[PATCH] IB/mthca: add mthca_table_find() function

Add mthca_table_find() function, which returns the lowmem address of an entry
in a mem-free HCA's context tables.  This will be used by the FMR
implementation.

Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <roland@topspin.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 35 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.c b/drivers/infiniband/hw/mthca/mthca_memfree.c
index 46981d48c232..ea45de8c5b8e 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.c
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.c
@@ -192,6 +192,40 @@ void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int o
         up(&table->mutex);
 }
 
+void *mthca_table_find(struct mthca_icm_table *table, int obj)
+{
+        int idx, offset, i;
+        struct mthca_icm_chunk *chunk;
+        struct mthca_icm *icm;
+        struct page *page = NULL;
+
+        if (!table->lowmem)
+                return NULL;
+
+        down(&table->mutex);
+
+        idx = (obj & (table->num_obj - 1)) * table->obj_size;
+        icm = table->icm[idx / MTHCA_TABLE_CHUNK_SIZE];
+        offset = idx % MTHCA_TABLE_CHUNK_SIZE;
+
+        if (!icm)
+                goto out;
+
+        list_for_each_entry(chunk, &icm->chunk_list, list) {
+                for (i = 0; i < chunk->npages; ++i) {
+                        if (chunk->mem[i].length >= offset) {
+                                page = chunk->mem[i].page;
+                                break;
+                        }
+                        offset -= chunk->mem[i].length;
+                }
+        }
+
+out:
+        up(&table->mutex);
+        return page ? lowmem_page_address(page) + offset : NULL;
+}
+
 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
                           int start, int end)
 {
diff --git a/drivers/infiniband/hw/mthca/mthca_memfree.h b/drivers/infiniband/hw/mthca/mthca_memfree.h
index ef72e430250a..fe7be2a6bc4a 100644
--- a/drivers/infiniband/hw/mthca/mthca_memfree.h
+++ b/drivers/infiniband/hw/mthca/mthca_memfree.h
@@ -85,6 +85,7 @@ struct mthca_icm_table *mthca_alloc_icm_table(struct mthca_dev *dev,
 void mthca_free_icm_table(struct mthca_dev *dev, struct mthca_icm_table *table);
 int mthca_table_get(struct mthca_dev *dev, struct mthca_icm_table *table, int obj);
 void mthca_table_put(struct mthca_dev *dev, struct mthca_icm_table *table, int obj);
+void *mthca_table_find(struct mthca_icm_table *table, int obj);
 int mthca_table_get_range(struct mthca_dev *dev, struct mthca_icm_table *table,
                           int start, int end);
 void mthca_table_put_range(struct mthca_dev *dev, struct mthca_icm_table *table,