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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/infiniband/sw/rxe/rxe_task.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/infiniband/sw/rxe/rxe_task.c')
-rw-r--r--drivers/infiniband/sw/rxe/rxe_task.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c
new file mode 100644
index 000000000..446ee2c3d
--- /dev/null
+++ b/drivers/infiniband/sw/rxe/rxe_task.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
+ */
+
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/hardirq.h>
+
+#include "rxe.h"
+
+int __rxe_do_task(struct rxe_task *task)
+
+{
+ int ret;
+
+ while ((ret = task->func(task->arg)) == 0)
+ ;
+
+ task->ret = ret;
+
+ return ret;
+}
+
+/*
+ * this locking is due to a potential race where
+ * a second caller finds the task already running
+ * but looks just after the last call to func
+ */
+void rxe_do_task(struct tasklet_struct *t)
+{
+ int cont;
+ int ret;
+ struct rxe_task *task = from_tasklet(task, t, tasklet);
+ unsigned int iterations = RXE_MAX_ITERATIONS;
+
+ spin_lock_bh(&task->state_lock);
+ switch (task->state) {
+ case TASK_STATE_START:
+ task->state = TASK_STATE_BUSY;
+ spin_unlock_bh(&task->state_lock);
+ break;
+
+ case TASK_STATE_BUSY:
+ task->state = TASK_STATE_ARMED;
+ fallthrough;
+ case TASK_STATE_ARMED:
+ spin_unlock_bh(&task->state_lock);
+ return;
+
+ default:
+ spin_unlock_bh(&task->state_lock);
+ pr_warn("%s failed with bad state %d\n", __func__, task->state);
+ return;
+ }
+
+ do {
+ cont = 0;
+ ret = task->func(task->arg);
+
+ spin_lock_bh(&task->state_lock);
+ switch (task->state) {
+ case TASK_STATE_BUSY:
+ if (ret) {
+ task->state = TASK_STATE_START;
+ } else if (iterations--) {
+ cont = 1;
+ } else {
+ /* reschedule the tasklet and exit
+ * the loop to give up the cpu
+ */
+ tasklet_schedule(&task->tasklet);
+ task->state = TASK_STATE_START;
+ }
+ break;
+
+ /* someone tried to run the task since the last time we called
+ * func, so we will call one more time regardless of the
+ * return value
+ */
+ case TASK_STATE_ARMED:
+ task->state = TASK_STATE_BUSY;
+ cont = 1;
+ break;
+
+ default:
+ pr_warn("%s failed with bad state %d\n", __func__,
+ task->state);
+ }
+ spin_unlock_bh(&task->state_lock);
+ } while (cont);
+
+ task->ret = ret;
+}
+
+int rxe_init_task(struct rxe_task *task, void *arg, int (*func)(void *))
+{
+ task->arg = arg;
+ task->func = func;
+ task->destroyed = false;
+
+ tasklet_setup(&task->tasklet, rxe_do_task);
+
+ task->state = TASK_STATE_START;
+ spin_lock_init(&task->state_lock);
+
+ return 0;
+}
+
+void rxe_cleanup_task(struct rxe_task *task)
+{
+ bool idle;
+
+ /*
+ * Mark the task, then wait for it to finish. It might be
+ * running in a non-tasklet (direct call) context.
+ */
+ task->destroyed = true;
+
+ do {
+ spin_lock_bh(&task->state_lock);
+ idle = (task->state == TASK_STATE_START);
+ spin_unlock_bh(&task->state_lock);
+ } while (!idle);
+
+ tasklet_kill(&task->tasklet);
+}
+
+void rxe_run_task(struct rxe_task *task)
+{
+ if (task->destroyed)
+ return;
+
+ rxe_do_task(&task->tasklet);
+}
+
+void rxe_sched_task(struct rxe_task *task)
+{
+ if (task->destroyed)
+ return;
+
+ tasklet_schedule(&task->tasklet);
+}
+
+void rxe_disable_task(struct rxe_task *task)
+{
+ tasklet_disable(&task->tasklet);
+}
+
+void rxe_enable_task(struct rxe_task *task)
+{
+ tasklet_enable(&task->tasklet);
+}