[PATCH v3 01/57] PCI: Convert to_pci_dev() into an inline function

Clang's context analysis checker performs alias analysis on expressions
passed to annotations like __acquires(). Clang's alias analysis does not
support container_of(). Convert to_pci_dev() from a macro into an inline
function such that Clang recognizes multiple to_pci_dev() expressions as
identical if the 'dev' argument is the same.

It is on purpose that to_pci_dev() accepts a const pointer and returns a
pointer that is not const. Any other choice, e.g. accepting a non-const
pointer or returning a const pointer, triggers compiler errors in code
that uses the to_pci_dev() macro.

While _Generic() could be used to support const and non-const struct
device pointers in a more elegant way, Clang's alias analysis does not
support _Generic().

Acked-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Bart Van Assche <[email protected]>
---
 include/linux/pci.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/pci.h b/include/linux/pci.h
index ebb5b9d76360..727050c5425a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -605,7 +605,10 @@ static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
 
 struct pci_dev *pci_alloc_dev(struct pci_bus *bus);
 
-#define	to_pci_dev(n) container_of(n, struct pci_dev, dev)
+static inline struct pci_dev *to_pci_dev(const struct device *dev)
+{
+	return container_of(dev, struct pci_dev, dev);
+}
 #define for_each_pci_dev(d) while ((d = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, d)) != NULL)
 #define for_each_pci_dev_reverse(d) \
 	while ((d = pci_get_device_reverse(PCI_ANY_ID, PCI_ANY_ID, d)) != NULL)