ice: simplify VF MSI-X managing

After implementing pf->msix.max field, base vector for other use cases
(like VFs) can be fixed. This simplify code when changing MSI-X amount
on particular VF, because there is no need to move a base vector.

A fixed base vector allows to reserve vectors from the beginning
instead of from the end, which is also simpler in code.

Store total and rest value in the same struct as max and min for PF.
Move tracking vectors from ice_sriov.c to ice_irq.c as it can be also
use for other none PF use cases (SIOV).

Tested-by: Rafal Romanowski <[email protected]>
Signed-off-by: Michal Swiatkowski <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>

Author: Michal Swiatkowski

drivers/net/ethernet/intel/ice/ice.h

@@ -543,6 +543,8 @@ struct ice_pf_msix {
 	u32 cur;
 	u32 min;
 	u32 max;
+	u32 total;
+	u32 rest;
 };
 
 struct ice_pf {
@@ -559,13 +561,7 @@ struct ice_pf {
 	/* OS reserved IRQ details */
 	struct msix_entry *msix_entries;
 	struct ice_irq_tracker irq_tracker;
-	/* First MSIX vector used by SR-IOV VFs. Calculated by subtracting the
-	 * number of MSIX vectors needed for all SR-IOV VFs from the number of
-	 * MSIX vectors allowed on this PF.
-	 */
-	u16 sriov_base_vector;
-	unsigned long *sriov_irq_bm;	/* bitmap to track irq usage */
-	u16 sriov_irq_size;		/* size of the irq_bm bitmap */
+	struct ice_virt_irq_tracker virt_irq_tracker;
 
 	u16 ctrl_vsi_idx;		/* control VSI index in pf->vsi array */
 

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

@@ -20,6 +20,19 @@ ice_init_irq_tracker(struct ice_pf *pf, unsigned int max_vectors,
 	xa_init_flags(&pf->irq_tracker.entries, XA_FLAGS_ALLOC);
 }
 
+static int
+ice_init_virt_irq_tracker(struct ice_pf *pf, u32 base, u32 num_entries)
+{
+	pf->virt_irq_tracker.bm = bitmap_zalloc(num_entries, GFP_KERNEL);
+	if (!pf->virt_irq_tracker.bm)
+		return -ENOMEM;
+
+	pf->virt_irq_tracker.num_entries = num_entries;
+	pf->virt_irq_tracker.base = base;
+
+	return 0;
+}
+
 /**
  * ice_deinit_irq_tracker - free xarray tracker
  * @pf: board private structure
@@ -29,6 +42,11 @@ static void ice_deinit_irq_tracker(struct ice_pf *pf)
 	xa_destroy(&pf->irq_tracker.entries);
 }
 
+static void ice_deinit_virt_irq_tracker(struct ice_pf *pf)
+{
+	bitmap_free(pf->virt_irq_tracker.bm);
+}
+
 /**
  * ice_free_irq_res - free a block of resources
  * @pf: board private structure
@@ -101,6 +119,7 @@ void ice_clear_interrupt_scheme(struct ice_pf *pf)
 {
 	pci_free_irq_vectors(pf->pdev);
 	ice_deinit_irq_tracker(pf);
+	ice_deinit_virt_irq_tracker(pf);
 }
 
 /**
@@ -120,6 +139,9 @@ int ice_init_interrupt_scheme(struct ice_pf *pf)
 		pf->msix.max = min(total_vectors,
 				   ice_get_default_msix_amount(pf));
 
+	pf->msix.total = total_vectors;
+	pf->msix.rest = total_vectors - pf->msix.max;
+
 	if (pci_msix_can_alloc_dyn(pf->pdev))
 		vectors = pf->msix.min;
 	else
@@ -132,7 +154,7 @@ int ice_init_interrupt_scheme(struct ice_pf *pf)
 
 	ice_init_irq_tracker(pf, pf->msix.max, vectors);
 
-	return 0;
+	return ice_init_virt_irq_tracker(pf, pf->msix.max, pf->msix.rest);
 }
 
 /**
@@ -159,7 +181,6 @@ int ice_init_interrupt_scheme(struct ice_pf *pf)
  */
 struct msi_map ice_alloc_irq(struct ice_pf *pf, bool dyn_allowed)
 {
-	int sriov_base_vector = pf->sriov_base_vector;
 	struct msi_map map = { .index = -ENOENT };
 	struct device *dev = ice_pf_to_dev(pf);
 	struct ice_irq_entry *entry;
@@ -168,10 +189,6 @@ struct msi_map ice_alloc_irq(struct ice_pf *pf, bool dyn_allowed)
 	if (!entry)
 		return map;
 
-	/* fail if we're about to violate SRIOV vectors space */
-	if (sriov_base_vector && entry->index >= sriov_base_vector)
-		goto exit_free_res;
-
 	if (pci_msix_can_alloc_dyn(pf->pdev) && entry->dynamic) {
 		map = pci_msix_alloc_irq_at(pf->pdev, entry->index, NULL);
 		if (map.index < 0)
@@ -219,26 +236,40 @@ void ice_free_irq(struct ice_pf *pf, struct msi_map map)
 }
 
 /**
- * ice_get_max_used_msix_vector - Get the max used interrupt vector
- * @pf: board private structure
+ * ice_virt_get_irqs - get irqs for SR-IOV usacase
+ * @pf: pointer to PF structure
+ * @needed: number of irqs to get
  *
- * Return index of maximum used interrupt vectors with respect to the
- * beginning of the MSIX table. Take into account that some interrupts
- * may have been dynamically allocated after MSIX was initially enabled.
+ * This returns the first MSI-X vector index in PF space that is used by this
+ * VF. This index is used when accessing PF relative registers such as
+ * GLINT_VECT2FUNC and GLINT_DYN_CTL.
+ * This will always be the OICR index in the AVF driver so any functionality
+ * using vf->first_vector_idx for queue configuration_id: id of VF which will
+ * use this irqs
  */
-int ice_get_max_used_msix_vector(struct ice_pf *pf)
+int ice_virt_get_irqs(struct ice_pf *pf, u32 needed)
 {
-	unsigned long start, index, max_idx;
-	void *entry;
+	int res = bitmap_find_next_zero_area(pf->virt_irq_tracker.bm,
+					     pf->virt_irq_tracker.num_entries,
+					     0, needed, 0);
 
-	/* Treat all preallocated interrupts as used */
-	start = pf->irq_tracker.num_static;
-	max_idx = start - 1;
+	if (res >= pf->virt_irq_tracker.num_entries)
+		return -ENOENT;
 
-	xa_for_each_start(&pf->irq_tracker.entries, index, entry, start) {
-		if (index > max_idx)
-			max_idx = index;
-	}
+	bitmap_set(pf->virt_irq_tracker.bm, res, needed);
 
-	return max_idx;
+	/* conversion from number in bitmap to global irq index */
+	return res + pf->virt_irq_tracker.base;
+}
+
+/**
+ * ice_virt_free_irqs - free irqs used by the VF
+ * @pf: pointer to PF structure
+ * @index: first index to be free
+ * @irqs: number of irqs to free
+ */
+void ice_virt_free_irqs(struct ice_pf *pf, u32 index, u32 irqs)
+{
+	bitmap_clear(pf->virt_irq_tracker.bm, index - pf->virt_irq_tracker.base,
+		     irqs);
 }

drivers/net/ethernet/intel/ice/ice_irq.h

@@ -15,11 +15,22 @@ struct ice_irq_tracker {
 	u16 num_static;	/* preallocated entries */
 };
 
+struct ice_virt_irq_tracker {
+	unsigned long *bm;	/* bitmap to track irq usage */
+	u32 num_entries;
+	/* First MSIX vector used by SR-IOV VFs. Calculated by subtracting the
+	 * number of MSIX vectors needed for all SR-IOV VFs from the number of
+	 * MSIX vectors allowed on this PF.
+	 */
+	u32 base;
+};
+
 int ice_init_interrupt_scheme(struct ice_pf *pf);
 void ice_clear_interrupt_scheme(struct ice_pf *pf);
 
 struct msi_map ice_alloc_irq(struct ice_pf *pf, bool dyn_only);
 void ice_free_irq(struct ice_pf *pf, struct msi_map map);
-int ice_get_max_used_msix_vector(struct ice_pf *pf);
 
+int ice_virt_get_irqs(struct ice_pf *pf, u32 needed);
+void ice_virt_free_irqs(struct ice_pf *pf, u32 index, u32 irqs);
 #endif