[PATCH net-next v3 2/8] bnxt_en: Add logical RSS indirection table structure.

[Michael Chan <michael.chan@broadcom.com>]

The driver currently does not keep track of the logical RSS indirection
table.  The hardware RSS table is set up with standard default ring
distribution when initializing the chip.  This makes it difficult to
support user sepcified indirection table entries.  As a first step, add
the logical table in the main bnxt structure and allocate it according
to chip specific table size.  Add a function that sets up default
RSS distribution based on the number of RX rings.

v2: Use kmalloc_array() since we init. all entries afterwards.
    Use ALIGN() to roundup the RSS table size.
    Use ethtool_rxfh_indir_default() to init. the default entries.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
---
 drivers/net/ethernet/broadcom/bnxt/bnxt.c | 51 +++++++++++++++++++++++++++++++
 drivers/net/ethernet/broadcom/bnxt/bnxt.h |  4 +++
 2 files changed, 55 insertions(+)

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index 4afc1df..70f8302 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -4830,6 +4830,48 @@ static u16 bnxt_cp_ring_for_tx(struct bnxt *bp, struct bnxt_tx_ring_info *txr)
 	}
 }
 
+static int bnxt_alloc_rss_indir_tbl(struct bnxt *bp)
+{
+	int entries;
+
+	if (bp->flags & BNXT_FLAG_CHIP_P5)
+		entries = BNXT_MAX_RSS_TABLE_ENTRIES_P5;
+	else
+		entries = HW_HASH_INDEX_SIZE;
+
+	bp->rss_indir_tbl_entries = entries;
+	bp->rss_indir_tbl = kmalloc_array(entries, sizeof(*bp->rss_indir_tbl),
+					  GFP_KERNEL);
+	if (!bp->rss_indir_tbl)
+		return -ENOMEM;
+	return 0;
+}
+
+static void bnxt_set_dflt_rss_indir_tbl(struct bnxt *bp)
+{
+	u16 max_rings, max_entries, pad, i;
+
+	if (!bp->rx_nr_rings)
+		return;
+
+	if (BNXT_CHIP_TYPE_NITRO_A0(bp))
+		max_rings = bp->rx_nr_rings - 1;
+	else
+		max_rings = bp->rx_nr_rings;
+
+	if (bp->flags & BNXT_FLAG_CHIP_P5)
+		max_entries = ALIGN(max_rings, BNXT_RSS_TABLE_ENTRIES_P5);
+	else
+		max_entries = HW_HASH_INDEX_SIZE;
+
+	for (i = 0; i < max_entries; i++)
+		bp->rss_indir_tbl[i] = ethtool_rxfh_indir_default(i, max_rings);
+
+	pad = bp->rss_indir_tbl_entries - max_entries;
+	if (pad)
+		memset(&bp->rss_indir_tbl[i], 0, pad * sizeof(u16));
+}
+
 static int bnxt_hwrm_vnic_set_rss(struct bnxt *bp, u16 vnic_id, bool set_rss)
 {
 	u32 i, j, max_rings;
@@ -11514,6 +11556,8 @@ static void bnxt_remove_one(struct pci_dev *pdev)
 	bnxt_free_ctx_mem(bp);
 	kfree(bp->ctx);
 	bp->ctx = NULL;
+	kfree(bp->rss_indir_tbl);
+	bp->rss_indir_tbl = NULL;
 	bnxt_free_port_stats(bp);
 	free_netdev(dev);
 }
@@ -12034,6 +12078,11 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	 */
 	bp->tx_nr_rings_per_tc = bp->tx_nr_rings;
 
+	rc = bnxt_alloc_rss_indir_tbl(bp);
+	if (rc)
+		goto init_err_pci_clean;
+	bnxt_set_dflt_rss_indir_tbl(bp);
+
 	if (BNXT_PF(bp)) {
 		if (!bnxt_pf_wq) {
 			bnxt_pf_wq =
@@ -12078,6 +12127,8 @@ static int bnxt_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	bnxt_free_ctx_mem(bp);
 	kfree(bp->ctx);
 	bp->ctx = NULL;
+	kfree(bp->rss_indir_tbl);
+	bp->rss_indir_tbl = NULL;
 
 init_err_free:
 	free_netdev(dev);
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.h b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
index 5883b246..6de2813 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.h
@@ -1023,6 +1023,8 @@ struct bnxt_vnic_info {
 #define BNXT_RSS_TABLE_MAX_TBL_P5	8
 #define BNXT_MAX_RSS_TABLE_SIZE_P5				\
 	(BNXT_RSS_TABLE_SIZE_P5 * BNXT_RSS_TABLE_MAX_TBL_P5)
+#define BNXT_MAX_RSS_TABLE_ENTRIES_P5				\
+	(BNXT_RSS_TABLE_ENTRIES_P5 * BNXT_RSS_TABLE_MAX_TBL_P5)
 
 	u32		rx_mask;
 
@@ -1655,6 +1657,8 @@ struct bnxt {
 	struct bnxt_ring_grp_info	*grp_info;
 	struct bnxt_vnic_info	*vnic_info;
 	int			nr_vnics;
+	u16			*rss_indir_tbl;
+	u16			rss_indir_tbl_entries;
 	u32			rss_hash_cfg;
 
 	u16			max_mtu;
-- 
1.8.3.1