From 107c3f4d42adc9af393019b795dd2177fbe9e465 Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Wed, 2 Mar 2011 13:00:49 +0000 Subject: cnic: Prevent status block race conditions with hardware The status block index is used to acknowledge interrupt events and must be read before checking for the interrupt events, so we need to add rmb() to guarantee that. Signed-off-by: Michael Chan Signed-off-by: David S. Miller --- drivers/net/cnic.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'drivers/net/cnic.c') diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c index 7ff170cbc7dc..b0d9e4ab6467 100644 --- a/drivers/net/cnic.c +++ b/drivers/net/cnic.c @@ -2760,6 +2760,8 @@ static u32 cnic_service_bnx2_queues(struct cnic_dev *dev) u32 status_idx = (u16) *cp->kcq1.status_idx_ptr; int kcqe_cnt; + /* status block index must be read before reading other fields */ + rmb(); cp->kwq_con_idx = *cp->kwq_con_idx_ptr; while ((kcqe_cnt = cnic_get_kcqes(dev, &cp->kcq1))) { @@ -2770,6 +2772,8 @@ static u32 cnic_service_bnx2_queues(struct cnic_dev *dev) barrier(); if (status_idx != *cp->kcq1.status_idx_ptr) { status_idx = (u16) *cp->kcq1.status_idx_ptr; + /* status block index must be read first */ + rmb(); cp->kwq_con_idx = *cp->kwq_con_idx_ptr; } else break; @@ -2888,6 +2892,8 @@ static u32 cnic_service_bnx2x_kcq(struct cnic_dev *dev, struct kcq_info *info) u32 last_status = *info->status_idx_ptr; int kcqe_cnt; + /* status block index must be read before reading the KCQ */ + rmb(); while ((kcqe_cnt = cnic_get_kcqes(dev, info))) { service_kcqes(dev, kcqe_cnt); @@ -2898,6 +2904,8 @@ static u32 cnic_service_bnx2x_kcq(struct cnic_dev *dev, struct kcq_info *info) break; last_status = *info->status_idx_ptr; + /* status block index must be read before reading the KCQ */ + rmb(); } return last_status; } -- cgit v1.2.3 From 0197b087ed6384760656f1e4a620a3e92d8dc0b0 Mon Sep 17 00:00:00 2001 From: Michael Chan Date: Wed, 2 Mar 2011 13:00:50 +0000 Subject: cnic: Fix lost interrupt on bnx2x We service 2 queues (kcq1 and kcq2) in cnic_service_bnx2x_bh(). If the status block index has changed when servicing the kcq2, we must go back and check kcq1. The latest status block index will be used to acknowledge the interrupt, and without looping back to check kcq1, we may miss events on kcq1. Signed-off-by: Michael Chan Signed-off-by: David S. Miller --- drivers/net/cnic.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'drivers/net/cnic.c') diff --git a/drivers/net/cnic.c b/drivers/net/cnic.c index b0d9e4ab6467..302be4aa69d6 100644 --- a/drivers/net/cnic.c +++ b/drivers/net/cnic.c @@ -2914,26 +2914,35 @@ static void cnic_service_bnx2x_bh(unsigned long data) { struct cnic_dev *dev = (struct cnic_dev *) data; struct cnic_local *cp = dev->cnic_priv; - u32 status_idx; + u32 status_idx, new_status_idx; if (unlikely(!test_bit(CNIC_F_CNIC_UP, &dev->flags))) return; - status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq1); + while (1) { + status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq1); - CNIC_WR16(dev, cp->kcq1.io_addr, cp->kcq1.sw_prod_idx + MAX_KCQ_IDX); + CNIC_WR16(dev, cp->kcq1.io_addr, + cp->kcq1.sw_prod_idx + MAX_KCQ_IDX); - if (BNX2X_CHIP_IS_E2(cp->chip_id)) { - status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq2); + if (!BNX2X_CHIP_IS_E2(cp->chip_id)) { + cnic_ack_bnx2x_int(dev, cp->bnx2x_igu_sb_id, USTORM_ID, + status_idx, IGU_INT_ENABLE, 1); + break; + } + + new_status_idx = cnic_service_bnx2x_kcq(dev, &cp->kcq2); + + if (new_status_idx != status_idx) + continue; CNIC_WR16(dev, cp->kcq2.io_addr, cp->kcq2.sw_prod_idx + MAX_KCQ_IDX); cnic_ack_igu_sb(dev, cp->bnx2x_igu_sb_id, IGU_SEG_ACCESS_DEF, status_idx, IGU_INT_ENABLE, 1); - } else { - cnic_ack_bnx2x_int(dev, cp->bnx2x_igu_sb_id, USTORM_ID, - status_idx, IGU_INT_ENABLE, 1); + + break; } } -- cgit v1.2.3