From: Brett Creeley <brett.cree...@intel.com>
The current MSI-X enablement logic either tries to enable best-case
MSI-X vectors and if that fails we only support a bare-minimum set.
This is not very flexible and the current logic is broken when actually
allocating and reserving MSI-X in the driver. Fix this by improving the
fall-back logic and fixing the allocation/reservation of MSI-X when the
best-case MSI-X vectors are not received from the OS.
The new fall-back logic is described below with each [#] being an
attempt at enabling a certain number of MSI-X. If any of the steps
succeed, then return the number of MSI-X enabled from
ice_ena_msix_range(). If any of the attempts fail, then goto the next
step.
Attempt [0]: Enable the best-case scenario MSI-X vectors.
Attempt [1]: Enable MSI-X vectors with the number of pf->num_lan_msix
reduced by a factor of 2 from the previous attempt (i.e.
num_online_cpus() / 2).
Attempt [2]: Same as attempt [1], except reduce by a factor of 4.
Attempt [3]: Enable the bare-minimum MSI-X vectors.
Also, if the adjusted_base_msix ever hits the minimum required for LAN,
then just set the needed MSI-X for that feature to the minimum
(similar to attempt [3]).
To fix the allocation/reservation of MSI-X, the PF VSI needs to take
into account the pf->num_lan_msix available and only allocate up to that
many MSI-X vectors. To do this, limit the number of Tx and Rx queues
based on pf->num_lan_msix. This is done because we don't want more than
1 Tx/Rx queue per interrupt due to performance concerns. Also, limit the
number of MSI-X based on pf->num_lan_msix available.
Also, prevent users from enabling more combined queues than there are
MSI-X available via ethtool.
Fixes: 152b978a1f90 ("ice: Rework ice_ena_msix_range")
Signed-off-by: Brett Creeley <brett.cree...@intel.com>
Tested-by: Tony Brelinski <tonyx.brelin...@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.ngu...@intel.com>
---
drivers/net/ethernet/intel/ice/ice.h | 4 +-
drivers/net/ethernet/intel/ice/ice_ethtool.c | 8 +-
drivers/net/ethernet/intel/ice/ice_lib.c | 15 +-
drivers/net/ethernet/intel/ice/ice_main.c | 161 ++++++++++---------
4 files changed, 102 insertions(+), 86 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h
b/drivers/net/ethernet/intel/ice/ice.h
index 56725356a17b..3cf6f2bdca41 100644
--- a/drivers/net/ethernet/intel/ice/ice.h
+++ b/drivers/net/ethernet/intel/ice/ice.h
@@ -68,8 +68,10 @@
#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_FDIR_MSIX 1
+#define ICE_MIN_LAN_MSIX 1
+#define ICE_OICR_MSIX 1
+#define ICE_MIN_MSIX (ICE_MIN_LAN_MSIX + ICE_OICR_MSIX)
#define ICE_NO_VSI 0xffff
#define ICE_VSI_MAP_CONTIG 0
#define ICE_VSI_MAP_SCATTER 1
diff --git a/drivers/net/ethernet/intel/ice/ice_ethtool.c
b/drivers/net/ethernet/intel/ice/ice_ethtool.c
index 9e8e9531cd87..69c113a4de7e 100644
--- a/drivers/net/ethernet/intel/ice/ice_ethtool.c
+++ b/drivers/net/ethernet/intel/ice/ice_ethtool.c
@@ -3258,8 +3258,8 @@ ice_set_rxfh(struct net_device *netdev, const u32 *indir,
const u8 *key,
*/
static int ice_get_max_txq(struct ice_pf *pf)
{
- return min_t(int, num_online_cpus(),
- pf->hw.func_caps.common_cap.num_txq);
+ return min3(pf->num_lan_msix, (u16)num_online_cpus(),
+ (u16)pf->hw.func_caps.common_cap.num_txq);
}
/**
@@ -3268,8 +3268,8 @@ static int ice_get_max_txq(struct ice_pf *pf)
*/
static int ice_get_max_rxq(struct ice_pf *pf)
{
- return min_t(int, num_online_cpus(),
- pf->hw.func_caps.common_cap.num_rxq);
+ return min3(pf->num_lan_msix, (u16)num_online_cpus(),
+ (u16)pf->hw.func_caps.common_cap.num_rxq);
}
/**
diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c
b/drivers/net/ethernet/intel/ice/ice_lib.c
index 3df67486d42d..01da18ee17da 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -161,8 +161,10 @@ 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());
+ /* default to 1 Tx queue per MSI-X to not hurt our performance
*/
+ 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 +176,10 @@ 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());
+ /* default to 1 Rx queue per MSI-X to not hurt our
performance */
+ 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 +188,8 @@ 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 6e251dfffc91..040e868a0637 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -3367,95 +3367,105 @@ static int ice_init_pf(struct ice_pf *pf)
return 0;
}
+static int ice_alloc_msix_entries(struct ice_pf *pf, u16 num_entries)
+{
+ u16 i;
+
+ pf->msix_entries = devm_kcalloc(ice_pf_to_dev(pf), num_entries,
+ sizeof(*pf->msix_entries), GFP_KERNEL);
+ if (!pf->msix_entries)
+ return -ENOMEM;
+
+ for (i = 0; i < num_entries; i++)
+ pf->msix_entries[i].entry = i;
+
+ return 0;
+}
+
+static void ice_free_msix_entries(struct ice_pf *pf)
+{
+ devm_kfree(ice_pf_to_dev(pf), pf->msix_entries);
+ pf->msix_entries = NULL;
+}
+
/**
- * ice_ena_msix_range - Request a range of MSIX vectors from the OS
+ * ice_ena_msix_range - request a range of MSI-X vectors from the OS
* @pf: board private structure
*
- * compute the number of MSIX vectors required (v_budget) and request from
- * the OS. Return the number of vectors reserved or negative on failure
+ * The driver first tries to enable best-case scenario MSI-X vectors. If that
+ * doesn't succeed then a fall-back method is employed.
+ *
+ * The fall-back logic is described below with each [#] being an attempt at
+ * enabling a certain number of MSI-X. If any of the steps succeed, then return
+ * the number of MSI-X enabled from pci_ena_msix_exact(). If any of the
+ * attempts fail, then goto the next step.
+ *
+ * Attempt [0]: Enable the best-case scenario MSI-X vectors.
+ *
+ * Attempt [1]: Enable MSI-X vectors with the number of pf->num_lan_msix
reduced
+ * by a factor of 2 from the previous attempts (i.e. num_online_cpus() / 2).
+ *
+ * Attempt [2]: Same as attempt [1], except reduce both by a factor of 4.
+ *
+ * Attempt [3]: Enable the bare-minimum MSI-X vectors.
+ *
+ * Also, if the adjusted_base_msix ever hits the mimimum required for LAN, then
+ * just set the needed MSI-X for that feature to the minimum (similar to
+ * attempt [3]).
*/
static int ice_ena_msix_range(struct ice_pf *pf)
{
+ int err = -ENOSPC, num_cpus, attempt, adjusted_msix_divisor = 1, needed;
struct device *dev = ice_pf_to_dev(pf);
- int v_left, v_actual, v_budget = 0;
- int needed, err, i;
-
- v_left = pf->hw.func_caps.common_cap.num_msix_vectors;
-
- /* reserve one vector for miscellaneous handler */
- needed = 1;
- if (v_left < needed)
- goto no_hw_vecs_left_err;
- v_budget += needed;
- v_left -= needed;
-
- /* reserve vectors for LAN traffic */
- needed = min_t(int, num_online_cpus(), v_left);
- if (v_left < needed)
- goto no_hw_vecs_left_err;
- pf->num_lan_msix = needed;
- v_budget += needed;
- v_left -= needed;
-
- /* reserve one vector for flow director */
- if (test_bit(ICE_FLAG_FD_ENA, pf->flags)) {
- needed = ICE_FDIR_MSIX;
- if (v_left < needed)
- goto no_hw_vecs_left_err;
- v_budget += needed;
- v_left -= needed;
- }
-
- pf->msix_entries = devm_kcalloc(dev, v_budget,
- sizeof(*pf->msix_entries), GFP_KERNEL);
- if (!pf->msix_entries) {
- err = -ENOMEM;
- goto exit_err;
- }
+ num_cpus = num_online_cpus();
- for (i = 0; i < v_budget; i++)
- pf->msix_entries[i].entry = i;
+#define ICE_MAX_ENABLE_MSIX_ATTEMPTS 3
+ /* make multiple passes at enabling MSI-X vectors in case there aren't
+ * enough available for the best-case scenario
+ */
+ for (attempt = 0; attempt <= ICE_MAX_ENABLE_MSIX_ATTEMPTS; attempt++) {
+ int adjusted_base_msix = num_cpus / adjusted_msix_divisor;
- /* actually reserve the vectors */
- v_actual = pci_enable_msix_range(pf->pdev, pf->msix_entries,
- ICE_MIN_MSIX, v_budget);
-
- if (v_actual < 0) {
- dev_err(dev, "unable to reserve MSI-X vectors\n");
- err = v_actual;
- goto msix_err;
- }
-
- 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) {
- /* error if we can't get minimum vectors */
- pci_disable_msix(pf->pdev);
- err = -ERANGE;
- goto msix_err;
+ /* attempt to enable minimum MSI-X range */
+ if (attempt == ICE_MAX_ENABLE_MSIX_ATTEMPTS) {
+ needed = ICE_MIN_MSIX;
+ pf->num_lan_msix = ICE_MIN_LAN_MSIX;
} else {
- pf->num_lan_msix = ICE_MIN_LAN_VECS;
+ if (adjusted_base_msix > ICE_MIN_LAN_MSIX)
+ pf->num_lan_msix = adjusted_base_msix;
+ else
+ pf->num_lan_msix = ICE_MIN_LAN_MSIX;
+
+ needed = pf->num_lan_msix + ICE_OICR_MSIX;
}
- }
- return v_actual;
+ if (test_bit(ICE_FLAG_FD_ENA, pf->flags))
+ needed += ICE_FDIR_MSIX;
-msix_err:
- devm_kfree(dev, pf->msix_entries);
- goto exit_err;
+ err = ice_alloc_msix_entries(pf, needed);
+ if (err)
+ goto err_out;
+
+ dev_dbg(dev, "attempting to enable %d MSI-X vectors\n", needed);
+ err = pci_enable_msix_exact(pf->pdev, pf->msix_entries, needed);
+ if (err < 0) {
+ ice_free_msix_entries(pf);
+ dev_notice(dev, "Couldn't get %d MSI-X vectors due to
OS, Platform, and/or PCI-function limitations. Reducing request and retrying.",
+ needed);
+
+ adjusted_msix_divisor *= 2;
+ } else {
+ if (pf->num_lan_msix != num_cpus)
+ dev_notice(dev, "Enabled %d MSI-X vectors for
LAN traffic.\n",
+ pf->num_lan_msix);
+
+ return needed;
+ }
+ }
-no_hw_vecs_left_err:
- dev_err(dev, "not enough device MSI-X vectors. requested = %d,
available = %d\n",
- needed, v_left);
- err = -ERANGE;
-exit_err:
+err_out:
+ dev_err(dev, "failed to enable MSI-X vectors\n");
pf->num_lan_msix = 0;
return err;
}
@@ -3467,8 +3477,7 @@ static int ice_ena_msix_range(struct ice_pf *pf)
static void ice_dis_msix(struct ice_pf *pf)
{
pci_disable_msix(pf->pdev);
- devm_kfree(ice_pf_to_dev(pf), pf->msix_entries);
- pf->msix_entries = NULL;
+ ice_free_msix_entries(pf);
}
/**
--
2.26.2
