Commit cd0f4f3b authored by Jacob Keller's avatar Jacob Keller Committed by Tony Nguyen
Browse files

ice: pass num_vfs to ice_set_per_vf_res() 



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: default avatarJacob Keller <jacob.e.keller@intel.com>
Tested-by: default avatarKonrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: default avatarTony Nguyen <anthony.l.nguyen@intel.com>
parent b03d519d

drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c

+26 −61
Original line number Diff line number Diff line
@@ -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;