qed: Provide auxiliary for getting free VF SB

IOV code is very intrusive in its manipulation of the status block
database.
Add a new auxiliary function to allow the PF to find an available unused
status block to configure for a specific VF's MSI-x vector.
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/qlogic/qed/qed_int.c

@@ -1412,6 +1412,26 @@ void qed_int_sb_setup(struct qed_hwfn *p_hwfn,
 				    sb_info->igu_sb_id, 0, 0);
 }
 
+struct qed_igu_block *qed_get_igu_free_sb(struct qed_hwfn *p_hwfn, bool b_is_pf)
+{
+	struct qed_igu_block *p_block;
+	u16 igu_id;
+
+	for (igu_id = 0; igu_id < QED_MAPPING_MEMORY_SIZE(p_hwfn->cdev);
+	     igu_id++) {
+		p_block = &p_hwfn->hw_info.p_igu_info->entry[igu_id];
+
+		if (!(p_block->status & QED_IGU_STATUS_VALID) ||
+		    !(p_block->status & QED_IGU_STATUS_FREE))
+			continue;
+
+		if (!!(p_block->status & QED_IGU_STATUS_PF) == b_is_pf)
+			return p_block;
+	}
+
+	return NULL;
+}
+
 static u16 qed_get_pf_igu_sb_id(struct qed_hwfn *p_hwfn, u16 vector_id)
 {
 	struct qed_igu_block *p_block;

drivers/net/ethernet/qlogic/qed/qed_int.h

@@ -225,6 +225,17 @@ struct qed_igu_info {
 };
 
 /* TODO Names of function may change... */
+/**
+ * @brief return a pointer to an unused valid SB
+ *
+ * @param p_hwfn
+ * @param b_is_pf - true iff we want a SB belonging to a PF
+ *
+ * @return point to an igu_block, NULL if none is available
+ */
+struct qed_igu_block *qed_get_igu_free_sb(struct qed_hwfn *p_hwfn,
+					  bool b_is_pf);
+
 void qed_int_igu_init_pure_rt(struct qed_hwfn *p_hwfn,
 			      struct qed_ptt *p_ptt,
 			      bool b_set,

drivers/net/ethernet/qlogic/qed/qed_sriov.c

@@ -868,12 +868,11 @@ static u8 qed_iov_alloc_vf_igu_sbs(struct qed_hwfn *p_hwfn,
 				   struct qed_ptt *p_ptt,
 				   struct qed_vf_info *vf, u16 num_rx_queues)
 {
-	struct qed_igu_block *igu_blocks;
-	int qid = 0, igu_id = 0;
+	struct qed_igu_block *p_block;
+	struct cau_sb_entry sb_entry;
+	int qid = 0;
 	u32 val = 0;
 
-	igu_blocks = p_hwfn->hw_info.p_igu_info->entry;
-
 	if (num_rx_queues > p_hwfn->hw_info.p_igu_info->usage.free_cnt_iov)
 		num_rx_queues = p_hwfn->hw_info.p_igu_info->usage.free_cnt_iov;
 	p_hwfn->hw_info.p_igu_info->usage.free_cnt_iov -= num_rx_queues;
@@ -882,31 +881,23 @@ static u8 qed_iov_alloc_vf_igu_sbs(struct qed_hwfn *p_hwfn,
 	SET_FIELD(val, IGU_MAPPING_LINE_VALID, 1);
 	SET_FIELD(val, IGU_MAPPING_LINE_PF_VALID, 0);
 
-	while ((qid < num_rx_queues) &&
-	       (igu_id < QED_MAPPING_MEMORY_SIZE(p_hwfn->cdev))) {
-		if (igu_blocks[igu_id].status & QED_IGU_STATUS_FREE) {
-			struct cau_sb_entry sb_entry;
-
-			vf->igu_sbs[qid] = (u16)igu_id;
-			igu_blocks[igu_id].status &= ~QED_IGU_STATUS_FREE;
-
+	for (qid = 0; qid < num_rx_queues; qid++) {
+		p_block = qed_get_igu_free_sb(p_hwfn, false);
+		vf->igu_sbs[qid] = p_block->igu_sb_id;
+		p_block->status &= ~QED_IGU_STATUS_FREE;
 		SET_FIELD(val, IGU_MAPPING_LINE_VECTOR_NUMBER, qid);
 
 		qed_wr(p_hwfn, p_ptt,
-			       IGU_REG_MAPPING_MEMORY + sizeof(u32) * igu_id,
-			       val);
+		       IGU_REG_MAPPING_MEMORY +
+		       sizeof(u32) * p_block->igu_sb_id, val);
 
 		/* Configure igu sb in CAU which were marked valid */
 		qed_init_cau_sb_entry(p_hwfn, &sb_entry,
-					      p_hwfn->rel_pf_id,
-					      vf->abs_vf_id, 1);
+				      p_hwfn->rel_pf_id, vf->abs_vf_id, 1);
 		qed_dmae_host2grc(p_hwfn, p_ptt,
 				  (u64)(uintptr_t)&sb_entry,
 				  CAU_REG_SB_VAR_MEMORY +
-					  igu_id * sizeof(u64), 2, 0);
-			qid++;
-		}
-		igu_id++;
+				  p_block->igu_sb_id * sizeof(u64), 2, 0);
 	}
 
 	vf->num_sbs = (u8) num_rx_queues;