scsi: arcmsr: Use generic power management

Drivers should do only device-specific jobs. But in general, drivers using
legacy PCI PM framework for .suspend()/.resume() have to manage many PCI
PM-related tasks themselves which can be done by PCI Core itself. This
brings extra load on the driver and it directly calls PCI helper functions
to handle them.

Switch to the new generic framework by updating function signatures and
define a "struct dev_pm_ops" variable to bind PM callbacks. Also, remove
unnecessary calls to the PCI Helper functions along with the legacy
.suspend & .resume bindings.

Link: https://lore.kernel.org/r/20201102164730.324035-10-vaibhavgupta40@gmail.comSigned-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/arcmsr/arcmsr_hba.c

@@ -117,8 +117,8 @@ static int arcmsr_bios_param(struct scsi_device *sdev,
 static int arcmsr_queue_command(struct Scsi_Host *h, struct scsi_cmnd *cmd);
 static int arcmsr_probe(struct pci_dev *pdev,
 				const struct pci_device_id *id);
-static int arcmsr_suspend(struct pci_dev *pdev, pm_message_t state);
-static int arcmsr_resume(struct pci_dev *pdev);
+static int __maybe_unused arcmsr_suspend(struct device *dev);
+static int __maybe_unused arcmsr_resume(struct device *dev);
 static void arcmsr_remove(struct pci_dev *pdev);
 static void arcmsr_shutdown(struct pci_dev *pdev);
 static void arcmsr_iop_init(struct AdapterControlBlock *acb);
@@ -222,13 +222,14 @@ static struct pci_device_id arcmsr_device_id_table[] = {
 };
 MODULE_DEVICE_TABLE(pci, arcmsr_device_id_table);
 
+static SIMPLE_DEV_PM_OPS(arcmsr_pm_ops, arcmsr_suspend, arcmsr_resume);
+
 static struct pci_driver arcmsr_pci_driver = {
 	.name			= "arcmsr",
 	.id_table		= arcmsr_device_id_table,
 	.probe			= arcmsr_probe,
 	.remove			= arcmsr_remove,
-	.suspend		= arcmsr_suspend,
-	.resume			= arcmsr_resume,
+	.driver.pm		= &arcmsr_pm_ops,
 	.shutdown		= arcmsr_shutdown,
 };
 /*
@@ -1132,8 +1133,9 @@ static void arcmsr_free_irq(struct pci_dev *pdev,
 	pci_free_irq_vectors(pdev);
 }
 
-static int arcmsr_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused arcmsr_suspend(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct Scsi_Host *host = pci_get_drvdata(pdev);
 	struct AdapterControlBlock *acb =
 		(struct AdapterControlBlock *)host->hostdata;
@@ -1146,28 +1148,18 @@ static int arcmsr_suspend(struct pci_dev *pdev, pm_message_t state)
 	flush_work(&acb->arcmsr_do_message_isr_bh);
 	arcmsr_stop_adapter_bgrb(acb);
 	arcmsr_flush_adapter_cache(acb);
-	pci_set_drvdata(pdev, host);
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_set_power_state(pdev, pci_choose_state(pdev, state));
 	return 0;
 }
 
-static int arcmsr_resume(struct pci_dev *pdev)
+static int __maybe_unused arcmsr_resume(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
 	struct Scsi_Host *host = pci_get_drvdata(pdev);
 	struct AdapterControlBlock *acb =
 		(struct AdapterControlBlock *)host->hostdata;
 
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
-	if (pci_enable_device(pdev)) {
-		pr_warn("%s: pci_enable_device error\n", __func__);
-		return -ENODEV;
-	}
 	if (arcmsr_set_dma_mask(acb))
 		goto controller_unregister;
-	pci_set_master(pdev);
 	if (arcmsr_request_irq(pdev, acb) == FAILED)
 		goto controller_stop;
 	switch (acb->adapter_type) {
@@ -1212,9 +1204,7 @@ static int arcmsr_resume(struct pci_dev *pdev)
 	if (acb->adapter_type == ACB_ADAPTER_TYPE_F)
 		arcmsr_free_io_queue(acb);
 	arcmsr_unmap_pciregion(acb);
-	pci_release_regions(pdev);
 	scsi_host_put(host);
-	pci_disable_device(pdev);
 	return -ENODEV;
 }