[PATCH 02/10] cxgb4: DB Drop Recovery for RDMA and LLD queues.

[Vipul Pandya <vipul@chelsio.com>]

    - Add platform-specific callback functions for interrupts.  This is
    needed to do a single read-clear of the CAUSE register and then call
    out to platform specific functions for DB threshold interrupts and DB
    drop interrupts.

    - Add t4_mem_win_read_len() - mem-window reads for arbitrary lengths.
    This is used to read the CIDX/PIDX values from EC contexts during DB
    drop recovery.

    - Add t4_fwaddrspace_write() - sends addrspace write cmds to the fw.
    Needed to flush the sge eq context cache.

Signed-off-by: Vipul Pandya <vipul@chelsio.com>
Signed-off-by: Steve Wise <swise@opengridcomputing.com>
---
 drivers/net/ethernet/chelsio/cxgb4/t4_hw.c    |   69 +++++++++++++++++++++----
 drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h |    5 ++
 2 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
index 13609bf..32e1dd5 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4_hw.c
@@ -868,11 +868,14 @@ int t4_restart_aneg(struct adapter *adap, unsigned int mbox, unsigned int port)
 	return t4_wr_mbox(adap, mbox, &c, sizeof(c), NULL);
 }
 
+typedef void (*int_handler_t)(struct adapter *adap);
+
 struct intr_info {
 	unsigned int mask;       /* bits to check in interrupt status */
 	const char *msg;         /* message to print or NULL */
 	short stat_idx;          /* stat counter to increment or -1 */
 	unsigned short fatal;    /* whether the condition reported is fatal */
+	int_handler_t int_handler; /* platform-specific int handler */
 };
 
 /**
@@ -905,6 +908,8 @@ static int t4_handle_intr_status(struct adapter *adapter, unsigned int reg,
 		} else if (acts->msg && printk_ratelimit())
 			dev_warn(adapter->pdev_dev, "%s (0x%x)\n", acts->msg,
 				 status & acts->mask);
+		if (acts->int_handler)
+			acts->int_handler(adapter);
 		mask |= acts->mask;
 	}
 	status &= mask;
@@ -1013,9 +1018,9 @@ static void sge_intr_handler(struct adapter *adapter)
 		{ ERR_INVALID_CIDX_INC,
 		  "SGE GTS CIDX increment too large", -1, 0 },
 		{ ERR_CPL_OPCODE_0, "SGE received 0-length CPL", -1, 0 },
-		{ F_DBFIFO_LP_INT, NULL, -1, 0 },
-		{ F_DBFIFO_HP_INT, NULL, -1, 0 },
-		{ ERR_DROPPED_DB, "SGE doorbell dropped", -1, 0 },
+		{ F_DBFIFO_LP_INT, NULL, -1, 0, t4_db_full },
+		{ F_DBFIFO_HP_INT, NULL, -1, 0, t4_db_full },
+		{ F_ERR_DROPPED_DB, NULL, -1, 0, t4_db_dropped },
 		{ ERR_DATA_CPL_ON_HIGH_QID1 | ERR_DATA_CPL_ON_HIGH_QID0,
 		  "SGE IQID > 1023 received CPL for FL", -1, 0 },
 		{ ERR_BAD_DB_PIDX3, "SGE DBP 3 pidx increment too large", -1,
@@ -1036,20 +1041,14 @@ static void sge_intr_handler(struct adapter *adapter)
 	};
 
 	v = (u64)t4_read_reg(adapter, SGE_INT_CAUSE1) |
-	    ((u64)t4_read_reg(adapter, SGE_INT_CAUSE2) << 32);
+		((u64)t4_read_reg(adapter, SGE_INT_CAUSE2) << 32);
 	if (v) {
 		dev_alert(adapter->pdev_dev, "SGE parity error (%#llx)\n",
-			 (unsigned long long)v);
+				(unsigned long long)v);
 		t4_write_reg(adapter, SGE_INT_CAUSE1, v);
 		t4_write_reg(adapter, SGE_INT_CAUSE2, v >> 32);
 	}
 
-	err = t4_read_reg(adapter, A_SGE_INT_CAUSE3);
-	if (err & (F_DBFIFO_HP_INT|F_DBFIFO_LP_INT))
-		t4_db_full(adapter);
-	if (err & F_ERR_DROPPED_DB)
-		t4_db_dropped(adapter);
-
 	if (t4_handle_intr_status(adapter, SGE_INT_CAUSE3, sge_intr_info) ||
 	    v != 0)
 		t4_fatal_err(adapter);
@@ -1995,6 +1994,54 @@ int t4_wol_pat_enable(struct adapter *adap, unsigned int port, unsigned int map,
 	(var).retval_len16 = htonl(FW_LEN16(var)); \
 } while (0)
 
+int t4_fwaddrspace_write(struct adapter *adap, unsigned int mbox,
+			  u32 addr, u32 val)
+{
+	struct fw_ldst_cmd c;
+
+	memset(&c, 0, sizeof(c));
+	c.op_to_addrspace = htonl(V_FW_CMD_OP(FW_LDST_CMD) | F_FW_CMD_REQUEST |
+			    F_FW_CMD_WRITE |
+			    V_FW_LDST_CMD_ADDRSPACE(FW_LDST_ADDRSPC_FIRMWARE));
+	c.cycles_to_len16 = htonl(FW_LEN16(c));
+	c.u.addrval.addr = htonl(addr);
+	c.u.addrval.val = htonl(val);
+
+	return t4_wr_mbox(adap, mbox, &c, sizeof(c), NULL);
+}
+
+/*
+ *     t4_mem_win_read_len - read memory through PCIE memory window
+ *     @adap: the adapter
+ *     @addr: address of first byte requested aligned on 32b.
+ *     @data: len bytes to hold the data read
+ *     @len: amount of data to read from window.  Must be <=
+ *            MEMWIN0_APERATURE after adjusting for 16B alignment
+ *            requirements of the the memory window.
+ *
+ *     Read len bytes of data from MC starting at @addr.
+ */
+int t4_mem_win_read_len(struct adapter *adap, u32 addr, __be32 *data, int len)
+{
+	int i;
+	int off;
+
+	/*
+	 * Align on a 16B boundary.
+	 */
+	off = addr & 15;
+	if ((addr & 3) || (len + off) > MEMWIN0_APERTURE)
+		return -EINVAL;
+
+	t4_write_reg(adap, A_PCIE_MEM_ACCESS_OFFSET, addr & ~15);
+	t4_read_reg(adap, A_PCIE_MEM_ACCESS_OFFSET);
+
+	for (i = 0; i < len; i += 4)
+		*data++ = t4_read_reg(adap, (MEMWIN0_BASE + off + i));
+
+	return 0;
+}
+
 /**
  *	t4_mdio_rd - read a PHY register through MDIO
  *	@adap: the adapter
diff --git a/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h b/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
index edcfd7e..83ca454 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
+++ b/drivers/net/ethernet/chelsio/cxgb4/t4fw_api.h
@@ -1620,4 +1620,9 @@ struct fw_hdr {
 #define FW_HDR_FW_VER_MINOR_GET(x) (((x) >> 16) & 0xff)
 #define FW_HDR_FW_VER_MICRO_GET(x) (((x) >> 8) & 0xff)
 #define FW_HDR_FW_VER_BUILD_GET(x) (((x) >> 0) & 0xff)
+
+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);
+
 #endif /* _T4FW_INTERFACE_H_ */
-- 
1.7.1