PCI: Use 'pci_channel_state_t' instead of 'enum pci_channel_state'

The method struct pci_error_handlers.error_detected() is defined and
documented as taking an 'enum pci_channel_state' for the second argument,
but most drivers use 'pci_channel_state_t' instead.

This 'pci_channel_state_t' is not a typedef for the enum but a typedef for
a bitwise type in order to have better/stricter typechecking.

Consolidate everything by using 'pci_channel_state_t' in the method's
definition, in the related helpers and in the drivers.

Enforce use of 'pci_channel_state_t' by replacing 'enum pci_channel_state'
with an anonymous 'enum'.

Note: Currently, from a typechecking point of view this patch changes
nothing because only the constants defined by the enum are bitwise, not the
enum itself (sparse doesn't have the notion of 'bitwise enum'). This may
change in some not too far future, hence the patch.

[bhelgaas: squash in
  https://lore.kernel.org/r/20200702162651.49526-3-luc.vanoostenryck@gmail.com
  https://lore.kernel.org/r/20200702162651.49526-4-luc.vanoostenryck@gmail.com]
Link: https://lore.kernel.org/r/20200702162651.49526-2-luc.vanoostenryck@gmail.com
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/pci.h b/include/linux/pci.h
index c79d83304e52..adcee9e30bfa 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -179,7 +179,7 @@ static inline const char *pci_power_name(pci_power_t state)
  */
 typedef unsigned int __bitwise pci_channel_state_t;
 
-enum pci_channel_state {
+enum {
 	/* I/O channel is in normal state */
 	pci_channel_io_normal = (__force pci_channel_state_t) 1,
 
@@ -785,7 +785,7 @@ enum pci_ers_result {
 struct pci_error_handlers {
 	/* PCI bus error detected on this device */
 	pci_ers_result_t (*error_detected)(struct pci_dev *dev,
-					   enum pci_channel_state error);
+					   pci_channel_state_t error);
 
 	/* MMIO has been re-enabled, but not DMA */
 	pci_ers_result_t (*mmio_enabled)(struct pci_dev *dev);