net: airoha: Fix schedule while atomic in airoha_ppe_deinit()

[ Upstream commit 6abcf751bc084804a9e5b3051442e8a2ce67f48a ]

airoha_ppe_deinit() runs airoha_npu_ppe_deinit() in atomic context.
airoha_npu_ppe_deinit routine allocates ppe_data buffer with GFP_KERNEL
flag. Rely on rcu_replace_pointer in airoha_ppe_deinit routine in order
to fix schedule while atomic issue in airoha_npu_ppe_deinit() since we
do not need atomic context there.

Fixes: 00a7678310fe3 ("net: airoha: Introduce flowtable offload support")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://patch.msgid.link/20260105-airoha-fw-ethtool-v2-1-3b32b158cc31@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/airoha/airoha_ppe.c b/drivers/net/ethernet/airoha/airoha_ppe.c
index c0e17035db18ed2441d9703e515c970c098d2286..190d98970014fa5e4dc216712905fcda9cf305cd 100644 (file)
--- a/drivers/net/ethernet/airoha/airoha_ppe.c
+++ b/drivers/net/ethernet/airoha/airoha_ppe.c
@@ -1466,13 +1466,16 @@ void airoha_ppe_deinit(struct airoha_eth *eth)
 {
        struct airoha_npu *npu;
 
-       rcu_read_lock();
-       npu = rcu_dereference(eth->npu);
+       mutex_lock(&flow_offload_mutex);
+
+       npu = rcu_replace_pointer(eth->npu, NULL,
+                                 lockdep_is_held(&flow_offload_mutex));
        if (npu) {
                npu->ops.ppe_deinit(npu);
                airoha_npu_put(npu);
        }
-       rcu_read_unlock();
+
+       mutex_unlock(&flow_offload_mutex);
 
        rhashtable_destroy(&eth->ppe->l2_flows);
        rhashtable_destroy(&eth->flow_table);