[PATCH rdma-next 1/5] RDMA/hns: Implement the disassociate_ucontext API

From: Wei Hu (Xavier)
Date: Thu May 17 2018 - 02:33:04 EST


This patch Implements the IB core disassociate_ucontext API.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@xxxxxxxxxx>
---
drivers/infiniband/hw/hns/hns_roce_main.c | 36 +++++++++++++++++++++++++++++++
1 file changed, 36 insertions(+)

diff --git a/drivers/infiniband/hw/hns/hns_roce_main.c b/drivers/infiniband/hw/hns/hns_roce_main.c
index 96fb6a9..7fafe9d 100644
--- a/drivers/infiniband/hw/hns/hns_roce_main.c
+++ b/drivers/infiniband/hw/hns/hns_roce_main.c
@@ -33,6 +33,9 @@
#include <linux/acpi.h>
#include <linux/of_platform.h>
#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/sched/task.h>
#include <rdma/ib_addr.h>
#include <rdma/ib_smi.h>
#include <rdma/ib_user_verbs.h>
@@ -422,6 +425,38 @@ static int hns_roce_port_immutable(struct ib_device *ib_dev, u8 port_num,
return 0;
}

+static void hns_roce_disassociate_ucontext(struct ib_ucontext *ibcontext)
+{
+ struct task_struct *process;
+ struct mm_struct *mm;
+
+ process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
+ if (!process)
+ return;
+
+ mm = get_task_mm(process);
+ if (!mm) {
+ pr_info("no mm, disassociate ucontext is pending task termination\n");
+ while (1) {
+ put_task_struct(process);
+ usleep_range(1000, 2000);
+ process = get_pid_task(ibcontext->tgid, PIDTYPE_PID);
+ if (!process || process->state == TASK_DEAD) {
+ pr_info("disassociate ucontext done, task was terminated\n");
+ /* if task was dead, need to release the task
+ * struct.
+ */
+ if (process)
+ put_task_struct(process);
+ return;
+ }
+ }
+ }
+
+ mmput(mm);
+ put_task_struct(process);
+}
+
static void hns_roce_unregister_device(struct hns_roce_dev *hr_dev)
{
struct hns_roce_ib_iboe *iboe = &hr_dev->iboe;
@@ -516,6 +551,7 @@ static int hns_roce_register_device(struct hns_roce_dev *hr_dev)

/* OTHERS */
ib_dev->get_port_immutable = hns_roce_port_immutable;
+ ib_dev->disassociate_ucontext = hns_roce_disassociate_ucontext;

ib_dev->driver_id = RDMA_DRIVER_HNS;
ret = ib_register_device(ib_dev, NULL);
--
1.9.1