| Message ID | 1428009019-19563-1-git-send-email-sean.stalley@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
On Thu, Apr 02, 2015 at 02:10:19PM -0700, Sean O. Stalley wrote: > Reading both fields at the same time lets us parse the > list with half the number of configspace reads. > > Signed-off-by: Sean O. Stalley <sean.stalley@intel.com> Applied to pci/misc for v4.1, thanks Sean! > --- > drivers/pci/pci.c | 11 +++++++---- > 1 file changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 5e3c8e9..db7f3d6 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -145,19 +145,22 @@ static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, > u8 pos, int cap, int *ttl) > { > u8 id; > + u16 ent; > + > + pci_bus_read_config_byte(bus, devfn, pos, &pos); > > while ((*ttl)--) { > - pci_bus_read_config_byte(bus, devfn, pos, &pos); > if (pos < 0x40) > break; > pos &= ~3; > - pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID, > - &id); > + pci_bus_read_config_word(bus, devfn, pos, &ent); > + > + id = ent & 0xff; > if (id == 0xff) > break; > if (id == cap) > return pos; > - pos += PCI_CAP_LIST_NEXT; > + pos = (ent >> 8); > } > return 0; > } > -- > 1.9.1 > -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 5e3c8e9..db7f3d6 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -145,19 +145,22 @@ static int __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, u8 pos, int cap, int *ttl) { u8 id; + u16 ent; + + pci_bus_read_config_byte(bus, devfn, pos, &pos); while ((*ttl)--) { - pci_bus_read_config_byte(bus, devfn, pos, &pos); if (pos < 0x40) break; pos &= ~3; - pci_bus_read_config_byte(bus, devfn, pos + PCI_CAP_LIST_ID, - &id); + pci_bus_read_config_word(bus, devfn, pos, &ent); + + id = ent & 0xff; if (id == 0xff) break; if (id == cap) return pos; - pos += PCI_CAP_LIST_NEXT; + pos = (ent >> 8); } return 0; }
Reading both fields at the same time lets us parse the list with half the number of configspace reads. Signed-off-by: Sean O. Stalley <sean.stalley@intel.com> --- drivers/pci/pci.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)