On 08/22/2016 07:36 AM, Bjorn Helgaas wrote:
Hi David & Omer, On Fri, Aug 19, 2016 at 03:32:12PM -0700, Omer Khaliq wrote:From: David Daney <david.daney@xxxxxxxxxx> Some hardware presents an incorrect SR-IOV Function Dependency Link, add a function to allow this to be overridden in the PF driver for such devices. Signed-off-by: David Daney <david.daney@xxxxxxxxxx> Signed-off-by: Omer Khaliq <okhaliq@xxxxxxxxxxxxxxxxxx> --- drivers/pci/iov.c | 14 ++++++++++++++ include/linux/pci.h | 1 + 2 files changed, 15 insertions(+) diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index 2194b44..81f0672 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -640,6 +640,20 @@ int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn) EXPORT_SYMBOL_GPL(pci_enable_sriov); /** + * pci_sriov_fdl_override - fix incorrect Function Dependency Link + * @dev: the PCI device + * @fdl: the corrected Function Dependency Link value + * + * For hardware presenting an incorrect Function Dependency Link in + * the SR-IOV Extended Capability, allow a driver to override it. + */ +void pci_sriov_fdl_override(struct pci_dev *dev, u8 fdl) +{ + dev->sriov->link = fdl; +} +EXPORT_SYMBOL_GPL(pci_sriov_fdl_override);We usually use quirks to work around problems in config space. That's a nice mechanism because we don't have to add new PCI core interfaces and it makes it clear that we're working around a hardware problem. Can you use a quirk here? We allocate dev->sriov in the pci_init_capabilities() path, so it looks like a pci_fixup_final quirk should work.
The struct pci_sriov definition is private to drivers/pci, so in order to use a quirk to fix this, we would have to put it in drivers/pci/quirks.c. I was trying to keep this very device specific code in the driver, which requires an accessor to be able to manipulate the dev->sriov->link field.
If you prefer a quirk in drivers/pci/quirks.c, we can certainly do that instead.
Thanks for taking the time to look at this, David Daney
+ +/** * pci_disable_sriov - disable the SR-IOV capability * @dev: the PCI device */ diff --git a/include/linux/pci.h b/include/linux/pci.h index 2599a98..da8a5b3 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1823,6 +1823,7 @@ int pci_num_vf(struct pci_dev *dev); int pci_vfs_assigned(struct pci_dev *dev); int pci_sriov_set_totalvfs(struct pci_dev *dev, u16 numvfs); int pci_sriov_get_totalvfs(struct pci_dev *dev); +void pci_sriov_fdl_override(struct pci_dev *dev, u8 fdl); resource_size_t pci_iov_resource_size(struct pci_dev *dev, int resno); #else static inline int pci_iov_virtfn_bus(struct pci_dev *dev, int id) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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