[PATCH 6.4 377/800] RDMA/bnxt_re: Avoid calling wake_up threads from spin_lock context

Greg Kroah-Hartman
2023-07-16T20:10:34Z

From: Kashyap Desai <kashyap.desai@broadcom.com>

[ Upstream commit 3099bcdc19b701f732f638ee45679858c08559bb ]

bnxt_qplib_service_creq can be called from interrupt or tasklet or
process context. So the function take irq variant of spin_lock.
But when wake_up is invoked with the lock held, it is putting the
calling context to sleep.

[exception RIP: __wake_up_common+190]
RIP: ffffffffb7539d7e RSP: ffffa73300207ad8 RFLAGS: 00000083
RAX: 0000000000000001 RBX: ffff91fa295f69b8 RCX: dead000000000200
RDX: ffffa733344af940 RSI: ffffa73336527940 RDI: ffffa73336527940
RBP: 000000000000001c R8: 0000000000000002 R9: 00000000000299c0
R10: 0000017230de82c5 R11: 0000000000000002 R12: ffffa73300207b28
R13: 0000000000000000 R14: ffffa733341bf928 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018

Call the wakeup after releasing the lock.

Fixes: 1ac5a4047975 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Link: https://lore.kernel.org/r/1686308514-11996-3-git-send-email-selvin.xavier@broadcom.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/infiniband/hw/bnxt_re/qplib_rcfw.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
index d4ce82bebb0a5..c11b8e708844c 100644
--- a/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
+++ b/drivers/infiniband/hw/bnxt_re/qplib_rcfw.c
@@ -295,7 +295,8 @@ static int bnxt_qplib_process_func_event(struct bnxt_qplib_rcfw *rcfw,
}

static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
- struct creq_qp_event *qp_event)
+ struct creq_qp_event *qp_event,
+ u32 *num_wait)
{
struct creq_qp_error_notification *err_event;
struct bnxt_qplib_hwq *hwq = &rcfw->cmdq.hwq;
@@ -304,6 +305,7 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
u16 cbit, blocked = 0;
struct pci_dev *pdev;
unsigned long flags;
+ u32 wait_cmds = 0;
__le16 mcookie;
u16 cookie;
int rc = 0;
@@ -363,9 +365,10 @@ static int bnxt_qplib_process_qp_event(struct bnxt_qplib_rcfw *rcfw,
crsqe->req_size = 0;

if (!blocked)
- wake_up(&rcfw->cmdq.waitq);
+ wait_cmds++;
spin_unlock_irqrestore(&hwq->lock, flags);
}
+ *num_wait += wait_cmds;
return rc;
}

@@ -379,6 +382,7 @@ static void bnxt_qplib_service_creq(struct tasklet_struct *t)
struct creq_base *creqe;
u32 sw_cons, raw_cons;
unsigned long flags;
+ u32 num_wakeup = 0;

/* Service the CREQ until budget is over */
spin_lock_irqsave(&hwq->lock, flags);
@@ -397,7 +401,8 @@ static void bnxt_qplib_service_creq(struct tasklet_struct *t)
switch (type) {
case CREQ_BASE_TYPE_QP_EVENT:
bnxt_qplib_process_qp_event
- (rcfw, (struct creq_qp_event *)creqe);
+ (rcfw, (struct creq_qp_event *)creqe,
+ &num_wakeup);
creq->stats.creq_qp_event_processed++;
break;
case CREQ_BASE_TYPE_FUNC_EVENT:
@@ -425,6 +430,8 @@ static void bnxt_qplib_service_creq(struct tasklet_struct *t)
rcfw->res->cctx, true);
}
spin_unlock_irqrestore(&hwq->lock, flags);
+ if (num_wakeup)
+ wake_up_nr(&rcfw->cmdq.waitq, num_wakeup);
}

static irqreturn_t bnxt_qplib_creq_irq(int irq, void *dev_instance)
--
2.39.2