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Commit e83f195a authored by Jason Gunthorpe's avatar Jason Gunthorpe
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RDMA/cm: Pull duplicated code into cm_queue_work_unlock() 

While unlocking a spinlock held by the caller is a disturbing pattern,
this extensively duplicated code is even worse. Pull all the duplicates
into a function and explain the purpose of the algorithm.

The on creation side call in cm_req_handler() which is different has been
micro-optimized on the basis that the work_count == -1 during creation,
remove that and just use the normal function.

Link: https://lore.kernel.org/r/20200506074701.9775-5-leon@kernel.orgSigned-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
parent 42113eed
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Showing with 44 additions and 102 deletions
drivers/infiniband/core/cm.c
View file @ e83f195a
......@@ -81,8 +81,11 @@ const char *__attribute_const__ ibcm_reject_msg(int reason)
EXPORT_SYMBOL(ibcm_reject_msg);
struct cm_id_private;
struct cm_work;
static int cm_add_one(struct ib_device *device);
static void cm_remove_one(struct ib_device *device, void *client_data);
static void cm_process_work(struct cm_id_private *cm_id_priv,
struct cm_work *work);
static int cm_send_sidr_rep_locked(struct cm_id_private *cm_id_priv,
struct ib_cm_sidr_rep_param *param);
static int cm_send_dreq_locked(struct cm_id_private *cm_id_priv,
......@@ -907,6 +910,35 @@ static void cm_free_work(struct cm_work *work)
kfree(work);
}
static void cm_queue_work_unlock(struct cm_id_private *cm_id_priv,
struct cm_work *work)
{
bool immediate;
/*
* To deliver the event to the user callback we have the drop the
* spinlock, however, we need to ensure that the user callback is single
* threaded and receives events in the temporal order. If there are
* already events being processed then thread new events onto a list,
* the thread currently processing will pick them up.
*/
immediate = atomic_inc_and_test(&cm_id_priv->work_count);
if (!immediate) {
list_add_tail(&work->list, &cm_id_priv->work_list);
/*
* This routine always consumes incoming reference. Once queued
* to the work_list then a reference is held by the thread
* currently running cm_process_work() and this reference is not
* needed.
*/
cm_deref_id(cm_id_priv);
}
spin_unlock_irq(&cm_id_priv->lock);
if (immediate)
cm_process_work(cm_id_priv, work);
}
static inline int cm_convert_to_ms(int iba_time)
{
/* approximate conversion to ms from 4.096us x 2^iba_time */
......@@ -2144,9 +2176,7 @@ static int cm_req_handler(struct cm_work *work)
/* Refcount belongs to the event, pairs with cm_process_work() */
refcount_inc(&cm_id_priv->refcount);
atomic_inc(&cm_id_priv->work_count);
spin_unlock_irq(&cm_id_priv->lock);
cm_process_work(cm_id_priv, work);
cm_queue_work_unlock(cm_id_priv, work);
/*
* Since this ID was just created and was not made visible to other MAD
* handlers until the cm_finalize_id() above we know that the
......@@ -2492,15 +2522,7 @@ static int cm_rep_handler(struct cm_work *work)
cm_id_priv->alt_av.timeout - 1);
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
error:
......@@ -2511,7 +2533,6 @@ static int cm_rep_handler(struct cm_work *work)
static int cm_establish_handler(struct cm_work *work)
{
struct cm_id_private *cm_id_priv;
int ret;
/* See comment in cm_establish about lookup. */
cm_id_priv = cm_acquire_id(work->local_id, work->remote_id);
......@@ -2525,15 +2546,7 @@ static int cm_establish_handler(struct cm_work *work)
}
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
cm_deref_id(cm_id_priv);
......@@ -2544,7 +2557,6 @@ static int cm_rtu_handler(struct cm_work *work)
{
struct cm_id_private *cm_id_priv;
struct cm_rtu_msg *rtu_msg;
int ret;
rtu_msg = (struct cm_rtu_msg *)work->mad_recv_wc->recv_buf.mad;
cm_id_priv = cm_acquire_id(
......@@ -2567,15 +2579,7 @@ static int cm_rtu_handler(struct cm_work *work)
cm_id_priv->id.state = IB_CM_ESTABLISHED;
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
cm_deref_id(cm_id_priv);
......@@ -2768,7 +2772,6 @@ static int cm_dreq_handler(struct cm_work *work)
struct cm_id_private *cm_id_priv;
struct cm_dreq_msg *dreq_msg;
struct ib_mad_send_buf *msg = NULL;
int ret;
dreq_msg = (struct cm_dreq_msg *)work->mad_recv_wc->recv_buf.mad;
cm_id_priv = cm_acquire_id(
......@@ -2833,15 +2836,7 @@ static int cm_dreq_handler(struct cm_work *work)
}
cm_id_priv->id.state = IB_CM_DREQ_RCVD;
cm_id_priv->tid = dreq_msg->hdr.tid;
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
unlock: spin_unlock_irq(&cm_id_priv->lock);
......@@ -2853,7 +2848,6 @@ static int cm_drep_handler(struct cm_work *work)
{
struct cm_id_private *cm_id_priv;
struct cm_drep_msg *drep_msg;
int ret;
drep_msg = (struct cm_drep_msg *)work->mad_recv_wc->recv_buf.mad;
cm_id_priv = cm_acquire_id(
......@@ -2874,15 +2868,7 @@ static int cm_drep_handler(struct cm_work *work)
cm_enter_timewait(cm_id_priv);
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
cm_deref_id(cm_id_priv);
......@@ -3010,7 +2996,6 @@ static int cm_rej_handler(struct cm_work *work)
{
struct cm_id_private *cm_id_priv;
struct cm_rej_msg *rej_msg;
int ret;
rej_msg = (struct cm_rej_msg *)work->mad_recv_wc->recv_buf.mad;
cm_id_priv = cm_acquire_rejected_id(rej_msg);
......@@ -3059,15 +3044,7 @@ static int cm_rej_handler(struct cm_work *work)
goto out;
}
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
cm_deref_id(cm_id_priv);
......@@ -3177,7 +3154,7 @@ static int cm_mra_handler(struct cm_work *work)
{
struct cm_id_private *cm_id_priv;
struct cm_mra_msg *mra_msg;
int timeout, ret;
int timeout;
mra_msg = (struct cm_mra_msg *)work->mad_recv_wc->recv_buf.mad;
cm_id_priv = cm_acquire_mraed_id(mra_msg);
......@@ -3237,15 +3214,7 @@ static int cm_mra_handler(struct cm_work *work)
cm_id_priv->msg->context[1] = (void *) (unsigned long)
cm_id_priv->id.state;
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
spin_unlock_irq(&cm_id_priv->lock);
......@@ -3380,15 +3349,7 @@ static int cm_lap_handler(struct cm_work *work)
cm_id_priv->id.lap_state = IB_CM_LAP_RCVD;
cm_id_priv->tid = lap_msg->hdr.tid;
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
unlock: spin_unlock_irq(&cm_id_priv->lock);
......@@ -3400,7 +3361,6 @@ static int cm_apr_handler(struct cm_work *work)
{
struct cm_id_private *cm_id_priv;
struct cm_apr_msg *apr_msg;
int ret;
/* Currently Alternate path messages are not supported for
* RoCE link layer.
......@@ -3435,16 +3395,7 @@ static int cm_apr_handler(struct cm_work *work)
cm_id_priv->id.lap_state = IB_CM_LAP_IDLE;
ib_cancel_mad(cm_id_priv->av.port->mad_agent, cm_id_priv->msg);
cm_id_priv->msg = NULL;
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
cm_deref_id(cm_id_priv);
......@@ -3455,7 +3406,6 @@ static int cm_timewait_handler(struct cm_work *work)
{
struct cm_timewait_info *timewait_info;
struct cm_id_private *cm_id_priv;
int ret;
timewait_info = container_of(work, struct cm_timewait_info, work);
spin_lock_irq(&cm.lock);
......@@ -3474,15 +3424,7 @@ static int cm_timewait_handler(struct cm_work *work)
goto out;
}
cm_id_priv->id.state = IB_CM_IDLE;
ret = atomic_inc_and_test(&cm_id_priv->work_count);
if (!ret)
list_add_tail(&work->list, &cm_id_priv->work_list);
spin_unlock_irq(&cm_id_priv->lock);
if (ret)
cm_process_work(cm_id_priv, work);
else
cm_deref_id(cm_id_priv);
cm_queue_work_unlock(cm_id_priv, work);
return 0;
out:
cm_deref_id(cm_id_priv);
......
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