[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>

diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index fba0a53..1827400 100644 (file)
--- 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])