cciss: factor out scatter gather chain block allocation and freeing

cciss: factor out scatter gather chain block allocation and freeing
Rationale is that I want to use this code from the scsi half of the
driver.

Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 58 insertions, 50 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index cd8c7c20b1c3..eddb916d2908 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -257,6 +257,59 @@ static inline void removeQ(CommandList_struct *c)
         hlist_del_init(&c->list);
 }
 
+static void cciss_free_sg_chain_blocks(struct Cmd_sg_list **cmd_sg_list,
+        int nr_cmds)
+{
+        int i;
+
+        if (!cmd_sg_list)
+                return;
+        for (i = 0; i < nr_cmds; i++) {
+                if (cmd_sg_list[i]) {
+                        kfree(cmd_sg_list[i]->sgchain);
+                        kfree(cmd_sg_list[i]);
+                        cmd_sg_list[i] = NULL;
+                }
+        }
+        kfree(cmd_sg_list);
+}
+
+static struct Cmd_sg_list **cciss_allocate_sg_chain_blocks(ctlr_info_t *h,
+        int chainsize, int nr_cmds)
+{
+        int j;
+        struct Cmd_sg_list **cmd_sg_list;
+
+        if (chainsize <= 0)
+                return NULL;
+
+        cmd_sg_list = kmalloc(sizeof(*cmd_sg_list) * nr_cmds, GFP_KERNEL);
+        if (!cmd_sg_list)
+                return NULL;
+
+        /* Build up chain blocks for each command */
+        for (j = 0; j < nr_cmds; j++) {
+                cmd_sg_list[j] = kmalloc(sizeof(*cmd_sg_list[j]), GFP_KERNEL);
+                if (!cmd_sg_list[j]) {
+                        dev_err(&h->pdev->dev, "Cannot get memory "
+                                "for chain block.\n");
+                        goto clean;
+                }
+                /* Need a block of chainsized s/g elements. */
+                cmd_sg_list[j]->sgchain = kmalloc((chainsize *
+                        sizeof(SGDescriptor_struct)), GFP_KERNEL);
+                if (!cmd_sg_list[j]->sgchain) {
+                        dev_err(&h->pdev->dev, "Cannot get memory "
+                                "for s/g chains.\n");
+                        goto clean;
+                }
+        }
+        return cmd_sg_list;
+clean:
+        cciss_free_sg_chain_blocks(cmd_sg_list, nr_cmds);
+        return NULL;
+}
+
 #include "cciss_scsi.c"         /* For SCSI tape support */
 
 static const char *raid_label[] = { "0", "4", "1(1+0)", "5", "5+1", "ADG",
@@ -4238,37 +4291,10 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
                         goto clean4;
                 }
         }
-        hba[i]->cmd_sg_list = kmalloc(sizeof(struct Cmd_sg_list *) *
-                                                hba[i]->nr_cmds,
-                                                GFP_KERNEL);
-        if (!hba[i]->cmd_sg_list) {
-                printk(KERN_ERR "cciss%d: Cannot get memory for "
-                        "s/g chaining.\n", i);
+        hba[i]->cmd_sg_list = cciss_allocate_sg_chain_blocks(hba[i],
+                hba[i]->chainsize, hba[i]->nr_cmds);
+        if (!hba[i]->cmd_sg_list && hba[i]->chainsize > 0)
                 goto clean4;
-        }
-        /* Build up chain blocks for each command */
-        if (hba[i]->chainsize > 0) {
-                for (j = 0; j < hba[i]->nr_cmds; j++) {
-                        hba[i]->cmd_sg_list[j] =
-                                        kmalloc(sizeof(struct Cmd_sg_list),
-                                                        GFP_KERNEL);
-                        if (!hba[i]->cmd_sg_list[j]) {
-                                printk(KERN_ERR "cciss%d: Cannot get memory "
-                                        "for chain block.\n", i);
-                                goto clean4;
-                        }
-                        /* Need a block of chainsized s/g elements. */
-                        hba[i]->cmd_sg_list[j]->sgchain =
-                                        kmalloc((hba[i]->chainsize *
-                                                sizeof(SGDescriptor_struct)),
-                                                GFP_KERNEL);
-                        if (!hba[i]->cmd_sg_list[j]->sgchain) {
-                                printk(KERN_ERR "cciss%d: Cannot get memory "
-                                        "for s/g chains\n", i);
-                                goto clean4;
-                        }
-                }
-        }
 
         spin_lock_init(&hba[i]->lock);
 
@@ -4327,16 +4353,7 @@ clean4:
         for (k = 0; k < hba[i]->nr_cmds; k++)
                 kfree(hba[i]->scatter_list[k]);
         kfree(hba[i]->scatter_list);
-        /* Only free up extra s/g lists if controller supports them */
-        if (hba[i]->chainsize > 0) {
-                for (j = 0; j < hba[i]->nr_cmds; j++) {
-                        if (hba[i]->cmd_sg_list[j]) {
-                                kfree(hba[i]->cmd_sg_list[j]->sgchain);
-                                kfree(hba[i]->cmd_sg_list[j]);
-                        }
-                }
-                kfree(hba[i]->cmd_sg_list);
-        }
+        cciss_free_sg_chain_blocks(hba[i]->cmd_sg_list, hba[i]->nr_cmds);
         if (hba[i]->cmd_pool)
                 pci_free_consistent(hba[i]->pdev,
                                     hba[i]->nr_cmds * sizeof(CommandList_struct),
@@ -4454,16 +4471,7 @@ static void __devexit cciss_remove_one(struct pci_dev *pdev)
         for (j = 0; j < hba[i]->nr_cmds; j++)
                 kfree(hba[i]->scatter_list[j]);
         kfree(hba[i]->scatter_list);
-        /* Only free up extra s/g lists if controller supports them */
-        if (hba[i]->chainsize > 0) {
-                for (j = 0; j < hba[i]->nr_cmds; j++) {
-                        if (hba[i]->cmd_sg_list[j]) {
-                                kfree(hba[i]->cmd_sg_list[j]->sgchain);
-                                kfree(hba[i]->cmd_sg_list[j]);
-                        }
-                }
-                kfree(hba[i]->cmd_sg_list);
-        }
+        cciss_free_sg_chain_blocks(hba[i]->cmd_sg_list, hba[i]->nr_cmds);
         /*
          * Deliberately omit pci_disable_device(): it does something nasty to
          * Smart Array controllers that pci_enable_device does not undo