Commit ca2d5f1f authored by Venkata Sudheer Kumar Bhavaraju's avatar Venkata Sudheer Kumar Bhavaraju Committed by David S. Miller
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qed: prevent a fw assert during device shutdown 



Device firmware can assert if the device shutdown path in driver
encounters an async. events from mfw (processed in
qed_mcp_handle_events()) after qed_mcp_unload_req() returns.
A call to qed_mcp_unload_req() currently marks the device as inactive
and thus stops any new events, but there is a windows where in-flight
events might still be received by the driver.

To prevent this race condition, atomically set QED_MCP_BYPASS_PROC_BIT
in qed_mcp_unload_req() to make sure qed_mcp_handle_events() ignores all
events. Wait for any event that might already be in-process to complete
by monitoring QED_MCP_IN_PROCESSING_BIT.

Signed-off-by: default avatarPravin Kumar Ganesh Dhende <pdhende@marvell.com>
Signed-off-by: default avatarVenkata Sudheer Kumar Bhavaraju <vbhavaraju@marvell.com>
Signed-off-by: default avatarAlok Prasad <palok@marvell.com>
Signed-off-by: default avatarAriel Elior <aelior@marvell.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 57ea56b0

drivers/net/ethernet/qlogic/qed/qed_dev.c

+3 −0
Original line number Diff line number Diff line
@@ -3098,6 +3098,9 @@ int qed_hw_init(struct qed_dev *cdev, struct qed_hw_init_params *p_params) 
			continue;

		}



		/* Some flows may keep variable set */

		p_hwfn->mcp_info->mcp_handling_status = 0;



		rc = qed_calc_hw_mode(p_hwfn);

		if (rc)

			return rc;

drivers/net/ethernet/qlogic/qed/qed_mcp.c

+40 −2
Original line number Diff line number Diff line
@@ -140,7 +140,7 @@ static struct qed_mcp_cmd_elem *qed_mcp_cmd_get_elem(struct qed_hwfn *p_hwfn, 
int qed_mcp_free(struct qed_hwfn *p_hwfn)

{

	if (p_hwfn->mcp_info) {

		struct qed_mcp_cmd_elem *p_cmd_elem, *p_tmp;

		struct qed_mcp_cmd_elem *p_cmd_elem = NULL, *p_tmp;



		kfree(p_hwfn->mcp_info->mfw_mb_cur);

		kfree(p_hwfn->mcp_info->mfw_mb_shadow);
@@ -249,6 +249,7 @@ int qed_mcp_cmd_init(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) 
	/* Initialize the MFW spinlock */

	spin_lock_init(&p_info->cmd_lock);

	spin_lock_init(&p_info->link_lock);

	spin_lock_init(&p_info->unload_lock);



	INIT_LIST_HEAD(&p_info->cmd_list);
@@ -1095,10 +1096,15 @@ int qed_mcp_load_done(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) 
	return 0;

}



#define MFW_COMPLETION_MAX_ITER 5000

#define MFW_COMPLETION_INTERVAL_MS 1



int qed_mcp_unload_req(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)

{

	struct qed_mcp_mb_params mb_params;

	u32 cnt = MFW_COMPLETION_MAX_ITER;

	u32 wol_param;

	int rc;



	switch (p_hwfn->cdev->wol_config) {

	case QED_OV_WOL_DISABLED:
@@ -1121,7 +1127,23 @@ int qed_mcp_unload_req(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt) 
	mb_params.param = wol_param;

	mb_params.flags = QED_MB_FLAG_CAN_SLEEP | QED_MB_FLAG_AVOID_BLOCK;



	return qed_mcp_cmd_and_union(p_hwfn, p_ptt, &mb_params);

	spin_lock_bh(&p_hwfn->mcp_info->unload_lock);

	set_bit(QED_MCP_BYPASS_PROC_BIT,

		&p_hwfn->mcp_info->mcp_handling_status);

	spin_unlock_bh(&p_hwfn->mcp_info->unload_lock);



	rc = qed_mcp_cmd_and_union(p_hwfn, p_ptt, &mb_params);



	while (test_bit(QED_MCP_IN_PROCESSING_BIT,

			&p_hwfn->mcp_info->mcp_handling_status) && --cnt)

		msleep(MFW_COMPLETION_INTERVAL_MS);



	if (!cnt)

		DP_NOTICE(p_hwfn,

			  "Failed to wait MFW event completion after %d msec\n",

			  MFW_COMPLETION_MAX_ITER * MFW_COMPLETION_INTERVAL_MS);



	return rc;

}



int qed_mcp_unload_done(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
@@ -2021,6 +2043,19 @@ int qed_mcp_handle_events(struct qed_hwfn *p_hwfn, 
			   "Msg [%d] - old CMD 0x%02x, new CMD 0x%02x\n",

			   i, info->mfw_mb_shadow[i], info->mfw_mb_cur[i]);



		spin_lock_bh(&p_hwfn->mcp_info->unload_lock);

		if (test_bit(QED_MCP_BYPASS_PROC_BIT,

			     &p_hwfn->mcp_info->mcp_handling_status)) {

			spin_unlock_bh(&p_hwfn->mcp_info->unload_lock);

			DP_INFO(p_hwfn,

				"Msg [%d] is bypassed on unload flow\n", i);

			continue;

		}



		set_bit(QED_MCP_IN_PROCESSING_BIT,

			&p_hwfn->mcp_info->mcp_handling_status);

		spin_unlock_bh(&p_hwfn->mcp_info->unload_lock);



		switch (i) {

		case MFW_DRV_MSG_LINK_CHANGE:

			qed_mcp_handle_link_change(p_hwfn, p_ptt, false);
@@ -2074,6 +2109,9 @@ int qed_mcp_handle_events(struct qed_hwfn *p_hwfn, 
			DP_INFO(p_hwfn, "Unimplemented MFW message %d\n", i);

			rc = -EINVAL;

		}



		clear_bit(QED_MCP_IN_PROCESSING_BIT,

			  &p_hwfn->mcp_info->mcp_handling_status);

	}



	/* ACK everything */

drivers/net/ethernet/qlogic/qed/qed_mcp.h

+8 −0
Original line number Diff line number Diff line
@@ -788,6 +788,14 @@ struct qed_mcp_info { 


	/* S/N for debug data mailbox commands */

	atomic_t dbg_data_seq;



	/* Spinlock used to sync the flag mcp_handling_status with

	 * the mfw events handler

	 */

	spinlock_t unload_lock;

	unsigned long mcp_handling_status;

#define QED_MCP_BYPASS_PROC_BIT 0

#define QED_MCP_IN_PROCESSING_BIT       1

};



struct qed_mcp_mb_params {