IB/ehca: Support small QP queues

eHCA2 supports QP queues that can be as small as 512 bytes. This
greatly reduces memory overhead for consumers that use lots of QPs
with small queues (e.g. RDMA-only QPs). Apart from dealing with
firmware, this code needs to manage bite-sized chunks of kernel pages,
making sure that no kernel page is shared between different protection
domains.

Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_main.c b/drivers/infiniband/hw/ehca/ehca_main.c
index bb104b7f73e3..99036b65bb84 100644
--- a/drivers/infiniband/hw/ehca/ehca_main.c
+++ b/drivers/infiniband/hw/ehca/ehca_main.c
@@ -181,6 +181,12 @@ static int ehca_create_slab_caches(void)
                 goto create_slab_caches5;
         }
 
+        ret = ehca_init_small_qp_cache();
+        if (ret) {
+                ehca_gen_err("Cannot create small queue SLAB cache.");
+                goto create_slab_caches6;
+        }
+
 #ifdef CONFIG_PPC_64K_PAGES
         ctblk_cache = kmem_cache_create("ehca_cache_ctblk",
                                         EHCA_PAGESIZE, H_CB_ALIGNMENT,
@@ -188,12 +194,15 @@ static int ehca_create_slab_caches(void)
                                         NULL);
         if (!ctblk_cache) {
                 ehca_gen_err("Cannot create ctblk SLAB cache.");
-                ehca_cleanup_mrmw_cache();
-                goto create_slab_caches5;
+                ehca_cleanup_small_qp_cache();
+                goto create_slab_caches6;
         }
 #endif
         return 0;
 
+create_slab_caches6:
+        ehca_cleanup_mrmw_cache();
+
 create_slab_caches5:
         ehca_cleanup_av_cache();
 
@@ -211,6 +220,7 @@ create_slab_caches2:
 
 static void ehca_destroy_slab_caches(void)
 {
+        ehca_cleanup_small_qp_cache();
         ehca_cleanup_mrmw_cache();
         ehca_cleanup_av_cache();
         ehca_cleanup_qp_cache();