scsi: aacraid: 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/20201102164730.324035-6-vaibhavgupta40@gmail.comAcked-by: Balsundar P <balsundar.p@microchip.com>
Signed-off-by: Vaibhav Gupta <vaibhavgupta40@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/aacraid/linit.c

@@ -1853,11 +1853,9 @@ static int aac_acquire_resources(struct aac_dev *dev)
 
 }
 
-#if (defined(CONFIG_PM))
-static int aac_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused aac_suspend(struct device *dev)
 {
-
-	struct Scsi_Host *shost = pci_get_drvdata(pdev);
+	struct Scsi_Host *shost = dev_get_drvdata(dev);
 	struct aac_dev *aac = (struct aac_dev *)shost->hostdata;
 
 	scsi_host_block(shost);
@@ -1866,28 +1864,14 @@ static int aac_suspend(struct pci_dev *pdev, pm_message_t state)
 
 	aac_release_resources(aac);
 
-	pci_set_drvdata(pdev, shost);
-	pci_save_state(pdev);
-	pci_disable_device(pdev);
-	pci_set_power_state(pdev, pci_choose_state(pdev, state));
-
 	return 0;
 }
 
-static int aac_resume(struct pci_dev *pdev)
+static int __maybe_unused aac_resume(struct device *dev)
 {
-	struct Scsi_Host *shost = pci_get_drvdata(pdev);
+	struct Scsi_Host *shost = dev_get_drvdata(dev);
 	struct aac_dev *aac = (struct aac_dev *)shost->hostdata;
-	int r;
-
-	pci_set_power_state(pdev, PCI_D0);
-	pci_restore_state(pdev);
-	r = pci_enable_device(pdev);
-
-	if (r)
-		goto fail_device;
 
-	pci_set_master(pdev);
 	if (aac_acquire_resources(aac))
 		goto fail_device;
 	/*
@@ -1902,10 +1886,8 @@ static int aac_resume(struct pci_dev *pdev)
 fail_device:
 	printk(KERN_INFO "%s%d: resume failed.\n", aac->name, aac->id);
 	scsi_host_put(shost);
-	pci_disable_device(pdev);
 	return -ENODEV;
 }
-#endif
 
 static void aac_shutdown(struct pci_dev *dev)
 {
@@ -2050,15 +2032,14 @@ static struct pci_error_handlers aac_pci_err_handler = {
 	.resume			= aac_pci_resume,
 };
 
+static SIMPLE_DEV_PM_OPS(aac_pm_ops, aac_suspend, aac_resume);
+
 static struct pci_driver aac_pci_driver = {
 	.name		= AAC_DRIVERNAME,
 	.id_table	= aac_pci_tbl,
 	.probe		= aac_probe_one,
 	.remove		= aac_remove_one,
-#if (defined(CONFIG_PM))
-	.suspend	= aac_suspend,
-	.resume		= aac_resume,
-#endif
+	.driver.pm      = &aac_pm_ops,
 	.shutdown	= aac_shutdown,
 	.err_handler    = &aac_pci_err_handler,
 };