| Message ID | 20201129164626.12887-1-puranjay12@gmail.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | [v1] PCI: Return u8 from pci_find_capability() | expand |
On Sun, Nov 29, 2020 at 10:16:26PM +0530, Puranjay Mohan wrote: > PCI Capabilities are linked in a list that must appear in the first 256 > bytes of config space. The pointer to capabilities is of 8 bits. > > Change the return type of pci_find_capability() and supporting > functions from int to u8 to match the specification. > > Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> Applied to pci/enumeration for v5.11, thanks! I added a few more related changes and some whitespace and typo fixes. Interdiff from your posting below. > --- > v1 - change return types of supporting functions of pci_find_capability. > --- > drivers/pci/pci.c | 8 ++++---- > include/linux/pci.h | 4 ++-- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index e578d34095e9..5caae09e0d20 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -399,7 +399,7 @@ static int pci_dev_str_match(struct pci_dev *dev, const char *p, > return 1; > } > > -static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, > +static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, > u8 pos, int cap, int *ttl) > { > u8 id; > @@ -438,7 +438,7 @@ int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) > } > EXPORT_SYMBOL_GPL(pci_find_next_capability); > > -static int __pci_bus_find_cap_start(struct pci_bus *bus, > +static u8 __pci_bus_find_cap_start(struct pci_bus *bus, > unsigned int devfn, u8 hdr_type) > { > u16 status; > @@ -477,9 +477,9 @@ static int __pci_bus_find_cap_start(struct pci_bus *bus, > * %PCI_CAP_ID_PCIX PCI-X > * %PCI_CAP_ID_EXP PCI Express > */ > -int pci_find_capability(struct pci_dev *dev, int cap) > +u8 pci_find_capability(struct pci_dev *dev, int cap) > { > - int pos; > + u8 pos; > > pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); > if (pos) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 22207a79762c..19a817702ea9 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1063,7 +1063,7 @@ void pci_sort_breadthfirst(void); > > /* Generic PCI functions exported to card drivers */ > > -int pci_find_capability(struct pci_dev *dev, int cap); > +u8 pci_find_capability(struct pci_dev *dev, int cap); > int pci_find_next_capability(struct pci_dev *dev, u8 pos, int 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); > @@ -1719,7 +1719,7 @@ static inline int __pci_register_driver(struct pci_driver *drv, > static inline int pci_register_driver(struct pci_driver *drv) > { return 0; } > static inline void pci_unregister_driver(struct pci_driver *drv) { } > -static inline int pci_find_capability(struct pci_dev *dev, int cap) > +static inline u8 pci_find_capability(struct pci_dev *dev, int cap) > { return 0; } > static inline int pci_find_next_capability(struct pci_dev *dev, u8 post, > int cap) > -- > 2.27.0 diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 5caae09e0d20..b3761e98377b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -400,7 +400,7 @@ static int pci_dev_str_match(struct pci_dev *dev, const char *p, } static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, - u8 pos, int cap, int *ttl) + u8 pos, int cap, int *ttl) { u8 id; u16 ent; @@ -423,15 +423,15 @@ static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, return 0; } -static int __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, - u8 pos, int cap) +static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, + u8 pos, int cap) { int ttl = PCI_FIND_CAP_TTL; return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl); } -int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) +u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) { return __pci_find_next_cap(dev->bus, dev->devfn, pos + PCI_CAP_LIST_NEXT, cap); @@ -502,10 +502,9 @@ EXPORT_SYMBOL(pci_find_capability); * device's PCI configuration space or 0 in case the device does not * support it. */ -int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap) +u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap) { - int pos; - u8 hdr_type; + u8 hdr_type, pos; pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type); @@ -623,7 +622,7 @@ u64 pci_get_dsn(struct pci_dev *dev) } EXPORT_SYMBOL_GPL(pci_get_dsn); -static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) +static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap) { int rc, ttl = PCI_FIND_CAP_TTL; u8 cap, mask; @@ -650,11 +649,12 @@ static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) return 0; } + /** - * pci_find_next_ht_capability - query a device's Hypertransport capabilities + * pci_find_next_ht_capability - query a device's HyperTransport capabilities * @dev: PCI device to query * @pos: Position from which to continue searching - * @ht_cap: Hypertransport capability code + * @ht_cap: HyperTransport capability code * * To be used in conjunction with pci_find_ht_capability() to search for * all capabilities matching @ht_cap. @pos should always be a value returned @@ -663,26 +663,26 @@ static int __pci_find_next_ht_cap(struct pci_dev *dev, int pos, int ht_cap) * NB. To be 100% safe against broken PCI devices, the caller should take * steps to avoid an infinite loop. */ -int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap) +u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap) { return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap); } EXPORT_SYMBOL_GPL(pci_find_next_ht_capability); /** - * pci_find_ht_capability - query a device's Hypertransport capabilities + * pci_find_ht_capability - query a device's HyperTransport capabilities * @dev: PCI device to query - * @ht_cap: Hypertransport capability code + * @ht_cap: HyperTransport capability code * - * Tell if a device supports a given Hypertransport capability. + * Tell if a device supports a given HyperTransport capability. * Returns an address within the device's PCI configuration space * or 0 in case the device does not support the request capability. * The address points to the PCI capability, of type PCI_CAP_ID_HT, - * which has a Hypertransport capability matching @ht_cap. + * which has a HyperTransport capability matching @ht_cap. */ -int pci_find_ht_capability(struct pci_dev *dev, int ht_cap) +u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap) { - int pos; + u8 pos; pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); if (pos) diff --git a/include/linux/pci.h b/include/linux/pci.h index 19a817702ea9..7c5749ad37ca 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1063,12 +1063,13 @@ void pci_sort_breadthfirst(void); /* Generic PCI functions exported to card drivers */ +u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap); u8 pci_find_capability(struct pci_dev *dev, int cap); -int pci_find_next_capability(struct pci_dev *dev, u8 pos, 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); -int pci_find_ht_capability(struct pci_dev *dev, int ht_cap); -int pci_find_next_ht_capability(struct pci_dev *dev, int pos, int ht_cap); struct pci_bus *pci_find_next_bus(const struct pci_bus *from); u64 pci_get_dsn(struct pci_dev *dev); @@ -1279,7 +1280,6 @@ void set_pcie_port_type(struct pci_dev *pdev); void set_pcie_hotplug_bridge(struct pci_dev *pdev); /* Functions for PCI Hotplug drivers to use */ -int pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap); unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge); unsigned int pci_rescan_bus(struct pci_bus *bus); void pci_lock_rescan_remove(void);
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@google.com>
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@google.com>
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);
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index e578d34095e9..5caae09e0d20 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -399,7 +399,7 @@ static int pci_dev_str_match(struct pci_dev *dev, const char *p, return 1; } -static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, +static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap, int *ttl) { u8 id; @@ -438,7 +438,7 @@ int pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) } EXPORT_SYMBOL_GPL(pci_find_next_capability); -static int __pci_bus_find_cap_start(struct pci_bus *bus, +static u8 __pci_bus_find_cap_start(struct pci_bus *bus, unsigned int devfn, u8 hdr_type) { u16 status; @@ -477,9 +477,9 @@ static int __pci_bus_find_cap_start(struct pci_bus *bus, * %PCI_CAP_ID_PCIX PCI-X * %PCI_CAP_ID_EXP PCI Express */ -int pci_find_capability(struct pci_dev *dev, int cap) +u8 pci_find_capability(struct pci_dev *dev, int cap) { - int pos; + u8 pos; pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); if (pos) diff --git a/include/linux/pci.h b/include/linux/pci.h index 22207a79762c..19a817702ea9 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1063,7 +1063,7 @@ void pci_sort_breadthfirst(void); /* Generic PCI functions exported to card drivers */ -int pci_find_capability(struct pci_dev *dev, int cap); +u8 pci_find_capability(struct pci_dev *dev, int cap); int pci_find_next_capability(struct pci_dev *dev, u8 pos, int 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); @@ -1719,7 +1719,7 @@ static inline int __pci_register_driver(struct pci_driver *drv, static inline int pci_register_driver(struct pci_driver *drv) { return 0; } static inline void pci_unregister_driver(struct pci_driver *drv) { } -static inline int pci_find_capability(struct pci_dev *dev, int cap) +static inline u8 pci_find_capability(struct pci_dev *dev, int cap) { return 0; } static inline int pci_find_next_capability(struct pci_dev *dev, u8 post, int cap)
PCI Capabilities are linked in a list that must appear in the first 256 bytes of config space. The pointer to capabilities is of 8 bits. Change the return type of pci_find_capability() and supporting functions from int to u8 to match the specification. Signed-off-by: Puranjay Mohan <puranjay12@gmail.com> --- v1 - change return types of supporting functions of pci_find_capability. --- drivers/pci/pci.c | 8 ++++---- include/linux/pci.h | 4 ++-- 2 files changed, 6 insertions(+), 6 deletions(-)