scsi: hisi_sas: add v2 hw internal abort timeout workaround

This patch is a workaround for a SoC bug where an internal abort command
may timeout. In v2 hw, the channel should become idle in order to finish
abort process. If the target side has been sending HOLD, host side
channel failed to complete the frame to send, and can not enter the idle
state. Then internal abort command will timeout.

As this issue is only in v2 hw, we deal with it in the hw layer.  Our
workaround solution is: If abort is not finished within a certain period
of time, we will check HOLD status. If HOLD has been sending, we will
send break command.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -138,6 +138,7 @@ struct hisi_sas_slot {
 	struct hisi_sas_sge_page *sge_page;
 	dma_addr_t sge_page_dma;
 	struct work_struct abort_slot;
+	struct timer_list internal_abort_timer;
 };
 
 struct hisi_sas_tmf_task {

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -1224,7 +1224,7 @@ hisi_sas_internal_task_abort(struct hisi_hba *hisi_hba,
 	task->task_done = hisi_sas_task_done;
 	task->slow_task->timer.data = (unsigned long)task;
 	task->slow_task->timer.function = hisi_sas_tmf_timedout;
-	task->slow_task->timer.expires = jiffies + 20*HZ;
+	task->slow_task->timer.expires = jiffies + msecs_to_jiffies(110);
 	add_timer(&task->slow_task->timer);
 
 	/* Lock as we are alloc'ing a slot, which cannot be interrupted */

drivers/scsi/hisi_sas/hisi_sas_v2_hw.c

@@ -2260,15 +2260,18 @@ slot_complete_v2_hw(struct hisi_hba *hisi_hba, struct hisi_sas_slot *slot)
 	case STAT_IO_COMPLETE:
 		/* internal abort command complete */
 		ts->stat = TMF_RESP_FUNC_SUCC;
+		del_timer(&slot->internal_abort_timer);
 		goto out;
 	case STAT_IO_NO_DEVICE:
 		ts->stat = TMF_RESP_FUNC_COMPLETE;
+		del_timer(&slot->internal_abort_timer);
 		goto out;
 	case STAT_IO_NOT_VALID:
 		/* abort single io, controller don't find
 		 * the io need to abort
 		 */
 		ts->stat = TMF_RESP_FUNC_FAILED;
+		del_timer(&slot->internal_abort_timer);
 		goto out;
 	default:
 		break;
@@ -2502,6 +2505,40 @@ static int prep_ata_v2_hw(struct hisi_hba *hisi_hba,
 	return 0;
 }
 
+static void hisi_sas_internal_abort_quirk_timeout(unsigned long data)
+{
+	struct hisi_sas_slot *slot = (struct hisi_sas_slot *)data;
+	struct hisi_sas_port *port = slot->port;
+	struct asd_sas_port *asd_sas_port;
+	struct asd_sas_phy *sas_phy;
+
+	if (!port)
+		return;
+
+	asd_sas_port = &port->sas_port;
+
+	/* Kick the hardware - send break command */
+	list_for_each_entry(sas_phy, &asd_sas_port->phy_list, port_phy_el) {
+		struct hisi_sas_phy *phy = sas_phy->lldd_phy;
+		struct hisi_hba *hisi_hba = phy->hisi_hba;
+		int phy_no = sas_phy->id;
+		u32 link_dfx2;
+
+		link_dfx2 = hisi_sas_phy_read32(hisi_hba, phy_no, LINK_DFX2);
+		if ((link_dfx2 == LINK_DFX2_RCVR_HOLD_STS_MSK) ||
+		    (link_dfx2 & LINK_DFX2_SEND_HOLD_STS_MSK)) {
+			u32 txid_auto;
+
+			txid_auto = hisi_sas_phy_read32(hisi_hba, phy_no,
+							TXID_AUTO);
+			txid_auto |= TXID_AUTO_CTB_MSK;
+			hisi_sas_phy_write32(hisi_hba, phy_no, TXID_AUTO,
+					     txid_auto);
+			return;
+		}
+	}
+}
+
 static int prep_abort_v2_hw(struct hisi_hba *hisi_hba,
 		struct hisi_sas_slot *slot,
 		int device_id, int abort_flag, int tag_to_abort)
@@ -2510,6 +2547,13 @@ static int prep_abort_v2_hw(struct hisi_hba *hisi_hba,
 	struct domain_device *dev = task->dev;
 	struct hisi_sas_cmd_hdr *hdr = slot->cmd_hdr;
 	struct hisi_sas_port *port = slot->port;
+	struct timer_list *timer = &slot->internal_abort_timer;
+
+	/* setup the quirk timer */
+	setup_timer(timer, hisi_sas_internal_abort_quirk_timeout,
+		    (unsigned long)slot);
+	/* Set the timeout to 10ms less than internal abort timeout */
+	mod_timer(timer, jiffies + msecs_to_jiffies(100));
 
 	/* dw0 */
 	hdr->dw0 = cpu_to_le32((5 << CMD_HDR_CMD_OFF) | /*abort*/