| Message ID | 20210529192527.2708-3-ameynarkhede03@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Expose and manage PCI device reset | expand |
On 5/29/21 2:25 PM, Amey Narkhede wrote: > Introduce a new array reset_methods in struct pci_dev > to keep track of reset mechanisms supported by the > device and their ordering. Also refactor probing and reset > functions to take advantage of calling convention of reset > functions. > > Reviewed-by: Alex Williamson <alex.williamson@redhat.com> > Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > Co-developed-by: Alex Williamson <alex.williamson@redhat.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> Tested-by: Shanker Donthineni <sdonthineni@nvidia.com>
On Sun, May 30, 2021 at 12:55:22AM +0530, Amey Narkhede wrote: > Introduce a new array reset_methods in struct pci_dev > to keep track of reset mechanisms supported by the > device and their ordering. Also refactor probing and reset > functions to take advantage of calling convention of reset > functions. Rewrap above to use 75 columns. > Reviewed-by: Alex Williamson <alex.williamson@redhat.com> > Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com> > Co-developed-by: Alex Williamson <alex.williamson@redhat.com> > Signed-off-by: Alex Williamson <alex.williamson@redhat.com> > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com> > --- > drivers/pci/pci.c | 107 ++++++++++++++++++++++++++------------------ > drivers/pci/pci.h | 8 +++- > drivers/pci/probe.c | 5 +-- > include/linux/pci.h | 7 +++ > 4 files changed, 80 insertions(+), 47 deletions(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 3bf36924c..67a2605d4 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -72,6 +72,14 @@ static void pci_dev_d3_sleep(struct pci_dev *dev) > msleep(delay); > } > > +bool pci_reset_supported(struct pci_dev *dev) > +{ > + u8 null_reset_methods[PCI_RESET_METHODS_NUM] = { 0 }; > + > + return memcmp(null_reset_methods, > + dev->reset_methods, PCI_RESET_METHODS_NUM); > +} > + > #ifdef CONFIG_PCI_DOMAINS > int pci_domains_supported = 1; > #endif > @@ -5107,6 +5115,19 @@ static void pci_dev_restore(struct pci_dev *dev) > err_handler->reset_done(dev); > } > > +/* > + * The ordering for functions in pci_reset_fn_methods > + * is required for reset_methods byte array defined > + * in struct pci_dev. Rewrap to fill 75-78 columns. > + */ > +const struct pci_reset_fn_method pci_reset_fn_methods[] = { > + { &pci_dev_specific_reset, .name = "device_specific" }, > + { &pcie_reset_flr, .name = "flr" }, > + { &pci_af_flr, .name = "af_flr" }, > + { &pci_pm_reset, .name = "pm" }, > + { &pci_reset_bus_function, .name = "bus" }, > +}; > + > /** > * __pci_reset_function_locked - reset a PCI device function while holding > * the @dev mutex lock. > @@ -5129,65 +5150,65 @@ static void pci_dev_restore(struct pci_dev *dev) > */ > int __pci_reset_function_locked(struct pci_dev *dev) > { > - int rc; > + int i, rc = -ENOTTY; > + u8 prio; > > might_sleep(); > > - /* > - * A reset method returns -ENOTTY if it doesn't support this device > - * and we should try the next method. > - * > - * If it returns 0 (success), we're finished. If it returns any > - * 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; > - rc = pcie_reset_flr(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; > - return pci_reset_bus_function(dev, 0); > + for (prio = PCI_RESET_METHODS_NUM; prio; prio--) { > + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { > + if (dev->reset_methods[i] == prio) { > + /* > + * A reset method returns -ENOTTY if it doesn't support this device > + * and we should try the next method. > + * > + * If it returns 0 (success), we're finished. If it returns any > + * other error, we're also finished: this indicates that further > + * reset mechanisms might be broken on the device. Rewrap to fit in 80 columns. > + */ > + rc = pci_reset_fn_methods[i].reset_fn(dev, 0); > + if (rc != -ENOTTY) > + return rc; > + break; > + } > + } > + if (i == PCI_RESET_METHODS_NUM) > + break; > + } > + return rc; > } > EXPORT_SYMBOL_GPL(__pci_reset_function_locked); > > /** > - * pci_probe_reset_function - check whether the device can be safely reset > - * @dev: PCI device to reset > + * pci_init_reset_methods - check whether device can be safely reset > + * and store supported reset mechanisms. > + * @dev: PCI device to check for reset mechanisms > * > * Some devices allow an individual function to be reset without affecting > * other functions in the same device. The PCI device must be responsive > - * to PCI config space in order to use this function. > + * to reads and writes to its PCI config space in order to use this function. > * > - * Returns 0 if the device function can be reset or negative if the > - * device doesn't support resetting a single function. > + * Stores reset mechanisms supported by device in reset_methods byte array > + * which is a member of struct pci_dev. > */ > -int pci_probe_reset_function(struct pci_dev *dev) > +void pci_init_reset_methods(struct pci_dev *dev) > { > - int rc; > + int i, rc; > + u8 prio = PCI_RESET_METHODS_NUM; > + u8 reset_methods[PCI_RESET_METHODS_NUM] = { 0 }; > > - might_sleep(); > + BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_RESET_METHODS_NUM); > > - rc = pci_dev_specific_reset(dev, 1); > - if (rc != -ENOTTY) > - return rc; > - rc = pcie_reset_flr(dev, 1); > - if (rc != -ENOTTY) > - return rc; > - rc = pci_af_flr(dev, 1); > - if (rc != -ENOTTY) > - return rc; > - rc = pci_pm_reset(dev, 1); > - if (rc != -ENOTTY) > - return rc; > + might_sleep(); > > - return pci_reset_bus_function(dev, 1); > + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { > + rc = pci_reset_fn_methods[i].reset_fn(dev, 1); > + if (!rc) > + reset_methods[i] = prio--; > + else if (rc != -ENOTTY) > + break; > + } > + memcpy(dev->reset_methods, reset_methods, sizeof(reset_methods)); > } > > /** > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h > index 37c913bbc..13ec6bd6f 100644 > --- a/drivers/pci/pci.h > +++ b/drivers/pci/pci.h > @@ -33,7 +33,7 @@ enum pci_mmap_api { > int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai, > enum pci_mmap_api mmap_api); > > -int pci_probe_reset_function(struct pci_dev *dev); > +void pci_init_reset_methods(struct pci_dev *dev); > int pci_bridge_secondary_bus_reset(struct pci_dev *dev); > int pci_bus_error_reset(struct pci_dev *dev); > > @@ -606,6 +606,12 @@ struct pci_dev_reset_methods { > int (*reset)(struct pci_dev *dev, int probe); > }; > > +struct pci_reset_fn_method { > + int (*reset_fn)(struct pci_dev *pdev, int probe); > + char *name; > +}; > + > +extern const struct pci_reset_fn_method pci_reset_fn_methods[]; > #ifdef CONFIG_PCI_QUIRKS > int pci_dev_specific_reset(struct pci_dev *dev, int probe); > #else > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c > index 3a62d09b8..8cf532681 100644 > --- a/drivers/pci/probe.c > +++ b/drivers/pci/probe.c > @@ -2404,9 +2404,8 @@ static void pci_init_capabilities(struct pci_dev *dev) > pci_rcec_init(dev); /* Root Complex Event Collector */ > > pcie_report_downtraining(dev); > - > - if (pci_probe_reset_function(dev) == 0) > - dev->reset_fn = 1; > + pci_init_reset_methods(dev); > + dev->reset_fn = pci_reset_supported(dev); > } > > /* > diff --git a/include/linux/pci.h b/include/linux/pci.h > index 20b90c205..0955246f8 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -49,6 +49,8 @@ > PCI_STATUS_SIG_TARGET_ABORT | \ > PCI_STATUS_PARITY) > > +#define PCI_RESET_METHODS_NUM 5 > + > /* > * The PCI interface treats multi-function devices as independent > * devices. The slot/function address of each device is encoded > @@ -505,6 +507,10 @@ struct pci_dev { > char *driver_override; /* Driver name to force a match */ > > unsigned long priv_flags; /* Private flags for the PCI driver */ > + /* > + * See pci_reset_fn_methods array in pci.c for ordering. > + */ > + u8 reset_methods[PCI_RESET_METHODS_NUM]; /* Reset methods ordered by priority */ > }; > > static inline struct pci_dev *pci_physfn(struct pci_dev *dev) > @@ -1227,6 +1233,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, > void pcie_print_link_status(struct pci_dev *dev); > int pcie_reset_flr(struct pci_dev *dev, int probe); > int pcie_flr(struct pci_dev *dev); > +bool pci_reset_supported(struct pci_dev *dev); > int __pci_reset_function_locked(struct pci_dev *dev); > int pci_reset_function(struct pci_dev *dev); > int pci_reset_function_locked(struct pci_dev *dev); > -- > 2.31.1 >
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 3bf36924c..67a2605d4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -72,6 +72,14 @@ static void pci_dev_d3_sleep(struct pci_dev *dev) msleep(delay); } +bool pci_reset_supported(struct pci_dev *dev) +{ + u8 null_reset_methods[PCI_RESET_METHODS_NUM] = { 0 }; + + return memcmp(null_reset_methods, + dev->reset_methods, PCI_RESET_METHODS_NUM); +} + #ifdef CONFIG_PCI_DOMAINS int pci_domains_supported = 1; #endif @@ -5107,6 +5115,19 @@ static void pci_dev_restore(struct pci_dev *dev) err_handler->reset_done(dev); } +/* + * The ordering for functions in pci_reset_fn_methods + * is required for reset_methods byte array defined + * in struct pci_dev. + */ +const struct pci_reset_fn_method pci_reset_fn_methods[] = { + { &pci_dev_specific_reset, .name = "device_specific" }, + { &pcie_reset_flr, .name = "flr" }, + { &pci_af_flr, .name = "af_flr" }, + { &pci_pm_reset, .name = "pm" }, + { &pci_reset_bus_function, .name = "bus" }, +}; + /** * __pci_reset_function_locked - reset a PCI device function while holding * the @dev mutex lock. @@ -5129,65 +5150,65 @@ static void pci_dev_restore(struct pci_dev *dev) */ int __pci_reset_function_locked(struct pci_dev *dev) { - int rc; + int i, rc = -ENOTTY; + u8 prio; might_sleep(); - /* - * A reset method returns -ENOTTY if it doesn't support this device - * and we should try the next method. - * - * If it returns 0 (success), we're finished. If it returns any - * 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; - rc = pcie_reset_flr(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; - return pci_reset_bus_function(dev, 0); + for (prio = PCI_RESET_METHODS_NUM; prio; prio--) { + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { + if (dev->reset_methods[i] == prio) { + /* + * A reset method returns -ENOTTY if it doesn't support this device + * and we should try the next method. + * + * If it returns 0 (success), we're finished. If it returns any + * other error, we're also finished: this indicates that further + * reset mechanisms might be broken on the device. + */ + rc = pci_reset_fn_methods[i].reset_fn(dev, 0); + if (rc != -ENOTTY) + return rc; + break; + } + } + if (i == PCI_RESET_METHODS_NUM) + break; + } + return rc; } EXPORT_SYMBOL_GPL(__pci_reset_function_locked); /** - * pci_probe_reset_function - check whether the device can be safely reset - * @dev: PCI device to reset + * pci_init_reset_methods - check whether device can be safely reset + * and store supported reset mechanisms. + * @dev: PCI device to check for reset mechanisms * * Some devices allow an individual function to be reset without affecting * other functions in the same device. The PCI device must be responsive - * to PCI config space in order to use this function. + * to reads and writes to its PCI config space in order to use this function. * - * Returns 0 if the device function can be reset or negative if the - * device doesn't support resetting a single function. + * Stores reset mechanisms supported by device in reset_methods byte array + * which is a member of struct pci_dev. */ -int pci_probe_reset_function(struct pci_dev *dev) +void pci_init_reset_methods(struct pci_dev *dev) { - int rc; + int i, rc; + u8 prio = PCI_RESET_METHODS_NUM; + u8 reset_methods[PCI_RESET_METHODS_NUM] = { 0 }; - might_sleep(); + BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_RESET_METHODS_NUM); - rc = pci_dev_specific_reset(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pcie_reset_flr(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_af_flr(dev, 1); - if (rc != -ENOTTY) - return rc; - rc = pci_pm_reset(dev, 1); - if (rc != -ENOTTY) - return rc; + might_sleep(); - return pci_reset_bus_function(dev, 1); + for (i = 0; i < PCI_RESET_METHODS_NUM; i++) { + rc = pci_reset_fn_methods[i].reset_fn(dev, 1); + if (!rc) + reset_methods[i] = prio--; + else if (rc != -ENOTTY) + break; + } + memcpy(dev->reset_methods, reset_methods, sizeof(reset_methods)); } /** diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index 37c913bbc..13ec6bd6f 100644 --- a/drivers/pci/pci.h +++ b/drivers/pci/pci.h @@ -33,7 +33,7 @@ enum pci_mmap_api { int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai, enum pci_mmap_api mmap_api); -int pci_probe_reset_function(struct pci_dev *dev); +void pci_init_reset_methods(struct pci_dev *dev); int pci_bridge_secondary_bus_reset(struct pci_dev *dev); int pci_bus_error_reset(struct pci_dev *dev); @@ -606,6 +606,12 @@ struct pci_dev_reset_methods { int (*reset)(struct pci_dev *dev, int probe); }; +struct pci_reset_fn_method { + int (*reset_fn)(struct pci_dev *pdev, int probe); + char *name; +}; + +extern const struct pci_reset_fn_method pci_reset_fn_methods[]; #ifdef CONFIG_PCI_QUIRKS int pci_dev_specific_reset(struct pci_dev *dev, int probe); #else diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c index 3a62d09b8..8cf532681 100644 --- a/drivers/pci/probe.c +++ b/drivers/pci/probe.c @@ -2404,9 +2404,8 @@ static void pci_init_capabilities(struct pci_dev *dev) pci_rcec_init(dev); /* Root Complex Event Collector */ pcie_report_downtraining(dev); - - if (pci_probe_reset_function(dev) == 0) - dev->reset_fn = 1; + pci_init_reset_methods(dev); + dev->reset_fn = pci_reset_supported(dev); } /* diff --git a/include/linux/pci.h b/include/linux/pci.h index 20b90c205..0955246f8 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -49,6 +49,8 @@ PCI_STATUS_SIG_TARGET_ABORT | \ PCI_STATUS_PARITY) +#define PCI_RESET_METHODS_NUM 5 + /* * The PCI interface treats multi-function devices as independent * devices. The slot/function address of each device is encoded @@ -505,6 +507,10 @@ struct pci_dev { char *driver_override; /* Driver name to force a match */ unsigned long priv_flags; /* Private flags for the PCI driver */ + /* + * See pci_reset_fn_methods array in pci.c for ordering. + */ + u8 reset_methods[PCI_RESET_METHODS_NUM]; /* Reset methods ordered by priority */ }; static inline struct pci_dev *pci_physfn(struct pci_dev *dev) @@ -1227,6 +1233,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, void pcie_print_link_status(struct pci_dev *dev); int pcie_reset_flr(struct pci_dev *dev, int probe); int pcie_flr(struct pci_dev *dev); +bool pci_reset_supported(struct pci_dev *dev); int __pci_reset_function_locked(struct pci_dev *dev); int pci_reset_function(struct pci_dev *dev); int pci_reset_function_locked(struct pci_dev *dev);