[PATCH] i40iw: Remove MSS change support

[PATCH] i40iw: Remove MSS change support

[Shiraz Saleem]

MSS change on active QPs is not supported. Store new MSS
value for new QPs only. Remove code to modify MSS on the fly.
This also resolves a crash on QP modify to QP 0.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: i40iw_sc_qp_modify+0x22/0x280 [i40iw]
Oops: 0000 [#1] SMP KASAN
CPU: 2 PID: 1236 Comm: kworker/u16:4 Not tainted 4.12.0-rc1 #5
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Q87M-D2H,
BIOS F7 01/17/2014
Workqueue: l2params i40iw_l2params_worker [i40iw]
task: ffff88070f5a9b40 task.stack: ffff88070f5a0000
RIP: 0010:i40iw_sc_qp_modify+0x22/0x280 [i40iw]
...
Call Trace:
i40iw_exec_cqp_cmd+0x2ce/0x410 [i40iw]
? _raw_spin_lock_irqsave+0x6f/0x80
? i40iw_process_cqp_cmd+0x1d/0x80 [i40iw]
i40iw_process_cqp_cmd+0x7c/0x80 [i40iw]
i40iw_handle_cqp_op+0x2f/0x200 [i40iw]
? trace_hardirqs_off+0xd/0x10
? _raw_spin_unlock_irqrestore+0x46/0x50
i40iw_hw_modify_qp+0x5e/0x90 [i40iw]
i40iw_qp_mss_modify+0x52/0x60 [i40iw]
i40iw_change_l2params+0x145/0x160 [i40iw]
i40iw_l2params_worker+0x1f/0x40 [i40iw]
process_one_work+0x1f5/0x650
? process_one_work+0x161/0x650
worker_thread+0x48/0x3b0
kthread+0x112/0x150
? process_one_work+0x650/0x650
? kthread_create_on_node+0x40/0x40
ret_from_fork+0x2e/0x40
Code: 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 56 41 55 41 89 cd 41 54 49 89 fc
53 48 89 f3 48 89 d6 48 83 ec 08 48 8b 87 10 01 00 00 <48> 8b 40 08 4c 8b b0 40 04
00 00 4c 89 f7 e8 1b e5 ff ff 48 85
RIP: i40iw_sc_qp_modify+0x22/0x280 [i40iw] RSP: ffff88070f5a7c28
CR2: 0000000000000008
---[ end trace 77a405931e296060 ]---

Reported-by: Stefan Assmann <sassmann-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
Signed-off-by: Shiraz Saleem <shiraz.saleem-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/hw/i40iw/i40iw_ctrl.c  | 12 +-----------
 drivers/infiniband/hw/i40iw/i40iw_osdep.h |  1 -
 drivers/infiniband/hw/i40iw/i40iw_type.h  |  2 --
 drivers/infiniband/hw/i40iw/i40iw_utils.c | 17 -----------------
 4 files changed, 1 insertion(+), 31 deletions(-)

diff --git a/drivers/infiniband/hw/i40iw/i40iw_ctrl.c b/drivers/infiniband/hw/i40iw/i40iw_ctrl.c
index f82483b..a027e20 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_ctrl.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_ctrl.c
@@ -285,28 +285,20 @@ void i40iw_change_l2params(struct i40iw_sc_vsi *vsi, struct i40iw_l2params *l2pa
 	struct i40iw_sc_dev *dev = vsi->dev;
 	struct i40iw_sc_qp *qp = NULL;
 	bool qs_handle_change = false;
-	bool mss_change = false;
 	unsigned long flags;
 	u16 qs_handle;
 	int i;
 
-	if (vsi->mss != l2params->mss) {
-		mss_change = true;
-		vsi->mss = l2params->mss;
-	}
+	vsi->mss = l2params->mss;
 
 	i40iw_fill_qos_list(l2params->qs_handle_list);
 	for (i = 0; i < I40IW_MAX_USER_PRIORITY; i++) {
 		qs_handle = l2params->qs_handle_list[i];
 		if (vsi->qos[i].qs_handle != qs_handle)
 			qs_handle_change = true;
-		else if (!mss_change)
-			continue;       /* no MSS nor qs handle change */
 		spin_lock_irqsave(&vsi->qos[i].lock, flags);
 		qp = i40iw_get_qp(&vsi->qos[i].qplist, qp);
 		while (qp) {
-			if (mss_change)
-				i40iw_qp_mss_modify(dev, qp);
 			if (qs_handle_change) {
 				qp->qs_handle = qs_handle;
 				/* issue cqp suspend command */
@@ -2395,7 +2387,6 @@ static enum i40iw_status_code i40iw_sc_qp_modify(
 
 	set_64bit_val(wqe,
 		      8,
-		      LS_64(info->new_mss, I40IW_CQPSQ_QP_NEWMSS) |
 		      LS_64(term_len, I40IW_CQPSQ_QP_TERMLEN));
 
 	set_64bit_val(wqe, 16, qp->hw_host_ctx_pa);
@@ -2410,7 +2401,6 @@ static enum i40iw_status_code i40iw_sc_qp_modify(
 		 LS_64(info->cq_num_valid, I40IW_CQPSQ_QP_CQNUMVALID) |
 		 LS_64(info->force_loopback, I40IW_CQPSQ_QP_FORCELOOPBACK) |
 		 LS_64(qp->qp_type, I40IW_CQPSQ_QP_QPTYPE) |
-		 LS_64(info->mss_change, I40IW_CQPSQ_QP_MSSCHANGE) |
 		 LS_64(info->static_rsrc, I40IW_CQPSQ_QP_STATRSRC) |
 		 LS_64(info->remove_hash_idx, I40IW_CQPSQ_QP_REMOVEHASHENTRY) |
 		 LS_64(term_actions, I40IW_CQPSQ_QP_TERMACT) |
diff --git a/drivers/infiniband/hw/i40iw/i40iw_osdep.h b/drivers/infiniband/hw/i40iw/i40iw_osdep.h
index aa66c1c..f27be3e 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_osdep.h
+++ b/drivers/infiniband/hw/i40iw/i40iw_osdep.h
@@ -199,7 +199,6 @@ void i40iw_cqp_spawn_worker(struct i40iw_sc_dev *dev,
 			    struct i40iw_virtchnl_work_info *work_info, u32 iw_vf_idx);
 void *i40iw_remove_head(struct list_head *list);
 void i40iw_qp_suspend_resume(struct i40iw_sc_dev *dev, struct i40iw_sc_qp *qp, bool suspend);
-void i40iw_qp_mss_modify(struct i40iw_sc_dev *dev, struct i40iw_sc_qp *qp);
 
 void i40iw_term_modify_qp(struct i40iw_sc_qp *qp, u8 next_state, u8 term, u8 term_len);
 void i40iw_terminate_done(struct i40iw_sc_qp *qp, int timeout_occurred);
diff --git a/drivers/infiniband/hw/i40iw/i40iw_type.h b/drivers/infiniband/hw/i40iw/i40iw_type.h
index 7b76259..959ec81 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_type.h
+++ b/drivers/infiniband/hw/i40iw/i40iw_type.h
@@ -541,7 +541,6 @@ struct i40iw_create_qp_info {
 struct i40iw_modify_qp_info {
 	u64 rx_win0;
 	u64 rx_win1;
-	u16 new_mss;
 	u8 next_iwarp_state;
 	u8 termlen;
 	bool ord_valid;
@@ -554,7 +553,6 @@ struct i40iw_modify_qp_info {
 	bool dont_send_term;
 	bool dont_send_fin;
 	bool cached_var_valid;
-	bool mss_change;
 	bool force_loopback;
 };
 
diff --git a/drivers/infiniband/hw/i40iw/i40iw_utils.c b/drivers/infiniband/hw/i40iw/i40iw_utils.c
index 409a378..56d9869 100644
--- a/drivers/infiniband/hw/i40iw/i40iw_utils.c
+++ b/drivers/infiniband/hw/i40iw/i40iw_utils.c
@@ -757,23 +757,6 @@ void i40iw_qp_suspend_resume(struct i40iw_sc_dev *dev, struct i40iw_sc_qp *qp, b
 }
 
 /**
- * i40iw_qp_mss_modify - modify mss for qp
- * @dev: hardware control device structure
- * @qp: hardware control qp
- */
-void i40iw_qp_mss_modify(struct i40iw_sc_dev *dev, struct i40iw_sc_qp *qp)
-{
-	struct i40iw_device *iwdev = (struct i40iw_device *)dev->back_dev;
-	struct i40iw_qp *iwqp = (struct i40iw_qp *)qp->back_qp;
-	struct i40iw_modify_qp_info info;
-
-	memset(&info, 0, sizeof(info));
-	info.mss_change = true;
-	info.new_mss = qp->vsi->mss;
-	i40iw_hw_modify_qp(iwdev, iwqp, &info, false);
-}
-
-/**
  * i40iw_term_modify_qp - modify qp for term message
  * @qp: hardware control qp
  * @next_state: qp's next state
-- 
2.1.3

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Re: [PATCH] i40iw: Remove MSS change support

[Doug Ledford]

On Fri, 2017-05-19 at 16:14 -0500, Shiraz Saleem wrote:
> MSS change on active QPs is not supported. Store new MSS
> value for new QPs only. Remove code to modify MSS on the fly.
> This also resolves a crash on QP modify to QP 0.

Thanks, applied.

-- 
Doug Ledford <dledford-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
    GPG KeyID: B826A3330E572FDD
   
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