ice: Refactor interrupt tracking

Currently we have two MSI-x (IRQ) trackers, one for OS requested MSI-x
entries (sw_irq_tracker) and one for hardware MSI-x vectors
(hw_irq_tracker). Generally the sw_irq_tracker has less entries than the
hw_irq_tracker because the hw_irq_tracker has entries equal to the max
allowed MSI-x per PF and the sw_irq_tracker is mainly the minimum (non
SR-IOV portion of the vectors, kernel granted IRQs). All of the non
SR-IOV portions of the driver (i.e. LAN queues, RDMA queues, OICR, etc.)
take at least one of each type of tracker resource. SR-IOV only grabs
entries from the hw_irq_tracker. There are a few issues with this approach
that can be seen when doing any kind of device reconfiguration (i.e.
ethtool -L, SR-IOV, etc.). One of them being, any time the driver creates
an ice_q_vector and associates it to a LAN queue pair it will grab and
use one entry from the hw_irq_tracker and one from the sw_irq_tracker.
If the indices on these does not match it will cause a Tx timeout, which
will cause a reset and then the indices will match up again and traffic
will resume. The mismatched indices come from the trackers not being the
same size and/or the search_hint in the two trackers not being equal.
Another reason for the refactor is the co-existence of features with
SR-IOV. If SR-IOV is enabled and the interrupts are taken from the end
of the sw_irq_tracker then other features can no longer use this space
because the hardware has now given the remaining interrupts to SR-IOV.

This patch reworks how we track MSI-x vectors by removing the
hw_irq_tracker completely and instead MSI-x resources needed for SR-IOV
are determined all at once instead of per VF. This can be done because
when creating VFs we know how many are wanted and how many MSI-x vectors
each VF needs. This also allows us to start using MSI-x resources from
the end of the PF's allowed MSI-x vectors so we are less likely to use
entries needed for other features (i.e. RDMA, L2 Offload, etc).

This patch also reworks the ice_res_tracker structure by removing the
search_hint and adding a new member - "end". Instead of having a
search_hint we will always search from 0. The new member, "end", will be
used to manipulate the end of the ice_res_tracker (specifically
sw_irq_tracker) during runtime based on MSI-x vectors needed by SR-IOV.
In the normal case, the end of ice_res_tracker will be equal to the
ice_res_tracker's num_entries.

The sriov_base_vector member was added to the PF structure. It is used
to represent the starting MSI-x index of all the needed MSI-x vectors
for all SR-IOV VFs. Depending on how many MSI-x are needed, SR-IOV may
have to take resources from the sw_irq_tracker. This is done by setting
the sw_irq_tracker->end equal to the pf->sriov_base_vector. When all
SR-IOV VFs are removed then the sw_irq_tracker->end is reset back to
sw_irq_tracker->num_entries. The sriov_base_vector, along with the VF's
number of MSI-x (pf->num_vf_msix), vf_id, and the base MSI-x index on
the PF (pf->hw.func_caps.common_cap.msix_vector_first_id), is used to
calculate the first HW absolute MSI-x index for each VF, which is used
to write to the VPINT_ALLOC[_PCI] and GLINT_VECT2FUNC registers to
program the VFs MSI-x PCI configuration bits. Also, the sriov_base_vector
is used along with VF's num_vf_msix, vf_id, and q_vector->v_idx to
determine the MSI-x register index (used for writing to GLINT_DYN_CTL)
within the PF's space.

Interrupt changes removed any references to hw_base_vector, hw_oicr_idx,
and hw_irq_tracker. Only sw_base_vector, sw_oicr_idx, and sw_irq_tracker
variables remain. Change all of these by removing the "sw_" prefix to
help avoid confusion with these variables and their use.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 52 insertions, 127 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 95323ee49e58..515b154547c5 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -1168,61 +1168,32 @@ err_out:
 static int ice_vsi_setup_vector_base(struct ice_vsi *vsi)
 {
 	struct ice_pf *pf = vsi->back;
-	int num_q_vectors = 0;
+	u16 num_q_vectors;
 
-	if (vsi->sw_base_vector || vsi->hw_base_vector) {
-		dev_dbg(&pf->pdev->dev, "VSI %d has non-zero HW base vector %d or SW base vector %d\n",
-			vsi->vsi_num, vsi->hw_base_vector, vsi->sw_base_vector);
+	/* SRIOV doesn't grab irq_tracker entries for each VSI */
+	if (vsi->type == ICE_VSI_VF)
+		return 0;
+
+	if (vsi->base_vector) {
+		dev_dbg(&pf->pdev->dev, "VSI %d has non-zero base vector %d\n",
+			vsi->vsi_num, vsi->base_vector);
 		return -EEXIST;
 	}
 
 	if (!test_bit(ICE_FLAG_MSIX_ENA, pf->flags))
 		return -ENOENT;
 
-	switch (vsi->type) {
-	case ICE_VSI_PF:
-		num_q_vectors = vsi->num_q_vectors;
-		/* reserve slots from OS requested IRQs */
-		vsi->sw_base_vector = ice_get_res(pf, pf->sw_irq_tracker,
-						  num_q_vectors, vsi->idx);
-		if (vsi->sw_base_vector < 0) {
-			dev_err(&pf->pdev->dev,
-				"Failed to get tracking for %d SW vectors for VSI %d, err=%d\n",
-				num_q_vectors, vsi->vsi_num,
-				vsi->sw_base_vector);
-			return -ENOENT;
-		}
-		pf->num_avail_sw_msix -= num_q_vectors;
-
-		/* reserve slots from HW interrupts */
-		vsi->hw_base_vector = ice_get_res(pf, pf->hw_irq_tracker,
-						  num_q_vectors, vsi->idx);
-		break;
-	case ICE_VSI_VF:
-		/* take VF misc vector and data vectors into account */
-		num_q_vectors = pf->num_vf_msix;
-		/* For VF VSI, reserve slots only from HW interrupts */
-		vsi->hw_base_vector = ice_get_res(pf, pf->hw_irq_tracker,
-						  num_q_vectors, vsi->idx);
-		break;
-	default:
-		dev_warn(&pf->pdev->dev, "Unknown VSI type %d\n", vsi->type);
-		break;
-	}
-
-	if (vsi->hw_base_vector < 0) {
+	num_q_vectors = vsi->num_q_vectors;
+	/* reserve slots from OS requested IRQs */
+	vsi->base_vector = ice_get_res(pf, pf->irq_tracker, num_q_vectors,
+				       vsi->idx);
+	if (vsi->base_vector < 0) {
 		dev_err(&pf->pdev->dev,
-			"Failed to get tracking for %d HW vectors for VSI %d, err=%d\n",
-			num_q_vectors, vsi->vsi_num, vsi->hw_base_vector);
-		if (vsi->type != ICE_VSI_VF) {
-			ice_free_res(pf->sw_irq_tracker,
-				     vsi->sw_base_vector, vsi->idx);
-			pf->num_avail_sw_msix += num_q_vectors;
-		}
+			"Failed to get tracking for %d vectors for VSI %d, err=%d\n",
+			num_q_vectors, vsi->vsi_num, vsi->base_vector);
 		return -ENOENT;
 	}
-
-	pf->num_avail_hw_msix -= num_q_vectors;
+	pf->num_avail_sw_msix -= num_q_vectors;
 
 	return 0;
 }
@@ -2261,7 +2232,14 @@ ice_vsi_set_q_vectors_reg_idx(struct ice_vsi *vsi)
 			goto clear_reg_idx;
 		}
 
-		q_vector->reg_idx = q_vector->v_idx + vsi->hw_base_vector;
+		if (vsi->type == ICE_VSI_VF) {
+			struct ice_vf *vf = &vsi->back->vf[vsi->vf_id];
+
+			q_vector->reg_idx = ice_calc_vf_reg_idx(vf, q_vector);
+		} else {
+			q_vector->reg_idx =
+				q_vector->v_idx + vsi->base_vector;
+		}
 	}
 
 	return 0;
@@ -2416,17 +2394,6 @@ ice_vsi_setup(struct ice_pf *pf, struct ice_port_info *pi,
 		if (ret)
 			goto unroll_alloc_q_vector;
 
-		/* Setup Vector base only during VF init phase or when VF asks
-		 * for more vectors than assigned number. In all other cases,
-		 * assign hw_base_vector to the value given earlier.
-		 */
-		if (test_bit(ICE_VF_STATE_CFG_INTR, pf->vf[vf_id].vf_states)) {
-			ret = ice_vsi_setup_vector_base(vsi);
-			if (ret)
-				goto unroll_vector_base;
-		} else {
-			vsi->hw_base_vector = pf->vf[vf_id].first_vector_idx;
-		}
 		ret = ice_vsi_set_q_vectors_reg_idx(vsi);
 		if (ret)
 			goto unroll_vector_base;
@@ -2470,11 +2437,8 @@ ice_vsi_setup(struct ice_pf *pf, struct ice_port_info *pi,
 
 unroll_vector_base:
 	/* reclaim SW interrupts back to the common pool */
-	ice_free_res(pf->sw_irq_tracker, vsi->sw_base_vector, vsi->idx);
+	ice_free_res(pf->irq_tracker, vsi->base_vector, vsi->idx);
 	pf->num_avail_sw_msix += vsi->num_q_vectors;
-	/* reclaim HW interrupt back to the common pool */
-	ice_free_res(pf->hw_irq_tracker, vsi->hw_base_vector, vsi->idx);
-	pf->num_avail_hw_msix += vsi->num_q_vectors;
 unroll_alloc_q_vector:
 	ice_vsi_free_q_vectors(vsi);
 unroll_vsi_init:
@@ -2495,17 +2459,17 @@ unroll_get_qs:
 static void ice_vsi_release_msix(struct ice_vsi *vsi)
 {
 	struct ice_pf *pf = vsi->back;
-	u16 vector = vsi->hw_base_vector;
 	struct ice_hw *hw = &pf->hw;
 	u32 txq = 0;
 	u32 rxq = 0;
 	int i, q;
 
-	for (i = 0; i < vsi->num_q_vectors; i++, vector++) {
+	for (i = 0; i < vsi->num_q_vectors; i++) {
 		struct ice_q_vector *q_vector = vsi->q_vectors[i];
+		u16 reg_idx = q_vector->reg_idx;
 
-		wr32(hw, GLINT_ITR(ICE_IDX_ITR0, vector), 0);
-		wr32(hw, GLINT_ITR(ICE_IDX_ITR1, vector), 0);
+		wr32(hw, GLINT_ITR(ICE_IDX_ITR0, reg_idx), 0);
+		wr32(hw, GLINT_ITR(ICE_IDX_ITR1, reg_idx), 0);
 		for (q = 0; q < q_vector->num_ring_tx; q++) {
 			wr32(hw, QINT_TQCTL(vsi->txq_map[txq]), 0);
 			txq++;
@@ -2527,7 +2491,7 @@ static void ice_vsi_release_msix(struct ice_vsi *vsi)
 void ice_vsi_free_irq(struct ice_vsi *vsi)
 {
 	struct ice_pf *pf = vsi->back;
-	int base = vsi->sw_base_vector;
+	int base = vsi->base_vector;
 
 	if (test_bit(ICE_FLAG_MSIX_ENA, pf->flags)) {
 		int i;
@@ -2623,11 +2587,11 @@ int ice_free_res(struct ice_res_tracker *res, u16 index, u16 id)
 	int count = 0;
 	int i;
 
-	if (!res || index >= res->num_entries)
+	if (!res || index >= res->end)
 		return -EINVAL;
 
 	id |= ICE_RES_VALID_BIT;
-	for (i = index; i < res->num_entries && res->list[i] == id; i++) {
+	for (i = index; i < res->end && res->list[i] == id; i++) {
 		res->list[i] = 0;
 		count++;
 	}
@@ -2645,10 +2609,9 @@ int ice_free_res(struct ice_res_tracker *res, u16 index, u16 id)
  */
 static int ice_search_res(struct ice_res_tracker *res, u16 needed, u16 id)
 {
-	int start = res->search_hint;
-	int end = start;
+	int start = 0, end = 0;
 
-	if ((start + needed) > res->num_entries)
+	if (needed > res->end)
 		return -ENOMEM;
 
 	id |= ICE_RES_VALID_BIT;
@@ -2657,7 +2620,7 @@ static int ice_search_res(struct ice_res_tracker *res, u16 needed, u16 id)
 		/* skip already allocated entries */
 		if (res->list[end++] & ICE_RES_VALID_BIT) {
 			start = end;
-			if ((start + needed) > res->num_entries)
+			if ((start + needed) > res->end)
 				break;
 		}
 
@@ -2668,13 +2631,9 @@ static int ice_search_res(struct ice_res_tracker *res, u16 needed, u16 id)
 			while (i != end)
 				res->list[i++] = id;
 
-			if (end == res->num_entries)
-				end = 0;
-
-			res->search_hint = end;
 			return start;
 		}
-	} while (1);
+	} while (end < res->end);
 
 	return -ENOMEM;
 }
@@ -2686,16 +2645,11 @@ static int ice_search_res(struct ice_res_tracker *res, u16 needed, u16 id)
  * @needed: size of the block needed
  * @id: identifier to track owner
  *
- * Returns the base item index of the block, or -ENOMEM for error
- * The search_hint trick and lack of advanced fit-finding only works
- * because we're highly likely to have all the same sized requests.
- * Linear search time and any fragmentation should be minimal.
+ * Returns the base item index of the block, or negative for error
  */
 int
 ice_get_res(struct ice_pf *pf, struct ice_res_tracker *res, u16 needed, u16 id)
 {
-	int ret;
-
 	if (!res || !pf)
 		return -EINVAL;
 
@@ -2706,16 +2660,7 @@ ice_get_res(struct ice_pf *pf, struct ice_res_tracker *res, u16 needed, u16 id)
 		return -EINVAL;
 	}
 
-	/* search based on search_hint */
-	ret = ice_search_res(res, needed, id);
-
-	if (ret < 0) {
-		/* previous search failed. Reset search hint and try again */
-		res->search_hint = 0;
-		ret = ice_search_res(res, needed, id);
-	}
-
-	return ret;
+	return ice_search_res(res, needed, id);
 }
 
 /**
@@ -2724,7 +2669,7 @@ ice_get_res(struct ice_pf *pf, struct ice_res_tracker *res, u16 needed, u16 id)
  */
 void ice_vsi_dis_irq(struct ice_vsi *vsi)
 {
-	int base = vsi->sw_base_vector;
+	int base = vsi->base_vector;
 	struct ice_pf *pf = vsi->back;
 	struct ice_hw *hw = &pf->hw;
 	u32 val;
@@ -2777,15 +2722,12 @@ void ice_vsi_dis_irq(struct ice_vsi *vsi)
  */
 int ice_vsi_release(struct ice_vsi *vsi)
 {
-	struct ice_vf *vf = NULL;
 	struct ice_pf *pf;
 
 	if (!vsi->back)
 		return -ENODEV;
 	pf = vsi->back;
 
-	if (vsi->type == ICE_VSI_VF)
-		vf = &pf->vf[vsi->vf_id];
 	/* do not unregister while driver is in the reset recovery pending
 	 * state. Since reset/rebuild happens through PF service task workqueue,
 	 * it's not a good idea to unregister netdev that is associated to the
@@ -2803,21 +2745,15 @@ int ice_vsi_release(struct ice_vsi *vsi)
 		ice_vsi_dis_irq(vsi);
 	ice_vsi_close(vsi);
 
-	/* reclaim interrupt vectors back to PF */
+	/* SR-IOV determines needed MSIX resources all at once instead of per
+	 * VSI since when VFs are spawned we know how many VFs there are and how
+	 * many interrupts each VF needs. SR-IOV MSIX resources are also
+	 * cleared in the same manner.
+	 */
 	if (vsi->type != ICE_VSI_VF) {
 		/* reclaim SW interrupts back to the common pool */
-		ice_free_res(pf->sw_irq_tracker, vsi->sw_base_vector, vsi->idx);
+		ice_free_res(pf->irq_tracker, vsi->base_vector, vsi->idx);
 		pf->num_avail_sw_msix += vsi->num_q_vectors;
-		/* reclaim HW interrupts back to the common pool */
-		ice_free_res(pf->hw_irq_tracker, vsi->hw_base_vector, vsi->idx);
-		pf->num_avail_hw_msix += vsi->num_q_vectors;
-	} else if (test_bit(ICE_VF_STATE_CFG_INTR, vf->vf_states)) {
-		/* Reclaim VF resources back only while freeing all VFs or
-		 * vector reassignment is requested
-		 */
-		ice_free_res(pf->hw_irq_tracker, vf->first_vector_idx,
-			     vsi->idx);
-		pf->num_avail_hw_msix += pf->num_vf_msix;
 	}
 
 	if (vsi->type == ICE_VSI_PF)
@@ -2873,24 +2809,17 @@ int ice_vsi_rebuild(struct ice_vsi *vsi)
 	ice_rm_vsi_lan_cfg(vsi->port_info, vsi->idx);
 	ice_vsi_free_q_vectors(vsi);
 
+	/* SR-IOV determines needed MSIX resources all at once instead of per
+	 * VSI since when VFs are spawned we know how many VFs there are and how
+	 * many interrupts each VF needs. SR-IOV MSIX resources are also
+	 * cleared in the same manner.
+	 */
 	if (vsi->type != ICE_VSI_VF) {
 		/* reclaim SW interrupts back to the common pool */
-		ice_free_res(pf->sw_irq_tracker, vsi->sw_base_vector, vsi->idx);
+		ice_free_res(pf->irq_tracker, vsi->base_vector, vsi->idx);
 		pf->num_avail_sw_msix += vsi->num_q_vectors;
-		vsi->sw_base_vector = 0;
-		/* reclaim HW interrupts back to the common pool */
-		ice_free_res(pf->hw_irq_tracker, vsi->hw_base_vector,
-			     vsi->idx);
-		pf->num_avail_hw_msix += vsi->num_q_vectors;
-	} else {
-		/* Reclaim VF resources back to the common pool for reset and
-		 * and rebuild, with vector reassignment
-		 */
-		ice_free_res(pf->hw_irq_tracker, vf->first_vector_idx,
-			     vsi->idx);
-		pf->num_avail_hw_msix += pf->num_vf_msix;
+		vsi->base_vector = 0;
 	}
-	vsi->hw_base_vector = 0;
 
 	ice_vsi_clear_rings(vsi);
 	ice_vsi_free_arrays(vsi);
@@ -2916,10 +2845,6 @@ int ice_vsi_rebuild(struct ice_vsi *vsi)
 		if (ret)
 			goto err_rings;
 
-		ret = ice_vsi_setup_vector_base(vsi);
-		if (ret)
-			goto err_vectors;
-
 		ret = ice_vsi_set_q_vectors_reg_idx(vsi);
 		if (ret)
 			goto err_vectors;