2 files changed, 39 insertions, 92 deletions

diff --git a/drivers/ieee1394/sbp2.c b/drivers/ieee1394/sbp2.c
index 0037305f599e..c52f6e6e8af2 100644
--- a/drivers/ieee1394/sbp2.c
+++ b/drivers/ieee1394/sbp2.c
@@ -656,24 +656,11 @@ static struct sbp2_command_info *sbp2util_allocate_command_orb(
 static void sbp2util_mark_command_completed(struct sbp2_lu *lu,
                                             struct sbp2_command_info *cmd)
 {
-        struct hpsb_host *host = lu->ud->ne->host;
-
-        if (cmd->cmd_dma) {
-                if (cmd->dma_type == CMD_DMA_SINGLE)
-                        dma_unmap_single(host->device.parent, cmd->cmd_dma,
-                                         cmd->dma_size, cmd->dma_dir);
-                else if (cmd->dma_type == CMD_DMA_PAGE)
-                        dma_unmap_page(host->device.parent, cmd->cmd_dma,
-                                       cmd->dma_size, cmd->dma_dir);
-                /* XXX: Check for CMD_DMA_NONE bug */
-                cmd->dma_type = CMD_DMA_NONE;
-                cmd->cmd_dma = 0;
-        }
-        if (cmd->sge_buffer) {
-                dma_unmap_sg(host->device.parent, cmd->sge_buffer,
-                             cmd->dma_size, cmd->dma_dir);
-                cmd->sge_buffer = NULL;
-        }
+        if (scsi_sg_count(cmd->Current_SCpnt))
+                dma_unmap_sg(lu->ud->ne->host->device.parent,
+                             scsi_sglist(cmd->Current_SCpnt),
+                             scsi_sg_count(cmd->Current_SCpnt),
+                             cmd->Current_SCpnt->sc_data_direction);
         list_move_tail(&cmd->list, &lu->cmd_orb_completed);
 }
 
@@ -838,6 +825,10 @@ static struct sbp2_lu *sbp2_alloc_device(struct unit_directory *ud)
 #endif
         }
 
+        if (dma_get_max_seg_size(hi->host->device.parent) > SBP2_MAX_SEG_SIZE)
+                BUG_ON(dma_set_max_seg_size(hi->host->device.parent,
+                                            SBP2_MAX_SEG_SIZE));
+
         /* Prevent unloading of the 1394 host */
         if (!try_module_get(hi->host->driver->owner)) {
                 SBP2_ERR("failed to get a reference on 1394 host driver");
@@ -1512,76 +1503,41 @@ static int sbp2_agent_reset(struct sbp2_lu *lu, int wait)
 static int sbp2_prep_command_orb_sg(struct sbp2_command_orb *orb,
                                     struct sbp2_fwhost_info *hi,
                                     struct sbp2_command_info *cmd,
-                                    unsigned int scsi_use_sg,
+                                    unsigned int sg_count,
                                     struct scatterlist *sg,
                                     u32 orb_direction,
                                     enum dma_data_direction dma_dir)
 {
         struct device *dmadev = hi->host->device.parent;
+        struct sbp2_unrestricted_page_table *pt;
+        int i, n;
+
+        n = dma_map_sg(dmadev, sg, sg_count, dma_dir);
+        if (n == 0)
+                return -ENOMEM;
 
-        cmd->dma_dir = dma_dir;
         orb->data_descriptor_hi = ORB_SET_NODE_ID(hi->host->node_id);
         orb->misc |= ORB_SET_DIRECTION(orb_direction);
 
         /* special case if only one element (and less than 64KB in size) */
-        if (scsi_use_sg == 1 && sg->length <= SBP2_MAX_SG_ELEMENT_LENGTH) {
-
-                cmd->dma_size = sg->length;
-                cmd->dma_type = CMD_DMA_PAGE;
-                cmd->cmd_dma = dma_map_page(dmadev, sg_page(sg), sg->offset,
-                                            cmd->dma_size, cmd->dma_dir);
-                if (dma_mapping_error(dmadev, cmd->cmd_dma)) {
-                        cmd->cmd_dma = 0;
-                        return -ENOMEM;
-                }
-
-                orb->data_descriptor_lo = cmd->cmd_dma;
-                orb->misc |= ORB_SET_DATA_SIZE(cmd->dma_size);
-
+        if (n == 1) {
+                orb->misc |= ORB_SET_DATA_SIZE(sg_dma_len(sg));
+                orb->data_descriptor_lo = sg_dma_address(sg);
         } else {
-                struct sbp2_unrestricted_page_table *sg_element =
-                                                &cmd->scatter_gather_element[0];
-                u32 sg_count, sg_len;
-                dma_addr_t sg_addr;
-                int i, count = dma_map_sg(dmadev, sg, scsi_use_sg, dma_dir);
-
-                cmd->dma_size = scsi_use_sg;
-                cmd->sge_buffer = sg;
-
-                /* use page tables (s/g) */
-                orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1);
-                orb->data_descriptor_lo = cmd->sge_dma;
+                pt = &cmd->scatter_gather_element[0];
 
                 dma_sync_single_for_cpu(dmadev, cmd->sge_dma,
                                         sizeof(cmd->scatter_gather_element),
                                         DMA_TO_DEVICE);
 
-                /* loop through and fill out our SBP-2 page tables
-                 * (and split up anything too large) */
-                for (i = 0, sg_count = 0; i < count; i++, sg = sg_next(sg)) {
-                        sg_len = sg_dma_len(sg);
-                        sg_addr = sg_dma_address(sg);
-                        while (sg_len) {
-                                sg_element[sg_count].segment_base_lo = sg_addr;
-                                if (sg_len > SBP2_MAX_SG_ELEMENT_LENGTH) {
-                                        sg_element[sg_count].length_segment_base_hi =
-                                                PAGE_TABLE_SET_SEGMENT_LENGTH(SBP2_MAX_SG_ELEMENT_LENGTH);
-                                        sg_addr += SBP2_MAX_SG_ELEMENT_LENGTH;
-                                        sg_len -= SBP2_MAX_SG_ELEMENT_LENGTH;
-                                } else {
-                                        sg_element[sg_count].length_segment_base_hi =
-                                                PAGE_TABLE_SET_SEGMENT_LENGTH(sg_len);
-                                        sg_len = 0;
-                                }
-                                sg_count++;
-                        }
+                for_each_sg(sg, sg, n, i) {
+                        pt[i].high = cpu_to_be32(sg_dma_len(sg) << 16);
+                        pt[i].low = cpu_to_be32(sg_dma_address(sg));
                 }
 
-                orb->misc |= ORB_SET_DATA_SIZE(sg_count);
-
-                sbp2util_cpu_to_be32_buffer(sg_element,
-                                (sizeof(struct sbp2_unrestricted_page_table)) *
-                                sg_count);
+                orb->misc |= ORB_SET_PAGE_TABLE_PRESENT(0x1) |
+                             ORB_SET_DATA_SIZE(n);
+                orb->data_descriptor_lo = cmd->sge_dma;
 
                 dma_sync_single_for_device(dmadev, cmd->sge_dma,
                                            sizeof(cmd->scatter_gather_element),
@@ -2048,6 +2004,8 @@ static int sbp2scsi_slave_configure(struct scsi_device *sdev)
                 sdev->start_stop_pwr_cond = 1;
         if (lu->workarounds & SBP2_WORKAROUND_128K_MAX_TRANS)
                 blk_queue_max_sectors(sdev->request_queue, 128 * 1024 / 512);
+
+        blk_queue_max_segment_size(sdev->request_queue, SBP2_MAX_SEG_SIZE);
         return 0;
 }
 
diff --git a/drivers/ieee1394/sbp2.h b/drivers/ieee1394/sbp2.h
index 875428bc8d29..c5036f1cc5b0 100644
--- a/drivers/ieee1394/sbp2.h
+++ b/drivers/ieee1394/sbp2.h
@@ -139,13 +139,10 @@ struct sbp2_logout_orb {
         u32 status_fifo_lo;
 } __attribute__((packed));
 
-#define PAGE_TABLE_SET_SEGMENT_BASE_HI(v)       ((v) & 0xffff)
-#define PAGE_TABLE_SET_SEGMENT_LENGTH(v)        (((v) & 0xffff) << 16)
-
 struct sbp2_unrestricted_page_table {
-        u32 length_segment_base_hi;
-        u32 segment_base_lo;
-} __attribute__((packed));
+        __be32 high;
+        __be32 low;
+};
 
 #define RESP_STATUS_REQUEST_COMPLETE            0x0
 #define RESP_STATUS_TRANSPORT_FAILURE           0x1
@@ -216,15 +213,18 @@ struct sbp2_status_block {
 #define SBP2_UNIT_SPEC_ID_ENTRY                 0x0000609e
 #define SBP2_SW_VERSION_ENTRY                   0x00010483
 
-
 /*
- * SCSI specific definitions
+ * The default maximum s/g segment size of a FireWire controller is
+ * usually 0x10000, but SBP-2 only allows 0xffff. Since buffers have to
+ * be quadlet-aligned, we set the length limit to 0xffff & ~3.
  */
+#define SBP2_MAX_SEG_SIZE                       0xfffc
 
-#define SBP2_MAX_SG_ELEMENT_LENGTH              0xf000
-/* There is no real limitation of the queue depth (i.e. length of the linked
+/*
+ * There is no real limitation of the queue depth (i.e. length of the linked
  * list of command ORBs) at the target. The chosen depth is merely an
- * implementation detail of the sbp2 driver. */
+ * implementation detail of the sbp2 driver.
+ */
 #define SBP2_MAX_CMDS                           8
 
 #define SBP2_SCSI_STATUS_GOOD                   0x0
@@ -240,12 +240,6 @@ struct sbp2_status_block {
  * Representations of commands and devices
  */
 
-enum sbp2_dma_types {
-        CMD_DMA_NONE,
-        CMD_DMA_PAGE,
-        CMD_DMA_SINGLE
-};
-
 /* Per SCSI command */
 struct sbp2_command_info {
         struct list_head list;
@@ -258,11 +252,6 @@ struct sbp2_command_info {
         struct sbp2_unrestricted_page_table
                 scatter_gather_element[SG_ALL] __attribute__((aligned(8)));
         dma_addr_t sge_dma;
-        void *sge_buffer;
-        dma_addr_t cmd_dma;
-        enum sbp2_dma_types dma_type;
-        unsigned long dma_size;
-        enum dma_data_direction dma_dir;
 };
 
 /* Per FireWire host */