[RFC PATCH v5 26/27] qedn: Add Connection and IO level recovery flows

Shai Malin
2021-05-19T12:42:34Z

This patch will present the connection level functionalities:
- conn clear-sq: will release the FW restrictions in order to flush all
the pending IOs.
- drain: in case clear-sq is stuck, will release all the device FW
restrictions in order to flush all the pending IOs.
- task cleanup - will flush the IO level resources.

Acked-by: Igor Russkikh <irusskikh@marvell.com>
Signed-off-by: Prabhakar Kushwaha <pkushwaha@marvell.com>
Signed-off-by: Omkar Kulkarni <okulkarni@marvell.com>
Signed-off-by: Michal Kalderon <mkalderon@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Shai Malin <smalin@marvell.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
drivers/nvme/hw/qedn/qedn.h | 8 ++
drivers/nvme/hw/qedn/qedn_conn.c | 128 ++++++++++++++++++++++++++++++-
drivers/nvme/hw/qedn/qedn_main.c | 1 +
drivers/nvme/hw/qedn/qedn_task.c | 27 ++++++-
4 files changed, 161 insertions(+), 3 deletions(-)

diff --git a/drivers/nvme/hw/qedn/qedn.h b/drivers/nvme/hw/qedn/qedn.h
index a7be866de6f6..e01584bd8d20 100644
--- a/drivers/nvme/hw/qedn/qedn.h
+++ b/drivers/nvme/hw/qedn/qedn.h
@@ -50,6 +50,8 @@

#define QEDN_FW_CQ_FP_WQ_WORKQUEUE "qedn_fw_cq_fp_wq"

+#define QEDN_DRAIN_MAX_ATTEMPTS 3
+
/* Protocol defines */
#define QEDN_MAX_IO_SIZE QED_NVMETCP_MAX_IO_SIZE
#define QEDN_MAX_PDU_SIZE 0x80000 /* 512KB */
@@ -105,6 +107,8 @@
/* Timeouts and delay constants */
#define QEDN_WAIT_CON_ESTABLSH_TMO 10000 /* 10 seconds */
#define QEDN_RLS_CONS_TMO 5000 /* 5 sec */
+#define QEDN_TASK_CLEANUP_TMO 3000 /* 3 sec */
+#define QEDN_DRAIN_TMO 1000 /* 1 sec */

enum qedn_state {
QEDN_STATE_CORE_PROBED = 0,
@@ -187,7 +191,9 @@ struct qedn_ctx {
};

enum qedn_task_flags {
+ QEDN_TASK_IS_ICREQ,
QEDN_TASK_USED_BY_FW,
+ QEDN_TASK_WAIT_FOR_CLEANUP,
};

struct qedn_task_ctx {
@@ -331,6 +337,8 @@ struct qedn_conn_ctx {
struct list_head active_task_list;
atomic_t num_active_tasks;
atomic_t num_active_fw_tasks;
+ atomic_t task_cleanups_cnt;
+ wait_queue_head_t cleanup_waitq;

/* Connection resources - turned on to indicate what resource was
* allocated, to that it can later be released.
diff --git a/drivers/nvme/hw/qedn/qedn_conn.c b/drivers/nvme/hw/qedn/qedn_conn.c
index ed60ac0306d5..46de8ba17df9 100644
--- a/drivers/nvme/hw/qedn/qedn_conn.c
+++ b/drivers/nvme/hw/qedn/qedn_conn.c
@@ -598,6 +598,11 @@ static int qedn_handle_icresp(struct qedn_conn_ctx *conn_ctx)
return rc;
}

+void qedn_error_recovery(struct nvme_ctrl *nctrl)
+{
+ nvme_tcp_ofld_error_recovery(nctrl);
+}
+
/* Slowpath EQ Callback */
int qedn_event_cb(void *context, u8 fw_event_code, void *event_ring_data)
{
@@ -657,6 +662,7 @@ int qedn_event_cb(void *context, u8 fw_event_code, void *event_ring_data)
}

break;
+
case NVMETCP_EVENT_TYPE_ASYN_TERMINATE_DONE:
if (conn_ctx->state != CONN_STATE_WAIT_FOR_DESTROY_DONE)
pr_err("CID=0x%x - ASYN_TERMINATE_DONE: Unexpected connection state %u\n",
@@ -665,6 +671,19 @@ int qedn_event_cb(void *context, u8 fw_event_code, void *event_ring_data)
queue_work(qctrl->sp_wq, &conn_ctx->sp_wq_entry);

break;
+
+ case NVMETCP_EVENT_TYPE_ASYN_CLOSE_RCVD:
+ case NVMETCP_EVENT_TYPE_ASYN_ABORT_RCVD:
+ case NVMETCP_EVENT_TYPE_ASYN_MAX_RT_TIME:
+ case NVMETCP_EVENT_TYPE_ASYN_MAX_RT_CNT:
+ case NVMETCP_EVENT_TYPE_ASYN_SYN_RCVD:
+ case NVMETCP_EVENT_TYPE_ASYN_MAX_KA_PROBES_CNT:
+ case NVMETCP_EVENT_TYPE_NVMETCP_CONN_ERROR:
+ case NVMETCP_EVENT_TYPE_TCP_CONN_ERROR:
+ qedn_error_recovery(&conn_ctx->ctrl->nctrl);
+
+ break;
+
default:
pr_err("CID=0x%x - Recv Unknown Event %u\n", conn_ctx->fw_cid, fw_event_code);
break;
@@ -798,6 +817,107 @@ static int qedn_prep_and_offload_queue(struct qedn_conn_ctx *conn_ctx)
return -EINVAL;
}

+static void qedn_cleanup_fw_task(struct qedn_ctx *qedn, struct qedn_task_ctx *qedn_task)
+{
+ struct qedn_conn_ctx *conn_ctx = qedn_task->qedn_conn;
+ struct nvmetcp_task_params task_params;
+ struct nvmetcp_wqe *chain_sqe;
+ struct nvmetcp_wqe local_sqe;
+ unsigned long lock_flags;
+
+ /* Take lock to prevent race with fastpath, we don't want to
+ * invoke cleanup flows on tasks that already returned.
+ */
+ spin_lock_irqsave(&qedn_task->lock, lock_flags);
+ if (!qedn_task->valid) {
+ spin_unlock_irqrestore(&qedn_task->lock, lock_flags);
+
+ return;
+ }
+ /* Skip tasks not used by FW */
+ if (!test_bit(QEDN_TASK_USED_BY_FW, &qedn_task->flags)) {
+ spin_unlock_irqrestore(&qedn_task->lock, lock_flags);
+
+ return;
+ }
+ /* Skip tasks that were already invoked for cleanup */
+ if (unlikely(test_bit(QEDN_TASK_WAIT_FOR_CLEANUP, &qedn_task->flags))) {
+ spin_unlock_irqrestore(&qedn_task->lock, lock_flags);
+
+ return;
+ }
+ set_bit(QEDN_TASK_WAIT_FOR_CLEANUP, &qedn_task->flags);
+ spin_unlock_irqrestore(&qedn_task->lock, lock_flags);
+
+ atomic_inc(&conn_ctx->task_cleanups_cnt);
+
+ task_params.sqe = &local_sqe;
+ task_params.itid = qedn_task->itid;
+ qed_ops->init_task_cleanup(&task_params);
+
+ /* spin_lock - doorbell is accessed both Rx flow and response flow */
+ spin_lock(&conn_ctx->ep.doorbell_lock);
+ chain_sqe = qed_chain_produce(&conn_ctx->ep.fw_sq_chain);
+ memcpy(chain_sqe, &local_sqe, sizeof(local_sqe));
+ qedn_ring_doorbell(conn_ctx);
+ spin_unlock(&conn_ctx->ep.doorbell_lock);
+}
+
+inline int qedn_drain(struct qedn_conn_ctx *conn_ctx)
+{
+ int drain_iter = QEDN_DRAIN_MAX_ATTEMPTS;
+ struct qedn_ctx *qedn = conn_ctx->qedn;
+ int wrc;
+
+ while (drain_iter) {
+ qed_ops->common->drain(qedn->cdev);
+ msleep(100);
+
+ wrc = wait_event_interruptible_timeout(conn_ctx->cleanup_waitq,
+ !atomic_read(&conn_ctx->task_cleanups_cnt),
+ msecs_to_jiffies(QEDN_DRAIN_TMO));
+ if (!wrc) {
+ drain_iter--;
+ continue;
+ }
+
+ return 0;
+ }
+
+ pr_err("CID 0x%x: cleanup after drain failed - need hard reset.\n", conn_ctx->fw_cid);
+
+ return -EINVAL;
+}
+
+void qedn_cleanup_all_fw_tasks(struct qedn_conn_ctx *conn_ctx)
+{
+ struct qedn_task_ctx *qedn_task, *task_tmp;
+ struct qedn_ctx *qedn = conn_ctx->qedn;
+ int wrc;
+
+ list_for_each_entry_safe_reverse(qedn_task, task_tmp, &conn_ctx->active_task_list, entry) {
+ qedn_cleanup_fw_task(qedn, qedn_task);
+ }
+
+ wrc = wait_event_interruptible_timeout(conn_ctx->cleanup_waitq,
+ atomic_read(&conn_ctx->task_cleanups_cnt) == 0,
+ msecs_to_jiffies(QEDN_TASK_CLEANUP_TMO));
+ if (!wrc) {
+ if (qedn_drain(conn_ctx))
+ return;
+ }
+}
+
+static void qedn_clear_fw_sq(struct qedn_conn_ctx *conn_ctx)
+{
+ struct qedn_ctx *qedn = conn_ctx->qedn;
+ int rc;
+
+ rc = qed_ops->clear_sq(qedn->cdev, conn_ctx->conn_handle);
+ if (rc)
+ pr_warn("clear_sq failed - rc %u\n", rc);
+}
+
void qedn_destroy_connection(struct qedn_conn_ctx *conn_ctx)
{
struct qedn_ctx *qedn = conn_ctx->qedn;
@@ -808,7 +928,13 @@ void qedn_destroy_connection(struct qedn_conn_ctx *conn_ctx)
if (qedn_set_con_state(conn_ctx, CONN_STATE_WAIT_FOR_DESTROY_DONE))
return;

- /* Placeholder - task cleanup */
+ if (atomic_read(&conn_ctx->num_active_fw_tasks)) {
+ conn_ctx->abrt_flag = QEDN_ABORTIVE_TERMINATION;
+ qedn_clear_fw_sq(conn_ctx);
+ qedn_cleanup_all_fw_tasks(conn_ctx);
+ } else {
+ conn_ctx->abrt_flag = QEDN_NON_ABORTIVE_TERMINATION;
+ }

rc = qed_ops->destroy_conn(qedn->cdev, conn_ctx->conn_handle,
conn_ctx->abrt_flag);
diff --git a/drivers/nvme/hw/qedn/qedn_main.c b/drivers/nvme/hw/qedn/qedn_main.c
index c2721a771822..2a1135fb4ae3 100644
--- a/drivers/nvme/hw/qedn/qedn_main.c
+++ b/drivers/nvme/hw/qedn/qedn_main.c
@@ -299,6 +299,7 @@ static int qedn_create_queue(struct nvme_tcp_ofld_queue *queue, int qid, size_t
qedn_set_pdu_params(conn_ctx);

init_waitqueue_head(&conn_ctx->conn_waitq);
+ init_waitqueue_head(&conn_ctx->cleanup_waitq);
atomic_set(&conn_ctx->est_conn_indicator, 0);
atomic_set(&conn_ctx->destroy_conn_indicator, 0);

diff --git a/drivers/nvme/hw/qedn/qedn_task.c b/drivers/nvme/hw/qedn/qedn_task.c
index 44e5ea2a693a..4fca9a4707cd 100644
--- a/drivers/nvme/hw/qedn/qedn_task.c
+++ b/drivers/nvme/hw/qedn/qedn_task.c
@@ -327,6 +327,17 @@ void qedn_return_active_tasks(struct qedn_conn_ctx *conn_ctx)
/* Return tasks that aren't "Used by FW" to the pool */
list_for_each_entry_safe(qedn_task, task_tmp,
&conn_ctx->active_task_list, entry) {
+ /* If we got this far, cleanup was already done
+ * in which case we want to return the task to the pool and
+ * release it. So we make sure the cleanup indication is down
+ */
+ clear_bit(QEDN_TASK_WAIT_FOR_CLEANUP, &qedn_task->flags);
+
+ /* Special handling in case of ICREQ task */
+ if (unlikely(conn_ctx->state == CONN_STATE_WAIT_FOR_IC_COMP &&
+ test_bit(QEDN_TASK_IS_ICREQ, &(qedn_task)->flags)))
+ qedn_common_clear_fw_sgl(&qedn_task->sgl_task_params);
+
qedn_clear_task(conn_ctx, qedn_task);
num_returned_tasks++;
}
@@ -700,7 +711,8 @@ void qedn_io_work_cq(struct qedn_ctx *qedn, struct nvmetcp_fw_cqe *cqe)
return;

if (likely(cqe->cqe_type == NVMETCP_FW_CQE_TYPE_NORMAL)) {
- /* Placeholder - verify the connection was established */
+ if (unlikely(test_bit(QEDN_TASK_WAIT_FOR_CLEANUP, &qedn_task->flags)))
+ return;

switch (cqe->task_type) {
case NVMETCP_TASK_TYPE_HOST_WRITE:
@@ -741,6 +753,17 @@ void qedn_io_work_cq(struct qedn_ctx *qedn, struct nvmetcp_fw_cqe *cqe)
pr_info("Could not identify task type\n");
}
} else {
- /* Placeholder - Recovery flows */
+ if (cqe->cqe_type == NVMETCP_FW_CQE_TYPE_CLEANUP) {
+ clear_bit(QEDN_TASK_WAIT_FOR_CLEANUP, &qedn_task->flags);
+ qedn_return_task_to_pool(conn_ctx, qedn_task);
+ atomic_dec(&conn_ctx->task_cleanups_cnt);
+ wake_up_interruptible(&conn_ctx->cleanup_waitq);
+
+ return;
+ }
+
+ /* The else is NVMETCP_FW_CQE_TYPE_DUMMY - in which don't return the task.
+ * The task will return during NVMETCP_FW_CQE_TYPE_CLEANUP.
+ */
}
}