Subject: [PATCH v4] bnx2x: Fix error recovering in switch configuration

From: Thinh Tran <[email-masked]>
Date: Fri, 28 Jul 2023 16:11:33 -0500

As the BCM57810 and other I/O adapters are connected
through a PCIe switch, the bnx2x driver causes unexpected
system hang/crash while handling PCIe switch errors, if
its error handler is called after other drivers' handlers.

In this case, after numbers of bnx2x_tx_timout(), the
bnx2x_nic_unload() is  called, frees up resources and
calls bnx2x_napi_disable(). Then when EEH calls its
error handler, the bnx2x_io_error_detected() and
bnx2x_io_slot_reset() also calling bnx2x_napi_disable()
and freeing the resources.

Signed-off-by: Thinh Tran <[email-masked]>
Reviewed-by: Manish Chopra <[email-masked]>
Tested-by: Abdul Haleem <[email-masked]>
Tested-by: David Christensen <[email-masked]>

Reviewed-by: Simon Horman <[email-masked]>

  v4:
   - factoring common code into new function bnx2x_stop_nic()
     that disables and releases IRQs and NAPIs 
  v3:
    - no changes, just repatched to the latest driver level
    - updated the reviewed-by Manish in October, 2022

  v2:
   - Check the state of the NIC before calling disable nappi
     and freeing the IRQ
   - Prevent recurrence of TX timeout by turning off the carrier,
     calling netif_carrier_off() in bnx2x_tx_timeout()
   - Check and bail out early if fp->page_pool already freed

---
 drivers/net/ethernet/broadcom/bnx2x/bnx2x.h   |  2 ++
 .../net/ethernet/broadcom/bnx2x/bnx2x_cmn.c   | 18 +++++++------
 .../net/ethernet/broadcom/bnx2x/bnx2x_cmn.h   | 18 +++++++++++++
 .../net/ethernet/broadcom/bnx2x/bnx2x_main.c  | 25 +++----------------
 .../net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c  |  9 ++-----
 5 files changed, 36 insertions(+), 36 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
index 8bcde0a6e011..e2a4e1088b7f 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -1508,6 +1508,8 @@ struct bnx2x {
 	bool			cnic_loaded;
 	struct cnic_eth_dev	*(*cnic_probe)(struct net_device *);
 
+	bool                    nic_stopped;
+
 	/* Flag that indicates that we can start looking for FCoE L2 queue
 	 * completions in the default status block.
 	 */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
index 6ea5521074d3..b4143c427936 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.c
@@ -2715,6 +2715,7 @@ int bnx2x_nic_load(struct bnx2x *bp, int load_mode)
 	bnx2x_add_all_napi(bp);
 	DP(NETIF_MSG_IFUP, "napi added\n");
 	bnx2x_napi_enable(bp);
+	bp->nic_stopped = false;
 
 	if (IS_PF(bp)) {
 		/* set pf load just before approaching the MCP */
@@ -2960,6 +2961,7 @@ int bnx2x_nic_load(struct bnx2x *bp, int load_mode)
 load_error1:
 	bnx2x_napi_disable(bp);
 	bnx2x_del_all_napi(bp);
+	bp->nic_stopped = true;
 
 	/* clear pf_load status, as it was already set */
 	if (IS_PF(bp))
@@ -3095,14 +3097,8 @@ int bnx2x_nic_unload(struct bnx2x *bp, int unload_mode, bool keep_link)
 		if (!CHIP_IS_E1x(bp))
 			bnx2x_pf_disable(bp);
 
-		/* Disable HW interrupts, NAPI */
-		bnx2x_netif_stop(bp, 1);
-		/* Delete all NAPI objects */
-		bnx2x_del_all_napi(bp);
-		if (CNIC_LOADED(bp))
-			bnx2x_del_all_napi_cnic(bp);
-		/* Release IRQs */
-		bnx2x_free_irq(bp);
+		/* Disable HW interrupts, delete NAPIs, Release IRQs */
+		bnx2x_stop_nic(bp);
 
 		/* Report UNLOAD_DONE to MCP */
 		bnx2x_send_unload_done(bp, false);
@@ -4987,6 +4983,12 @@ void bnx2x_tx_timeout(struct net_device *dev, unsigned int txqueue)
 {
 	struct bnx2x *bp = netdev_priv(dev);
 
+	/* Immediately indicate link as down */
+	bp->link_vars.link_up = 0;
+	bp->force_link_down = true;
+	netif_carrier_off(dev);
+	BNX2X_ERR("Indicating link is down due to Tx-timeout\n");
+
 	/* We want the information of the dump logged,
 	 * but calling bnx2x_panic() would kill all chances of recovery.
 	 */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
index d8b1824c334d..f5ecbe8d604a 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h
@@ -1015,6 +1015,9 @@ static inline void bnx2x_free_rx_sge_range(struct bnx2x *bp,
 {
 	int i;
 
+	if (!fp->page_pool.page)
+		return;
+
 	if (fp->mode == TPA_MODE_DISABLED)
 		return;
 
@@ -1399,5 +1402,20 @@ void bnx2x_set_os_driver_state(struct bnx2x *bp, u32 state);
  */
 int bnx2x_nvram_read(struct bnx2x *bp, u32 offset, u8 *ret_buf,
 		     int buf_size);
+static inline void bnx2x_stop_nic(struct bnx2x *bp)
+{
+	if (!bp->nic_stopped) {
+		/* Disable HW interrupts, NAPI */
+		bnx2x_netif_stop(bp, 1);
+		/* Delete all NAPI objects */
+		bnx2x_del_all_napi(bp);
+		if (CNIC_LOADED(bp))
+			bnx2x_del_all_napi_cnic(bp);
+		/* Release IRQs */
+		bnx2x_free_irq(bp);
+		bp->nic_stopped = true;
+	}
+}
+
 
 #endif /* BNX2X_CMN_H */
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
index 1e7a6f1d4223..e40c83b8b32e 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
@@ -9474,15 +9474,8 @@ void bnx2x_chip_cleanup(struct bnx2x *bp, int unload_mode, bool keep_link)
 		}
 	}
 
-	/* Disable HW interrupts, NAPI */
-	bnx2x_netif_stop(bp, 1);
-	/* Delete all NAPI objects */
-	bnx2x_del_all_napi(bp);
-	if (CNIC_LOADED(bp))
-		bnx2x_del_all_napi_cnic(bp);
-
-	/* Release IRQs */
-	bnx2x_free_irq(bp);
+	/* Disable HW interrupts, delete NAPIs, Release IRQs */
+	bnx2x_stop_nic(bp);
 
 	/* Reset the chip, unless PCI function is offline. If we reach this
 	 * point following a PCI error handling, it means device is really
@@ -10273,12 +10266,6 @@ static void bnx2x_sp_rtnl_task(struct work_struct *work)
 		bp->sp_rtnl_state = 0;
 		smp_mb();
 
-		/* Immediately indicate link as down */
-		bp->link_vars.link_up = 0;
-		bp->force_link_down = true;
-		netif_carrier_off(bp->dev);
-		BNX2X_ERR("Indicating link is down due to Tx-timeout\n");
-
 		bnx2x_nic_unload(bp, UNLOAD_NORMAL, true);
 		/* When ret value shows failure of allocation failure,
 		 * the nic is rebooted again. If open still fails, a error
@@ -14238,13 +14225,9 @@ static pci_ers_result_t bnx2x_io_slot_reset(struct pci_dev *pdev)
 		}
 		bnx2x_drain_tx_queues(bp);
 		bnx2x_send_unload_req(bp, UNLOAD_RECOVERY);
-		bnx2x_netif_stop(bp, 1);
-		bnx2x_del_all_napi(bp);
-
-		if (CNIC_LOADED(bp))
-			bnx2x_del_all_napi_cnic(bp);
 
-		bnx2x_free_irq(bp);
+		/* Disable HW interrupts, delete NAPIs, Release IRQs */
+		bnx2x_stop_nic(bp);
 
 		/* Report UNLOAD_DONE to MCP */
 		bnx2x_send_unload_done(bp, true);
diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
index 0657a0f5170f..d8af7c453172 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_vfpf.c
@@ -529,13 +529,8 @@ void bnx2x_vfpf_close_vf(struct bnx2x *bp)
 	bnx2x_vfpf_finalize(bp, &req->first_tlv);
 
 free_irq:
-	/* Disable HW interrupts, NAPI */
-	bnx2x_netif_stop(bp, 0);
-	/* Delete all NAPI objects */
-	bnx2x_del_all_napi(bp);
-
-	/* Release IRQs */
-	bnx2x_free_irq(bp);
+	/* Disable HW interrupts, delete NAPIs, Release IRQs */
+	bnx2x_stop_nic(bp);
 }
 
 static void bnx2x_leading_vfq_init(struct bnx2x *bp, struct bnx2x_virtf *vf,
-- 
2.31.1