| Message ID | 20180914211808.2564-2-okaya@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI: Add reset type parameter to PCI reset functions | expand |
On Fri, 14 Sep 2018 21:18:03 +0000 Sinan Kaya <okaya@kernel.org> wrote: > We need a contract between the reset API users and the PCI core about the > types of reset that a user needs vs. what PCI core can do internally. > If a platform supports hotplug, we need to do hotplug reset as an example. > > Expose the reset types to the drivers and try different reset types based > on the new reset_type parameter. > > Most users are expected to use PCI_RESET_ANY, PCI_RESET_FUNC or > PCI_RESET_LINK parameters. > > Suggested-by: Alex Williamson <alex.williamson@redhat.com> > Signed-off-by: Sinan Kaya <okaya@kernel.org> > --- > .../net/ethernet/cavium/liquidio/lio_main.c | 2 +- > drivers/pci/pci.c | 59 ++++++++++++------- > drivers/xen/xen-pciback/pci_stub.c | 6 +- > include/linux/pci.h | 13 +++- > 4 files changed, 55 insertions(+), 25 deletions(-) > > diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c > index 6fb13fa73b27..0ff76722734d 100644 > --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c > +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c > @@ -989,7 +989,7 @@ static void octeon_pci_flr(struct octeon_device *oct) > pci_write_config_word(oct->pci_dev, PCI_COMMAND, > PCI_COMMAND_INTX_DISABLE); > > - rc = __pci_reset_function_locked(oct->pci_dev); > + rc = __pci_reset_function_locked(oct->pci_dev, PCI_RESET_ANY); > > if (rc != 0) > dev_err(&oct->pci_dev->dev, "Error %d resetting PCI function %d\n", > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 1835f3a7aa8d..8912c8ba3b2b 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4673,6 +4673,7 @@ static void pci_dev_restore(struct pci_dev *dev) > * __pci_reset_function_locked - reset a PCI device function while holding > * the @dev mutex lock. > * @dev: PCI device to reset > + * @reset_type: reset mask to try > * > * Some devices allow an individual function to be reset without affecting > * other functions in the same device. The PCI device must be responsive > @@ -4688,9 +4689,9 @@ static void pci_dev_restore(struct pci_dev *dev) > * Returns 0 if the device function was successfully reset or negative if the > * device doesn't support resetting a single function. > */ > -int __pci_reset_function_locked(struct pci_dev *dev) > +int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type) > { > - int rc; > + int rc = 0; What's the proper return value when a user passes zero for reset_type? It seems to currently be: user provided no options, therefore we tried none, therefore success. I'm torn whether that's entirely bogus to the point of that we should WARN_ON (ie. caller bug), or simply return -EINVAL, which the caller can ignore, or if there's some value to allow the behavior here. Thanks, Alex > > might_sleep(); > > @@ -4702,24 +4703,42 @@ int __pci_reset_function_locked(struct pci_dev *dev) > * other error, we're also finished: this indicates that further > * reset mechanisms might be broken on the device. > */ > - rc = pci_dev_specific_reset(dev, 0); > - if (rc != -ENOTTY) > - return rc; > - if (pcie_has_flr(dev)) { > - rc = pcie_flr(dev); > + if (reset_type & PCI_RESET_DEV_SPECIFIC) { > + rc = pci_dev_specific_reset(dev, 0); > if (rc != -ENOTTY) > return rc; > } > - rc = pci_af_flr(dev, 0); > - if (rc != -ENOTTY) > - return rc; > - rc = pci_pm_reset(dev, 0); > - if (rc != -ENOTTY) > - return rc; > - rc = pci_dev_reset_slot_function(dev, 0); > - if (rc != -ENOTTY) > - return rc; > - return pci_parent_bus_reset(dev, 0); > + > + if (reset_type & PCI_RESET_FLR) { > + if (pcie_has_flr(dev)) { > + rc = pcie_flr(dev); > + if (rc != -ENOTTY) > + return rc; > + } > + rc = pci_af_flr(dev, 0); > + if (rc != -ENOTTY) > + return rc; > + } > + > + if (reset_type & PCI_RESET_PM) { > + rc = pci_pm_reset(dev, 0); > + if (rc != -ENOTTY) > + return rc; > + } > + > + if (reset_type & PCI_RESET_SLOT) { > + rc = pci_dev_reset_slot_function(dev, 0); > + if (rc != -ENOTTY) > + return rc; > + } > + > + if (reset_type & PCI_RESET_BUS) { > + rc = pci_parent_bus_reset(dev, 0); > + if (rc != -ENOTTY) > + return rc; > + } > + > + return rc; > } > EXPORT_SYMBOL_GPL(__pci_reset_function_locked); > > @@ -4784,7 +4803,7 @@ int pci_reset_function(struct pci_dev *dev) > pci_dev_lock(dev); > pci_dev_save_and_disable(dev); > > - rc = __pci_reset_function_locked(dev); > + rc = __pci_reset_function_locked(dev, PCI_RESET_ANY); > > pci_dev_restore(dev); > pci_dev_unlock(dev); > @@ -4819,7 +4838,7 @@ int pci_reset_function_locked(struct pci_dev *dev) > > pci_dev_save_and_disable(dev); > > - rc = __pci_reset_function_locked(dev); > + rc = __pci_reset_function_locked(dev, PCI_RESET_ANY); > > pci_dev_restore(dev); > > @@ -4844,7 +4863,7 @@ int pci_try_reset_function(struct pci_dev *dev) > return -EAGAIN; > > pci_dev_save_and_disable(dev); > - rc = __pci_reset_function_locked(dev); > + rc = __pci_reset_function_locked(dev, PCI_RESET_ANY); > pci_dev_restore(dev); > pci_dev_unlock(dev); > > diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c > index 59661db144e5..6dfb805bcb19 100644 > --- a/drivers/xen/xen-pciback/pci_stub.c > +++ b/drivers/xen/xen-pciback/pci_stub.c > @@ -105,7 +105,7 @@ static void pcistub_device_release(struct kref *kref) > /* Call the reset function which does not take lock as this > * is called from "unbind" which takes a device_lock mutex. > */ > - __pci_reset_function_locked(dev); > + __pci_reset_function_locked(dev, PCI_RESET_ANY); > if (pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state)) > dev_info(&dev->dev, "Could not reload PCI state\n"); > else > @@ -283,7 +283,7 @@ void pcistub_put_pci_dev(struct pci_dev *dev) > * (so it's ready for the next domain) > */ > device_lock_assert(&dev->dev); > - __pci_reset_function_locked(dev); > + __pci_reset_function_locked(dev, PCI_RESET_ANY); > > dev_data = pci_get_drvdata(dev); > ret = pci_load_saved_state(dev, dev_data->pci_saved_state); > @@ -417,7 +417,7 @@ static int pcistub_init_device(struct pci_dev *dev) > dev_err(&dev->dev, "Could not store PCI conf saved state!\n"); > else { > dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n"); > - __pci_reset_function_locked(dev); > + __pci_reset_function_locked(dev, PCI_RESET_ANY); > pci_restore_state(dev); > } > /* Now disable the device (this also ensures some private device > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 6925828f9f25..d2e0a8c8177b 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -849,6 +849,17 @@ enum { > PCI_SCAN_ALL_PCIE_DEVS = 0x00000040, /* Scan all, not just dev 0 */ > }; > > +#define PCI_RESET_DEV_SPECIFIC (1 << 0) > +#define PCI_RESET_FLR (1 << 1) > +#define PCI_RESET_PM (1 << 2) > +#define PCI_RESET_SLOT (1 << 3) > +#define PCI_RESET_BUS (1 << 4) > + > +#define PCI_RESET_ANY (~0) > +#define PCI_RESET_FUNC (PCI_RESET_DEV_SPECIFIC | \ > + PCI_RESET_FLR | PCI_RESET_PM) > +#define PCI_RESET_LINK (PCI_RESET_SLOT | PCI_RESET_BUS) > + > /* These external functions are only available when PCI support is enabled */ > #ifdef CONFIG_PCI > > @@ -1111,7 +1122,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, > void pcie_print_link_status(struct pci_dev *dev); > bool pcie_has_flr(struct pci_dev *dev); > int pcie_flr(struct pci_dev *dev); > -int __pci_reset_function_locked(struct pci_dev *dev); > +int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type); > int pci_reset_function(struct pci_dev *dev); > int pci_reset_function_locked(struct pci_dev *dev); > int pci_try_reset_function(struct pci_dev *dev);
On 9/14/2018 6:27 PM, Alex Williamson wrote: >> +int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type) >> { >> - int rc; >> + int rc = 0; > What's the proper return value when a user passes zero for reset_type? > It seems to currently be: user provided no options, therefore we tried > none, therefore success. I'm torn whether that's entirely bogus to the > point of that we should WARN_ON (ie. caller bug), or simply return > -EINVAL, which the caller can ignore, or if there's some value to allow > the behavior here. Thanks, Yeah, even I'm inconsistent in this series. I return -EINVAL on pci_reset_bus() as an example. Maybe, I'll just return -EINVAL here too. WARN_ON would be too much IMO.
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c index 6fb13fa73b27..0ff76722734d 100644 --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c @@ -989,7 +989,7 @@ static void octeon_pci_flr(struct octeon_device *oct) pci_write_config_word(oct->pci_dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); - rc = __pci_reset_function_locked(oct->pci_dev); + rc = __pci_reset_function_locked(oct->pci_dev, PCI_RESET_ANY); if (rc != 0) dev_err(&oct->pci_dev->dev, "Error %d resetting PCI function %d\n", diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 1835f3a7aa8d..8912c8ba3b2b 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -4673,6 +4673,7 @@ static void pci_dev_restore(struct pci_dev *dev) * __pci_reset_function_locked - reset a PCI device function while holding * the @dev mutex lock. * @dev: PCI device to reset + * @reset_type: reset mask to try * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive @@ -4688,9 +4689,9 @@ static void pci_dev_restore(struct pci_dev *dev) * Returns 0 if the device function was successfully reset or negative if the * device doesn't support resetting a single function. */ -int __pci_reset_function_locked(struct pci_dev *dev) +int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type) { - int rc; + int rc = 0; might_sleep(); @@ -4702,24 +4703,42 @@ int __pci_reset_function_locked(struct pci_dev *dev) * other error, we're also finished: this indicates that further * reset mechanisms might be broken on the device. */ - rc = pci_dev_specific_reset(dev, 0); - if (rc != -ENOTTY) - return rc; - if (pcie_has_flr(dev)) { - rc = pcie_flr(dev); + if (reset_type & PCI_RESET_DEV_SPECIFIC) { + rc = pci_dev_specific_reset(dev, 0); if (rc != -ENOTTY) return rc; } - rc = pci_af_flr(dev, 0); - if (rc != -ENOTTY) - return rc; - rc = pci_pm_reset(dev, 0); - if (rc != -ENOTTY) - return rc; - rc = pci_dev_reset_slot_function(dev, 0); - if (rc != -ENOTTY) - return rc; - return pci_parent_bus_reset(dev, 0); + + if (reset_type & PCI_RESET_FLR) { + if (pcie_has_flr(dev)) { + rc = pcie_flr(dev); + if (rc != -ENOTTY) + return rc; + } + rc = pci_af_flr(dev, 0); + if (rc != -ENOTTY) + return rc; + } + + if (reset_type & PCI_RESET_PM) { + rc = pci_pm_reset(dev, 0); + if (rc != -ENOTTY) + return rc; + } + + if (reset_type & PCI_RESET_SLOT) { + rc = pci_dev_reset_slot_function(dev, 0); + if (rc != -ENOTTY) + return rc; + } + + if (reset_type & PCI_RESET_BUS) { + rc = pci_parent_bus_reset(dev, 0); + if (rc != -ENOTTY) + return rc; + } + + return rc; } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); @@ -4784,7 +4803,7 @@ int pci_reset_function(struct pci_dev *dev) pci_dev_lock(dev); pci_dev_save_and_disable(dev); - rc = __pci_reset_function_locked(dev); + rc = __pci_reset_function_locked(dev, PCI_RESET_ANY); pci_dev_restore(dev); pci_dev_unlock(dev); @@ -4819,7 +4838,7 @@ int pci_reset_function_locked(struct pci_dev *dev) pci_dev_save_and_disable(dev); - rc = __pci_reset_function_locked(dev); + rc = __pci_reset_function_locked(dev, PCI_RESET_ANY); pci_dev_restore(dev); @@ -4844,7 +4863,7 @@ int pci_try_reset_function(struct pci_dev *dev) return -EAGAIN; pci_dev_save_and_disable(dev); - rc = __pci_reset_function_locked(dev); + rc = __pci_reset_function_locked(dev, PCI_RESET_ANY); pci_dev_restore(dev); pci_dev_unlock(dev); diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index 59661db144e5..6dfb805bcb19 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -105,7 +105,7 @@ static void pcistub_device_release(struct kref *kref) /* Call the reset function which does not take lock as this * is called from "unbind" which takes a device_lock mutex. */ - __pci_reset_function_locked(dev); + __pci_reset_function_locked(dev, PCI_RESET_ANY); if (pci_load_and_free_saved_state(dev, &dev_data->pci_saved_state)) dev_info(&dev->dev, "Could not reload PCI state\n"); else @@ -283,7 +283,7 @@ void pcistub_put_pci_dev(struct pci_dev *dev) * (so it's ready for the next domain) */ device_lock_assert(&dev->dev); - __pci_reset_function_locked(dev); + __pci_reset_function_locked(dev, PCI_RESET_ANY); dev_data = pci_get_drvdata(dev); ret = pci_load_saved_state(dev, dev_data->pci_saved_state); @@ -417,7 +417,7 @@ static int pcistub_init_device(struct pci_dev *dev) dev_err(&dev->dev, "Could not store PCI conf saved state!\n"); else { dev_dbg(&dev->dev, "resetting (FLR, D3, etc) the device\n"); - __pci_reset_function_locked(dev); + __pci_reset_function_locked(dev, PCI_RESET_ANY); pci_restore_state(dev); } /* Now disable the device (this also ensures some private device diff --git a/include/linux/pci.h b/include/linux/pci.h index 6925828f9f25..d2e0a8c8177b 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -849,6 +849,17 @@ enum { PCI_SCAN_ALL_PCIE_DEVS = 0x00000040, /* Scan all, not just dev 0 */ }; +#define PCI_RESET_DEV_SPECIFIC (1 << 0) +#define PCI_RESET_FLR (1 << 1) +#define PCI_RESET_PM (1 << 2) +#define PCI_RESET_SLOT (1 << 3) +#define PCI_RESET_BUS (1 << 4) + +#define PCI_RESET_ANY (~0) +#define PCI_RESET_FUNC (PCI_RESET_DEV_SPECIFIC | \ + PCI_RESET_FLR | PCI_RESET_PM) +#define PCI_RESET_LINK (PCI_RESET_SLOT | PCI_RESET_BUS) + /* These external functions are only available when PCI support is enabled */ #ifdef CONFIG_PCI @@ -1111,7 +1122,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, void pcie_print_link_status(struct pci_dev *dev); bool pcie_has_flr(struct pci_dev *dev); int pcie_flr(struct pci_dev *dev); -int __pci_reset_function_locked(struct pci_dev *dev); +int __pci_reset_function_locked(struct pci_dev *dev, u32 reset_type); int pci_reset_function(struct pci_dev *dev); int pci_reset_function_locked(struct pci_dev *dev); int pci_try_reset_function(struct pci_dev *dev);
We need a contract between the reset API users and the PCI core about the types of reset that a user needs vs. what PCI core can do internally. If a platform supports hotplug, we need to do hotplug reset as an example. Expose the reset types to the drivers and try different reset types based on the new reset_type parameter. Most users are expected to use PCI_RESET_ANY, PCI_RESET_FUNC or PCI_RESET_LINK parameters. Suggested-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Sinan Kaya <okaya@kernel.org> --- .../net/ethernet/cavium/liquidio/lio_main.c | 2 +- drivers/pci/pci.c | 59 ++++++++++++------- drivers/xen/xen-pciback/pci_stub.c | 6 +- include/linux/pci.h | 13 +++- 4 files changed, 55 insertions(+), 25 deletions(-)