| Message ID | 1235112888-9524-4-git-send-email-yu.zhao@intel.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Fri, Feb 20, 2009 at 02:54:44PM +0800, Yu Zhao wrote: > +static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn) > +{ > + u16 bdf; > + > + bdf = (dev->bus->number << 8) + dev->devfn + > + dev->sriov->offset + dev->sriov->stride * id; > + *busnr = bdf >> 8; > + *devfn = bdf & 0xff; > +} I find the interface here a bit clunky -- a function returning void while having two OUT parameters. How about this variation on the theme (viewers are encouraged to come up with their own preferred implementations and interfaces): static inline __pure u16 virtfn_bdf(struct pci_dev *dev, int id) { return (dev->bus->number << 8) + dev->devfn + dev->sriov->offset + dev->sriov->stride * id; } #define VIRT_BUS(dev, id) (virtfn_bdf(dev, id) >> 8) #define VIRT_DEVFN(dev, id) (virtfn_bdf(dev, id) & 0xff) We rely on GCC to do CSE and not actually invoke virtfn_bdf more than once.
On Sat, Mar 07, 2009 at 04:20:24AM +0800, Matthew Wilcox wrote: > On Fri, Feb 20, 2009 at 02:54:44PM +0800, Yu Zhao wrote: > > +static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn) > > +{ > > + u16 bdf; > > + > > + bdf = (dev->bus->number << 8) + dev->devfn + > > + dev->sriov->offset + dev->sriov->stride * id; > > + *busnr = bdf >> 8; > > + *devfn = bdf & 0xff; > > +} > > I find the interface here a bit clunky -- a function returning void > while having two OUT parameters. How about this variation on the theme > (viewers are encouraged to come up with their own preferred > implementations and interfaces): > > static inline __pure u16 virtfn_bdf(struct pci_dev *dev, int id) > { > return (dev->bus->number << 8) + dev->devfn + dev->sriov->offset + > dev->sriov->stride * id; > } > > #define VIRT_BUS(dev, id) (virtfn_bdf(dev, id) >> 8) > #define VIRT_DEVFN(dev, id) (virtfn_bdf(dev, id) & 0xff) > > We rely on GCC to do CSE and not actually invoke virtfn_bdf more than > once. Yes, that's a good idea. Will replace that function with macros. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Yu Zhao wrote: > On Sat, Mar 07, 2009 at 04:20:24AM +0800, Matthew Wilcox wrote: >> On Fri, Feb 20, 2009 at 02:54:44PM +0800, Yu Zhao wrote: >>> +static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn) >>> +{ >>> + u16 bdf; >>> + >>> + bdf = (dev->bus->number << 8) + dev->devfn + >>> + dev->sriov->offset + dev->sriov->stride * id; >>> + *busnr = bdf >> 8; >>> + *devfn = bdf & 0xff; >>> +} >> I find the interface here a bit clunky -- a function returning void >> while having two OUT parameters. How about this variation on the theme >> (viewers are encouraged to come up with their own preferred >> implementations and interfaces): >> >> static inline __pure u16 virtfn_bdf(struct pci_dev *dev, int id) >> { >> return (dev->bus->number << 8) + dev->devfn + dev->sriov->offset + >> dev->sriov->stride * id; >> } >> >> #define VIRT_BUS(dev, id) (virtfn_bdf(dev, id) >> 8) >> #define VIRT_DEVFN(dev, id) (virtfn_bdf(dev, id) & 0xff) >> >> We rely on GCC to do CSE and not actually invoke virtfn_bdf more than >> once. > > Yes, that's a good idea. Will replace that function with macros. That's the opposite of most changes lately. I.e., functions (with typechecking) are preferred.
On Mon, Mar 09, 2009 at 11:09:02AM -0700, Randy Dunlap wrote: > >> static inline __pure u16 virtfn_bdf(struct pci_dev *dev, int id) > >> { > >> return (dev->bus->number << 8) + dev->devfn + dev->sriov->offset + > >> dev->sriov->stride * id; > >> } > >> > >> #define VIRT_BUS(dev, id) (virtfn_bdf(dev, id) >> 8) > >> #define VIRT_DEVFN(dev, id) (virtfn_bdf(dev, id) & 0xff) > >> > >> We rely on GCC to do CSE and not actually invoke virtfn_bdf more than > >> once. > > > > Yes, that's a good idea. Will replace that function with macros. > > That's the opposite of most changes lately. I.e., functions (with > typechecking) are preferred. There's every bit as much typechecking with the approach I outlined as there was with the original.
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 3bca8f8..0b80437 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -14,6 +14,16 @@ #include "pci.h" +static inline void virtfn_bdf(struct pci_dev *dev, int id, u8 *busnr, u8 *devfn) +{ + u16 bdf; + + bdf = (dev->bus->number << 8) + dev->devfn + + dev->sriov->offset + dev->sriov->stride * id; + *busnr = bdf >> 8; + *devfn = bdf & 0xff; +} + static int sriov_init(struct pci_dev *dev, int pos) { int i; @@ -208,3 +218,27 @@ void pci_restore_iov_state(struct pci_dev *dev) if (dev->sriov) sriov_restore_state(dev); } + +/** + * pci_iov_bus_range - find bus range used by Virtual Function + * @bus: the PCI bus + * + * Returns max number of buses (exclude current one) used by Virtual + * Functions. + */ +int pci_iov_bus_range(struct pci_bus *bus) +{ + int max = 0; + u8 busnr, devfn; + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (!dev->sriov) + continue; + virtfn_bdf(dev, dev->sriov->total - 1, &busnr, &devfn); + if (busnr > max) + max = busnr; + } + + return max ? max - bus->number : 0; +} diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index b24c9e2..2cf32f5 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -217,6 +217,7 @@ extern void pci_iov_release(struct pci_dev *dev); extern int pci_iov_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type); extern void pci_restore_iov_state(struct pci_dev *dev); +extern int pci_iov_bus_range(struct pci_bus *bus); #else static inline int pci_iov_init(struct pci_dev *dev) { @@ -234,6 +235,10 @@ static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno, static inline void pci_restore_iov_state(struct pci_dev *dev) { } +static inline int pci_iov_bus_range(struct pci_bus *bus) +{ + return 0; +} #endif /* CONFIG_PCI_IOV */ #endif /* DRIVERS_PCI_H */ diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 03b6f29..4c8abd0 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -1078,6 +1078,9 @@ unsigned int __devinit pci_scan_child_bus(struct pci_bus *bus) for (devfn = 0; devfn < 0x100; devfn += 8) pci_scan_slot(bus, devfn); + /* Reserve buses for SR-IOV capability. */ + max += pci_iov_bus_range(bus); + /* * After performing arch-dependent fixup of the bus, look behind * all PCI-to-PCI bridges on this bus.
Signed-off-by: Yu Zhao <yu.zhao@intel.com> --- drivers/pci/iov.c | 34 ++++++++++++++++++++++++++++++++++ drivers/pci/pci.h | 5 +++++ drivers/pci/probe.c | 3 +++ 3 files changed, 42 insertions(+), 0 deletions(-)