[PATCH 14/27] IB/rdmavt: Adding timer logic to rdmavt

[Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

From: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

To move common code across target to rdmavt for code reuse.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Reviewed-by: Brian Welty <brian.welty-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/sw/rdmavt/qp.c |  183 +++++++++++++++++++++++++++++++++++++
 include/rdma/rdma_vt.h            |   19 ++++
 include/rdma/rdmavt_qp.h          |    6 +
 3 files changed, 206 insertions(+), 2 deletions(-)

diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index 444b06c..db4315f 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -55,6 +55,46 @@
 #include "vt.h"
 #include "trace.h"
 
+static void rvt_rc_timeout(unsigned long arg);
+
+/*
+ * Convert the AETH RNR timeout code into the number of microseconds.
+ */
+static const u32 ib_rvt_rnr_table[32] = {
+	655360, /* 00: 655.36 */
+	10,     /* 01:    .01 */
+	20,     /* 02     .02 */
+	30,     /* 03:    .03 */
+	40,     /* 04:    .04 */
+	60,     /* 05:    .06 */
+	80,     /* 06:    .08 */
+	120,    /* 07:    .12 */
+	160,    /* 08:    .16 */
+	240,    /* 09:    .24 */
+	320,    /* 0A:    .32 */
+	480,    /* 0B:    .48 */
+	640,    /* 0C:    .64 */
+	960,    /* 0D:    .96 */
+	1280,   /* 0E:   1.28 */
+	1920,   /* 0F:   1.92 */
+	2560,   /* 10:   2.56 */
+	3840,   /* 11:   3.84 */
+	5120,   /* 12:   5.12 */
+	7680,   /* 13:   7.68 */
+	10240,  /* 14:  10.24 */
+	15360,  /* 15:  15.36 */
+	20480,  /* 16:  20.48 */
+	30720,  /* 17:  30.72 */
+	40960,  /* 18:  40.96 */
+	61440,  /* 19:  61.44 */
+	81920,  /* 1A:  81.92 */
+	122880, /* 1B: 122.88 */
+	163840, /* 1C: 163.84 */
+	245760, /* 1D: 245.76 */
+	327680, /* 1E: 327.68 */
+	491520  /* 1F: 491.52 */
+};
+
 /*
  * Note that it is OK to post send work requests in the SQE and ERR
  * states; rvt_do_send() will process them and generate error
@@ -200,7 +240,8 @@ int rvt_driver_qp_init(struct rvt_dev_info *rdi)
 	if (!rdi->driver_f.free_all_qps ||
 	    !rdi->driver_f.qp_priv_alloc ||
 	    !rdi->driver_f.qp_priv_free ||
-	    !rdi->driver_f.notify_qp_reset)
+	    !rdi->driver_f.notify_qp_reset ||
+	    !rdi->driver_f.notify_restart_rc)
 		return -EINVAL;
 
 	/* allocate parent object */
@@ -587,6 +628,7 @@ static void rvt_reset_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
 
 		/* Let drivers flush their waitlist */
 		rdi->driver_f.flush_qp_waiters(qp);
+		rvt_stop_rc_timers(qp);
 		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_ANY_WAIT);
 		spin_unlock(&qp->s_lock);
 		spin_unlock(&qp->s_hlock);
@@ -594,7 +636,7 @@ static void rvt_reset_qp(struct rvt_dev_info *rdi, struct rvt_qp *qp,
 
 		/* Stop the send queue and the retry timer */
 		rdi->driver_f.stop_send_queue(qp);
-
+		rvt_del_timers_sync(qp);
 		/* Wait for things to stop */
 		rdi->driver_f.quiesce_qp(qp);
 
@@ -730,6 +772,11 @@ struct ib_qp *rvt_create_qp(struct ib_pd *ibpd,
 			if (!qp->s_ack_queue)
 				goto bail_qp;
 		}
+		/* initialize timers needed for rc qp */
+		setup_timer(&qp->s_timer, rvt_rc_timeout, (unsigned long)qp);
+		hrtimer_init(&qp->s_rnr_timer, CLOCK_MONOTONIC,
+			     HRTIMER_MODE_REL);
+		qp->s_rnr_timer.function = rvt_rc_rnr_retry;
 
 		/*
 		 * Driver needs to set up it's private QP structure and do any
@@ -1906,3 +1953,135 @@ void rvt_rc_error(struct rvt_qp *qp, enum ib_wc_status err)
 	}
 }
 EXPORT_SYMBOL(rvt_rc_error);
+
+static inline unsigned long rvt_aeth_to_usec(u32 aeth)
+{
+	return ib_rvt_rnr_table[(aeth >> RVT_AETH_CREDIT_SHIFT) &
+				  RVT_AETH_CREDIT_MASK];
+}
+
+/*
+ *  rvt_add_retry_timer - add/start a retry timer
+ *  @qp - the QP
+ *  add a retry timer on the QP
+ */
+void rvt_add_retry_timer(struct rvt_qp *qp)
+{
+	struct ib_qp *ibqp = &qp->ibqp;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	lockdep_assert_held(&qp->s_lock);
+	qp->s_flags |= RVT_S_TIMER;
+       /* 4.096 usec. * (1 << qp->timeout) */
+	qp->s_timer.expires = jiffies + qp->timeout_jiffies +
+			     rdi->busy_jiffies;
+	add_timer(&qp->s_timer);
+}
+EXPORT_SYMBOL(rvt_add_retry_timer);
+
+/**
+ * rvt_add_rnr_timer - add/start an rnr timer
+ * @qp - the QP
+ * @aeth - aeth of RNR timeout, simulated aeth for loopback
+ * add an rnr timer on the QP
+ */
+void rvt_add_rnr_timer(struct rvt_qp *qp, u32 aeth)
+{
+	u32 to;
+
+	lockdep_assert_held(&qp->s_lock);
+	qp->s_flags |= RVT_S_WAIT_RNR;
+	to = rvt_aeth_to_usec(aeth);
+	hrtimer_start(&qp->s_rnr_timer,
+		      ns_to_ktime(1000 * to), HRTIMER_MODE_REL);
+}
+EXPORT_SYMBOL(rvt_add_rnr_timer);
+
+/**
+ * rvt_stop_rc_timers - stop all timers
+ * @qp - the QP
+ * stop any pending timers
+ */
+void rvt_stop_rc_timers(struct rvt_qp *qp)
+{
+	lockdep_assert_held(&qp->s_lock);
+	/* Remove QP from all timers */
+	if (qp->s_flags & (RVT_S_TIMER | RVT_S_WAIT_RNR)) {
+		qp->s_flags &= ~(RVT_S_TIMER | RVT_S_WAIT_RNR);
+		del_timer(&qp->s_timer);
+		hrtimer_try_to_cancel(&qp->s_rnr_timer);
+	}
+}
+EXPORT_SYMBOL(rvt_stop_rc_timers);
+
+/**
+ * rvt_stop_rnr_timer - stop an rnr timer
+ * @qp - the QP
+ *
+ * stop an rnr timer and return if the timer
+ * had been pending.
+ */
+static int rvt_stop_rnr_timer(struct rvt_qp *qp)
+{
+	int rval = 0;
+
+	lockdep_assert_held(&qp->s_lock);
+	/* Remove QP from rnr timer */
+	if (qp->s_flags & RVT_S_WAIT_RNR) {
+		qp->s_flags &= ~RVT_S_WAIT_RNR;
+		rval = hrtimer_try_to_cancel(&qp->s_rnr_timer);
+	}
+	return rval;
+}
+
+/**
+ * rvt_del_timers_sync - wait for any timeout routines to exit
+ * @qp - the QP
+ */
+void rvt_del_timers_sync(struct rvt_qp *qp)
+{
+	del_timer_sync(&qp->s_timer);
+	hrtimer_cancel(&qp->s_rnr_timer);
+}
+EXPORT_SYMBOL(rvt_del_timers_sync);
+
+/**
+ * This is called from s_timer for missing responses.
+ */
+static void rvt_rc_timeout(unsigned long arg)
+{
+	struct rvt_qp *qp = (struct rvt_qp *)arg;
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	unsigned long flags;
+
+	spin_lock_irqsave(&qp->r_lock, flags);
+	spin_lock(&qp->s_lock);
+	if (qp->s_flags & RVT_S_TIMER) {
+		qp->s_flags &= ~RVT_S_TIMER;
+		del_timer(&qp->s_timer);
+		if (rdi->driver_f.notify_restart_rc)
+			rdi->driver_f.notify_restart_rc(qp,
+							qp->s_last_psn + 1,
+							1);
+		rdi->driver_f.schedule_send(qp);
+	}
+	spin_unlock(&qp->s_lock);
+	spin_unlock_irqrestore(&qp->r_lock, flags);
+}
+
+/*
+ * This is called from s_timer for RNR timeouts.
+ */
+enum hrtimer_restart rvt_rc_rnr_retry(struct hrtimer *t)
+{
+	struct rvt_qp *qp = container_of(t, struct rvt_qp, s_rnr_timer);
+	struct rvt_dev_info *rdi = ib_to_rvt(qp->ibqp.device);
+	unsigned long flags;
+
+	spin_lock_irqsave(&qp->s_lock, flags);
+	rvt_stop_rnr_timer(qp);
+	rdi->driver_f.schedule_send(qp);
+	spin_unlock_irqrestore(&qp->s_lock, flags);
+	return HRTIMER_NORESTART;
+}
+EXPORT_SYMBOL(rvt_rc_rnr_retry);
diff --git a/include/rdma/rdma_vt.h b/include/rdma/rdma_vt.h
index 861e23e..a69dee3 100644
--- a/include/rdma/rdma_vt.h
+++ b/include/rdma/rdma_vt.h
@@ -335,6 +335,8 @@ struct rvt_driver_provided {
 	/* Notify driver a mad agent has been removed */
 	void (*notify_free_mad_agent)(struct rvt_dev_info *rdi, int port_idx);
 
+	/* Notify driver to restart rc */
+	void (*notify_restart_rc)(struct rvt_qp *qp, u32 psn, int wait);
 };
 
 struct rvt_dev_info {
@@ -483,6 +485,23 @@ static inline u16 rvt_get_pkey(struct rvt_dev_info *rdi,
 	return qp;
 }
 
+/**
+ * rvt_mod_retry_timer - mod a retry timer
+ * @qp - the QP
+ * Modify a potentially already running retry timer
+ */
+static inline void rvt_mod_retry_timer(struct rvt_qp *qp)
+{
+	struct ib_qp *ibqp = &qp->ibqp;
+	struct rvt_dev_info *rdi = ib_to_rvt(ibqp->device);
+
+	lockdep_assert_held(&qp->s_lock);
+	qp->s_flags |= RVT_S_TIMER;
+	/* 4.096 usec. * (1 << qp->timeout) */
+	mod_timer(&qp->s_timer, jiffies + qp->timeout_jiffies +
+		  rdi->busy_jiffies);
+}
+
 struct rvt_dev_info *rvt_alloc_device(size_t size, int nports);
 void rvt_dealloc_device(struct rvt_dev_info *rdi);
 int rvt_register_device(struct rvt_dev_info *rvd);
diff --git a/include/rdma/rdmavt_qp.h b/include/rdma/rdmavt_qp.h
index a92e7dc..0b1cbff 100644
--- a/include/rdma/rdmavt_qp.h
+++ b/include/rdma/rdmavt_qp.h
@@ -370,6 +370,7 @@ struct rvt_qp {
 
 	struct rvt_sge_state s_ack_rdma_sge;
 	struct timer_list s_timer;
+	struct hrtimer s_rnr_timer;
 
 	atomic_t local_ops_pending; /* number of fast_reg/local_inv reqs */
 
@@ -641,5 +642,10 @@ static inline u32 rvt_div_mtu(struct rvt_qp *qp, u32 len)
 void rvt_comm_est(struct rvt_qp *qp);
 int rvt_error_qp(struct rvt_qp *qp, enum ib_wc_status err);
 void rvt_rc_error(struct rvt_qp *qp, enum ib_wc_status err);
+enum hrtimer_restart rvt_rc_rnr_retry(struct hrtimer *t);
+void rvt_add_rnr_timer(struct rvt_qp *qp, u32 aeth);
+void rvt_del_timers_sync(struct rvt_qp *qp);
+void rvt_stop_rc_timers(struct rvt_qp *qp);
+void rvt_add_retry_timer(struct rvt_qp *qp);
 
 #endif          /* DEF_RDMAVT_INCQP_H */

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