| Message ID | 20170413145339.20186-2-hch@lst.de (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Herbert Xu |
| Headers | show |
[+cc Alex] On Thu, Apr 13, 2017 at 04:53:33PM +0200, Christoph Hellwig wrote: > Currently we opencode the FLR sequence in lots of place, export a core > helper instead. We split out the probing for FLR support as all the > non-core callers already know their hardware. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > --- > drivers/pci/pci.c | 34 +++++++++++++++++++++++++--------- > include/linux/pci.h | 1 + > 2 files changed, 26 insertions(+), 9 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 7904d02ffdb9..3256a63c5d08 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -3773,24 +3773,38 @@ static void pci_flr_wait(struct pci_dev *dev) > (i - 1) * 100); > } > > -static int pcie_flr(struct pci_dev *dev, int probe) > +/** > + * pcie_has_flr - check if a device supports function level resets > + * @dev: device to check > + * > + * Returns true if the device advertises support for PCIe function level > + * resets. > + */ > +static bool pcie_has_flr(struct pci_dev *dev) > { > u32 cap; > > pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); > - if (!(cap & PCI_EXP_DEVCAP_FLR)) > - return -ENOTTY; > - > - if (probe) > - return 0; > + return cap & PCI_EXP_DEVCAP_FLR; > +} > > +/** > + * pcie_flr - initiate a PCIe function level reset > + * @dev: device to reset > + * > + * Initiate a function level reset on @dev. The caller should ensure the > + * device supports FLR before calling this function, e.g. by using the > + * pcie_has_flr helper. s/pcie_has_flr/pcie_has_flr()/ > + */ > +void pcie_flr(struct pci_dev *dev) > +{ > if (!pci_wait_for_pending_transaction(dev)) > dev_err(&dev->dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); > > pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); > pci_flr_wait(dev); > - return 0; > } > +EXPORT_SYMBOL_GPL(pcie_flr); > > static int pci_af_flr(struct pci_dev *dev, int probe) > { > @@ -3971,9 +3985,11 @@ static int __pci_dev_reset(struct pci_dev *dev, int probe) > if (rc != -ENOTTY) > goto done; > > - rc = pcie_flr(dev, probe); > - if (rc != -ENOTTY) > + if (pcie_has_flr(dev)) { > + pcie_flr(dev); > + rc = 0; > goto done; > + } This performs an FLR (if supported) always, regardless of "probe". I think it should look something like this instead: if (pcie_has_flr(dev)) { if (!probe) pcie_flr(dev); rc = 0; goto done; } > rc = pci_af_flr(dev, probe); > if (rc != -ENOTTY) > diff --git a/include/linux/pci.h b/include/linux/pci.h > index eb3da1a04e6c..f35e51eddad0 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1052,6 +1052,7 @@ int pcie_get_mps(struct pci_dev *dev); > int pcie_set_mps(struct pci_dev *dev, int mps); > int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, > enum pcie_link_width *width); > +void pcie_flr(struct pci_dev *dev); > int __pci_reset_function(struct pci_dev *dev); > int __pci_reset_function_locked(struct pci_dev *dev); > int pci_reset_function(struct pci_dev *dev); > -- > 2.11.0 >
> s/pcie_has_flr/pcie_has_flr()/ Ok. > This performs an FLR (if supported) always, regardless of "probe". > I think it should look something like this instead: > > if (pcie_has_flr(dev)) { > if (!probe) > pcie_flr(dev); > rc = 0; > goto done; > } Indeed!
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 7904d02ffdb9..3256a63c5d08 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -3773,24 +3773,38 @@ static void pci_flr_wait(struct pci_dev *dev) (i - 1) * 100); } -static int pcie_flr(struct pci_dev *dev, int probe) +/** + * pcie_has_flr - check if a device supports function level resets + * @dev: device to check + * + * Returns true if the device advertises support for PCIe function level + * resets. + */ +static bool pcie_has_flr(struct pci_dev *dev) { u32 cap; pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); - if (!(cap & PCI_EXP_DEVCAP_FLR)) - return -ENOTTY; - - if (probe) - return 0; + return cap & PCI_EXP_DEVCAP_FLR; +} +/** + * pcie_flr - initiate a PCIe function level reset + * @dev: device to reset + * + * Initiate a function level reset on @dev. The caller should ensure the + * device supports FLR before calling this function, e.g. by using the + * pcie_has_flr helper. + */ +void pcie_flr(struct pci_dev *dev) +{ if (!pci_wait_for_pending_transaction(dev)) dev_err(&dev->dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); pci_flr_wait(dev); - return 0; } +EXPORT_SYMBOL_GPL(pcie_flr); static int pci_af_flr(struct pci_dev *dev, int probe) { @@ -3971,9 +3985,11 @@ static int __pci_dev_reset(struct pci_dev *dev, int probe) if (rc != -ENOTTY) goto done; - rc = pcie_flr(dev, probe); - if (rc != -ENOTTY) + if (pcie_has_flr(dev)) { + pcie_flr(dev); + rc = 0; goto done; + } rc = pci_af_flr(dev, probe); if (rc != -ENOTTY) diff --git a/include/linux/pci.h b/include/linux/pci.h index eb3da1a04e6c..f35e51eddad0 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1052,6 +1052,7 @@ int pcie_get_mps(struct pci_dev *dev); int pcie_set_mps(struct pci_dev *dev, int mps); int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, enum pcie_link_width *width); +void pcie_flr(struct pci_dev *dev); int __pci_reset_function(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev);
Currently we opencode the FLR sequence in lots of place, export a core helper instead. We split out the probing for FLR support as all the non-core callers already know their hardware. Signed-off-by: Christoph Hellwig <hch@lst.de> --- drivers/pci/pci.c | 34 +++++++++++++++++++++++++--------- include/linux/pci.h | 1 + 2 files changed, 26 insertions(+), 9 deletions(-)