RDMA/nes: Free kmap() resources

We fail when creating many qps as kmap() fails for sq_vbase.
Fix this by doing kunmap() as soon as we are done with sq_vbase.
We do kunmap() in one of the locations below:

(1) nes_destroy_qp()
(2) nes_accept()
(3) nes_connect_event

We keep a flag to avoid multiple calls to kunmap().

Signed-off-by: Faisal Latif <faisal.latif@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 19 insertions, 2 deletions

diff --git a/drivers/infiniband/hw/nes/nes_cm.c b/drivers/infiniband/hw/nes/nes_cm.c
index a25816812ced..b139806a9667 100644
--- a/drivers/infiniband/hw/nes/nes_cm.c
+++ b/drivers/infiniband/hw/nes/nes_cm.c
@@ -52,6 +52,7 @@
 #include <linux/random.h>
 #include <linux/list.h>
 #include <linux/threads.h>
+#include <linux/highmem.h>
 #include <net/arp.h>
 #include <net/neighbour.h>
 #include <net/route.h>
@@ -2836,6 +2837,10 @@ int nes_accept(struct iw_cm_id *cm_id, struct iw_cm_conn_param *conn_param)
                         cpu_to_le32(conn_param->private_data_len +
                         sizeof(struct ietf_mpa_frame));
                 wqe->wqe_words[NES_IWARP_SQ_WQE_STAG0_IDX] = ibmr->lkey;
+                if (nesqp->sq_kmapped) {
+                        nesqp->sq_kmapped = 0;
+                        kunmap(nesqp->page);
+                }
 
                 nesqp->nesqp_context->ird_ord_sizes |=
                         cpu_to_le32(NES_QPCONTEXT_ORDIRD_LSMM_PRESENT |
@@ -3304,6 +3309,11 @@ static void cm_event_connected(struct nes_cm_event *event)
                 wqe->wqe_words[NES_IWARP_SQ_WQE_LENGTH0_IDX] = 0;
                 wqe->wqe_words[NES_IWARP_SQ_WQE_STAG0_IDX] = 0;
 
+                if (nesqp->sq_kmapped) {
+                        nesqp->sq_kmapped = 0;
+                        kunmap(nesqp->page);
+                }
+
                 /* use the reserved spot on the WQ for the extra first WQE */
                 nesqp->nesqp_context->ird_ord_sizes &=
                         cpu_to_le32(~(NES_QPCONTEXT_ORDIRD_LSMM_PRESENT |
diff --git a/drivers/infiniband/hw/nes/nes_verbs.c b/drivers/infiniband/hw/nes/nes_verbs.c
index 53dc39f43008..64d3136e3747 100644
--- a/drivers/infiniband/hw/nes/nes_verbs.c
+++ b/drivers/infiniband/hw/nes/nes_verbs.c
@@ -1015,6 +1015,7 @@ static int nes_setup_virt_qp(struct nes_qp *nesqp, struct nes_pbl *nespbl,
                 kunmap(nesqp->page);
                 return -ENOMEM;
         }
+        nesqp->sq_kmapped = 1;
         nesqp->hwqp.q2_vbase = mem;
         mem += 256;
         memset(nesqp->hwqp.q2_vbase, 0, 256);
@@ -1092,7 +1093,10 @@ static inline void nes_free_qp_mem(struct nes_device *nesdev,
                 pci_free_consistent(nesdev->pcidev, nesqp->qp_mem_size, nesqp->hwqp.q2_vbase, nesqp->hwqp.q2_pbase);
                 pci_free_consistent(nesdev->pcidev, 256, nesqp->pbl_vbase, nesqp->pbl_pbase );
                 nesqp->pbl_vbase = NULL;
-                kunmap(nesqp->page);
+                if (nesqp->sq_kmapped) {
+                        nesqp->sq_kmapped = 0;
+                        kunmap(nesqp->page);
+                }
         }
 }
 
@@ -1501,8 +1505,10 @@ static int nes_destroy_qp(struct ib_qp *ibqp)
                                 nes_ucontext->first_free_wq = nesqp->mmap_sq_db_index;
                         }
                 }
-                if (nesqp->pbl_pbase)
+                if (nesqp->pbl_pbase && nesqp->sq_kmapped) {
+                        nesqp->sq_kmapped = 0;
                         kunmap(nesqp->page);
+                }
         } else {
                 /* Clean any pending completions from the cq(s) */
                 if (nesqp->nesscq)
diff --git a/drivers/infiniband/hw/nes/nes_verbs.h b/drivers/infiniband/hw/nes/nes_verbs.h
index cc7a60481e50..2df9993e0cac 100644
--- a/drivers/infiniband/hw/nes/nes_verbs.h
+++ b/drivers/infiniband/hw/nes/nes_verbs.h
@@ -175,5 +175,6 @@ struct nes_qp {
         u8                    hw_iwarp_state;
         u8                    hw_tcp_state;
         u8                    term_flags;
+        u8                    sq_kmapped;
 };
 #endif                  /* NES_VERBS_H */