scsi: hisi_sas: Create a scsi_host_template per HW module

When a SCSI host is registered, the SCSI mid-layer takes a reference to a
module in Scsi_host.hostt.module. In doing this, we are prevented from
removing the driver module for the host in dangerous scenario, like when a
disk is mounted.

Currently there is only one scsi_host_template (sht) for all HW versions,
and this is the main.c module. So this means that we can possibly remove
the HW module in this dangerous scenario, as SCSI mid-layer is only
referencing the main.c module.

To fix this, create a sht per module, referencing that same module to
create the Scsi host.

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>

5 files changed, 86 insertions, 33 deletions

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index b4717bd8af3f..37c9a6246dc8 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -248,6 +248,7 @@ struct hisi_sas_hw {
 				u8 reg_index, u8 reg_count, u8 *write_data);
 	int max_command_entries;
 	int complete_hdr_size;
+	struct scsi_host_template *sht;
 };
 
 struct hisi_hba {
@@ -440,8 +441,6 @@ struct hisi_sas_slot_buf_table {
 };
 
 extern struct scsi_transport_template *hisi_sas_stt;
-extern struct scsi_host_template *hisi_sas_sht;
-
 extern void hisi_sas_stop_phys(struct hisi_hba *hisi_hba);
 extern int hisi_sas_alloc(struct hisi_hba *hisi_hba, struct Scsi_Host *shost);
 extern void hisi_sas_free(struct hisi_hba *hisi_hba);
@@ -456,6 +455,11 @@ extern int hisi_sas_probe(struct platform_device *pdev,
 			  const struct hisi_sas_hw *ops);
 extern int hisi_sas_remove(struct platform_device *pdev);
 
+extern int hisi_sas_slave_configure(struct scsi_device *sdev);
+extern int hisi_sas_scan_finished(struct Scsi_Host *shost, unsigned long time);
+extern void hisi_sas_scan_start(struct Scsi_Host *shost);
+extern struct device_attribute *host_attrs[];
+extern int hisi_sas_host_reset(struct Scsi_Host *shost, int reset_type);
 extern void hisi_sas_phy_down(struct hisi_hba *hisi_hba, int phy_no, int rdy);
 extern void hisi_sas_slot_task_free(struct hisi_hba *hisi_hba,
 				    struct sas_task *task,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index c8e647a65b30..664aaf7f5147 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -719,7 +719,7 @@ err_out:
 	return rc;
 }
 
-static int hisi_sas_slave_configure(struct scsi_device *sdev)
+int hisi_sas_slave_configure(struct scsi_device *sdev)
 {
 	struct domain_device *dev = sdev_to_domain_dev(sdev);
 	int ret = sas_slave_configure(sdev);
@@ -731,15 +731,17 @@ static int hisi_sas_slave_configure(struct scsi_device *sdev)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(hisi_sas_slave_configure);
 
-static void hisi_sas_scan_start(struct Scsi_Host *shost)
+void hisi_sas_scan_start(struct Scsi_Host *shost)
 {
 	struct hisi_hba *hisi_hba = shost_priv(shost);
 
 	hisi_hba->hw->phys_init(hisi_hba);
 }
+EXPORT_SYMBOL_GPL(hisi_sas_scan_start);
 
-static int hisi_sas_scan_finished(struct Scsi_Host *shost, unsigned long time)
+int hisi_sas_scan_finished(struct Scsi_Host *shost, unsigned long time)
 {
 	struct hisi_hba *hisi_hba = shost_priv(shost);
 	struct sas_ha_struct *sha = &hisi_hba->sha;
@@ -751,6 +753,7 @@ static int hisi_sas_scan_finished(struct Scsi_Host *shost, unsigned long time)
 	sas_drain_work(sha);
 	return 1;
 }
+EXPORT_SYMBOL_GPL(hisi_sas_scan_finished);
 
 static void hisi_sas_phyup_work(struct work_struct *work)
 {
@@ -1824,34 +1827,11 @@ EXPORT_SYMBOL_GPL(hisi_sas_kill_tasklets);
 struct scsi_transport_template *hisi_sas_stt;
 EXPORT_SYMBOL_GPL(hisi_sas_stt);
 
-static struct device_attribute *host_attrs[] = {
+struct device_attribute *host_attrs[] = {
 	&dev_attr_phy_event_threshold,
 	NULL,
 };
-
-static struct scsi_host_template _hisi_sas_sht = {
-	.module			= THIS_MODULE,
-	.name			= DRV_NAME,
-	.queuecommand		= sas_queuecommand,
-	.target_alloc		= sas_target_alloc,
-	.slave_configure	= hisi_sas_slave_configure,
-	.scan_finished		= hisi_sas_scan_finished,
-	.scan_start		= hisi_sas_scan_start,
-	.change_queue_depth	= sas_change_queue_depth,
-	.bios_param		= sas_bios_param,
-	.can_queue		= 1,
-	.this_id		= -1,
-	.sg_tablesize		= SG_ALL,
-	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
-	.use_clustering		= ENABLE_CLUSTERING,
-	.eh_device_reset_handler = sas_eh_device_reset_handler,
-	.eh_target_reset_handler = sas_eh_target_reset_handler,
-	.target_destroy		= sas_target_destroy,
-	.ioctl			= sas_ioctl,
-	.shost_attrs		= host_attrs,
-};
-struct scsi_host_template *hisi_sas_sht = &_hisi_sas_sht;
-EXPORT_SYMBOL_GPL(hisi_sas_sht);
+EXPORT_SYMBOL_GPL(host_attrs);
 
 static struct sas_domain_function_template hisi_sas_transport_ops = {
 	.lldd_dev_found		= hisi_sas_dev_found,
@@ -2161,7 +2141,7 @@ static struct Scsi_Host *hisi_sas_shost_alloc(struct platform_device *pdev,
 	struct hisi_hba *hisi_hba;
 	struct device *dev = &pdev->dev;
 
-	shost = scsi_host_alloc(hisi_sas_sht, sizeof(*hisi_hba));
+	shost = scsi_host_alloc(hw->sht, sizeof(*hisi_hba));
 	if (!shost) {
 		dev_err(dev, "scsi host alloc failed\n");
 		return NULL;
@@ -2211,7 +2191,7 @@ err_out:
 }
 
 int hisi_sas_probe(struct platform_device *pdev,
-			 const struct hisi_sas_hw *hw)
+		   const struct hisi_sas_hw *hw)
 {
 	struct Scsi_Host *shost;
 	struct hisi_hba *hisi_hba;
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
index 8fa79d0968a6..8d5d8575d939 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
@@ -1788,6 +1788,28 @@ static int hisi_sas_v1_init(struct hisi_hba *hisi_hba)
 	return 0;
 }
 
+static struct scsi_host_template sht_v1_hw = {
+	.name			= DRV_NAME,
+	.module			= THIS_MODULE,
+	.queuecommand		= sas_queuecommand,
+	.target_alloc		= sas_target_alloc,
+	.slave_configure	= hisi_sas_slave_configure,
+	.scan_finished		= hisi_sas_scan_finished,
+	.scan_start		= hisi_sas_scan_start,
+	.change_queue_depth	= sas_change_queue_depth,
+	.bios_param		= sas_bios_param,
+	.can_queue		= 1,
+	.this_id		= -1,
+	.sg_tablesize		= SG_ALL,
+	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
+	.use_clustering		= ENABLE_CLUSTERING,
+	.eh_device_reset_handler = sas_eh_device_reset_handler,
+	.eh_target_reset_handler = sas_eh_target_reset_handler,
+	.target_destroy		= sas_target_destroy,
+	.ioctl			= sas_ioctl,
+	.shost_attrs		= host_attrs,
+};
+
 static const struct hisi_sas_hw hisi_sas_v1_hw = {
 	.hw_init = hisi_sas_v1_init,
 	.setup_itct = setup_itct_v1_hw,
@@ -1807,6 +1829,7 @@ static const struct hisi_sas_hw hisi_sas_v1_hw = {
 	.get_wideport_bitmap = get_wideport_bitmap_v1_hw,
 	.max_command_entries = HISI_SAS_COMMAND_ENTRIES_V1_HW,
 	.complete_hdr_size = sizeof(struct hisi_sas_complete_v1_hdr),
+	.sht = &sht_v1_hw,
 };
 
 static int hisi_sas_v1_probe(struct platform_device *pdev)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
index fb0e966a44a8..8def327c4f46 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
@@ -3501,6 +3501,29 @@ static int write_gpio_v2_hw(struct hisi_hba *hisi_hba, u8 reg_type,
 	return 0;
 }
 
+
+static struct scsi_host_template sht_v2_hw = {
+	.name			= DRV_NAME,
+	.module			= THIS_MODULE,
+	.queuecommand		= sas_queuecommand,
+	.target_alloc		= sas_target_alloc,
+	.slave_configure	= hisi_sas_slave_configure,
+	.scan_finished		= hisi_sas_scan_finished,
+	.scan_start		= hisi_sas_scan_start,
+	.change_queue_depth	= sas_change_queue_depth,
+	.bios_param		= sas_bios_param,
+	.can_queue		= 1,
+	.this_id		= -1,
+	.sg_tablesize		= SG_ALL,
+	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
+	.use_clustering		= ENABLE_CLUSTERING,
+	.eh_device_reset_handler = sas_eh_device_reset_handler,
+	.eh_target_reset_handler = sas_eh_target_reset_handler,
+	.target_destroy		= sas_target_destroy,
+	.ioctl			= sas_ioctl,
+	.shost_attrs		= host_attrs,
+};
+
 static const struct hisi_sas_hw hisi_sas_v2_hw = {
 	.hw_init = hisi_sas_v2_init,
 	.setup_itct = setup_itct_v2_hw,
@@ -3529,6 +3552,7 @@ static const struct hisi_sas_hw hisi_sas_v2_hw = {
 	.soft_reset = soft_reset_v2_hw,
 	.get_phys_state = get_phys_state_v2_hw,
 	.write_gpio = write_gpio_v2_hw,
+	.sht = &sht_v2_hw,
 };
 
 static int hisi_sas_v2_probe(struct platform_device *pdev)
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index a043d9cdbf48..13d21349d1ba 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2015,6 +2015,28 @@ static int write_gpio_v3_hw(struct hisi_hba *hisi_hba, u8 reg_type,
 	return 0;
 }
 
+static struct scsi_host_template sht_v3_hw = {
+	.name			= DRV_NAME,
+	.module			= THIS_MODULE,
+	.queuecommand		= sas_queuecommand,
+	.target_alloc		= sas_target_alloc,
+	.slave_configure	= hisi_sas_slave_configure,
+	.scan_finished		= hisi_sas_scan_finished,
+	.scan_start		= hisi_sas_scan_start,
+	.change_queue_depth	= sas_change_queue_depth,
+	.bios_param		= sas_bios_param,
+	.can_queue		= 1,
+	.this_id		= -1,
+	.sg_tablesize		= SG_ALL,
+	.max_sectors		= SCSI_DEFAULT_MAX_SECTORS,
+	.use_clustering		= ENABLE_CLUSTERING,
+	.eh_device_reset_handler = sas_eh_device_reset_handler,
+	.eh_target_reset_handler = sas_eh_target_reset_handler,
+	.target_destroy		= sas_target_destroy,
+	.ioctl			= sas_ioctl,
+	.shost_attrs		= host_attrs,
+};
+
 static const struct hisi_sas_hw hisi_sas_v3_hw = {
 	.hw_init = hisi_sas_v3_init,
 	.setup_itct = setup_itct_v3_hw,
@@ -2050,7 +2072,7 @@ hisi_sas_shost_alloc_pci(struct pci_dev *pdev)
 	struct hisi_hba *hisi_hba;
 	struct device *dev = &pdev->dev;
 
-	shost = scsi_host_alloc(hisi_sas_sht, sizeof(*hisi_hba));
+	shost = scsi_host_alloc(&sht_v3_hw, sizeof(*hisi_hba));
 	if (!shost) {
 		dev_err(dev, "shost alloc failed\n");
 		return NULL;