Merge: PCI: Explicitly put devices into D0 when initializing

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-10/-/merge_requests/1257

```
JIRA: https://issues.redhat.com/browse/RHEL-90801
Upstream Status: 4d4c10f

    - Set all devices to D0 during enumeration to ensure ACPI opregion is
      connected via _REG (Mario Limonciello)

    - Set up runtime PM even for devices that lack a PM Capability as we
       did before 4d4c10f ("PCI: Explicitly put devices into D0 when
       initializing"), which broke resume in some VFIO scenarios (Mario
       Limonciello)

    * pci/pm:
      PCI: Explicitly put devices into D0 when initializing
      PCI/PM: Set up runtime PM even for devices without PCI PM

Signed-off-by: Myron Stowe <mstowe@redhat.com>
```

Approved-by: John W. Linville <linville@redhat.com>
Approved-by: Steve Best <sbest@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Julio Faracco <jfaracco@redhat.com>

Author: jcfaracco

drivers/pci/pci-driver.c

@@ -564,12 +564,6 @@ static void pci_pm_default_resume(struct pci_dev *pci_dev)
 	pci_enable_wake(pci_dev, PCI_D0, false);
 }
 
-static void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
-{
-	pci_power_up(pci_dev);
-	pci_update_current_state(pci_dev, PCI_D0);
-}
-
 static void pci_pm_default_resume_early(struct pci_dev *pci_dev)
 {
 	pci_pm_power_up_and_verify_state(pci_dev);

drivers/pci/pci.c

@@ -3192,6 +3192,12 @@ void pci_d3cold_disable(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_d3cold_disable);
 
+void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev)
+{
+	pci_power_up(pci_dev);
+	pci_update_current_state(pci_dev, PCI_D0);
+}
+
 /**
  * pci_pm_init - Initialize PM functions of given PCI device
  * @dev: PCI device to handle.
@@ -3202,9 +3208,6 @@ void pci_pm_init(struct pci_dev *dev)
 	u16 status;
 	u16 pmc;
 
-	pm_runtime_forbid(&dev->dev);
-	pm_runtime_set_active(&dev->dev);
-	pm_runtime_enable(&dev->dev);
 	device_enable_async_suspend(&dev->dev);
 	dev->wakeup_prepared = false;
 
@@ -3214,14 +3217,14 @@ void pci_pm_init(struct pci_dev *dev)
 	/* find PCI PM capability in list */
 	pm = pci_find_capability(dev, PCI_CAP_ID_PM);
 	if (!pm)
-		return;
+		goto poweron;
 	/* Check device's ability to generate PME# */
 	pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc);
 
 	if ((pmc & PCI_PM_CAP_VER_MASK) > 3) {
 		pci_err(dev, "unsupported PM cap regs version (%u)\n",
 			pmc & PCI_PM_CAP_VER_MASK);
-		return;
+		goto poweron;
 	}
 
 	dev->pm_cap = pm;
@@ -3266,6 +3269,11 @@ void pci_pm_init(struct pci_dev *dev)
 	pci_read_config_word(dev, PCI_STATUS, &status);
 	if (status & PCI_STATUS_IMM_READY)
 		dev->imm_ready = 1;
+poweron:
+	pci_pm_power_up_and_verify_state(dev);
+	pm_runtime_forbid(&dev->dev);
+	pm_runtime_set_active(&dev->dev);
+	pm_runtime_enable(&dev->dev);
 }
 
 static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop)

drivers/pci/pci.h

@@ -148,6 +148,7 @@ void pci_dev_adjust_pme(struct pci_dev *dev);
 void pci_dev_complete_resume(struct pci_dev *pci_dev);
 void pci_config_pm_runtime_get(struct pci_dev *dev);
 void pci_config_pm_runtime_put(struct pci_dev *dev);
+void pci_pm_power_up_and_verify_state(struct pci_dev *pci_dev);
 void pci_pm_init(struct pci_dev *dev);
 void pci_ea_init(struct pci_dev *dev);
 void pci_msi_init(struct pci_dev *dev);