[PATCH 1/7] PCI: Add pcim_set_mwi(), a device-managed pci_set_mwi()

[Kai-Heng Feng]

From: Heiner Kallweit <hkallweit1 at gmail.com>

BugLink: https://bugs.launchpad.net/bugs/1752772

Add pcim_set_mwi(), a device-managed version of pci_set_mwi().
First user is the Realtek r8169 driver.

Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
Acked-by: Bjorn Helgaas <bhelgaas at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit fc0f9f4d2f26b12fd2eda239bb8f18ceaf192c91)
Signed-off-by: Kai-Heng Feng <kai.heng.feng at canonical.com>
---
 drivers/pci/pci.c   | 25 +++++++++++++++++++++++++
 include/linux/pci.h |  1 +
 2 files changed, 26 insertions(+)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 2174f8f9da8e..f953042c7cdf 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -1459,6 +1459,7 @@ struct pci_devres {
 	unsigned int pinned:1;
 	unsigned int orig_intx:1;
 	unsigned int restore_intx:1;
+	unsigned int mwi:1;
 	u32 region_mask;
 };
 
@@ -1477,6 +1478,9 @@ static void pcim_release(struct device *gendev, void *res)
 		if (this->region_mask & (1 << i))
 			pci_release_region(dev, i);
 
+	if (this->mwi)
+		pci_clear_mwi(dev);
+
 	if (this->restore_intx)
 		pci_intx(dev, this->orig_intx);
 
@@ -3720,6 +3724,27 @@ int pci_set_mwi(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pci_set_mwi);
 
+/**
+ * pcim_set_mwi - a device-managed pci_set_mwi()
+ * @dev: 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)
+{
+	struct pci_devres *dr;
+
+	dr = find_pci_dr(dev);
+	if (!dr)
+		return -ENOMEM;
+
+	dr->mwi = 1;
+	return pci_set_mwi(dev);
+}
+EXPORT_SYMBOL(pcim_set_mwi);
+
 /**
  * pci_try_set_mwi - enables memory-write-invalidate PCI transaction
  * @dev: the PCI device for which MWI is enabled
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 0962a3a36d62..db81cad70970 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1074,6 +1074,7 @@ int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state);
 int pci_set_cacheline_size(struct pci_dev *dev);
 #define HAVE_PCI_SET_MWI
 int __must_check pci_set_mwi(struct pci_dev *dev);
+int __must_check pcim_set_mwi(struct pci_dev *dev);
 int pci_try_set_mwi(struct pci_dev *dev);
 void pci_clear_mwi(struct pci_dev *dev);
 void pci_intx(struct pci_dev *dev, int enable);
-- 
2.17.0