[Intel-wired-lan] [net-next PATCH 03/11] ice: pass num_vfs to ice_set_per_vf_res()
Jacob Keller
jacob.e.keller at intel.com
Wed Feb 16 01:31:19 UTC 2022
We are planning to replace the simple array structure tracking VFs with
a hash table. This change will also remove the "num_alloc_vfs" variable.
Instead, new access functions to use the hash table as the source of
truth will be introduced. These will generally be equivalent to existing
checks, except during VF initialization.
Specifically, ice_set_per_vf_res() cannot use the hash table as it will
be operating prior to VF structures being inserted into the hash table.
Instead of using pf->num_alloc_vfs, simply pass the num_vfs value in
from the caller.
Note that a sub-function of ice_set_per_vf_res, ice_determine_res, also
implicitly depends on pf->num_alloc_vfs. Replace ice_determine_res with
a simpler inline implementation based on rounddown_pow_of_two. Note that
we must explicitly check that the argument is non-zero since it does not
play well with zero as a value.
Instead of using the function and while loop, simply calculate the
number of queues we have available by dividing by num_vfs. Check if the
desired queues are available. If not, round down to the nearest power of
2 that fits within our available queues.
This matches the behavior of ice_determine_res but is easier to follow
as simple in-line logic. Remove ice_determine_res entirely.
With this change, we no longer depend on the pf->num_alloc_vfs during
the initialization phase of VFs. This will allow us to safely remove it
in a future planned refactor of the VF data structures.
Signed-off-by: Jacob Keller <jacob.e.keller at intel.com>
---
.../net/ethernet/intel/ice/ice_virtchnl_pf.c | 87 ++++++-------------
1 file changed, 26 insertions(+), 61 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
index d86d47b8fee2..44037d569755 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
@@ -1069,45 +1069,6 @@ static void ice_ena_vf_mappings(struct ice_vf *vf)
ice_ena_vf_q_mappings(vf, vsi->alloc_txq, vsi->alloc_rxq);
}
-/**
- * ice_determine_res
- * @pf: pointer to the PF structure
- * @avail_res: available resources in the PF structure
- * @max_res: maximum resources that can be given per VF
- * @min_res: minimum resources that can be given per VF
- *
- * Returns non-zero value if resources (queues/vectors) are available or
- * returns zero if PF cannot accommodate for all num_alloc_vfs.
- */
-static int
-ice_determine_res(struct ice_pf *pf, u16 avail_res, u16 max_res, u16 min_res)
-{
- bool checked_min_res = false;
- int res;
-
- /* start by checking if PF can assign max number of resources for
- * all num_alloc_vfs.
- * if yes, return number per VF
- * If no, divide by 2 and roundup, check again
- * repeat the loop till we reach a point where even minimum resources
- * are not available, in that case return 0
- */
- res = max_res;
- while ((res >= min_res) && !checked_min_res) {
- int num_all_res;
-
- num_all_res = pf->num_alloc_vfs * res;
- if (num_all_res <= avail_res)
- return res;
-
- if (res == min_res)
- checked_min_res = true;
-
- res = DIV_ROUND_UP(res, 2);
- }
- return 0;
-}
-
/**
* ice_calc_vf_reg_idx - Calculate the VF's register index in the PF space
* @vf: VF to calculate the register index for
@@ -1187,6 +1148,7 @@ static int ice_sriov_set_msix_res(struct ice_pf *pf, u16 num_msix_needed)
/**
* ice_set_per_vf_res - check if vectors and queues are available
* @pf: pointer to the PF structure
+ * @num_vfs: the number of SR-IOV VFs being configured
*
* First, determine HW interrupts from common pool. If we allocate fewer VFs, we
* get more vectors and can enable more queues per VF. Note that this does not
@@ -1205,20 +1167,20 @@ static int ice_sriov_set_msix_res(struct ice_pf *pf, u16 num_msix_needed)
* Lastly, set queue and MSI-X VF variables tracked by the PF so it can be used
* by each VF during VF initialization and reset.
*/
-static int ice_set_per_vf_res(struct ice_pf *pf)
+static int ice_set_per_vf_res(struct ice_pf *pf, u16 num_vfs)
{
int max_valid_res_idx = ice_get_max_valid_res_idx(pf->irq_tracker);
+ u16 num_msix_per_vf, num_txq, num_rxq, avail_qs;
int msix_avail_per_vf, msix_avail_for_sriov;
struct device *dev = ice_pf_to_dev(pf);
- u16 num_msix_per_vf, num_txq, num_rxq;
- if (!pf->num_alloc_vfs || max_valid_res_idx < 0)
+ if (!num_vfs || max_valid_res_idx < 0)
return -EINVAL;
/* determine MSI-X resources per VF */
msix_avail_for_sriov = pf->hw.func_caps.common_cap.num_msix_vectors -
pf->irq_tracker->num_entries;
- msix_avail_per_vf = msix_avail_for_sriov / pf->num_alloc_vfs;
+ msix_avail_per_vf = msix_avail_for_sriov / num_vfs;
if (msix_avail_per_vf >= ICE_NUM_VF_MSIX_MED) {
num_msix_per_vf = ICE_NUM_VF_MSIX_MED;
} else if (msix_avail_per_vf >= ICE_NUM_VF_MSIX_SMALL) {
@@ -1230,32 +1192,35 @@ static int ice_set_per_vf_res(struct ice_pf *pf)
} else {
dev_err(dev, "Only %d MSI-X interrupts available for SR-IOV. Not enough to support minimum of %d MSI-X interrupts per VF for %d VFs\n",
msix_avail_for_sriov, ICE_MIN_INTR_PER_VF,
- pf->num_alloc_vfs);
+ num_vfs);
return -EIO;
}
- /* determine queue resources per VF */
- num_txq = ice_determine_res(pf, ice_get_avail_txq_count(pf),
- min_t(u16,
- num_msix_per_vf - ICE_NONQ_VECS_VF,
- ICE_MAX_RSS_QS_PER_VF),
- ICE_MIN_QS_PER_VF);
+ num_txq = min_t(u16, num_msix_per_vf - ICE_NONQ_VECS_VF,
+ ICE_MAX_RSS_QS_PER_VF);
+ avail_qs = ice_get_avail_txq_count(pf) / num_vfs;
+ if (!avail_qs)
+ num_txq = 0;
+ else if (num_txq > avail_qs)
+ num_txq = rounddown_pow_of_two(avail_qs);
- num_rxq = ice_determine_res(pf, ice_get_avail_rxq_count(pf),
- min_t(u16,
- num_msix_per_vf - ICE_NONQ_VECS_VF,
- ICE_MAX_RSS_QS_PER_VF),
- ICE_MIN_QS_PER_VF);
+ num_rxq = min_t(u16, num_msix_per_vf - ICE_NONQ_VECS_VF,
+ ICE_MAX_RSS_QS_PER_VF);
+ avail_qs = ice_get_avail_rxq_count(pf) / num_vfs;
+ if (!avail_qs)
+ num_rxq = 0;
+ else if (num_rxq > avail_qs)
+ num_rxq = rounddown_pow_of_two(avail_qs);
- if (!num_txq || !num_rxq) {
+ if (num_txq < ICE_MIN_QS_PER_VF || num_rxq < ICE_MIN_QS_PER_VF) {
dev_err(dev, "Not enough queues to support minimum of %d queue pairs per VF for %d VFs\n",
- ICE_MIN_QS_PER_VF, pf->num_alloc_vfs);
+ ICE_MIN_QS_PER_VF, num_vfs);
return -EIO;
}
- if (ice_sriov_set_msix_res(pf, num_msix_per_vf * pf->num_alloc_vfs)) {
+ if (ice_sriov_set_msix_res(pf, num_msix_per_vf * num_vfs)) {
dev_err(dev, "Unable to set MSI-X resources for %d VFs\n",
- pf->num_alloc_vfs);
+ num_vfs);
return -EINVAL;
}
@@ -1263,7 +1228,7 @@ static int ice_set_per_vf_res(struct ice_pf *pf)
pf->num_qps_per_vf = min_t(int, num_txq, num_rxq);
pf->num_msix_per_vf = num_msix_per_vf;
dev_info(dev, "Enabling %d VFs with %d vectors and %d queues per VF\n",
- pf->num_alloc_vfs, pf->num_msix_per_vf, pf->num_qps_per_vf);
+ num_vfs, pf->num_msix_per_vf, pf->num_qps_per_vf);
return 0;
}
@@ -1977,7 +1942,7 @@ static int ice_ena_vfs(struct ice_pf *pf, u16 num_vfs)
if (ret)
goto err_pci_disable_sriov;
- if (ice_set_per_vf_res(pf)) {
+ if (ice_set_per_vf_res(pf, num_vfs)) {
dev_err(dev, "Not enough resources for %d VFs, try with fewer number of VFs\n",
num_vfs);
ret = -ENOSPC;
--
2.35.1.129.gb80121027d12
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