I also propose this follow-on patch to do the same for the extended
capabilities:
commit ee8b1c478a9f ("PCI: Return u16 from pci_find_ext_capability() and similar")
Author: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Date: Fri Dec 4 15:14:07 2020 -0600
PCI: Return u16 from pci_find_ext_capability() and similar
PCI Express Extended Capabilities are in config space between offsets 256
and 4K. These offsets all fit in 16 bits.
Change the return type of pci_find_ext_capability() and supporting
functions from int to u16 to match the specification. Many callers use
"int", which is fine, but there's no need to store more than a u16.
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index b3761e98377b..85cb873266d3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -527,11 +527,11 @@ EXPORT_SYMBOL(pci_bus_find_capability);
* not support it. Some capabilities can occur several times, e.g., the
* vendor-specific capability, and this provides a way to find them all.
*/
-int pci_find_next_ext_capability(struct pci_dev *dev, int start, int cap)
+u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 start, int cap)
{
u32 header;
int ttl;
- int pos = PCI_CFG_SPACE_SIZE;
+ u16 pos = PCI_CFG_SPACE_SIZE;
/* minimum 8 bytes per capability */
ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8;
@@ -582,7 +582,7 @@ EXPORT_SYMBOL_GPL(pci_find_next_ext_capability);
* %PCI_EXT_CAP_ID_DSN Device Serial Number
* %PCI_EXT_CAP_ID_PWR Power Budgeting
*/
-int pci_find_ext_capability(struct pci_dev *dev, int cap)
+u16 pci_find_ext_capability(struct pci_dev *dev, int cap)
{
return pci_find_next_ext_capability(dev, 0, cap);
}
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e615f8abdd79..441e5753da0c 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -381,7 +381,7 @@ struct pci_dev {
struct pcie_link_state *link_state; /* ASPM link state */
unsigned int ltr_path:1; /* Latency Tolerance Reporting
supported from root to here */
- int l1ss; /* L1SS Capability pointer */
+ u16 l1ss; /* L1SS Capability pointer */
#endif
unsigned int eetlp_prefix_path:1; /* End-to-End TLP Prefix */
@@ -1069,8 +1069,8 @@ u8 pci_find_capability(struct pci_dev *dev, int cap);
u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap);
u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap);
u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap);
-int pci_find_ext_capability(struct pci_dev *dev, int cap);
-int pci_find_next_ext_capability(struct pci_dev *dev, int pos, int cap);
+u16 pci_find_ext_capability(struct pci_dev *dev, int cap);
+u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 pos, int cap);
struct pci_bus *pci_find_next_bus(const struct pci_bus *from);
u64 pci_get_dsn(struct pci_dev *dev);
