PCI: Give pcim_set_mwi() its own devres cleanup callback

Managing pci_set_mwi() with devres can easily be done with its own
callback, without the necessity to store any state about it in a
device-related struct.

Remove the MWI state from struct pci_devres.  Give pcim_set_mwi() a
separate devres cleanup callback.

Link: https://lore.kernel.org/r/20240613115032.29098-10-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Author: Philipp Stanner

drivers/pci/devres.c

@@ -370,24 +370,34 @@ void __iomem *devm_pci_remap_cfg_resource(struct device *dev,
 }
 EXPORT_SYMBOL(devm_pci_remap_cfg_resource);
 
+static void __pcim_clear_mwi(void *pdev_raw)
+{
+	struct pci_dev *pdev = pdev_raw;
+
+	pci_clear_mwi(pdev);
+}
+
 /**
  * pcim_set_mwi - a device-managed pci_set_mwi()
- * @dev: the PCI device for which MWI is enabled
+ * @pdev: the PCI device for which MWI is enabled
  *
  * Managed pci_set_mwi().
  *
  * RETURNS: An appropriate -ERRNO error value on error, or zero for success.
  */
-int pcim_set_mwi(struct pci_dev *dev)
+int pcim_set_mwi(struct pci_dev *pdev)
 {
-	struct pci_devres *dr;
+	int ret;
 
-	dr = find_pci_dr(dev);
-	if (!dr)
-		return -ENOMEM;
+	ret = devm_add_action(&pdev->dev, __pcim_clear_mwi, pdev);
+	if (ret != 0)
+		return ret;
+
+	ret = pci_set_mwi(pdev);
+	if (ret != 0)
+		devm_remove_action(&pdev->dev, __pcim_clear_mwi, pdev);
 
-	dr->mwi = 1;
-	return pci_set_mwi(dev);
+	return ret;
 }
 EXPORT_SYMBOL(pcim_set_mwi);
 
@@ -401,9 +411,6 @@ static void pcim_release(struct device *gendev, void *res)
 	struct pci_dev *dev = to_pci_dev(gendev);
 	struct pci_devres *this = res;
 
-	if (this->mwi)
-		pci_clear_mwi(dev);
-
 	if (this->restore_intx)
 		pci_intx(dev, this->orig_intx);
 

drivers/pci/pci.h

@@ -823,7 +823,6 @@ static inline pci_power_t mid_pci_get_power_state(struct pci_dev *pdev)
 struct pci_devres {
 	unsigned int orig_intx:1;
 	unsigned int restore_intx:1;
-	unsigned int mwi:1;
 };
 
 struct pci_devres *find_pci_dr(struct pci_dev *pdev);