From: Jenishkumar Maheshbhai Patel <jpatel2@marvell.com>
Date: Fri, 19 Jan 2024 03:59:14 +0000 (-0800)
Subject: net: mvpp2: clear BM pool before initialization
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9f538b415db862e74b8c5d3abbccfc1b2b6caa38;p=linux.git

net: mvpp2: clear BM pool before initialization

Register value persist after booting the kernel using
kexec which results in kernel panic. Thus clear the
BM pool registers before initialisation to fix the issue.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Jenishkumar Maheshbhai Patel <jpatel2@marvell.com>
Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://lore.kernel.org/r/20240119035914.2595665-1-jpatel2@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 820b1fabe297a..23adf53c2aa1c 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -614,12 +614,38 @@ static void mvpp23_bm_set_8pool_mode(struct mvpp2 *priv)
 	mvpp2_write(priv, MVPP22_BM_POOL_BASE_ADDR_HIGH_REG, val);
 }
 
+/* Cleanup pool before actual initialization in the OS */
+static void mvpp2_bm_pool_cleanup(struct mvpp2 *priv, int pool_id)
+{
+	unsigned int thread = mvpp2_cpu_to_thread(priv, get_cpu());
+	u32 val;
+	int i;
+
+	/* Drain the BM from all possible residues left by firmware */
+	for (i = 0; i < MVPP2_BM_POOL_SIZE_MAX; i++)
+		mvpp2_thread_read(priv, thread, MVPP2_BM_PHY_ALLOC_REG(pool_id));
+
+	put_cpu();
+
+	/* Stop the BM pool */
+	val = mvpp2_read(priv, MVPP2_BM_POOL_CTRL_REG(pool_id));
+	val |= MVPP2_BM_STOP_MASK;
+	mvpp2_write(priv, MVPP2_BM_POOL_CTRL_REG(pool_id), val);
+}
+
 static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
 {
 	enum dma_data_direction dma_dir = DMA_FROM_DEVICE;
 	int i, err, poolnum = MVPP2_BM_POOLS_NUM;
 	struct mvpp2_port *port;
 
+	if (priv->percpu_pools)
+		poolnum = mvpp2_get_nrxqs(priv) * 2;
+
+	/* Clean up the pool state in case it contains stale state */
+	for (i = 0; i < poolnum; i++)
+		mvpp2_bm_pool_cleanup(priv, i);
+
 	if (priv->percpu_pools) {
 		for (i = 0; i < priv->port_count; i++) {
 			port = priv->port_list[i];
@@ -629,7 +655,6 @@ static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
 			}
 		}
 
-		poolnum = mvpp2_get_nrxqs(priv) * 2;
 		for (i = 0; i < poolnum; i++) {
 			/* the pool in use */
 			int pn = i / (poolnum / 2);