The struct rdma_id_private contains three bit-fields, tos_set,
timeout_set, and min_rnr_timer_set. These are set by accessor
functions without any synchronization. If two or all accessor
functions are invoked in close proximity in time, there will be
Read-Modify-Write from several contexts to the same variable, and the
result will be intermittent.
Replace with a flag variable and inline functions for set and get.
Signed-off-by: Håkon Bugge <haakon.bugge@xxxxxxxxxx>
Signed-off-by: Hans Westgaard Ry<hans.westgaard.ry@xxxxxxxxxx>
---
drivers/infiniband/core/cma.c | 24 +++++++++++-------------
drivers/infiniband/core/cma_priv.h | 28 +++++++++++++++++++++++++---
2 files changed, 36 insertions(+), 16 deletions(-)
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 2b9ffc2..fe609e7 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -844,9 +844,7 @@ static void cma_id_put(struct rdma_id_private *id_priv)
id_priv->id.event_handler = event_handler;
id_priv->id.ps = ps;
id_priv->id.qp_type = qp_type;
- id_priv->tos_set = false;
- id_priv->timeout_set = false;
- id_priv->min_rnr_timer_set = false;
+ id_priv->flags = 0;
id_priv->gid_type = IB_GID_TYPE_IB;
spin_lock_init(&id_priv->lock);
mutex_init(&id_priv->qp_mutex);
@@ -1134,10 +1132,10 @@ int rdma_init_qp_attr(struct rdma_cm_id *id, struct ib_qp_attr *qp_attr,
ret = -ENOSYS;
}
- if ((*qp_attr_mask & IB_QP_TIMEOUT) && id_priv->timeout_set)
+ if ((*qp_attr_mask & IB_QP_TIMEOUT) && get_TIMEOUT_SET(id_priv->flags))
qp_attr->timeout = id_priv->timeout;
- if ((*qp_attr_mask & IB_QP_MIN_RNR_TIMER) && id_priv->min_rnr_timer_set)
+ if ((*qp_attr_mask & IB_QP_MIN_RNR_TIMER) && get_MIN_RNR_TIMER_SET(id_priv->flags))
qp_attr->min_rnr_timer = id_priv->min_rnr_timer;
return ret;
@@ -2472,7 +2470,7 @@ static int cma_iw_listen(struct rdma_id_private *id_priv, int backlog)
return PTR_ERR(id);
id->tos = id_priv->tos;
- id->tos_set = id_priv->tos_set;
+ id->tos_set = get_TOS_SET(id_priv->flags);
id->afonly = id_priv->afonly;
id_priv->cm_id.iw = id;
@@ -2533,7 +2531,7 @@ static int cma_listen_on_dev(struct rdma_id_private *id_priv,
cma_id_get(id_priv);
dev_id_priv->internal_id = 1;
dev_id_priv->afonly = id_priv->afonly;
- dev_id_priv->tos_set = id_priv->tos_set;
+ dev_id_priv->flags = id_priv->flags;
dev_id_priv->tos = id_priv->tos;
ret = rdma_listen(&dev_id_priv->id, id_priv->backlog);
@@ -2582,7 +2580,7 @@ void rdma_set_service_type(struct rdma_cm_id *id, int tos)
id_priv = container_of(id, struct rdma_id_private, id);
id_priv->tos = (u8) tos;
- id_priv->tos_set = true;
+ set_TOS_SET(id_priv->flags);
}
EXPORT_SYMBOL(rdma_set_service_type);
@@ -2610,7 +2608,7 @@ int rdma_set_ack_timeout(struct rdma_cm_id *id, u8 timeout)
id_priv = container_of(id, struct rdma_id_private, id);
id_priv->timeout = timeout;
- id_priv->timeout_set = true;
+ set_TIMEOUT_SET(id_priv->flags);
return 0;
}
@@ -2647,7 +2645,7 @@ int rdma_set_min_rnr_timer(struct rdma_cm_id *id, u8 min_rnr_timer)
id_priv = container_of(id, struct rdma_id_private, id);
id_priv->min_rnr_timer = min_rnr_timer;
- id_priv->min_rnr_timer_set = true;
+ set_MIN_RNR_TIMER_SET(id_priv->flags);
return 0;
}
@@ -3033,7 +3031,7 @@ static int cma_resolve_iboe_route(struct rdma_id_private *id_priv)
u8 default_roce_tos = id_priv->cma_dev->default_roce_tos[id_priv->id.port_num -
rdma_start_port(id_priv->cma_dev->device)];
- u8 tos = id_priv->tos_set ? id_priv->tos : default_roce_tos;
+ u8 tos = get_TOS_SET(id_priv->flags) ? id_priv->tos : default_roce_tos;
work = kzalloc(sizeof *work, GFP_KERNEL);
@@ -3081,7 +3079,7 @@ static int cma_resolve_iboe_route(struct rdma_id_private *id_priv)
* PacketLifeTime = local ACK timeout/2
* as a reasonable approximation for RoCE networks.
*/
- route->path_rec->packet_life_time = id_priv->timeout_set ?
+ route->path_rec->packet_life_time = get_TIMEOUT_SET(id_priv->flags) ?
id_priv->timeout - 1 : CMA_IBOE_PACKET_LIFETIME;
if (!route->path_rec->mtu) {
@@ -4107,7 +4105,7 @@ static int cma_connect_iw(struct rdma_id_private *id_priv,
return PTR_ERR(cm_id);
cm_id->tos = id_priv->tos;
- cm_id->tos_set = id_priv->tos_set;
+ cm_id->tos_set = get_TOS_SET(id_priv->flags);
id_priv->cm_id.iw = cm_id;
memcpy(&cm_id->local_addr, cma_src_addr(id_priv),
diff --git a/drivers/infiniband/core/cma_priv.h b/drivers/infiniband/core/cma_priv.h
index 5c463da..2c1694f 100644
--- a/drivers/infiniband/core/cma_priv.h
+++ b/drivers/infiniband/core/cma_priv.h
@@ -82,11 +82,9 @@ struct rdma_id_private {
u32 qkey;
u32 qp_num;
u32 options;
+ unsigned long flags;
u8 srq;
u8 tos;
- u8 tos_set:1;
- u8 timeout_set:1;
- u8 min_rnr_timer_set:1;
u8 reuseaddr;
u8 afonly;
u8 timeout;
@@ -127,4 +125,28 @@ int cma_set_default_roce_tos(struct cma_device *dev, u32 port,
u8 default_roce_tos);
struct ib_device *cma_get_ib_dev(struct cma_device *dev);
+#define BIT_ACCESS_FUNCTIONS(b) \
+ static inline void set_##b(unsigned long flags) \
+ { \
+ /* set_bit() does not imply a memory barrier */ \
+ smp_mb__before_atomic(); \
+ set_bit(b, &flags); \
+ /* set_bit() does not imply a memory barrier */ \
+ smp_mb__after_atomic(); \
+ } \
+ static inline bool get_##b(unsigned long flags) \
+ { \
+ return test_bit(b, &flags); \
+ }
+
+enum cm_id_flag_bits {
+ TOS_SET,
+ TIMEOUT_SET,
+ MIN_RNR_TIMER_SET,
+};
+
+BIT_ACCESS_FUNCTIONS(TIMEOUT_SET);
+BIT_ACCESS_FUNCTIONS(TOS_SET);
+BIT_ACCESS_FUNCTIONS(MIN_RNR_TIMER_SET);
+
#endif /* _CMA_PRIV_H */
--
1.8.3.1
