cxgb4: Add code to dump SGE registers when hitting idma hangs

Based on original work by Casey Leedom <leedom@chelsio.com>

Signed-off-by: Kumar Sanghvi <kumaras@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4.h

@@ -1032,4 +1032,5 @@ void t4_db_dropped(struct adapter *adapter);
 int t4_mem_win_read_len(struct adapter *adap, u32 addr, __be32 *data, int len);
 int t4_fwaddrspace_write(struct adapter *adap, unsigned int mbox,
 			 u32 addr, u32 val);
+void t4_sge_decode_idma_state(struct adapter *adapter, int state);
 #endif /* __CXGB4_H__ */

drivers/net/ethernet/chelsio/cxgb4/t4_hw.c

@@ -2596,6 +2596,112 @@ int t4_mdio_wr(struct adapter *adap, unsigned int mbox, unsigned int phy_addr,
 	return t4_wr_mbox(adap, mbox, &c, sizeof(c), NULL);
 }
 
+/**
+ *	t4_sge_decode_idma_state - decode the idma state
+ *	@adap: the adapter
+ *	@state: the state idma is stuck in
+ */
+void t4_sge_decode_idma_state(struct adapter *adapter, int state)
+{
+	static const char * const t4_decode[] = {
+		"IDMA_IDLE",
+		"IDMA_PUSH_MORE_CPL_FIFO",
+		"IDMA_PUSH_CPL_MSG_HEADER_TO_FIFO",
+		"Not used",
+		"IDMA_PHYSADDR_SEND_PCIEHDR",
+		"IDMA_PHYSADDR_SEND_PAYLOAD_FIRST",
+		"IDMA_PHYSADDR_SEND_PAYLOAD",
+		"IDMA_SEND_FIFO_TO_IMSG",
+		"IDMA_FL_REQ_DATA_FL_PREP",
+		"IDMA_FL_REQ_DATA_FL",
+		"IDMA_FL_DROP",
+		"IDMA_FL_H_REQ_HEADER_FL",
+		"IDMA_FL_H_SEND_PCIEHDR",
+		"IDMA_FL_H_PUSH_CPL_FIFO",
+		"IDMA_FL_H_SEND_CPL",
+		"IDMA_FL_H_SEND_IP_HDR_FIRST",
+		"IDMA_FL_H_SEND_IP_HDR",
+		"IDMA_FL_H_REQ_NEXT_HEADER_FL",
+		"IDMA_FL_H_SEND_NEXT_PCIEHDR",
+		"IDMA_FL_H_SEND_IP_HDR_PADDING",
+		"IDMA_FL_D_SEND_PCIEHDR",
+		"IDMA_FL_D_SEND_CPL_AND_IP_HDR",
+		"IDMA_FL_D_REQ_NEXT_DATA_FL",
+		"IDMA_FL_SEND_PCIEHDR",
+		"IDMA_FL_PUSH_CPL_FIFO",
+		"IDMA_FL_SEND_CPL",
+		"IDMA_FL_SEND_PAYLOAD_FIRST",
+		"IDMA_FL_SEND_PAYLOAD",
+		"IDMA_FL_REQ_NEXT_DATA_FL",
+		"IDMA_FL_SEND_NEXT_PCIEHDR",
+		"IDMA_FL_SEND_PADDING",
+		"IDMA_FL_SEND_COMPLETION_TO_IMSG",
+		"IDMA_FL_SEND_FIFO_TO_IMSG",
+		"IDMA_FL_REQ_DATAFL_DONE",
+		"IDMA_FL_REQ_HEADERFL_DONE",
+	};
+	static const char * const t5_decode[] = {
+		"IDMA_IDLE",
+		"IDMA_ALMOST_IDLE",
+		"IDMA_PUSH_MORE_CPL_FIFO",
+		"IDMA_PUSH_CPL_MSG_HEADER_TO_FIFO",
+		"IDMA_SGEFLRFLUSH_SEND_PCIEHDR",
+		"IDMA_PHYSADDR_SEND_PCIEHDR",
+		"IDMA_PHYSADDR_SEND_PAYLOAD_FIRST",
+		"IDMA_PHYSADDR_SEND_PAYLOAD",
+		"IDMA_SEND_FIFO_TO_IMSG",
+		"IDMA_FL_REQ_DATA_FL",
+		"IDMA_FL_DROP",
+		"IDMA_FL_DROP_SEND_INC",
+		"IDMA_FL_H_REQ_HEADER_FL",
+		"IDMA_FL_H_SEND_PCIEHDR",
+		"IDMA_FL_H_PUSH_CPL_FIFO",
+		"IDMA_FL_H_SEND_CPL",
+		"IDMA_FL_H_SEND_IP_HDR_FIRST",
+		"IDMA_FL_H_SEND_IP_HDR",
+		"IDMA_FL_H_REQ_NEXT_HEADER_FL",
+		"IDMA_FL_H_SEND_NEXT_PCIEHDR",
+		"IDMA_FL_H_SEND_IP_HDR_PADDING",
+		"IDMA_FL_D_SEND_PCIEHDR",
+		"IDMA_FL_D_SEND_CPL_AND_IP_HDR",
+		"IDMA_FL_D_REQ_NEXT_DATA_FL",
+		"IDMA_FL_SEND_PCIEHDR",
+		"IDMA_FL_PUSH_CPL_FIFO",
+		"IDMA_FL_SEND_CPL",
+		"IDMA_FL_SEND_PAYLOAD_FIRST",
+		"IDMA_FL_SEND_PAYLOAD",
+		"IDMA_FL_REQ_NEXT_DATA_FL",
+		"IDMA_FL_SEND_NEXT_PCIEHDR",
+		"IDMA_FL_SEND_PADDING",
+		"IDMA_FL_SEND_COMPLETION_TO_IMSG",
+	};
+	static const u32 sge_regs[] = {
+		SGE_DEBUG_DATA_LOW_INDEX_2,
+		SGE_DEBUG_DATA_LOW_INDEX_3,
+		SGE_DEBUG_DATA_HIGH_INDEX_10,
+	};
+	const char **sge_idma_decode;
+	int sge_idma_decode_nstates;
+	int i;
+
+	if (is_t4(adapter->params.chip)) {
+		sge_idma_decode = (const char **)t4_decode;
+		sge_idma_decode_nstates = ARRAY_SIZE(t4_decode);
+	} else {
+		sge_idma_decode = (const char **)t5_decode;
+		sge_idma_decode_nstates = ARRAY_SIZE(t5_decode);
+	}
+
+	if (state < sge_idma_decode_nstates)
+		CH_WARN(adapter, "idma state %s\n", sge_idma_decode[state]);
+	else
+		CH_WARN(adapter, "idma state %d unknown\n", state);
+
+	for (i = 0; i < ARRAY_SIZE(sge_regs); i++)
+		CH_WARN(adapter, "SGE register %#x value %#x\n",
+			sge_regs[i], t4_read_reg(adapter, sge_regs[i]));
+}
+
 /**
  *      t4_fw_hello - establish communication with FW
  *      @adap: the adapter

drivers/net/ethernet/chelsio/cxgb4/t4_regs.h

@@ -278,6 +278,9 @@
 #define SGE_DEBUG_INDEX 0x10cc
 #define SGE_DEBUG_DATA_HIGH 0x10d0
 #define SGE_DEBUG_DATA_LOW 0x10d4
+#define SGE_DEBUG_DATA_LOW_INDEX_2	0x12c8
+#define SGE_DEBUG_DATA_LOW_INDEX_3	0x12cc
+#define SGE_DEBUG_DATA_HIGH_INDEX_10	0x12a8
 #define SGE_INGRESS_QUEUES_PER_PAGE_PF 0x10f4
 
 #define S_HP_INT_THRESH    28