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, 26 insertions, 15 deletions

diff --git a/drivers/infiniband/hw/ehca/ehca_classes.h b/drivers/infiniband/hw/ehca/ehca_classes.h
index 63b8b9f7c4f..3725aa8664d 100644
--- a/drivers/infiniband/hw/ehca/ehca_classes.h
+++ b/drivers/infiniband/hw/ehca/ehca_classes.h
@@ -43,7 +43,6 @@
 #ifndef __EHCA_CLASSES_H__
 #define __EHCA_CLASSES_H__
 
-
 struct ehca_module;
 struct ehca_qp;
 struct ehca_cq;
@@ -129,6 +128,10 @@ struct ehca_pd {
 	struct ib_pd ib_pd;
 	struct ipz_pd fw_pd;
 	u32 ownpid;
+	/* small queue mgmt */
+	struct mutex lock;
+	struct list_head free[2];
+	struct list_head full[2];
 };
 
 enum ehca_ext_qp_type {
@@ -307,6 +310,8 @@ int ehca_init_av_cache(void);
 void ehca_cleanup_av_cache(void);
 int ehca_init_mrmw_cache(void);
 void ehca_cleanup_mrmw_cache(void);
+int ehca_init_small_qp_cache(void);
+void ehca_cleanup_small_qp_cache(void);
 
 extern rwlock_t ehca_qp_idr_lock;
 extern rwlock_t ehca_cq_idr_lock;
@@ -324,7 +329,7 @@ struct ipzu_queue_resp {
 	u32 queue_length; /* queue length allocated in bytes */
 	u32 pagesize;
 	u32 toggle_state;
-	u32 dummy; /* padding for 8 byte alignment */
+	u32 offset; /* save offset within a page for small_qp */
 };
 
 struct ehca_create_cq_resp {
@@ -366,15 +371,29 @@ enum ehca_ll_comp_flags {
 	LLQP_COMP_MASK = 0x60,
 };
 
+struct ehca_alloc_queue_parms {
+	/* input parameters */
+	int max_wr;
+	int max_sge;
+	int page_size;
+	int is_small;
+
+	/* output parameters */
+	u16 act_nr_wqes;
+	u8  act_nr_sges;
+	u32 queue_size; /* bytes for small queues, pages otherwise */
+};
+
 struct ehca_alloc_qp_parms {
-/* input parameters */
+	struct ehca_alloc_queue_parms squeue;
+	struct ehca_alloc_queue_parms rqueue;
+
+	/* input parameters */
 	enum ehca_service_type servicetype;
+	int qp_storage;
 	int sigtype;
 	enum ehca_ext_qp_type ext_type;
 	enum ehca_ll_comp_flags ll_comp_flags;
-
-	int max_send_wr, max_recv_wr;
-	int max_send_sge, max_recv_sge;
 	int ud_av_l_key_ctl;
 
 	u32 token;
@@ -384,18 +403,10 @@ struct ehca_alloc_qp_parms {
 
 	u32 srq_qpn, srq_token, srq_limit;
 
-/* output parameters */
+	/* output parameters */
 	u32 real_qp_num;
 	struct ipz_qp_handle qp_handle;
 	struct h_galpas galpas;
-
-	u16 act_nr_send_wqes;
-	u16 act_nr_recv_wqes;
-	u8  act_nr_recv_sges;
-	u8  act_nr_send_sges;
-
-	u32 nr_rq_pages;
-	u32 nr_sq_pages;
 };
 
 int ehca_cq_assign_qp(struct ehca_cq *cq, struct ehca_qp *qp);