diff options
Diffstat (limited to 'drivers/infiniband/core/restrack.c')
-rw-r--r-- | drivers/infiniband/core/restrack.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/drivers/infiniband/core/restrack.c b/drivers/infiniband/core/restrack.c new file mode 100644 index 000000000000..857637bf46da --- /dev/null +++ b/drivers/infiniband/core/restrack.c @@ -0,0 +1,164 @@ +/* SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) */ +/* + * Copyright (c) 2017-2018 Mellanox Technologies. All rights reserved. + */ + +#include <rdma/ib_verbs.h> +#include <rdma/restrack.h> +#include <linux/mutex.h> +#include <linux/sched/task.h> +#include <linux/uaccess.h> +#include <linux/pid_namespace.h> + +void rdma_restrack_init(struct rdma_restrack_root *res) +{ + init_rwsem(&res->rwsem); +} + +void rdma_restrack_clean(struct rdma_restrack_root *res) +{ + WARN_ON_ONCE(!hash_empty(res->hash)); +} + +int rdma_restrack_count(struct rdma_restrack_root *res, + enum rdma_restrack_type type, + struct pid_namespace *ns) +{ + struct rdma_restrack_entry *e; + u32 cnt = 0; + + down_read(&res->rwsem); + hash_for_each_possible(res->hash, e, node, type) { + if (ns == &init_pid_ns || + (!rdma_is_kernel_res(e) && + ns == task_active_pid_ns(e->task))) + cnt++; + } + up_read(&res->rwsem); + return cnt; +} +EXPORT_SYMBOL(rdma_restrack_count); + +static void set_kern_name(struct rdma_restrack_entry *res) +{ + enum rdma_restrack_type type = res->type; + struct ib_qp *qp; + + if (type != RDMA_RESTRACK_QP) + /* PD and CQ types already have this name embedded in */ + return; + + qp = container_of(res, struct ib_qp, res); + if (!qp->pd) { + WARN_ONCE(true, "XRC QPs are not supported\n"); + /* Survive, despite the programmer's error */ + res->kern_name = " "; + return; + } + + res->kern_name = qp->pd->res.kern_name; +} + +static struct ib_device *res_to_dev(struct rdma_restrack_entry *res) +{ + enum rdma_restrack_type type = res->type; + struct ib_device *dev; + struct ib_xrcd *xrcd; + struct ib_pd *pd; + struct ib_cq *cq; + struct ib_qp *qp; + + switch (type) { + case RDMA_RESTRACK_PD: + pd = container_of(res, struct ib_pd, res); + dev = pd->device; + break; + case RDMA_RESTRACK_CQ: + cq = container_of(res, struct ib_cq, res); + dev = cq->device; + break; + case RDMA_RESTRACK_QP: + qp = container_of(res, struct ib_qp, res); + dev = qp->device; + break; + case RDMA_RESTRACK_XRCD: + xrcd = container_of(res, struct ib_xrcd, res); + dev = xrcd->device; + break; + default: + WARN_ONCE(true, "Wrong resource tracking type %u\n", type); + return NULL; + } + + return dev; +} + +void rdma_restrack_add(struct rdma_restrack_entry *res) +{ + struct ib_device *dev = res_to_dev(res); + + if (!dev) + return; + + if (!uaccess_kernel()) { + get_task_struct(current); + res->task = current; + res->kern_name = NULL; + } else { + set_kern_name(res); + res->task = NULL; + } + + kref_init(&res->kref); + init_completion(&res->comp); + res->valid = true; + + down_write(&dev->res.rwsem); + hash_add(dev->res.hash, &res->node, res->type); + up_write(&dev->res.rwsem); +} +EXPORT_SYMBOL(rdma_restrack_add); + +int __must_check rdma_restrack_get(struct rdma_restrack_entry *res) +{ + return kref_get_unless_zero(&res->kref); +} +EXPORT_SYMBOL(rdma_restrack_get); + +static void restrack_release(struct kref *kref) +{ + struct rdma_restrack_entry *res; + + res = container_of(kref, struct rdma_restrack_entry, kref); + complete(&res->comp); +} + +int rdma_restrack_put(struct rdma_restrack_entry *res) +{ + return kref_put(&res->kref, restrack_release); +} +EXPORT_SYMBOL(rdma_restrack_put); + +void rdma_restrack_del(struct rdma_restrack_entry *res) +{ + struct ib_device *dev; + + if (!res->valid) + return; + + dev = res_to_dev(res); + if (!dev) + return; + + rdma_restrack_put(res); + + wait_for_completion(&res->comp); + + down_write(&dev->res.rwsem); + hash_del(&res->node); + res->valid = false; + if (res->task) + put_task_struct(res->task); + up_write(&dev->res.rwsem); +} +EXPORT_SYMBOL(rdma_restrack_del); |