scsi: qla2xxx: Check for MB timeout while capturing ISP27/28xx FW dump

Add mailbox timeout checkout for ISP 27xx/28xx during FW dump procedure.
Without the timeout check, hardware lock can be held for long period. This
patch would shorten the dump procedure if a timeout condition is
encountered.

Link: https://lore.kernel.org/r/20190912180918.6436-12-hmadhani@marvell.comReviewed-by: Laurence Oberman <loberman@redhat.com>
Signed-off-by: Quinn Tran <qutran@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla2xxx/qla_tmpl.c

@@ -10,6 +10,7 @@
 #define ISPREG(vha)	(&(vha)->hw->iobase->isp24)
 #define IOBAR(reg)	offsetof(typeof(*(reg)), iobase_addr)
 #define IOBASE(vha)	IOBAR(ISPREG(vha))
+#define INVALID_ENTRY ((struct qla27xx_fwdt_entry *)0xffffffffffffffffUL)
 
 static inline void
 qla27xx_insert16(uint16_t value, void *buf, ulong *len)
@@ -261,6 +262,7 @@ qla27xx_fwdt_entry_t262(struct scsi_qla_host *vha,
 	ulong start = le32_to_cpu(ent->t262.start_addr);
 	ulong end = le32_to_cpu(ent->t262.end_addr);
 	ulong dwords;
+	int rc;
 
 	ql_dbg(ql_dbg_misc, vha, 0xd206,
 	    "%s: rdram(%x) [%lx]\n", __func__, ent->t262.ram_area, *len);
@@ -308,7 +310,13 @@ qla27xx_fwdt_entry_t262(struct scsi_qla_host *vha,
 	dwords = end - start + 1;
 	if (buf) {
 		buf += *len;
-		qla24xx_dump_ram(vha->hw, start, buf, dwords, &buf);
+		rc = qla24xx_dump_ram(vha->hw, start, buf, dwords, &buf);
+		if (rc != QLA_SUCCESS) {
+			ql_dbg(ql_dbg_async, vha, 0xffff,
+			    "%s: dump ram MB failed. Area %xh start %lxh end %lxh\n",
+			    __func__, area, start, end);
+			return INVALID_ENTRY;
+		}
 	}
 	*len += dwords * sizeof(uint32_t);
 done:
@@ -838,6 +846,13 @@ qla27xx_walk_template(struct scsi_qla_host *vha,
 		ent = qla27xx_find_entry(type)(vha, ent, buf, len);
 		if (!ent)
 			break;
+
+		if (ent == INVALID_ENTRY) {
+			*len = 0;
+			ql_dbg(ql_dbg_async, vha, 0xffff,
+			    "Unable to capture FW dump");
+			goto bailout;
+		}
 	}
 
 	if (tmp->count)
@@ -847,6 +862,9 @@ qla27xx_walk_template(struct scsi_qla_host *vha,
 	if (ent)
 		ql_dbg(ql_dbg_misc, vha, 0xd019,
 		    "%s: missing end entry\n", __func__);
+
+bailout:
+	cpu_to_le32s(&tmp->count);	/* endianize residual count */
 }
 
 static void
@@ -1010,7 +1028,9 @@ qla27xx_fwdump(scsi_qla_host_t *vha, int hardware_locked)
 			}
 			len = qla27xx_execute_fwdt_template(vha,
 			    fwdt->template, buf);
-			if (len != fwdt->dump_size) {
+			if (len == 0) {
+				goto bailout;
+			} else if (len != fwdt->dump_size) {
 				ql_log(ql_log_warn, vha, 0xd013,
 				    "-> fwdt%u fwdump residual=%+ld\n",
 				    j, fwdt->dump_size - len);
@@ -1025,6 +1045,7 @@ qla27xx_fwdump(scsi_qla_host_t *vha, int hardware_locked)
 		qla2x00_post_uevent_work(vha, QLA_UEVENT_CODE_FW_DUMP);
 	}
 
+bailout:
 #ifndef __CHECKER__
 	if (!hardware_locked)
 		spin_unlock_irqrestore(&vha->hw->hardware_lock, flags);