                                        *(srb->virt_addr)++ = byte;
-                                        srb->total_xfer_length--;
+                        while (left_io) {
+                                unsigned char *virt, *base = NULL;
+                                unsigned long flags = 0;
+                                size_t len = left_io;
+
+                                if (srb->cmd->use_sg) {
+                                        size_t offset = srb->request_length - left_io;
+                                        local_irq_save(flags);
+                                        /* Assumption: it's inside one page as it's at most 4 bytes and
+                                           I just assume it's on a 4-byte boundary */
+                                        base = scsi_kmap_atomic_sg((struct scatterlist *)srb->cmd->request_buffer,
+                                                                     srb->sg_count, &offset, &len);
+                                        virt = base + offset;
+                                } else {
+                                        virt = srb->cmd->request_buffer + srb->cmd->request_bufflen - left_io;
+                                        len = left_io;
+                                }
+                                left_io -= len;
+
+                                while (len) {
+                                        u8 byte;
+                                        byte = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
+                                        *virt++ = byte;
+
                                         if (debug_enabled(DBG_PIO))
                                                 printk(" %02x", byte);
+
+                                        d_left_counter--;
+                                        sg_subtract_one(srb);
+
+                                        len--;
+
+                                        fc = DC395x_read8(acb, TRM_S1040_SCSI_FIFOCNT);
+
+                                        if (fc == 0x40) {
+                                                left_io = 0;
+                                                break;
+                                        }
+                                }
+
+                                WARN_ON((fc != 0x40) == !d_left_counter);
+
+                                if (fc == 0x40 && (srb->dcb->sync_period & WIDE_SYNC)) {
+                                        /* Read the last byte ... */
+                                        if (srb->total_xfer_length > 0) {
+                                                u8 byte = DC395x_read8(acb, TRM_S1040_SCSI_FIFO);
+
+                                                *virt++ = byte;
+                                                srb->total_xfer_length--;
+                                                if (debug_enabled(DBG_PIO))
+                                                        printk(" %02x", byte);
+                                        }
+
+                                        DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2, 0);
+                                }
+
+                                if (srb->cmd->use_sg) {
+                                        scsi_kunmap_atomic_sg(base);
+                                        local_irq_restore(flags);
                                 }
-#endif
-                                DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2, 0);
                         }
                         /*printk(" %08x", *(u32*)(bus_to_virt (addr))); */
                         /*srb->total_xfer_length = 0; */
@@ -2509,22 +2504,43 @@ static void data_io_transfer(struct AdapterCtlBlk *acb,
                                       SCMD_FIFO_IN);
                 } else {        /* write */
                         int ln = srb->total_xfer_length;
+                        size_t left_io = srb->total_xfer_length;
+
                         if (srb->dcb->sync_period & WIDE_SYNC)
                                 DC395x_write8(acb, TRM_S1040_SCSI_CONFIG2,
                                      CFG2_WIDEFIFO);
-                        dprintkdbg(DBG_PIO,
-                                "data_io_transfer: PIO %i bytes from %p:",
-                                srb->total_xfer_length, srb->virt_addr);
 
-                        while (srb->total_xfer_length) {
-                                if (debug_enabled(DBG_PIO))
-                                        printk(" %02x", (unsigned char) *(srb->virt_addr));
+                        while (left_io) {
+                                unsigned char *virt, *base = NULL;
+                                unsigned long flags = 0;
+                                size_t len = left_io;
+
+                                if (srb->cmd->use_sg) {
+                                        size_t offset = srb->request_length - left_io;
+                                        local_irq_save(flags);
+                                        /* Again, max 4 bytes */
+                                        base = scsi_kmap_atomic_sg((struct scatterlist *)srb->cmd->request_buffer,
+                                                                     srb->sg_count, &offset, &len);
+                                        virt = base + offset;
+                                } else {
+                                        virt = srb->cmd->request_buffer + srb->cmd->request_bufflen - left_io;
+                                        len = left_io;
+                                }
+                                left_io -= len;
+
+                                while (len--) {
+                                        if (debug_enabled(DBG_PIO))
+                                                printk(" %02x", *virt);
 
-                                pio_trigger();
-                                DC395x_write8(acb, TRM_S1040_SCSI_FIFO, 
-                                     *(srb->virt_addr)++);
+                                        DC395x_write8(acb, TRM_S1040_SCSI_FIFO, *virt++);
 
-                                sg_subtract_one(srb);
+                                        sg_subtract_one(srb);
+                                }
+
+                                if (srb->cmd->use_sg) {
+                                        scsi_kunmap_atomic_sg(base);
+                                        local_irq_restore(flags);
+                                }
                         }
                         if (srb->dcb->sync_period & WIDE_SYNC) {
                                 if (ln % 2) {
@@ -3319,7 +3335,6 @@ static void pci_unmap_srb_sense(struct AdapterCtlBlk *acb,
             srb->segment_x[DC395x_MAX_SG_LISTENTRY - 1].address;
         srb->segment_x[0].length =
             srb->segment_x[DC395x_MAX_SG_LISTENTRY - 1].length;
-        srb->virt_addr = srb->virt_addr_req;
 }
 
 
@@ -3713,8 +3728,6 @@ static void request_sense(struct AdapterCtlBlk *acb, struct DeviceCtlBlk *dcb,
         srb->xferred = srb->total_xfer_length;
         /* srb->segment_x : a one entry of S/G list table */
         srb->total_xfer_length = sizeof(cmd->sense_buffer);
-        srb->virt_addr_req = srb->virt_addr;
-        srb->virt_addr = cmd->sense_buffer;
         srb->segment_x[0].length = sizeof(cmd->sense_buffer);
         /* Map sense buffer */
         srb->segment_x[0].address =
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7b0f9a3810d..57453ca0970 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2350,3 +2350,60 @@ scsi_target_unblock(struct device *dev)
                 device_for_each_child(dev, NULL, target_unblock);
 }
 EXPORT_SYMBOL_GPL(scsi_target_unblock);
+
+/**
+ * scsi_kmap_atomic_sg - find and atomically map an sg-elemnt
+ * @sg:         scatter-gather list
+ * @sg_count:   number of segments in sg
+ * @offset:     offset in bytes into sg, on return offset into the mapped area
+ * @len:        bytes to map, on return number of bytes mapped
+ *
+ * Returns virtual address of the start of the mapped page
+ */
+void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+                          size_t *offset, size_t *len)
+{
+        int i;
+        size_t sg_len = 0, len_complete = 0;
+        struct page *page;
+
+        for (i = 0; i < sg_count; i++) {
+                len_complete = sg_len; /* Complete sg-entries */
+                sg_len += sg[i].length;
+                if (sg_len > *offset)
+                        break;
+        }
+
+        if (unlikely(i == sg_count)) {
+                printk(KERN_ERR "%s: Bytes in sg: %u, requested offset %u, elements %d\n",
+                       __FUNCTION__, sg_len, *offset, sg_count);
+                WARN_ON(1);
+                return NULL;
+        }
+
+        /* Offset starting from the beginning of first page in this sg-entry */
+        *offset = *offset - len_complete + sg[i].offset;
+
+        /* Assumption: contiguous pages can be accessed as "page + i" */
+        page = nth_page(sg[i].page, (*offset >> PAGE_SHIFT));
+        *offset &= ~PAGE_MASK;
+
+        /* Bytes in this sg-entry from *offset to the end of the page */
+        sg_len = PAGE_SIZE - *offset;
+        if (*len > sg_len)
+                *len = sg_len;
+
+        return kmap_atomic(page, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kmap_atomic_sg);
+
+/**
+ * scsi_kunmap_atomic_sg - atomically unmap a virtual address, previously
+ *                         mapped with scsi_kmap_atomic_sg
+ * @virt:       virtual address to be unmapped
+ */
+void scsi_kunmap_atomic_sg(void *virt)
+{
+        kunmap_atomic(virt, KM_BIO_SRC_IRQ);
+}
+EXPORT_SYMBOL(scsi_kunmap_atomic_sg);
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index 1ace1b9fe53..7602b9b15a0 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -152,4 +152,8 @@ extern void scsi_put_command(struct scsi_cmnd *);
 extern void scsi_io_completion(struct scsi_cmnd *, unsigned int, unsigned int);
 extern void scsi_finish_command(struct scsi_cmnd *cmd);
 
+extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
+                                 size_t *offset, size_t *len);
+extern void scsi_kunmap_atomic_sg(void *virt);
+
 #endif /* _SCSI_SCSI_CMND_H */