Messages in this thread | | | Date | Wed, 16 May 2007 10:10:27 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH 1/2] PCI-X/PCI-Express read control interfaces |
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On Tue, 15 May 2007 13:59:13 +0200 Peter Oruba wrote:
> This patch introduces an interface to read and write PCI-X / PCI-Express > maximum read byte count values from PCI config space. There is a second > function that returns the maximum _designed_ read byte count, which marks the > maximum value for a device, since some drivers try to set MMRBC to the > highest allowed value and rely on such a function. > > Signed-off by: Peter Oruba <peter.oruba@amd.com> > Based on patch set by Stephen Hemminger <shemminger@linux-foundation.org> > > --- > diff -uprN -X linux-2.6.22-rc1.orig/Documentation/dontdiff > linux-2.6.22-rc1.orig/drivers/pci/pci.c linux-2.6.22-rc1/drivers/pci/pci.c > --- linux-2.6.22-rc1.orig/drivers/pci/pci.c 2007-05-14 11:29:39.473498000 > +0200 > +++ linux-2.6.22-rc1/drivers/pci/pci.c 2007-05-15 11:44:33.804254000 +0200 > @@ -1375,6 +1375,170 @@ pci_set_consistent_dma_mask(struct pci_d > #endif > > /** > + * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count > + * @dev: PCI device to query > + * > + * Returns mmrbc: maximum designed memory read count in bytes > + * or appropriate error value. > + */ > +int > +pcix_get_max_mmrbc(struct pci_dev *dev)
Kernel style is like so (referring to multiple occurrences):
int pcix_get_max_mmrbc(struct pci_dev *dev)
Yes, that source file does it both ways (and needs to be Fixed).
> +{ > + int ret, err, cap; > + u32 stat; > + > + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); > + if (!cap) > + return -EINVAL; > + > + err = pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat); > + if (err) > + return -EINVAL; > + > + ret = (stat & PCI_X_STATUS_MAX_READ) >> 12; > + > + return ret; > +} > +EXPORT_SYMBOL(pcix_get_max_mmrbc); > + > + > +/** > + * pcix_set_mmrbc - set PCI-X maximum memory read byte count > + * @dev: PCI device to query > + * @mmrbc: maximum memory read count in bytes > + * valid values are 512, 1024, 2048, 4096 > + * > + * If possible sets maximum memory read byte count, some bridges have erratas
"errata" is plural.
> + * that prevent this. > + */ > +int > +pcix_set_mmrbc(struct pci_dev *dev, int mmrbc) > +{ ... > +} > +EXPORT_SYMBOL(pcix_set_mmrbc); > + > +/** > + * pcie_get_readrq - get PCI Express read request size > + * @dev: PCI device to query > + * > + * Returns maximum memory read request in bytes > + * or appropriate error value. > + */ > +int pcie_get_readrq(struct pci_dev *dev)
:)
> +{ > + int ret, cap; > + u16 ctl; > + > + cap = pci_find_capability(dev, PCI_CAP_ID_EXP); > + if (!cap) > + return -EINVAL; > + > + ret = pci_read_config_word(dev, cap + PCI_EXP_DEVCTL, &ctl); > + if (!ret) > + ret = 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12); > + > + return ret; > +} > +EXPORT_SYMBOL(pcie_get_readrq); > +
--- ~Randy *** Remember to use Documentation/SubmitChecklist when testing your code *** - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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