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authorMike Marciniszyn <mike.marciniszyn@intel.com>2019-05-24 11:44:38 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-06-25 11:36:51 +0800
commit89dd40e0d1ac158c4b13f55125d14fbc6b5736a5 (patch)
tree1234075d1c2f2e3c27cff19fae8a878c5dfd20b0
parent56fc13864109d3b4d28cd56b57e42783265f53f7 (diff)
IB/rdmavt: Fix alloc_qpn() WARN_ON()
[ Upstream commit 2abae62a26a265129b364d8c1ef3be55e2c01309 ] 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 <kaike.wan@intel.com> Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r--drivers/infiniband/sw/rdmavt/qp.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/infiniband/sw/rdmavt/qp.c b/drivers/infiniband/sw/rdmavt/qp.c
index 22df09ae809e..b0309876f4bb 100644
--- a/drivers/infiniband/sw/rdmavt/qp.c
+++ b/drivers/infiniband/sw/rdmavt/qp.c
@@ -412,7 +412,8 @@ 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);
}