drivers: net: xgene: Fix module unload crash - hw resource cleanup

When the driver is configured as kernel module and when it gets
unloaded and reloaded, kernel crash was observed.  This patch
address the hardware resource cleanups by doing the following,

- Added mac_ops->clear() to do prefetch buffer clean up
- Fixed delete freepool buffers logic
- Reordered mac_enable and mac_disable
- Added Tx completion ring free
- Moved down delete_desc_rings after ring cleanup

Signed-off-by: Iyappan Subramanian <isubramanian@apm.com>
Tested-by: Fushen Chen <fchen@apm.com>
Tested-by: Toan Le <toanle@apm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 40 insertions, 2 deletions

diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c b/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c
index ba030dc1940b..d0b441934091 100644
--- a/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c
+++ b/drivers/net/ethernet/apm/xgene/xgene_enet_xgmac.c
@@ -292,8 +292,45 @@ static void xgene_enet_xgcle_bypass(struct xgene_enet_pdata *pdata,
 
 static void xgene_enet_shutdown(struct xgene_enet_pdata *pdata)
 {
-	if (!IS_ERR(pdata->clk))
-		clk_disable_unprepare(pdata->clk);
+	struct xgene_enet_desc_ring *ring;
+	u32 pb, val;
+	int i;
+
+	pb = 0;
+	for (i = 0; i < pdata->rxq_cnt; i++) {
+		ring = pdata->rx_ring[i]->buf_pool;
+
+		val = xgene_enet_ring_bufnum(ring->id);
+		pb |= BIT(val - 0x20);
+	}
+	xgene_enet_wr_ring_if(pdata, ENET_CFGSSQMIFPRESET_ADDR, pb);
+
+	pb = 0;
+	for (i = 0; i < pdata->txq_cnt; i++) {
+		ring = pdata->tx_ring[i];
+
+		val = xgene_enet_ring_bufnum(ring->id);
+		pb |= BIT(val);
+	}
+	xgene_enet_wr_ring_if(pdata, ENET_CFGSSQMIWQRESET_ADDR, pb);
+}
+
+static void xgene_enet_clear(struct xgene_enet_pdata *pdata,
+			     struct xgene_enet_desc_ring *ring)
+{
+	u32 addr, val, data;
+
+	val = xgene_enet_ring_bufnum(ring->id);
+
+	if (xgene_enet_is_bufpool(ring->id)) {
+		addr = ENET_CFGSSQMIFPRESET_ADDR;
+		data = BIT(val - 0x20);
+	} else {
+		addr = ENET_CFGSSQMIWQRESET_ADDR;
+		data = BIT(val);
+	}
+
+	xgene_enet_wr_ring_if(pdata, addr, data);
 }
 
 static void xgene_enet_link_state(struct work_struct *work)
@@ -340,6 +377,7 @@ const struct xgene_mac_ops xgene_xgmac_ops = {
 
 const struct xgene_port_ops xgene_xgport_ops = {
 	.reset = xgene_enet_reset,
+	.clear = xgene_enet_clear,
 	.cle_bypass = xgene_enet_xgcle_bypass,
 	.shutdown = xgene_enet_shutdown,
 };