qed: Avoid sending mailbox commands when MFW is not responsive

Keep sending mailbox commands to the MFW when it is not responsive ends up
with a redundant amount of timeout expiries.
This patch prints the MCP status on the first command which is not
responded, and blocks the following commands.
Since the (un)load request commands might be not responded due to other
PFs, the patch also adds the option to skip the blocking upon a failure.
Signed-off-by: Tomer Tayar <Tomer.Tayar@cavium.com>
Signed-off-by: Ariel Elior <Ariel.Elior@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -320,6 +320,12 @@ int qed_mcp_reset(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
 	u32 org_mcp_reset_seq, seq, delay = QED_MCP_RESP_ITER_US, cnt = 0;
 	int rc = 0;
 
+	if (p_hwfn->mcp_info->b_block_cmd) {
+		DP_NOTICE(p_hwfn,
+			  "The MFW is not responsive. Avoid sending MCP_RESET mailbox command.\n");
+		return -EBUSY;
+	}
+
 	/* Ensure that only a single thread is accessing the mailbox */
 	spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
 
@@ -445,6 +451,33 @@ static void __qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
 		   (p_mb_params->cmd | seq_num), p_mb_params->param);
 }
 
+static void qed_mcp_cmd_set_blocking(struct qed_hwfn *p_hwfn, bool block_cmd)
+{
+	p_hwfn->mcp_info->b_block_cmd = block_cmd;
+
+	DP_INFO(p_hwfn, "%s sending of mailbox commands to the MFW\n",
+		block_cmd ? "Block" : "Unblock");
+}
+
+static void qed_mcp_print_cpu_info(struct qed_hwfn *p_hwfn,
+				   struct qed_ptt *p_ptt)
+{
+	u32 cpu_mode, cpu_state, cpu_pc_0, cpu_pc_1, cpu_pc_2;
+	u32 delay = QED_MCP_RESP_ITER_US;
+
+	cpu_mode = qed_rd(p_hwfn, p_ptt, MCP_REG_CPU_MODE);
+	cpu_state = qed_rd(p_hwfn, p_ptt, MCP_REG_CPU_STATE);
+	cpu_pc_0 = qed_rd(p_hwfn, p_ptt, MCP_REG_CPU_PROGRAM_COUNTER);
+	udelay(delay);
+	cpu_pc_1 = qed_rd(p_hwfn, p_ptt, MCP_REG_CPU_PROGRAM_COUNTER);
+	udelay(delay);
+	cpu_pc_2 = qed_rd(p_hwfn, p_ptt, MCP_REG_CPU_PROGRAM_COUNTER);
+
+	DP_NOTICE(p_hwfn,
+		  "MCP CPU info: mode 0x%08x, state 0x%08x, pc {0x%08x, 0x%08x, 0x%08x}\n",
+		  cpu_mode, cpu_state, cpu_pc_0, cpu_pc_1, cpu_pc_2);
+}
+
 static int
 _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
 		       struct qed_ptt *p_ptt,
@@ -531,11 +564,15 @@ _qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
 		DP_NOTICE(p_hwfn,
 			  "The MFW failed to respond to command 0x%08x [param 0x%08x].\n",
 			  p_mb_params->cmd, p_mb_params->param);
+		qed_mcp_print_cpu_info(p_hwfn, p_ptt);
 
 		spin_lock_bh(&p_hwfn->mcp_info->cmd_lock);
 		qed_mcp_cmd_del_elem(p_hwfn, p_cmd_elem);
 		spin_unlock_bh(&p_hwfn->mcp_info->cmd_lock);
 
+		if (!QED_MB_FLAGS_IS_SET(p_mb_params, AVOID_BLOCK))
+			qed_mcp_cmd_set_blocking(p_hwfn, true);
+
 		return -EAGAIN;
 	}
 
@@ -573,6 +610,13 @@ static int qed_mcp_cmd_and_union(struct qed_hwfn *p_hwfn,
 		return -EBUSY;
 	}
 
+	if (p_hwfn->mcp_info->b_block_cmd) {
+		DP_NOTICE(p_hwfn,
+			  "The MFW is not responsive. Avoid sending mailbox command 0x%08x [param 0x%08x].\n",
+			  p_mb_params->cmd, p_mb_params->param);
+		return -EBUSY;
+	}
+
 	if (p_mb_params->data_src_size > union_data_size ||
 	    p_mb_params->data_dst_size > union_data_size) {
 		DP_ERR(p_hwfn,
@@ -806,7 +850,7 @@ __qed_mcp_load_req(struct qed_hwfn *p_hwfn,
 	mb_params.data_src_size = sizeof(load_req);
 	mb_params.p_data_dst = &load_rsp;
 	mb_params.data_dst_size = sizeof(load_rsp);
-	mb_params.flags = QED_MB_FLAG_CAN_SLEEP;
+	mb_params.flags = QED_MB_FLAG_CAN_SLEEP | QED_MB_FLAG_AVOID_BLOCK;
 
 	DP_VERBOSE(p_hwfn, QED_MSG_SP,
 		   "Load Request: param 0x%08x [init_hw %d, drv_type %d, hsi_ver %d, pda 0x%04x]\n",
@@ -1050,7 +1094,7 @@ int qed_mcp_unload_req(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
 	memset(&mb_params, 0, sizeof(mb_params));
 	mb_params.cmd = DRV_MSG_CODE_UNLOAD_REQ;
 	mb_params.param = wol_param;
-	mb_params.flags = QED_MB_FLAG_CAN_SLEEP;
+	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);
 }
@@ -2158,6 +2202,8 @@ int qed_mcp_halt(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
 		return -EBUSY;
 	}
 
+	qed_mcp_cmd_set_blocking(p_hwfn, true);
+
 	return 0;
 }
 
@@ -2182,6 +2228,8 @@ int qed_mcp_resume(struct qed_hwfn *p_hwfn, struct qed_ptt *p_ptt)
 		return -EBUSY;
 	}
 
+	qed_mcp_cmd_set_blocking(p_hwfn, false);
+
 	return 0;
 }
 

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

@@ -635,11 +635,14 @@ struct qed_mcp_info {
 	 */
 	spinlock_t				cmd_lock;
 
+	/* Flag to indicate whether sending a MFW mailbox command is blocked */
+	bool					b_block_cmd;
+
 	/* Spinlock used for syncing SW link-changes and link-changes
 	 * originating from attention context.
 	 */
 	spinlock_t				link_lock;
-	bool					block_mb_sending;
+
 	u32					public_base;
 	u32					drv_mb_addr;
 	u32					mfw_mb_addr;
@@ -670,6 +673,7 @@ struct qed_mcp_mb_params {
 	u32 mcp_param;
 	u32 flags;
 #define QED_MB_FLAG_CAN_SLEEP	(0x1 << 0)
+#define QED_MB_FLAG_AVOID_BLOCK	(0x1 << 1)
 #define QED_MB_FLAGS_IS_SET(params, flag) \
 	({ typeof(params) __params = (params); \
 	   (__params && (__params->flags & QED_MB_FLAG_ ## flag)); })

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

@@ -565,6 +565,7 @@
 #define MCP_REG_CPU_STATE_SOFT_HALTED	(0x1UL << 10)
 #define MCP_REG_CPU_EVENT_MASK \
 	0xe05008UL
+#define MCP_REG_CPU_PROGRAM_COUNTER	0xe0501cUL
 #define PGLUE_B_REG_PF_BAR0_SIZE \
 	0x2aae60UL
 #define PGLUE_B_REG_PF_BAR1_SIZE \