RDMA/core: Add Completion Counters to resource tracking

Track completion counter objects in the resource tracking database so
they are visible through the rdma netlink interface. The rdma tool
displays the comp_cntr count in the resource summary.

Add RDMA_RESTRACK_COMP_CNTR type, embed rdma_restrack_entry in
ib_comp_cntr, and add the res_to_dev mapping. Register the resource
on create and remove it on destroy.

Reviewed-by: Yonatan Nachum <ynachum@amazon.com>
Signed-off-by: Michael Margolin <mrgolin@amazon.com>
Link: https://patch.msgid.link/20260722083603.30334-5-mrgolin@amazon.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/core/nldev.c

@@ -451,8 +451,10 @@ static int fill_res_info(struct sk_buff *msg, struct ib_device *device,
 		[RDMA_RESTRACK_MR] = "mr",
 		[RDMA_RESTRACK_CTX] = "ctx",
 		[RDMA_RESTRACK_SRQ] = "srq",
+		[RDMA_RESTRACK_COMP_CNTR] = "comp_cntr",
 	};
 
+	struct ib_comp_cntr_caps comp_cntr_caps = {};
 	struct nlattr *table_attr;
 	u64 curr, max;
 	int ret, i;
@@ -464,6 +466,9 @@ static int fill_res_info(struct sk_buff *msg, struct ib_device *device,
 	if (!table_attr)
 		return -EMSGSIZE;
 
+	if (device->ops.query_comp_cntr_caps)
+		device->ops.query_comp_cntr_caps(device, &comp_cntr_caps, NULL);
+
 	for (i = 0; i < RDMA_RESTRACK_MAX; i++) {
 		if (!names[i])
 			continue;
@@ -484,6 +489,9 @@ static int fill_res_info(struct sk_buff *msg, struct ib_device *device,
 		case RDMA_RESTRACK_SRQ:
 			max = device->attrs.max_srq;
 			break;
+		case RDMA_RESTRACK_COMP_CNTR:
+			max = comp_cntr_caps.max_counters;
+			break;
 		default:
 			max = 0;
 		}

drivers/infiniband/core/restrack.c

@@ -104,6 +104,8 @@ static struct ib_device *res_to_dev(struct rdma_restrack_entry *res)
 		return container_of(res, struct ib_srq, res)->device;
 	case RDMA_RESTRACK_DMAH:
 		return container_of(res, struct ib_dmah, res)->device;
+	case RDMA_RESTRACK_COMP_CNTR:
+		return container_of(res, struct ib_comp_cntr, res)->device;
 	default:
 		WARN_ONCE(true, "Wrong resource tracking type %u\n", res->type);
 		return NULL;

drivers/infiniband/core/uverbs_std_types_comp_cntr.c

@@ -6,6 +6,7 @@
 #include <rdma/uverbs_std_types.h>
 #include "rdma_core.h"
 #include "uverbs.h"
+#include "restrack.h"
 
 static int uverbs_free_comp_cntr(struct ib_uobject *uobject, enum rdma_remove_reason why,
 				 struct uverbs_attr_bundle *attrs)
@@ -16,10 +17,14 @@ static int uverbs_free_comp_cntr(struct ib_uobject *uobject, enum rdma_remove_re
 	if (atomic_read(&cc->usecnt))
 		return -EBUSY;
 
+	rdma_restrack_begin_del(&cc->res);
 	ret = cc->device->ops.destroy_comp_cntr(cc);
-	if (ret)
+	if (ret) {
+		rdma_restrack_abort_del(&cc->res);
 		return ret;
+	}
 
+	rdma_restrack_commit_del(&cc->res);
 	kfree(cc);
 	return 0;
 }
@@ -44,15 +49,20 @@ static int UVERBS_HANDLER(UVERBS_METHOD_COMP_CNTR_CREATE)(struct uverbs_attr_bun
 	cc->device = ib_dev;
 	cc->uobject = uobj;
 
+	rdma_restrack_new(&cc->res, RDMA_RESTRACK_COMP_CNTR);
+	rdma_restrack_set_name(&cc->res, NULL);
+
 	ret = ib_dev->ops.create_comp_cntr(cc, attrs);
 	if (ret)
 		goto err_free;
 
 	uobj->object = cc;
+	rdma_restrack_add(&cc->res);
 	uverbs_finalize_uobj_create(attrs, UVERBS_ATTR_CREATE_COMP_CNTR_HANDLE);
 	return 0;
 
 err_free:
+	rdma_restrack_put(&cc->res);
 	kfree(cc);
 	return ret;
 }

include/rdma/ib_verbs.h

@@ -1765,6 +1765,7 @@ struct ib_comp_cntr {
 	struct ib_device *device;
 	struct ib_uobject *uobject;
 	atomic_t usecnt;
+	struct rdma_restrack_entry res;
 };
 
 enum ib_comp_cntr_entry {

include/rdma/restrack.h

@@ -60,6 +60,10 @@ enum rdma_restrack_type {
 	 * @RDMA_RESTRACK_DMAH: DMA handle
 	 */
 	RDMA_RESTRACK_DMAH,
+	/**
+	 * @RDMA_RESTRACK_COMP_CNTR: Completion Counter
+	 */
+	RDMA_RESTRACK_COMP_CNTR,
 	/**
 	 * @RDMA_RESTRACK_MAX: Last entry, used for array dclarations
 	 */