[PATCH v5 06/11] PCI: PM: Split out code from pci_pm_suspend_noirq() into helper

[Mario Limonciello (AMD)]

In order to unify suspend and hibernate codepaths without code duplication
the common code should be in common helpers.  Move it from
pci_pm_suspend_noirq() into a helper.  No intended functional changes.

Tested-by: Eric Naim <dnaim at cachyos.org>
Signed-off-by: Mario Limonciello (AMD) <superm1 at kernel.org>
---
v5:
 * Split from earlier patches
 * Add tags
v4:
 * https://lore.kernel.org/linux-pci/20250616175019.3471583-1-superm1@kernel.org/
---
 drivers/pci/pci-driver.c | 81 +++++++++++++++++++++++++---------------
 1 file changed, 51 insertions(+), 30 deletions(-)

diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index f201d298d7173..571a3809f163a 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -762,6 +762,54 @@ static void pci_pm_complete(struct device *dev)
 
 #endif /* !CONFIG_PM_SLEEP */
 
+#if defined(CONFIG_SUSPEND)
+/**
+ * pci_pm_suspend_noirq_common
+ * @pci_dev: pci device
+ * @skip_bus_pm: pointer to a boolean indicating whether to skip bus PM
+ *
+ * Prepare the device to go into a low power state by saving state and
+ * deciding whether to skip bus PM.
+ *
+ */
+static void pci_pm_suspend_noirq_common(struct pci_dev *pci_dev, bool *skip_bus_pm)
+{
+	if (!pci_dev->state_saved) {
+		pci_save_state(pci_dev);
+
+		/*
+		 * If the device is a bridge with a child in D0 below it,
+		 * it needs to stay in D0, so check skip_bus_pm to avoid
+		 * putting it into a low-power state in that case.
+		 */
+		if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
+			pci_prepare_to_sleep(pci_dev);
+	}
+
+	pci_dbg(pci_dev, "PCI PM: Sleep power state: %s\n",
+		pci_power_name(pci_dev->current_state));
+
+	if (pci_dev->current_state == PCI_D0) {
+		pci_dev->skip_bus_pm = true;
+		/*
+		 * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
+		 * downstream device is in D0, so avoid changing the power state
+		 * of the parent bridge by setting the skip_bus_pm flag for it.
+		 */
+		if (pci_dev->bus->self)
+			pci_dev->bus->self->skip_bus_pm = true;
+	}
+
+	if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
+		pci_dbg(pci_dev, "PCI PM: Skipped\n");
+		*skip_bus_pm = true;
+		return;
+	}
+
+	pci_pm_set_unknown_state(pci_dev);
+}
+#endif /* CONFIG_SUSPEND */
+
 #ifdef CONFIG_SUSPEND
 static void pcie_pme_root_status_cleanup(struct pci_dev *pci_dev)
 {
@@ -851,6 +899,7 @@ static int pci_pm_suspend_noirq(struct device *dev)
 {
 	struct pci_dev *pci_dev = to_pci_dev(dev);
 	const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
+	bool skip_bus_pm = false;
 
 	if (dev_pm_skip_suspend(dev))
 		return 0;
@@ -881,38 +930,10 @@ static int pci_pm_suspend_noirq(struct device *dev)
 		}
 	}
 
-	if (!pci_dev->state_saved) {
-		pci_save_state(pci_dev);
-
-		/*
-		 * If the device is a bridge with a child in D0 below it,
-		 * it needs to stay in D0, so check skip_bus_pm to avoid
-		 * putting it into a low-power state in that case.
-		 */
-		if (!pci_dev->skip_bus_pm && pci_power_manageable(pci_dev))
-			pci_prepare_to_sleep(pci_dev);
-	}
-
-	pci_dbg(pci_dev, "PCI PM: Suspend power state: %s\n",
-		pci_power_name(pci_dev->current_state));
+	pci_pm_suspend_noirq_common(pci_dev, &skip_bus_pm);
 
-	if (pci_dev->current_state == PCI_D0) {
-		pci_dev->skip_bus_pm = true;
-		/*
-		 * Per PCI PM r1.2, table 6-1, a bridge must be in D0 if any
-		 * downstream device is in D0, so avoid changing the power state
-		 * of the parent bridge by setting the skip_bus_pm flag for it.
-		 */
-		if (pci_dev->bus->self)
-			pci_dev->bus->self->skip_bus_pm = true;
-	}
-
-	if (pci_dev->skip_bus_pm && pm_suspend_no_platform()) {
-		pci_dbg(pci_dev, "PCI PM: Skipped\n");
+	if (skip_bus_pm)
 		goto Fixup;
-	}
-
-	pci_pm_set_unknown_state(pci_dev);
 
 	/*
 	 * Some BIOSes from ASUS have a bug: If a USB EHCI host controller's
-- 
2.43.0