[PATCH] IB/mthca: Handle context tables smaller than our chunk size

When creating a table in context memory where the table is smaller
than our chunk size, we don't want to allocate and map a full chunk.
Instead, allocate just enough memory to cover the table.

This can be pretty simple because all tables are a power-of-2 size, so
either the table is a multiple of the chunk size, or it's smaller than
one chunk.

Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index fba0a53ba6ea..1827400f189b 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -286,6 +286,7 @@ struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 {
         struct mthca_icm_table *table;
         int num_icm;
+        unsigned chunk_size;
         int i;
         u8 status;
 
@@ -306,7 +307,11 @@ struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
                 table->icm[i] = NULL;
 
         for (i = 0; i * MTHCA_TABLE_CHUNK_SIZE < reserved * obj_size; ++i) {
-                table->icm[i] = mthca_alloc_icm(dev, MTHCA_TABLE_CHUNK_SIZE >> PAGE_SHIFT,
+                chunk_size = MTHCA_TABLE_CHUNK_SIZE;
+                if ((i + 1) * MTHCA_TABLE_CHUNK_SIZE > nobj * obj_size)
+                        chunk_size = nobj * obj_size - i * MTHCA_TABLE_CHUNK_SIZE;
+
+                table->icm[i] = mthca_alloc_icm(dev, chunk_size >> PAGE_SHIFT,
                                                 (use_lowmem ? GFP_KERNEL : GFP_HIGHUSER) |
                                                 __GFP_NOWARN);
                 if (!table->icm[i])