Fix kexec kernel panic in mvpp2 (sonic-net#377)

Signed-off-by: Pavan Naregundi <[email protected]>

patch/0012-net-mvpp2-clear-BM-pool-before-initialization.patch

@@ -0,0 +1,72 @@
+From 09ca6f153d5d36f2f553f22dfca4e216654084fd Mon Sep 17 00:00:00 2001
+From: Jenishkumar Maheshbhai Patel <[email protected]>
+Date: Thu, 18 Jan 2024 19:59:14 -0800
+Subject: 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 <[email protected]>
+Reviewed-by: Maxime Chevallier <[email protected]>
+Link: https://lore.kernel.org/r/[email protected]
+Signed-off-by: Jakub Kicinski <[email protected]>
+---
+ .../net/ethernet/marvell/mvpp2/mvpp2_main.c   | 27 ++++++++++++++++++-
+ 1 file changed, 26 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+index b399bdb1c..5d6309ca7 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);
+-- 
+2.25.1
+

patch/series

@@ -156,6 +156,7 @@ cisco-npu-disable-other-bars.patch
 0009-dt-bindings-marvell-Add-ARMADA-7K-properties.patch
 0010-dts-marvell-Add-support-for-7020-comexpress.patch
 0011-arm64-dts-marvell-Add-Nokia-7215-IXS-A1-board.patch
+0012-net-mvpp2-clear-BM-pool-before-initialization.patch
 
 # amd-pensando elba support
 0000-Add-support-for-the-TI-TPS53659.patch