[PATCH 5.10 111/142] ice: Fix MSI-X vector fallback logic

Greg Kroah-Hartman
2021-02-02T19:35:04Z

From: Brett Creeley <brett.creeley@intel.com>

[ Upstream commit f3fe97f64384fa4073d9dc0278c4b351c92e295c ]

The current MSI-X enablement logic tries to enable best-case MSI-X
vectors and if that fails we only support a bare-minimum set. This
includes a single MSI-X for 1 Tx and 1 Rx queue and a single MSI-X
for the OICR interrupt. Unfortunately, the driver fails to load when we
don't get as many MSI-X as requested for a couple reasons.

First, the code to allocate MSI-X in the driver tries to allocate
num_online_cpus() MSI-X for LAN traffic without caring about the number
of MSI-X actually enabled/requested from the kernel for LAN traffic.
So, when calling ice_get_res() for the PF VSI, it returns failure
because the number of available vectors is less than requested. Fix
this by not allowing the PF VSI to allocation more than
pf->num_lan_msix MSI-X vectors and pf->num_lan_msix Rx/Tx queues.
Limiting the number of queues is done because we don't want more than
1 Tx/Rx queue per interrupt due to performance conerns.

Second, the driver assigns pf->num_lan_msix = 2, to account for LAN
traffic and the OICR. However, pf->num_lan_msix is only meant for LAN
MSI-X. This is causing a failure when the PF VSI tries to
allocate/reserve the minimum pf->num_lan_msix because the OICR MSI-X has
already been reserved, so there may not be enough MSI-X vectors left.
Fix this by setting pf->num_lan_msix = 1 for the failure case. Then the
ICE_MIN_MSIX accounts for the LAN MSI-X and the OICR MSI-X needed for
the failure case.

Update the related defines used in ice_ena_msix_range() to align with
the above behavior and remove the unused RDMA defines because RDMA is
currently not supported. Also, remove the now incorrect comment.

Fixes: 152b978a1f90 ("ice: Rework ice_ena_msix_range")
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Tony Brelinski <tonyx.brelinski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/intel/ice/ice.h | 4 +++-
drivers/net/ethernet/intel/ice/ice_lib.c | 14 +++++++++-----
drivers/net/ethernet/intel/ice/ice_main.c | 8 ++------
3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h
index a0723831c4e48..54cf382fddaf9 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -68,7 +68,9 @@
#define ICE_INT_NAME_STR_LEN (IFNAMSIZ + 16)
#define ICE_AQ_LEN 64
#define ICE_MBXSQ_LEN 64
-#define ICE_MIN_MSIX 2
+#define ICE_MIN_LAN_TXRX_MSIX 1
+#define ICE_MIN_LAN_OICR_MSIX 1
+#define ICE_MIN_MSIX (ICE_MIN_LAN_TXRX_MSIX + ICE_MIN_LAN_OICR_MSIX)
#define ICE_FDIR_MSIX 1
#define ICE_NO_VSI 0xffff
#define ICE_VSI_MAP_CONTIG 0
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 3df67486d42d9..ad9c22a1b97a0 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -161,8 +161,9 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id)

switch (vsi->type) {
case ICE_VSI_PF:
- vsi->alloc_txq = min_t(int, ice_get_avail_txq_count(pf),
- num_online_cpus());
+ vsi->alloc_txq = min3(pf->num_lan_msix,
+ ice_get_avail_txq_count(pf),
+ (u16)num_online_cpus());
if (vsi->req_txq) {
vsi->alloc_txq = vsi->req_txq;
vsi->num_txq = vsi->req_txq;
@@ -174,8 +175,9 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id)
if (!test_bit(ICE_FLAG_RSS_ENA, pf->flags)) {
vsi->alloc_rxq = 1;
} else {
- vsi->alloc_rxq = min_t(int, ice_get_avail_rxq_count(pf),
- num_online_cpus());
+ vsi->alloc_rxq = min3(pf->num_lan_msix,
+ ice_get_avail_rxq_count(pf),
+ (u16)num_online_cpus());
if (vsi->req_rxq) {
vsi->alloc_rxq = vsi->req_rxq;
vsi->num_rxq = vsi->req_rxq;
@@ -184,7 +186,9 @@ static void ice_vsi_set_num_qs(struct ice_vsi *vsi, u16 vf_id)

pf->num_lan_rx = vsi->alloc_rxq;

- vsi->num_q_vectors = max_t(int, vsi->alloc_rxq, vsi->alloc_txq);
+ vsi->num_q_vectors = min_t(int, pf->num_lan_msix,
+ max_t(int, vsi->alloc_rxq,
+ vsi->alloc_txq));
break;
case ICE_VSI_VF:
vf = &pf->vf[vsi->vf_id];
diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 7986c677cab59..bacb368063e34 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -3433,18 +3433,14 @@ static int ice_ena_msix_range(struct ice_pf *pf)
if (v_actual < v_budget) {
dev_warn(dev, "not enough OS MSI-X vectors. requested = %d, obtained = %d\n",
v_budget, v_actual);
-/* 2 vectors each for LAN and RDMA (traffic + OICR), one for flow director */
-#define ICE_MIN_LAN_VECS 2
-#define ICE_MIN_RDMA_VECS 2
-#define ICE_MIN_VECS (ICE_MIN_LAN_VECS + ICE_MIN_RDMA_VECS + 1)

- if (v_actual < ICE_MIN_LAN_VECS) {
+ if (v_actual < ICE_MIN_MSIX) {
/* error if we can't get minimum vectors */
pci_disable_msix(pf->pdev);
err = -ERANGE;
goto msix_err;
} else {
- pf->num_lan_msix = ICE_MIN_LAN_VECS;
+ pf->num_lan_msix = ICE_MIN_LAN_TXRX_MSIX;
}
}

--
2.27.0