From 2928db4c3c62552d3caf9ab53ccc6f7ae9865a23 Mon Sep 17 00:00:00 2001 From: Andre Detsch Date: Tue, 17 Aug 2010 05:49:12 +0000 Subject: ehea: Fix synchronization between HW and SW send queue ehea: Fix synchronization between HW and SW send queue When memory is added to / removed from a partition via the Memory DLPAR mechanism, the eHEA driver has to do a couple of things to reflect the memory change in its own IO address translation tables. This involves stopping and restarting the HW queues. During this operation, it is possible that HW and SW pointer into these queues get out of sync. This results in a situation where packets that are attached to a send queue are not transmitted immediately, but delayed until further X packets have been put on the queue. This patch detects such loss of synchronization, and resets the ehea port when needed. Signed-off-by: Jan-Bernd Themann Signed-off-by: Andre Detsch Signed-off-by: David S. Miller --- drivers/net/ehea/ehea_main.c | 60 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 59 insertions(+), 1 deletion(-) (limited to 'drivers/net/ehea/ehea_main.c') diff --git a/drivers/net/ehea/ehea_main.c b/drivers/net/ehea/ehea_main.c index 3beba70b7de..adb5994c125 100644 --- a/drivers/net/ehea/ehea_main.c +++ b/drivers/net/ehea/ehea_main.c @@ -776,6 +776,53 @@ static int ehea_proc_rwqes(struct net_device *dev, return processed; } +#define SWQE_RESTART_CHECK 0xdeadbeaff00d0000ull + +static void reset_sq_restart_flag(struct ehea_port *port) +{ + int i; + + for (i = 0; i < port->num_def_qps + port->num_add_tx_qps; i++) { + struct ehea_port_res *pr = &port->port_res[i]; + pr->sq_restart_flag = 0; + } +} + +static void check_sqs(struct ehea_port *port) +{ + struct ehea_swqe *swqe; + int swqe_index; + int i, k; + + for (i = 0; i < port->num_def_qps + port->num_add_tx_qps; i++) { + struct ehea_port_res *pr = &port->port_res[i]; + k = 0; + swqe = ehea_get_swqe(pr->qp, &swqe_index); + memset(swqe, 0, SWQE_HEADER_SIZE); + atomic_dec(&pr->swqe_avail); + + swqe->tx_control |= EHEA_SWQE_PURGE; + swqe->wr_id = SWQE_RESTART_CHECK; + swqe->tx_control |= EHEA_SWQE_SIGNALLED_COMPLETION; + swqe->tx_control |= EHEA_SWQE_IMM_DATA_PRESENT; + swqe->immediate_data_length = 80; + + ehea_post_swqe(pr->qp, swqe); + + while (pr->sq_restart_flag == 0) { + msleep(5); + if (++k == 100) { + ehea_error("HW/SW queues out of sync"); + ehea_schedule_port_reset(pr->port); + return; + } + } + } + + return; +} + + static struct ehea_cqe *ehea_proc_cqes(struct ehea_port_res *pr, int my_quota) { struct sk_buff *skb; @@ -793,6 +840,13 @@ static struct ehea_cqe *ehea_proc_cqes(struct ehea_port_res *pr, int my_quota) cqe_counter++; rmb(); + + if (cqe->wr_id == SWQE_RESTART_CHECK) { + pr->sq_restart_flag = 1; + swqe_av++; + break; + } + if (cqe->status & EHEA_CQE_STAT_ERR_MASK) { ehea_error("Bad send completion status=0x%04X", cqe->status); @@ -2675,8 +2729,10 @@ static void ehea_flush_sq(struct ehea_port *port) int k = 0; while (atomic_read(&pr->swqe_avail) < swqe_max) { msleep(5); - if (++k == 20) + if (++k == 20) { + ehea_error("WARNING: sq not flushed completely"); break; + } } } } @@ -2917,6 +2973,7 @@ static void ehea_rereg_mrs(struct work_struct *work) port_napi_disable(port); mutex_unlock(&port->port_lock); } + reset_sq_restart_flag(port); } /* Unregister old memory region */ @@ -2951,6 +3008,7 @@ static void ehea_rereg_mrs(struct work_struct *work) mutex_lock(&port->port_lock); port_napi_enable(port); ret = ehea_restart_qps(dev); + check_sqs(port); if (!ret) netif_wake_queue(dev); mutex_unlock(&port->port_lock); -- cgit v1.2.3-70-g09d2