From: Mike Marciniszyn Date: Fri, 24 May 2019 15:44:38 +0000 (-0400) Subject: IB/rdmavt: Fix alloc_qpn() WARN_ON() X-Git-Tag: v5.15~6212^2~5 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2abae62a26a265129b364d8c1ef3be55e2c01309;p=platform%2Fkernel%2Flinux-starfive.git IB/rdmavt: Fix alloc_qpn() WARN_ON() The qpn allocation logic has a WARN_ON() that intends to detect the use of an index that will introduce bits in the lower order bits of the QOS bits in the QPN. Unfortunately, it has the following bugs: - it misfires when wrapping QPN allocation for non-QOS - it doesn't correctly detect low order QOS bits (despite the comment) The WARN_ON() should not be applied to non-QOS (qos_shift == 1). Additionally, it SHOULD test the qpn bits per the table below: 2 data VLs: [qp7, qp6, qp5, qp4, qp3, qp2, qp1] ^ [ 0, 0, 0, 0, 0, 0, sc0], qp bit 1 always 0* 3-4 data VLs: [qp7, qp6, qp5, qp4, qp3, qp2, qp1] ^ [ 0, 0, 0, 0, 0, sc1, sc0], qp bits [21] always 0 5-8 data VLs: [qp7, qp6, qp5, qp4, qp3, qp2, qp1] ^ [ 0, 0, 0, 0, sc2, sc1, sc0] qp bits [321] always 0 Fix by qualifying the warning for qos_shift > 1 and producing the correct mask to insure the above bits are zero without generating a superfluous warning. Fixes: 501edc42446e ("IB/rdmavt: Correct warning during QPN allocation") Reviewed-by: Kaike Wan Signed-off-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro Signed-off-by: Jason Gunthorpe --- diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c index 31a2e65..c5a5061 100644 --- a/drivers/infiniband/sw/rdmavt/qp.c +++ b/drivers/infiniband/sw/rdmavt/qp.c @@ -594,7 +594,8 @@ static int alloc_qpn(struct rvt_dev_info *rdi, struct rvt_qpn_table *qpt, offset = qpt->incr | ((offset & 1) ^ 1); } /* there can be no set bits in low-order QoS bits */ - WARN_ON(offset & (BIT(rdi->dparms.qos_shift) - 1)); + WARN_ON(rdi->dparms.qos_shift > 1 && + offset & ((BIT(rdi->dparms.qos_shift - 1) - 1) << 1)); qpn = mk_qpn(qpt, map, offset); }