IB/mthca: Add module parameter for number of MTTs per segment

The current MTT allocator uses kmalloc() to allocate a buffer for its
buddy allocator, and thus is limited in the amount of MTT segments
that it can control.  As a result, the size of memory that can be
registered is limited too.  This patch uses a module parameter to
control the number of MTT entries that each segment represents,
allowing more memory to be registered with the same number of
segments.

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_mr.c b/drivers/infiniband/hw/mthca/mthca_mr.c
index 882e6b7..d606edf 100644
--- a/drivers/infiniband/hw/mthca/mthca_mr.c
+++ b/drivers/infiniband/hw/mthca/mthca_mr.c
@@ -220,7 +220,7 @@
 
 	mtt->buddy = buddy;
 	mtt->order = 0;
-	for (i = MTHCA_MTT_SEG_SIZE / 8; i < size; i <<= 1)
+	for (i = dev->limits.mtt_seg_size / 8; i < size; i <<= 1)
 		++mtt->order;
 
 	mtt->first_seg = mthca_alloc_mtt_range(dev, mtt->order, buddy);
@@ -267,7 +267,7 @@
 
 	while (list_len > 0) {
 		mtt_entry[0] = cpu_to_be64(dev->mr_table.mtt_base +
-					   mtt->first_seg * MTHCA_MTT_SEG_SIZE +
+					   mtt->first_seg * dev->limits.mtt_seg_size +
 					   start_index * 8);
 		mtt_entry[1] = 0;
 		for (i = 0; i < list_len && i < MTHCA_MAILBOX_SIZE / 8 - 2; ++i)
@@ -326,7 +326,7 @@
 	u64 __iomem *mtts;
 	int i;
 
-	mtts = dev->mr_table.tavor_fmr.mtt_base + mtt->first_seg * MTHCA_MTT_SEG_SIZE +
+	mtts = dev->mr_table.tavor_fmr.mtt_base + mtt->first_seg * dev->limits.mtt_seg_size +
 		start_index * sizeof (u64);
 	for (i = 0; i < list_len; ++i)
 		mthca_write64_raw(cpu_to_be64(buffer_list[i] | MTHCA_MTT_FLAG_PRESENT),
@@ -345,10 +345,10 @@
 	/* For Arbel, all MTTs must fit in the same page. */
 	BUG_ON(s / PAGE_SIZE != (s + list_len * sizeof(u64) - 1) / PAGE_SIZE);
 	/* Require full segments */
-	BUG_ON(s % MTHCA_MTT_SEG_SIZE);
+	BUG_ON(s % dev->limits.mtt_seg_size);
 
 	mtts = mthca_table_find(dev->mr_table.mtt_table, mtt->first_seg +
-				s / MTHCA_MTT_SEG_SIZE, &dma_handle);
+				s / dev->limits.mtt_seg_size, &dma_handle);
 
 	BUG_ON(!mtts);
 
@@ -479,7 +479,7 @@
 	if (mr->mtt)
 		mpt_entry->mtt_seg =
 			cpu_to_be64(dev->mr_table.mtt_base +
-				    mr->mtt->first_seg * MTHCA_MTT_SEG_SIZE);
+				    mr->mtt->first_seg * dev->limits.mtt_seg_size);
 
 	if (0) {
 		mthca_dbg(dev, "Dumping MPT entry %08x:\n", mr->ibmr.lkey);
@@ -626,7 +626,7 @@
 		goto err_out_table;
 	}
 
-	mtt_seg = mr->mtt->first_seg * MTHCA_MTT_SEG_SIZE;
+	mtt_seg = mr->mtt->first_seg * dev->limits.mtt_seg_size;
 
 	if (mthca_is_memfree(dev)) {
 		mr->mem.arbel.mtts = mthca_table_find(dev->mr_table.mtt_table,
@@ -908,7 +908,7 @@
 			 dev->mr_table.mtt_base);
 
 		dev->mr_table.tavor_fmr.mtt_base =
-			ioremap(addr, mtts * MTHCA_MTT_SEG_SIZE);
+			ioremap(addr, mtts * dev->limits.mtt_seg_size);
 		if (!dev->mr_table.tavor_fmr.mtt_base) {
 			mthca_warn(dev, "MTT ioremap for FMR failed.\n");
 			err = -ENOMEM;