3 files changed, 131 insertions, 14 deletions

diff --git a/drivers/scsi/hpsa.c b/drivers/scsi/hpsa.c
index 2e1edce9b20e..183d3a43c280 100644
--- a/drivers/scsi/hpsa.c
+++ b/drivers/scsi/hpsa.c
@@ -187,7 +187,6 @@ static struct scsi_host_template hpsa_driver_template = {
         .scan_finished          = hpsa_scan_finished,
         .change_queue_depth     = hpsa_change_queue_depth,
         .this_id                = -1,
-        .sg_tablesize           = MAXSGENTRIES,
         .use_clustering         = ENABLE_CLUSTERING,
         .eh_device_reset_handler = hpsa_eh_device_reset_handler,
         .ioctl                  = hpsa_ioctl,
@@ -844,6 +843,76 @@ static void hpsa_scsi_setup(struct ctlr_info *h)
         spin_lock_init(&h->devlock);
 }
 
+static void hpsa_free_sg_chain_blocks(struct ctlr_info *h)
+{
+        int i;
+
+        if (!h->cmd_sg_list)
+                return;
+        for (i = 0; i < h->nr_cmds; i++) {
+                kfree(h->cmd_sg_list[i]);
+                h->cmd_sg_list[i] = NULL;
+        }
+        kfree(h->cmd_sg_list);
+        h->cmd_sg_list = NULL;
+}
+
+static int hpsa_allocate_sg_chain_blocks(struct ctlr_info *h)
+{
+        int i;
+
+        if (h->chainsize <= 0)
+                return 0;
+
+        h->cmd_sg_list = kzalloc(sizeof(*h->cmd_sg_list) * h->nr_cmds,
+                                GFP_KERNEL);
+        if (!h->cmd_sg_list)
+                return -ENOMEM;
+        for (i = 0; i < h->nr_cmds; i++) {
+                h->cmd_sg_list[i] = kmalloc(sizeof(*h->cmd_sg_list[i]) *
+                                                h->chainsize, GFP_KERNEL);
+                if (!h->cmd_sg_list[i])
+                        goto clean;
+        }
+        return 0;
+
+clean:
+        hpsa_free_sg_chain_blocks(h);
+        return -ENOMEM;
+}
+
+static void hpsa_map_sg_chain_block(struct ctlr_info *h,
+        struct CommandList *c)
+{
+        struct SGDescriptor *chain_sg, *chain_block;
+        u64 temp64;
+
+        chain_sg = &c->SG[h->max_cmd_sg_entries - 1];
+        chain_block = h->cmd_sg_list[c->cmdindex];
+        chain_sg->Ext = HPSA_SG_CHAIN;
+        chain_sg->Len = sizeof(*chain_sg) *
+                (c->Header.SGTotal - h->max_cmd_sg_entries);
+        temp64 = pci_map_single(h->pdev, chain_block, chain_sg->Len,
+                                PCI_DMA_TODEVICE);
+        chain_sg->Addr.lower = (u32) (temp64 & 0x0FFFFFFFFULL);
+        chain_sg->Addr.upper = (u32) ((temp64 >> 32) & 0x0FFFFFFFFULL);
+}
+
+static void hpsa_unmap_sg_chain_block(struct ctlr_info *h,
+        struct CommandList *c)
+{
+        struct SGDescriptor *chain_sg;
+        union u64bit temp64;
+
+        if (c->Header.SGTotal <= h->max_cmd_sg_entries)
+                return;
+
+        chain_sg = &c->SG[h->max_cmd_sg_entries - 1];
+        temp64.val32.lower = chain_sg->Addr.lower;
+        temp64.val32.upper = chain_sg->Addr.upper;
+        pci_unmap_single(h->pdev, temp64.val, chain_sg->Len, PCI_DMA_TODEVICE);
+}
+
 static void complete_scsi_command(struct CommandList *cp,
         int timeout, u32 tag)
 {
@@ -860,6 +929,8 @@ static void complete_scsi_command(struct CommandList *cp,
         h = cp->h;
 
         scsi_dma_unmap(cmd); /* undo the DMA mappings */
+        if (cp->Header.SGTotal > h->max_cmd_sg_entries)
+                hpsa_unmap_sg_chain_block(h, cp);
 
         cmd->result = (DID_OK << 16);           /* host byte */
         cmd->result |= (COMMAND_COMPLETE << 8); /* msg byte */
@@ -1064,6 +1135,7 @@ static int hpsa_scsi_detect(struct ctlr_info *h)
         sh->max_id = HPSA_MAX_LUN;
         sh->can_queue = h->nr_cmds;
         sh->cmd_per_lun = h->nr_cmds;
+        sh->sg_tablesize = h->maxsgentries;
         h->scsi_host = sh;
         sh->hostdata[0] = (unsigned long) h;
         sh->irq = h->intr[PERF_MODE_INT];
@@ -1765,16 +1837,17 @@ out:
  * dma mapping  and fills in the scatter gather entries of the
  * hpsa command, cp.
  */
-static int hpsa_scatter_gather(struct pci_dev *pdev,
+static int hpsa_scatter_gather(struct ctlr_info *h,
                 struct CommandList *cp,
                 struct scsi_cmnd *cmd)
 {
         unsigned int len;
         struct scatterlist *sg;
         u64 addr64;
-        int use_sg, i;
+        int use_sg, i, sg_index, chained;
+        struct SGDescriptor *curr_sg;
 
-        BUG_ON(scsi_sg_count(cmd) > MAXSGENTRIES);
+        BUG_ON(scsi_sg_count(cmd) > h->maxsgentries);
 
         use_sg = scsi_dma_map(cmd);
         if (use_sg < 0)
@@ -1783,15 +1856,33 @@ static int hpsa_scatter_gather(struct pci_dev *pdev,
         if (!use_sg)
                 goto sglist_finished;
 
+        curr_sg = cp->SG;
+        chained = 0;
+        sg_index = 0;
         scsi_for_each_sg(cmd, sg, use_sg, i) {
+                if (i == h->max_cmd_sg_entries - 1 &&
+                        use_sg > h->max_cmd_sg_entries) {
+                        chained = 1;
+                        curr_sg = h->cmd_sg_list[cp->cmdindex];
+                        sg_index = 0;
+                }
                 addr64 = (u64) sg_dma_address(sg);
                 len  = sg_dma_len(sg);
-                cp->SG[i].Addr.lower =
-                        (u32) (addr64 & (u64) 0x00000000FFFFFFFF);
-                cp->SG[i].Addr.upper =
-                        (u32) ((addr64 >> 32) & (u64) 0x00000000FFFFFFFF);
-                cp->SG[i].Len = len;
-                cp->SG[i].Ext = 0;  /* we are not chaining */
+                curr_sg->Addr.lower = (u32) (addr64 & 0x0FFFFFFFFULL);
+                curr_sg->Addr.upper = (u32) ((addr64 >> 32) & 0x0FFFFFFFFULL);
+                curr_sg->Len = len;
+                curr_sg->Ext = 0;  /* we are not chaining */
+                curr_sg++;
+        }
+
+        if (use_sg + chained > h->maxSG)
+                h->maxSG = use_sg + chained;
+
+        if (chained) {
+                cp->Header.SGList = h->max_cmd_sg_entries;
+                cp->Header.SGTotal = (u16) (use_sg + 1);
+                hpsa_map_sg_chain_block(h, cp);
+                return 0;
         }
 
 sglist_finished:
@@ -1887,7 +1978,7 @@ static int hpsa_scsi_queue_command(struct scsi_cmnd *cmd,
                 break;
         }
 
-        if (hpsa_scatter_gather(h->pdev, c, cmd) < 0) { /* Fill SG list */
+        if (hpsa_scatter_gather(h, c, cmd) < 0) { /* Fill SG list */
                 cmd_free(h, c);
                 return SCSI_MLQUEUE_HOST_BUSY;
         }
@@ -3283,6 +3374,23 @@ static int __devinit hpsa_pci_init(struct ctlr_info *h, struct pci_dev *pdev)
 
         h->board_id = board_id;
         h->max_commands = readl(&(h->cfgtable->MaxPerformantModeCommands));
+        h->maxsgentries = readl(&(h->cfgtable->MaxScatterGatherElements));
+
+        /*
+         * Limit in-command s/g elements to 32 save dma'able memory.
+         * Howvever spec says if 0, use 31
+         */
+
+        h->max_cmd_sg_entries = 31;
+        if (h->maxsgentries > 512) {
+                h->max_cmd_sg_entries = 32;
+                h->chainsize = h->maxsgentries - h->max_cmd_sg_entries + 1;
+                h->maxsgentries--; /* save one for chain pointer */
+        } else {
+                h->maxsgentries = 31; /* default to traditional values */
+                h->chainsize = 0;
+        }
+
         h->product_name = products[prod_index].product_name;
         h->access = *(products[prod_index].access);
         /* Allow room for some ioctls */
@@ -3463,6 +3571,8 @@ static int __devinit hpsa_init_one(struct pci_dev *pdev,
                 rc = -ENOMEM;
                 goto clean4;
         }
+        if (hpsa_allocate_sg_chain_blocks(h))
+                goto clean4;
         spin_lock_init(&h->lock);
         spin_lock_init(&h->scan_lock);
         init_waitqueue_head(&h->scan_wait_queue);
@@ -3485,6 +3595,7 @@ static int __devinit hpsa_init_one(struct pci_dev *pdev,
         return 1;
 
 clean4:
+        hpsa_free_sg_chain_blocks(h);
         kfree(h->cmd_pool_bits);
         if (h->cmd_pool)
                 pci_free_consistent(h->pdev,
@@ -3560,6 +3671,7 @@ static void __devexit hpsa_remove_one(struct pci_dev *pdev)
         hpsa_unregister_scsi(h);        /* unhook from SCSI subsystem */
         hpsa_shutdown(pdev);
         iounmap(h->vaddr);
+        hpsa_free_sg_chain_blocks(h);
         pci_free_consistent(h->pdev,
                 h->nr_cmds * sizeof(struct CommandList),
                 h->cmd_pool, h->cmd_pool_dhandle);
diff --git a/drivers/scsi/hpsa.h b/drivers/scsi/hpsa.h
index fc15215145d9..1bb5233b09a0 100644
--- a/drivers/scsi/hpsa.h
+++ b/drivers/scsi/hpsa.h
@@ -83,6 +83,10 @@ struct ctlr_info {
         unsigned int maxQsinceinit;
         unsigned int maxSG;
         spinlock_t lock;
+        int maxsgentries;
+        u8 max_cmd_sg_entries;
+        int chainsize;
+        struct SGDescriptor **cmd_sg_list;
 
         /* pointers to command and error info pool */
         struct CommandList      *cmd_pool;
diff --git a/drivers/scsi/hpsa_cmd.h b/drivers/scsi/hpsa_cmd.h
index 43b6f1cffe34..cb0c2385f3f6 100644
--- a/drivers/scsi/hpsa_cmd.h
+++ b/drivers/scsi/hpsa_cmd.h
@@ -23,7 +23,8 @@
 
 /* general boundary defintions */
 #define SENSEINFOBYTES          32 /* may vary between hbas */
-#define MAXSGENTRIES            31
+#define MAXSGENTRIES            32
+#define HPSA_SG_CHAIN           0x80000000
 #define MAXREPLYQS              256
 
 /* Command Status value */
@@ -321,8 +322,8 @@ struct CommandList {
  */
 #define IS_32_BIT ((8 - sizeof(long))/4)
 #define IS_64_BIT (!IS_32_BIT)
-#define PAD_32 (8)
-#define PAD_64 (0)
+#define PAD_32 (24)
+#define PAD_64 (16)
 #define COMMANDLIST_PAD (IS_32_BIT * PAD_32 + IS_64_BIT * PAD_64)
         u8 pad[COMMANDLIST_PAD];
 };