PCI/VPD: Remove struct pci_vpd_ops

Some multi-function devices share VPD hardware across functions and don't
work correctly for concurrent VPD accesses to different functions.

Struct pci_vpd_ops was added by 932c435c ("PCI: Add dev_flags bit to
access VPD through function 0") so that on these devices, VPD accesses to
any function would always go to function 0.

It's easier to just check for the PCI_DEV_FLAGS_VPD_REF_F0 quirk bit in the
two places we need it than to deal with the struct pci_vpd_ops.

Simplify the code by removing struct pci_vpd_ops and removing the indirect
calls.

[bhelgaas: check for !func0_dev earlier, commit log]
Link: https://lore.kernel.org/r/b2532a41-df8b-860f-461f-d5c066c819d0@gmail.comSigned-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/vpd.c

@@ -13,13 +13,7 @@
 
 /* VPD access through PCI 2.2+ VPD capability */
 
-struct pci_vpd_ops {
-	ssize_t (*read)(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
-	ssize_t (*write)(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
-};
-
 struct pci_vpd {
-	const struct pci_vpd_ops *ops;
 	struct mutex	lock;
 	unsigned int	len;
 	u8		cap;
@@ -127,6 +121,9 @@ static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
 	loff_t end = pos + count;
 	u8 *buf = arg;
 
+	if (!vpd)
+		return -ENODEV;
+
 	if (pos < 0)
 		return -EINVAL;
 
@@ -193,6 +190,9 @@ static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
 	loff_t end = pos + count;
 	int ret = 0;
 
+	if (!vpd)
+		return -ENODEV;
+
 	if (pos < 0 || (pos & 3) || (count & 3))
 		return -EINVAL;
 
@@ -237,44 +237,6 @@ static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
 	return ret ? ret : count;
 }
 
-static const struct pci_vpd_ops pci_vpd_ops = {
-	.read = pci_vpd_read,
-	.write = pci_vpd_write,
-};
-
-static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
-			       void *arg)
-{
-	struct pci_dev *tdev = pci_get_func0_dev(dev);
-	ssize_t ret;
-
-	if (!tdev)
-		return -ENODEV;
-
-	ret = pci_read_vpd(tdev, pos, count, arg);
-	pci_dev_put(tdev);
-	return ret;
-}
-
-static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count,
-				const void *arg)
-{
-	struct pci_dev *tdev = pci_get_func0_dev(dev);
-	ssize_t ret;
-
-	if (!tdev)
-		return -ENODEV;
-
-	ret = pci_write_vpd(tdev, pos, count, arg);
-	pci_dev_put(tdev);
-	return ret;
-}
-
-static const struct pci_vpd_ops pci_vpd_f0_ops = {
-	.read = pci_vpd_f0_read,
-	.write = pci_vpd_f0_write,
-};
-
 void pci_vpd_init(struct pci_dev *dev)
 {
 	struct pci_vpd *vpd;
@@ -289,10 +251,6 @@ void pci_vpd_init(struct pci_dev *dev)
 		return;
 
 	vpd->len = PCI_VPD_MAX_SIZE;
-	if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
-		vpd->ops = &pci_vpd_f0_ops;
-	else
-		vpd->ops = &pci_vpd_ops;
 	mutex_init(&vpd->lock);
 	vpd->cap = cap;
 	vpd->valid = 0;
@@ -387,9 +345,19 @@ EXPORT_SYMBOL_GPL(pci_vpd_find_info_keyword);
  */
 ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
 {
-	if (!dev->vpd || !dev->vpd->ops)
-		return -ENODEV;
-	return dev->vpd->ops->read(dev, pos, count, buf);
+	ssize_t ret;
+
+	if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
+		dev = pci_get_func0_dev(dev);
+		if (!dev)
+			return -ENODEV;
+
+		ret = pci_vpd_read(dev, pos, count, buf);
+		pci_dev_put(dev);
+		return ret;
+	}
+
+	return pci_vpd_read(dev, pos, count, buf);
 }
 EXPORT_SYMBOL(pci_read_vpd);
 
@@ -402,9 +370,19 @@ EXPORT_SYMBOL(pci_read_vpd);
  */
 ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
 {
-	if (!dev->vpd || !dev->vpd->ops)
-		return -ENODEV;
-	return dev->vpd->ops->write(dev, pos, count, buf);
+	ssize_t ret;
+
+	if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
+		dev = pci_get_func0_dev(dev);
+		if (!dev)
+			return -ENODEV;
+
+		ret = pci_vpd_write(dev, pos, count, buf);
+		pci_dev_put(dev);
+		return ret;
+	}
+
+	return pci_vpd_write(dev, pos, count, buf);
 }
 EXPORT_SYMBOL(pci_write_vpd);