From: Xiang Chen <chenxiang66@hisilicon.com>
Date: Thu, 28 Feb 2019 22:51:01 +0800
Subject: scsi: hisi_sas: Send HARD RESET to clear the previous affiliation of
 STP target port
Git-commit: 57dbb2b218eb6b4faa39025e3e5974742a4e8986
Patch-mainline: v5.1-rc1
References: bsc#1135037

If we exchange SAS expander from one SAS controller to other SAS controller
without powering it down, the STP target port will maintain previous
affiliation and reject all subsequent connection requests from other STP
initiator ports with OPEN_REJECT (STP RESOURCES BUSY).

To solve this issue, send HARD RESET to clear the previous affiliation of
STP target port according to SPL (chapter 6.19.4).

We (re-)introduce dev status flag to know if to sleep in NEXUS reset code
or not for remote PHYs. The idea is that if the device is being
initialised, we don't require the delay, and caller would wait for link to
be established, cf. sas_ata_hard_reset().

Co-developed-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: Xiang Chen <chenxiang66@hisilicon.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/scsi/hisi_sas/hisi_sas.h       |    7 +++++
 drivers/scsi/hisi_sas/hisi_sas_main.c  |   43 ++++++++++++++++++++++++++++++---
 drivers/scsi/hisi_sas/hisi_sas_v2_hw.c |    1 
 3 files changed, 48 insertions(+), 3 deletions(-)

--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -18,6 +18,7 @@
 #include <linux/dmapool.h>
 #include <linux/iopoll.h>
 #include <linux/lcm.h>
+#include <linux/libata.h>
 #include <linux/mfd/syscon.h>
 #include <linux/module.h>
 #include <linux/of_address.h>
@@ -94,6 +95,11 @@ enum {
 	PORT_TYPE_SATA = (1U << 0),
 };
 
+enum dev_status {
+	HISI_SAS_DEV_INIT,
+	HISI_SAS_DEV_NORMAL,
+};
+
 enum {
 	HISI_SAS_INT_ABT_CMD = 0,
 	HISI_SAS_INT_ABT_DEV = 1,
@@ -195,6 +201,7 @@ struct hisi_sas_device {
 	struct hisi_sas_dq	*dq;
 	struct list_head	list;
 	enum sas_device_type	dev_type;
+	enum dev_status dev_status;
 	int device_id;
 	int sata_idx;
 	spinlock_t lock; /* For protecting slots */
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -732,6 +732,8 @@ static int hisi_sas_init_device(struct d
 	struct hisi_sas_tmf_task tmf_task;
 	int retry = HISI_SAS_SRST_ATA_DISK_CNT;
 	struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
+	struct device *dev = hisi_hba->dev;
+	struct sas_phy *local_phy;
 
 	switch (device->dev_type) {
 	case SAS_END_DEVICE:
@@ -747,6 +749,31 @@ static int hisi_sas_init_device(struct d
 	case SAS_SATA_PM:
 	case SAS_SATA_PM_PORT:
 	case SAS_SATA_PENDING:
+		/*
+		 * send HARD RESET to clear previous affiliation of
+		 * STP target port
+		 */
+		local_phy = sas_get_local_phy(device);
+		if (!scsi_is_sas_phy_local(local_phy)) {
+			unsigned long deadline = ata_deadline(jiffies, 20000);
+			struct sata_device *sata_dev = &device->sata_dev;
+			struct ata_host *ata_host = sata_dev->ata_host;
+			struct ata_port_operations *ops = ata_host->ops;
+			struct ata_port *ap = sata_dev->ap;
+			struct ata_link *link;
+			unsigned int classes;
+
+			ata_for_each_link(link, ap, EDGE)
+				rc = ops->hardreset(link, &classes,
+						    deadline);
+		}
+		sas_put_local_phy(local_phy);
+		if (rc) {
+			dev_warn(dev, "SATA disk hardreset fail: 0x%x\n",
+				 rc);
+			return rc;
+		}
+
 		while (retry-- > 0) {
 			rc = hisi_sas_softreset_ata_disk(device);
 			if (!rc)
@@ -809,6 +836,7 @@ static int hisi_sas_dev_found(struct dom
 	rc = hisi_sas_init_device(device);
 	if (rc)
 		goto err_out;
+	sas_dev->dev_status = HISI_SAS_DEV_NORMAL;
 	return 0;
 
 err_out:
@@ -1715,20 +1743,23 @@ static int hisi_sas_clear_aca(struct dom
 static int hisi_sas_debug_I_T_nexus_reset(struct domain_device *device)
 {
 	struct sas_phy *local_phy = sas_get_local_phy(device);
-	int rc, reset_type = (device->dev_type == SAS_SATA_DEV ||
-			(device->tproto & SAS_PROTOCOL_STP)) ? 0 : 1;
+	struct hisi_sas_device *sas_dev = device->lldd_dev;
 	struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
 	struct sas_ha_struct *sas_ha = &hisi_hba->sha;
 	struct asd_sas_phy *sas_phy = sas_ha->sas_phy[local_phy->number];
 	struct hisi_sas_phy *phy = container_of(sas_phy,
 			struct hisi_sas_phy, sas_phy);
 	DECLARE_COMPLETION_ONSTACK(phyreset);
+	int rc, reset_type;
 
 	if (scsi_is_sas_phy_local(local_phy)) {
 		phy->in_reset = 1;
 		phy->reset_completion = &phyreset;
 	}
 
+	reset_type = (sas_dev->dev_status == HISI_SAS_DEV_INIT ||
+		      !dev_is_sata(device)) ? 1 : 0;
+
 	rc = sas_phy_reset(local_phy, reset_type);
 	sas_put_local_phy(local_phy);
 
@@ -1744,8 +1775,13 @@ static int hisi_sas_debug_I_T_nexus_rese
 		/* report PHY down if timed out */
 		if (!ret)
 			hisi_sas_phy_down(hisi_hba, sas_phy->id, 0);
-	} else
+	} else if (sas_dev->dev_status != HISI_SAS_DEV_INIT) {
+		/*
+		 * If in init state, we rely on caller to wait for link to be
+		 * ready; otherwise, delay.
+		 */
 		msleep(2000);
+	}
 
 	return rc;
 }
@@ -2259,6 +2295,7 @@ int hisi_sas_alloc(struct hisi_hba *hisi
 	for (i = 0; i < HISI_SAS_MAX_DEVICES; i++) {
 		hisi_hba->devices[i].dev_type = SAS_PHY_UNUSED;
 		hisi_hba->devices[i].device_id = i;
+		hisi_hba->devices[i].dev_status = HISI_SAS_DEV_INIT;
 	}
 
 	for (i = 0; i < hisi_hba->queue_count; i++) {
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -868,6 +868,7 @@ hisi_sas_device *alloc_dev_quirk_v2_hw(s
 
 			hisi_hba->devices[i].device_id = i;
 			sas_dev = &hisi_hba->devices[i];
+			sas_dev->dev_status = HISI_SAS_DEV_INIT;
 			sas_dev->dev_type = device->dev_type;
 			sas_dev->hisi_hba = hisi_hba;
 			sas_dev->sas_device = device;